[2/3] vfio: vfio-pci device assignment driver

This adds the core of the QEMU VFIO-based PCI device assignment driver.
To make use of this driver, enable CONFIG_VFIO, CONFIG_VFIO_IOMMU_TYPE1,
and CONFIG_VFIO_PCI in your host Linux kernel config.  Load the vfio-pci
module.  To assign device 0000:05:00.0 to a guest, do the following:

for dev in $(ls /sys/bus/pci/devices/0000:05:00.0/iommu_group/devices); do
    vendor=$(cat /sys/bus/pci/devices/$dev/vendor)
    device=$(cat /sys/bus/pci/devices/$dev/device)
    if [ -e /sys/bus/pci/devices/$dev/driver ]; then
        echo $dev > /sys/bus/pci/devices/$dev/driver/unbind
    fi
    echo $vendor $device > /sys/bus/pci/drivers/vfio-pci/new_id
done

See Documentation/vfio.txt in the Linux kernel tree for further
description of IOMMU groups and VFIO.

Then launch qemu including the option:

-device vfio-pci,host=0000:05:00.0

Support for legacy PCI interrupts (INTx) is not yet included and will
be added in a future update.  Both MSI and MSI-X are supported here.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---

 hw/vfio_pci.c | 1853 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 hw/vfio_pci.h |  101 +++
 2 files changed, 1954 insertions(+)
 create mode 100644 hw/vfio_pci.c
 create mode 100644 hw/vfio_pci.h

Alex Williamson <alex.williamson@redhat.com> writes:

> This adds the core of the QEMU VFIO-based PCI device assignment driver.
> To make use of this driver, enable CONFIG_VFIO, CONFIG_VFIO_IOMMU_TYPE1,
> and CONFIG_VFIO_PCI in your host Linux kernel config.  Load the vfio-pci
> module.  To assign device 0000:05:00.0 to a guest, do the following:
>
> for dev in $(ls /sys/bus/pci/devices/0000:05:00.0/iommu_group/devices); do
>     vendor=$(cat /sys/bus/pci/devices/$dev/vendor)
>     device=$(cat /sys/bus/pci/devices/$dev/device)
>     if [ -e /sys/bus/pci/devices/$dev/driver ]; then
>         echo $dev > /sys/bus/pci/devices/$dev/driver/unbind
>     fi
>     echo $vendor $device > /sys/bus/pci/drivers/vfio-pci/new_id
> done
>
> See Documentation/vfio.txt in the Linux kernel tree for further
> description of IOMMU groups and VFIO.
>
> Then launch qemu including the option:
>
> -device vfio-pci,host=0000:05:00.0
>
> Support for legacy PCI interrupts (INTx) is not yet included and will
> be added in a future update.  Both MSI and MSI-X are supported here.
>
> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
> ---
>
>  hw/vfio_pci.c | 1853 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  hw/vfio_pci.h |  101 +++
>  2 files changed, 1954 insertions(+)
>  create mode 100644 hw/vfio_pci.c
>  create mode 100644 hw/vfio_pci.h
>
> diff --git a/hw/vfio_pci.c b/hw/vfio_pci.c
> new file mode 100644
> index 0000000..71bb1bd
> --- /dev/null
> +++ b/hw/vfio_pci.c
> @@ -0,0 +1,1853 @@
> +/*
> + * vfio based device assignment support
> + *
> + * Copyright Red Hat, Inc. 2012
> + *
> + * Authors:
> + *  Alex Williamson <alex.williamson@redhat.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2.  See
> + * the COPYING file in the top-level directory.
> + *
> + * Based on qemu-kvm device-assignment:
> + *  Adapted for KVM by Qumranet.
> + *  Copyright (c) 2007, Neocleus, Alex Novik (alex@neocleus.com)
> + *  Copyright (c) 2007, Neocleus, Guy Zana (guy@neocleus.com)
> + *  Copyright (C) 2008, Qumranet, Amit Shah (amit.shah@qumranet.com)
> + *  Copyright (C) 2008, Red Hat, Amit Shah (amit.shah@redhat.com)
> + *  Copyright (C) 2008, IBM, Muli Ben-Yehuda (muli@il.ibm.com)
> + */
> +
> +#include <dirent.h>
> +#include <unistd.h>
> +#include <sys/ioctl.h>
> +#include <sys/mman.h>
> +#include <sys/stat.h>
> +#include <sys/types.h>
> +#include <linux/vfio.h>
> +
> +#include "config.h"
> +#include "event_notifier.h"
> +#include "exec-memory.h"
> +#include "kvm.h"
> +#include "memory.h"
> +#include "msi.h"
> +#include "msix.h"
> +#include "qemu-error.h"
> +#include "range.h"
> +#include "vfio_pci.h"
> +
> +/* #define DEBUG_VFIO */
> +#ifdef DEBUG_VFIO
> +#define DPRINTF(fmt, ...) \
> +    do { fprintf(stderr, "vfio: " fmt, ## __VA_ARGS__); } while (0)
> +#else
> +#define DPRINTF(fmt, ...) \
> +    do { } while (0)
> +#endif
> +
> +#define MSIX_CAP_LENGTH 12
> +
> +static QLIST_HEAD(, VFIOContainer)
> +    container_list = QLIST_HEAD_INITIALIZER(container_list);
> +
> +static QLIST_HEAD(, VFIOGroup)
> +    group_list = QLIST_HEAD_INITIALIZER(group_list);
> +
> +static void vfio_disable_interrupts(VFIODevice *vdev);
> +static uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len);
> +
> +/*
> + * Common VFIO interrupt disable
> + */
> +static void vfio_disable_irqindex(VFIODevice *vdev, int index)
> +{
> +    struct vfio_irq_set irq_set = {
> +        .argsz = sizeof(irq_set),
> +        .flags = VFIO_IRQ_SET_DATA_NONE | VFIO_IRQ_SET_ACTION_TRIGGER,
> +        .index = index,
> +        .start = 0,
> +        .count = 0,
> +    };
> +
> +    ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, &irq_set);
> +
> +    vdev->interrupt = INT_NONE;
> +}
> +
> +/*
> + * INTx
> + */
> +static void vfio_unmask_intx(VFIODevice *vdev)
> +{
> +    struct vfio_irq_set irq_set = {
> +        .argsz = sizeof(irq_set),
> +        .flags = VFIO_IRQ_SET_DATA_NONE | VFIO_IRQ_SET_ACTION_UNMASK,
> +        .index = VFIO_PCI_INTX_IRQ_INDEX,
> +        .start = 0,
> +        .count = 1,
> +    };
> +
> +    ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, &irq_set);
> +}
> +
> +static void vfio_intx_interrupt(void *opaque)
> +{
> +    VFIODevice *vdev = opaque;
> +
> +    if (!event_notifier_test_and_clear(&vdev->intx.interrupt)) {
> +        return;
> +    }
> +
> +    DPRINTF("%s(%04x:%02x:%02x.%x) Pin %c\n", __func__, vdev->host.domain,
> +            vdev->host.bus, vdev->host.slot, vdev->host.function,
> +            'A' + vdev->intx.pin);
> +
> +    vdev->intx.pending = true;
> +    qemu_set_irq(vdev->pdev.irq[vdev->intx.pin], 1);
> +}
> +
> +static void vfio_eoi(VFIODevice *vdev)
> +{
> +    if (!vdev->intx.pending) {
> +        return;
> +    }
> +
> +    DPRINTF("%s(%04x:%02x:%02x.%x) EOI\n", __func__, vdev->host.domain,
> +            vdev->host.bus, vdev->host.slot, vdev->host.function);
> +
> +    vdev->intx.pending = false;
> +    qemu_set_irq(vdev->pdev.irq[vdev->intx.pin], 0);
> +    vfio_unmask_intx(vdev);
> +}
> +
> +struct vfio_irq_set_fd {
> +    struct vfio_irq_set irq_set;
> +    int32_t fd;
> +} QEMU_PACKED;
> +
> +static void vfio_enable_intx_kvm(VFIODevice *vdev)
> +{
> +#ifdef CONFIG_KVM
> +    /*
> +     * VFIO supports an eventfd for INTx notification and an irqfd-like
> +     * mechanism for unmasking INTx.  If we could get a level irqfd in
> +     * KVM and an eventfd triggered on EOI from guest, we could interlock
> +     * these and avoid userspace for INTx.  Work in progress.
> +     */
> +#endif
> +}
> +
> +static void vfio_disable_intx_kvm(VFIODevice *vdev)
> +{
> +#ifdef CONFIG_KVM
> +    /* Same. */
> +#endif
> +}
> +
> +static void vfio_update_irq(PCIDevice *pdev)
> +{
> +    VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
> +    PCIINTxRoute route;
> +
> +    if (vdev->interrupt != INT_INTx) {
> +        return;
> +    }
> +
> +    route = pci_device_route_intx_to_irq(&vdev->pdev, vdev->intx.pin);
> +    if (!memcmp(&route, &vdev->intx.route, sizeof(route))) {
> +        return; /* Nothing changed */
> +    }
> +
> +    DPRINTF("%s(%04x:%02x:%02x.%x) IRQ moved %d -> %d\n", __func__,
> +            vdev->host.domain, vdev->host.bus, vdev->host.slot,
> +            vdev->host.function, vdev->intx.route.irq, route.irq);
> +
> +    vfio_disable_intx_kvm(vdev);
> +    /* TBD - Disable QEMU eoi notifier */
> +
> +    vdev->intx.route = route;
> +
> +    if (route.mode == PCI_INTX_DISABLED) {
> +        return;
> +    }
> +
> +    /* TBD - Enable QEMU eoi notifier */
> +    vfio_enable_intx_kvm(vdev);
> +
> +    /* Re-enable the interrupt in cased we missed an EOI */
> +    vfio_eoi(vdev);
> +}
> +
> +static int vfio_enable_intx(VFIODevice *vdev)
> +{
> +    struct vfio_irq_set_fd irq_set_fd = {
> +        .irq_set = {
> +            .argsz = sizeof(irq_set_fd),
> +            .flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER,
> +            .index = VFIO_PCI_INTX_IRQ_INDEX,
> +            .start = 0,
> +            .count = 1,
> +        },
> +    };
> +    uint8_t pin = vfio_pci_read_config(&vdev->pdev, PCI_INTERRUPT_PIN, 1);
> +
> +    if (!pin) {
> +        return 0;
> +    }
> +
> +    vfio_disable_interrupts(vdev);
> +
> +    vdev->intx.pin = pin - 1; /* Pin A (1) -> irq[0] */
> +    vdev->intx.route = pci_device_route_intx_to_irq(&vdev->pdev,
> +                                                    vdev->intx.pin);
> +    /* TBD - Enable QEMU eoi notifier */
> +
> +    if (event_notifier_init(&vdev->intx.interrupt, 0)) {
> +        error_report("vfio: Error: event_notifier_init failed\n");
> +        return -1;
> +    }
> +
> +    irq_set_fd.fd = event_notifier_get_fd(&vdev->intx.interrupt);
> +    qemu_set_fd_handler(irq_set_fd.fd, vfio_intx_interrupt, NULL, vdev);
> +
> +    if (ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, &irq_set_fd)) {
> +        error_report("vfio: Error: Failed to setup INTx fd: %s\n",
> +                     strerror(errno));
> +        return -1;
> +    }
> +
> +    vfio_enable_intx_kvm(vdev);
> +
> +    vdev->interrupt = INT_INTx;
> +
> +    DPRINTF("%s(%04x:%02x:%02x.%x)\n", __func__, vdev->host.domain,
> +            vdev->host.bus, vdev->host.slot, vdev->host.function);
> +
> +    return 0;
> +}
> +
> +static void vfio_disable_intx(VFIODevice *vdev)
> +{
> +    int fd;
> +
> +    vfio_disable_intx_kvm(vdev);
> +    vfio_disable_irqindex(vdev, VFIO_PCI_INTX_IRQ_INDEX);
> +
> +    /* TBD - Disable QEMU eoi notifier */
> +
> +    fd = event_notifier_get_fd(&vdev->intx.interrupt);
> +    qemu_set_fd_handler(fd, NULL, NULL, vdev);
> +    event_notifier_cleanup(&vdev->intx.interrupt);
> +
> +    vdev->interrupt = INT_NONE;
> +
> +    DPRINTF("%s(%04x:%02x:%02x.%x)\n", __func__, vdev->host.domain,
> +            vdev->host.bus, vdev->host.slot, vdev->host.function);
> +}
> +
> +/*
> + * MSI/X
> + */
> +static void vfio_msi_interrupt(void *opaque)
> +{
> +    MSIVector *vec = opaque;
> +    VFIODevice *vdev = vec->vdev;
> +
> +    if (!event_notifier_test_and_clear(&vec->interrupt)) {
> +        return;
> +    }
> +
> +    DPRINTF("%s(%04x:%02x:%02x.%x) vector %d\n", __func__,
> +            vdev->host.domain, vdev->host.bus, vdev->host.slot,
> +            vdev->host.function, vec->vector);
> +
> +    if (vdev->interrupt == INT_MSIX) {
> +        msix_notify(&vdev->pdev, vec->vector);
> +    } else if (vdev->interrupt == INT_MSI) {
> +        msi_notify(&vdev->pdev, vec->vector);
> +    } else {
> +        error_report("vfio: MSI interrupt receieved, but not enabled?\n");
> +    }
> +}
> +
> +static int vfio_enable_vectors(VFIODevice *vdev, bool msix)
> +{
> +    struct vfio_irq_set *irq_set;
> +    int ret = 0, i, argsz;
> +    int32_t *fds;
> +
> +    argsz = sizeof(*irq_set) + (vdev->nr_vectors * sizeof(*fds));
> +
> +    irq_set = g_malloc0(argsz);
> +    irq_set->argsz = argsz;
> +    irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER;
> +    irq_set->index = msix ? VFIO_PCI_MSIX_IRQ_INDEX : VFIO_PCI_MSI_IRQ_INDEX;
> +    irq_set->start = 0;
> +    irq_set->count = vdev->nr_vectors;
> +    fds = (int32_t *)&irq_set->data;
> +
> +    for (i = 0; i < vdev->nr_vectors; i++) {
> +        if (!vdev->msi_vectors[i].use) {
> +            fds[i] = -1;
> +            continue;
> +        }
> +
> +        fds[i] = event_notifier_get_fd(&vdev->msi_vectors[i].interrupt);
> +    }
> +
> +    ret = ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, irq_set);
> +
> +    g_free(irq_set);
> +
> +    if (!ret) {
> +        vdev->interrupt = msix ? INT_MSIX : INT_MSI;
> +    }
> +
> +    return ret;
> +}
> +
> +static int vfio_msix_vector_use(PCIDevice *pdev,
> +                                unsigned int vector, MSIMessage msg)
> +{
> +    VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
> +    int ret, fd;
> +
> +    DPRINTF("%s(%04x:%02x:%02x.%x) vector %d used\n", __func__,
> +            vdev->host.domain, vdev->host.bus, vdev->host.slot,
> +            vdev->host.function, vector);
> +
> +    if (vdev->interrupt != INT_MSIX) {
> +        vfio_disable_interrupts(vdev);
> +    }
> +
> +    if (!vdev->msi_vectors) {
> +        vdev->msi_vectors = g_malloc0(vdev->msix->entries * sizeof(MSIVector));
> +    }
> +
> +    vdev->msi_vectors[vector].vdev = vdev;
> +    vdev->msi_vectors[vector].vector = vector;
> +    vdev->msi_vectors[vector].use = true;
> +
> +    msix_vector_use(pdev, vector);
> +
> +    if (event_notifier_init(&vdev->msi_vectors[vector].interrupt, 0)) {
> +        error_report("vfio: Error: event_notifier_init failed\n");
> +    }
> +
> +    fd = event_notifier_get_fd(&vdev->msi_vectors[vector].interrupt);
> +
> +    /*
> +     * Attempt to enable route through KVM irqchip,
> +     * default to userspace handling if unavailable.
> +     */
> +    vdev->msi_vectors[vector].virq = kvm_irqchip_add_msi_route(kvm_state, msg);
> +    if (vdev->msi_vectors[vector].virq < 0 ||
> +        kvm_irqchip_add_irqfd(kvm_state, fd,
> +                              vdev->msi_vectors[vector].virq) < 0) {
> +        qemu_set_fd_handler(fd, vfio_msi_interrupt, NULL,
> +                            &vdev->msi_vectors[vector]);
> +    }
> +
> +    /*
> +     * We don't want to have the host allocate all possible MSI vectors
> +     * for a device if they're not in use, so we shutdown and incrementally
> +     * increase them as needed.
> +     */
> +    if (vdev->nr_vectors < vector + 1) {
> +        int i;
> +
> +        vfio_disable_irqindex(vdev, VFIO_PCI_MSIX_IRQ_INDEX);
> +        vdev->nr_vectors = vector + 1;
> +        ret = vfio_enable_vectors(vdev, true);
> +        if (ret) {
> +            error_report("vfio: failed to enable vectors, %d\n", ret);
> +        }
> +
> +        /* We don't know if we've missed interrupts in the interim... */
> +        for (i = 0; i < vdev->msix->entries; i++) {
> +            if (vdev->msi_vectors[i].use) {
> +                msix_notify(&vdev->pdev, i);
> +            }
> +        }
> +    } else {
> +        struct vfio_irq_set_fd irq_set_fd = {
> +            .irq_set = {
> +                .argsz = sizeof(irq_set_fd),
> +                .flags = VFIO_IRQ_SET_DATA_EVENTFD |
> +                         VFIO_IRQ_SET_ACTION_TRIGGER,
> +                .index = VFIO_PCI_MSIX_IRQ_INDEX,
> +                .start = vector,
> +                .count = 1,
> +            },
> +            .fd = fd,
> +        };
> +        ret = ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, &irq_set_fd);
> +        if (ret) {
> +            error_report("vfio: failed to modify vector, %d\n", ret);
> +        }
> +        msix_notify(&vdev->pdev, vector);
> +    }
> +
> +    return 0;
> +}
> +
> +static void vfio_msix_vector_release(PCIDevice *pdev, unsigned int vector)
> +{
> +    VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
> +    struct vfio_irq_set_fd irq_set_fd = {
> +        .irq_set = {
> +            .argsz = sizeof(irq_set_fd),
> +            .flags = VFIO_IRQ_SET_DATA_EVENTFD |
> +                     VFIO_IRQ_SET_ACTION_TRIGGER,
> +            .index = VFIO_PCI_MSIX_IRQ_INDEX,
> +            .start = vector,
> +            .count = 1,
> +        },
> +        .fd = -1,
> +    };
> +    int fd;
> +
> +    DPRINTF("%s(%04x:%02x:%02x.%x) vector %d released\n", __func__,
> +            vdev->host.domain, vdev->host.bus, vdev->host.slot,
> +            vdev->host.function, vector);
> +
> +    /*
> +     * XXX What's the right thing to do here?  This turns off the interrupt
> +     * completely, but do we really just want to switch the interrupt to
> +     * bouncing through userspace and let msix.c drop it?  Not sure.
> +     */
> +    msix_vector_unuse(pdev, vector);
> +    ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, &irq_set_fd);
> +
> +    fd = event_notifier_get_fd(&vdev->msi_vectors[vector].interrupt);
> +
> +    if (vdev->msi_vectors[vector].virq < 0) {
> +        qemu_set_fd_handler(fd, NULL, NULL, NULL);
> +    } else {
> +        kvm_irqchip_remove_irqfd(kvm_state, fd, vdev->msi_vectors[vector].virq);
> +        kvm_irqchip_release_virq(kvm_state, vdev->msi_vectors[vector].virq);
> +        vdev->msi_vectors[vector].virq = -1;
> +    }
> +
> +    event_notifier_cleanup(&vdev->msi_vectors[vector].interrupt);
> +    vdev->msi_vectors[vector].use = false;
> +}
> +
> +/* XXX This should move to msi.c */
> +static MSIMessage msi_get_msg(PCIDevice *pdev, unsigned int vector)
> +{
> +    uint16_t flags = pci_get_word(pdev->config + pdev->msi_cap + PCI_MSI_FLAGS);
> +    bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;
> +    MSIMessage msg;
> +
> +    if (msi64bit) {
> +        msg.address = pci_get_quad(pdev->config +
> +                                   pdev->msi_cap + PCI_MSI_ADDRESS_LO);
> +    } else {
> +        msg.address = pci_get_long(pdev->config +
> +                                   pdev->msi_cap + PCI_MSI_ADDRESS_LO);
> +    }
> +
> +    msg.data = pci_get_word(pdev->config + pdev->msi_cap +
> +                            (msi64bit ? PCI_MSI_DATA_64 : PCI_MSI_DATA_32));
> +    msg.data += vector;
> +
> +    return msg;
> +}
> +
> +/* So should this */
> +static void msi_set_qsize(PCIDevice *pdev, uint8_t size)
> +{
> +    uint8_t *config = pdev->config + pdev->msi_cap;
> +    uint16_t flags;
> +
> +    flags = pci_get_word(config + PCI_MSI_FLAGS);
> +    flags = le16_to_cpu(flags);
> +    flags &= ~PCI_MSI_FLAGS_QSIZE;
> +    flags |= (size & 0x7) << 4;
> +    flags = cpu_to_le16(flags);
> +    pci_set_word(config + PCI_MSI_FLAGS, flags);
> +}
> +
> +static void vfio_enable_msi(VFIODevice *vdev)
> +{
> +    int ret, i;
> +
> +    vfio_disable_interrupts(vdev);
> +
> +    vdev->nr_vectors = msi_nr_vectors_allocated(&vdev->pdev);
> +retry:
> +    vdev->msi_vectors = g_malloc0(vdev->nr_vectors * sizeof(MSIVector));
> +
> +    for (i = 0; i < vdev->nr_vectors; i++) {
> +        MSIMessage msg;
> +        int fd;
> +
> +        vdev->msi_vectors[i].vdev = vdev;
> +        vdev->msi_vectors[i].vector = i;
> +        vdev->msi_vectors[i].use = true;
> +
> +        if (event_notifier_init(&vdev->msi_vectors[i].interrupt, 0)) {
> +            error_report("vfio: Error: event_notifier_init failed\n");
> +        }
> +
> +        fd = event_notifier_get_fd(&vdev->msi_vectors[i].interrupt);
> +
> +        msg = msi_get_msg(&vdev->pdev, i);
> +
> +        /*
> +         * Attempt to enable route through KVM irqchip,
> +         * default to userspace handling if unavailable.
> +         */
> +        vdev->msi_vectors[i].virq = kvm_irqchip_add_msi_route(kvm_state, msg);
> +        if (vdev->msi_vectors[i].virq < 0 ||
> +            kvm_irqchip_add_irqfd(kvm_state, fd,
> +                                  vdev->msi_vectors[i].virq) < 0) {
> +            qemu_set_fd_handler(fd, vfio_msi_interrupt, NULL,
> +                                &vdev->msi_vectors[i]);
> +        }
> +    }
> +
> +    ret = vfio_enable_vectors(vdev, false);
> +    if (ret) {
> +        if (ret < 0) {
> +            error_report("vfio: Error: Failed to setup MSI fds: %s\n",
> +                         strerror(errno));
> +        } else if (ret != vdev->nr_vectors) {
> +            error_report("vfio: Error: Failed to enable %d "
> +                         "MSI vectors, retry with %d\n", vdev->nr_vectors, ret);
> +        }
> +
> +        for (i = 0; i < vdev->nr_vectors; i++) {
> +            int fd = event_notifier_get_fd(&vdev->msi_vectors[i].interrupt);
> +            if (vdev->msi_vectors[i].virq >= 0) {
> +                kvm_irqchip_remove_irqfd(kvm_state, fd,
> +                                         vdev->msi_vectors[i].virq);
> +                kvm_irqchip_release_virq(kvm_state, vdev->msi_vectors[i].virq);
> +                vdev->msi_vectors[i].virq = -1;
> +            } else {
> +                qemu_set_fd_handler(fd, NULL, NULL, NULL);
> +            }
> +            event_notifier_cleanup(&vdev->msi_vectors[i].interrupt);
> +        }
> +
> +        g_free(vdev->msi_vectors);
> +
> +        if (ret > 0 && ret != vdev->nr_vectors) {
> +            vdev->nr_vectors = ret;
> +            goto retry;
> +        }
> +        vdev->nr_vectors = 0;
> +
> +        return;
> +    }
> +
> +    msi_set_qsize(&vdev->pdev, vdev->nr_vectors);
> +
> +    DPRINTF("%s(%04x:%02x:%02x.%x) Enabled %d MSI vectors\n", __func__,
> +            vdev->host.domain, vdev->host.bus, vdev->host.slot,
> +            vdev->host.function, vdev->nr_vectors);
> +}
> +
> +static void vfio_disable_msi_x(VFIODevice *vdev, bool msix)
> +{
> +    int i;
> +
> +    vfio_disable_irqindex(vdev, msix ? VFIO_PCI_MSIX_IRQ_INDEX :
> +                                       VFIO_PCI_MSI_IRQ_INDEX);
> +
> +    for (i = 0; i < vdev->nr_vectors; i++) {
> +        int fd;
> +
> +        if (!vdev->msi_vectors[i].use) {
> +            continue;
> +        }
> +
> +        fd = event_notifier_get_fd(&vdev->msi_vectors[i].interrupt);
> +
> +        if (vdev->msi_vectors[i].virq >= 0) {
> +            kvm_irqchip_remove_irqfd(kvm_state, fd, vdev->msi_vectors[i].virq);
> +            kvm_irqchip_release_virq(kvm_state, vdev->msi_vectors[i].virq);
> +            vdev->msi_vectors[i].virq = -1;
> +        } else {
> +            qemu_set_fd_handler(fd, NULL, NULL, NULL);
> +        }
> +
> +        if (msix) {
> +            msix_vector_unuse(&vdev->pdev, i);
> +        }
> +
> +        event_notifier_cleanup(&vdev->msi_vectors[i].interrupt);
> +    }
> +
> +    g_free(vdev->msi_vectors);
> +    vdev->msi_vectors = NULL;
> +    vdev->nr_vectors = 0;
> +
> +    if (!msix) {
> +        msi_set_qsize(&vdev->pdev, 0); /* Actually still means 1 vector */
> +    }
> +
> +    DPRINTF("%s(%04x:%02x:%02x.%x, msi%s)\n", __func__,
> +            vdev->host.domain, vdev->host.bus, vdev->host.slot,
> +            vdev->host.function, msix ? "x" : "");
> +
> +    vfio_enable_intx(vdev);
> +}
> +
> +/*
> + * IO Port/MMIO - Beware of the endians, VFIO is always little endian
> + */
> +static void vfio_bar_write(void *opaque, target_phys_addr_t addr,
> +                           uint64_t data, unsigned size)
> +{
> +    VFIOBAR *bar = opaque;
> +    uint8_t buf[8];
> +
> +    switch (size) {
> +    case 1:
> +        *buf = data & 0xff;
> +        break;
> +    case 2:
> +        *(uint16_t *)buf = cpu_to_le16(data);
> +        break;
> +    case 4:
> +        *(uint32_t *)buf = cpu_to_le32(data);
> +        break;
> +    default:
> +        hw_error("vfio: unsupported write size, %d bytes\n", size);
> +        break;
> +    }
> +
> +    if (pwrite(bar->fd, buf, size, bar->fd_offset + addr) != size) {
> +        error_report("%s(,0x%"PRIx64", 0x%"PRIx64", %d) failed: %s\n",
> +                     __func__, addr, data, size, strerror(errno));
> +    }
> +
> +    DPRINTF("%s(BAR%d+0x%"PRIx64", 0x%"PRIx64", %d)\n",
> +            __func__, bar->nr, addr, data, size);
> +}
> +
> +static uint64_t vfio_bar_read(void *opaque,
> +                              target_phys_addr_t addr, unsigned size)
> +{
> +    VFIOBAR *bar = opaque;
> +    uint8_t buf[8];
> +    uint64_t data = 0;
> +
> +    if (pread(bar->fd, buf, size, bar->fd_offset + addr) != size) {
> +        error_report("%s(,0x%"PRIx64", %d) failed: %s\n",
> +                     __func__, addr, size, strerror(errno));
> +        return (uint64_t)-1;
> +    }
> +
> +    switch (size) {
> +    case 1:
> +        data = buf[0];
> +        break;
> +    case 2:
> +        data = le16_to_cpu(*(uint16_t *)buf);
> +        break;
> +    case 4:
> +        data = le32_to_cpu(*(uint32_t *)buf);
> +        break;
> +    default:
> +        hw_error("vfio: unsupported read size, %d bytes\n", size);
> +        break;
> +    }
> +
> +    DPRINTF("%s(BAR%d+0x%"PRIx64", %d) = 0x%"PRIx64"\n",
> +            __func__, bar->nr, addr, size, data);
> +
> +    return data;
> +}
> +
> +static const MemoryRegionOps vfio_bar_ops = {
> +    .read = vfio_bar_read,
> +    .write = vfio_bar_write,
> +    .endianness = DEVICE_LITTLE_ENDIAN,
> +};
> +
> +/*
> + * PCI config space
> + */
> +static uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len)
> +{
> +    VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
> +    uint32_t val = 0;
> +
> +    /*
> +     * We only need QEMU PCI config support for the ROM BAR, the MSI and MSIX
> +     * capabilities, and the multifunction bit below.  We let VFIO handle
> +     * virtualizing everything else.  Performance is not a concern here.
> +     */
> +    if (ranges_overlap(addr, len, PCI_ROM_ADDRESS, 4) ||
> +        (pdev->cap_present & QEMU_PCI_CAP_MSIX &&
> +         ranges_overlap(addr, len, pdev->msix_cap, MSIX_CAP_LENGTH)) ||
> +        (pdev->cap_present & QEMU_PCI_CAP_MSI &&
> +         ranges_overlap(addr, len, pdev->msi_cap, vdev->msi_cap_size))) {
> +
> +        val = pci_default_read_config(pdev, addr, len);
> +    } else {
> +        if (pread(vdev->fd, &val, len, vdev->config_offset + addr) != len) {
> +            error_report("%s(%04x:%02x:%02x.%x, 0x%x, 0x%x) failed: %s\n",
> +                         __func__, vdev->host.domain, vdev->host.bus,
> +                         vdev->host.slot, vdev->host.function, addr, len,
> +                         strerror(errno));
> +            return -1;
> +        }
> +        val = le32_to_cpu(val);
> +    }
> +
> +    /* Multifunction bit is virualized in QEMU */
> +    if (unlikely(ranges_overlap(addr, len, PCI_HEADER_TYPE, 1))) {
> +        uint32_t mask = PCI_HEADER_TYPE_MULTI_FUNCTION;
> +
> +        if (len == 4) {
> +            mask <<= 16;
> +        }
> +
> +        if (pdev->cap_present & QEMU_PCI_CAP_MULTIFUNCTION) {
> +            val |= mask;
> +        } else {
> +            val &= ~mask;
> +        }
> +    }
> +
> +    DPRINTF("%s(%04x:%02x:%02x.%x, @0x%x, len=0x%x) %x\n", __func__,
> +            vdev->host.domain, vdev->host.bus, vdev->host.slot,
> +            vdev->host.function, addr, len, val);
> +
> +    return val;
> +}
> +
> +static void vfio_pci_write_config(PCIDevice *pdev, uint32_t addr,
> +                                  uint32_t val, int len)
> +{
> +    VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
> +    uint32_t val_le = cpu_to_le32(val);
> +
> +    DPRINTF("%s(%04x:%02x:%02x.%x, @0x%x, 0x%x, len=0x%x)\n", __func__,
> +            vdev->host.domain, vdev->host.bus, vdev->host.slot,
> +            vdev->host.function, addr, val, len);
> +
> +    /* Write everything to VFIO, let it filter out what we can't write */
> +    if (pwrite(vdev->fd, &val_le, len, vdev->config_offset + addr) != len) {
> +        error_report("%s(%04x:%02x:%02x.%x, 0x%x, 0x%x, 0x%x) failed: %s\n",
> +                     __func__, vdev->host.domain, vdev->host.bus,
> +                     vdev->host.slot, vdev->host.function, addr, val, len,
> +                     strerror(errno));
> +    }
> +
> +    /* Write standard header bits to emulation */
> +    if (addr < PCI_CONFIG_HEADER_SIZE) {
> +        pci_default_write_config(pdev, addr, val, len);
> +        return;
> +    }
> +
> +    /* MSI/MSI-X Enabling/Disabling */
> +    if (pdev->cap_present & QEMU_PCI_CAP_MSI &&
> +        ranges_overlap(addr, len, pdev->msi_cap, vdev->msi_cap_size)) {
> +        int is_enabled, was_enabled = msi_enabled(pdev);
> +
> +        pci_default_write_config(pdev, addr, val, len);
> +
> +        is_enabled = msi_enabled(pdev);
> +
> +        if (!was_enabled && is_enabled) {
> +            vfio_enable_msi(vdev);
> +        } else if (was_enabled && !is_enabled) {
> +            vfio_disable_msi_x(vdev, false);
> +        }
> +    }
> +
> +    if (pdev->cap_present & QEMU_PCI_CAP_MSIX &&
> +        ranges_overlap(addr, len, pdev->msix_cap, MSIX_CAP_LENGTH)) {
> +        int is_enabled, was_enabled = msix_enabled(pdev);
> +
> +        pci_default_write_config(pdev, addr, val, len);
> +
> +        is_enabled = msix_enabled(pdev);
> +
> +        if (!was_enabled && is_enabled) {
> +            /* vfio_msix_vector_use handles this automatically */
> +        } else if (was_enabled && !is_enabled) {
> +            vfio_disable_msi_x(vdev, true);
> +        }
> +    }
> +}
> +
> +/*
> + * DMA - Mapping and unmapping for the "type1" IOMMU interface used on x86
> + */
> +static int vfio_dma_map(VFIOContainer *container, target_phys_addr_t iova,
> +                        ram_addr_t size, void *vaddr, bool readonly)
> +{
> +    struct vfio_iommu_type1_dma_map map = {
> +        .argsz = sizeof(map),
> +        .flags = VFIO_DMA_MAP_FLAG_READ,
> +        .vaddr = (__u64)vaddr,
> +        .iova = iova,
> +        .size = size,
> +    };
> +
> +    if (!readonly) {
> +        map.flags |= VFIO_DMA_MAP_FLAG_WRITE;
> +    }
> +
> +    if (ioctl(container->fd, VFIO_IOMMU_MAP_DMA, &map)) {
> +        DPRINTF("VFIO_MAP_DMA: %d\n", -errno);
> +        return -errno;
> +    }
> +
> +    return 0;
> +}
> +
> +static int vfio_dma_unmap(VFIOContainer *container,
> +                          target_phys_addr_t iova, ram_addr_t size)
> +{
> +    struct vfio_iommu_type1_dma_unmap unmap = {
> +        .argsz = sizeof(unmap),
> +        .flags = 0,
> +        .iova = iova,
> +        .size = size,
> +    };
> +
> +    if (ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA, &unmap)) {
> +        DPRINTF("VFIO_UNMAP_DMA: %d\n", -errno);
> +        return -errno;
> +    }
> +
> +    return 0;
> +}
> +
> +static void vfio_listener_dummy1(MemoryListener *listener)
> +{
> +    /* We don't do batching (begin/commit) or care about logging */
> +}
> +
> +static void vfio_listener_dummy2(MemoryListener *listener,
> +                                 MemoryRegionSection *section)
> +{
> +    /* We don't do logging or care about nops */
> +}
> +
> +static void vfio_listener_dummy3(MemoryListener *listener,
> +                                 MemoryRegionSection *section,
> +                                 bool match_data, uint64_t data,
> +                                 EventNotifier *e)
> +{
> +    /* We don't care about eventfds */
> +}
> +
> +static bool vfio_listener_skipped_section(MemoryRegionSection *section)
> +{
> +    return !memory_region_is_ram(section->mr);
> +}
> +
> +static void vfio_listener_region_add(MemoryListener *listener,
> +                                     MemoryRegionSection *section)
> +{
> +    VFIOContainer *container = container_of(listener, VFIOContainer,
> +                                            iommu_data.listener);
> +    target_phys_addr_t iova, end;
> +    void *vaddr;
> +    int ret;
> +
> +    if (vfio_listener_skipped_section(section)) {
> +        DPRINTF("vfio: SKIPPING region_add %016lx - %016lx\n",
> +                section->offset_within_address_space,
> +                section->offset_within_address_space + section->size - 1);
> +        return;
> +    }
> +
> +    if (unlikely((section->offset_within_address_space & ~TARGET_PAGE_MASK) !=
> +                 (section->offset_within_region & ~TARGET_PAGE_MASK))) {
> +        error_report("%s received unaligned region\n", __func__);
> +        return;
> +    }
> +
> +    iova = TARGET_PAGE_ALIGN(section->offset_within_address_space);
> +    end = (section->offset_within_address_space + section->size) &
> +          TARGET_PAGE_MASK;
> +
> +    if (iova >= end) {
> +        return;
> +    }
> +
> +    vaddr = memory_region_get_ram_ptr(section->mr) +
> +            section->offset_within_region +
> +            (iova - section->offset_within_address_space);
> +
> +    DPRINTF("vfio: region_add %016lx - %016lx [%p]\n",
> +            iova, end - 1, vaddr);
> +
> +    ret = vfio_dma_map(container, iova, end - iova, vaddr, section->readonly);
> +    if (ret) {
> +        error_report("vfio_dma_map(%p, 0x%016lx, 0x%lx, %p) = %d (%s)\n",
> +                     container, iova, end - iova, vaddr, ret, strerror(errno));
> +    }
> +}
> +
> +static void vfio_listener_region_del(MemoryListener *listener,
> +                                     MemoryRegionSection *section)
> +{
> +    VFIOContainer *container = container_of(listener, VFIOContainer,
> +                                            iommu_data.listener);
> +    target_phys_addr_t iova, end;
> +    int ret;
> +
> +    if (vfio_listener_skipped_section(section)) {
> +        DPRINTF("vfio: SKIPPING region_del %016lx - %016lx\n",
> +                section->offset_within_address_space,
> +                section->offset_within_address_space + section->size - 1);
> +        return;
> +    }
> +
> +    if (unlikely((section->offset_within_address_space & ~TARGET_PAGE_MASK) !=
> +                 (section->offset_within_region & ~TARGET_PAGE_MASK))) {
> +        error_report("%s received unaligned region\n", __func__);
> +        return;
> +    }
> +
> +    iova = TARGET_PAGE_ALIGN(section->offset_within_address_space);
> +    end = (section->offset_within_address_space + section->size) &
> +          TARGET_PAGE_MASK;
> +
> +    if (iova >= end) {
> +        return;
> +    }
> +
> +    DPRINTF("vfio: region_del %016lx - %016lx\n", iova, end - 1);
> +
> +    ret = vfio_dma_unmap(container, iova, end - iova);
> +    if (ret) {
> +        error_report("vfio_dma_unmap(%p, 0x%016lx, 0x%lx) = %d (%s)\n",
> +                     container, iova, end - iova, ret, strerror(errno));
> +    }
> +}
> +
> +static void vfio_listener_release(VFIOContainer *container)
> +{
> +    memory_listener_unregister(&container->iommu_data.listener);
> +}
> +
> +/*
> + * Interrupt setup
> + */
> +static void vfio_disable_interrupts(VFIODevice *vdev)
> +{
> +    switch (vdev->interrupt) {
> +    case INT_INTx:
> +        vfio_disable_intx(vdev);
> +        break;
> +    case INT_MSI:
> +        vfio_disable_msi_x(vdev, false);
> +        break;
> +    case INT_MSIX:
> +        vfio_disable_msi_x(vdev, true);
> +        break;
> +    }
> +}
> +
> +static int vfio_setup_msi(VFIODevice *vdev, int pos)
> +{
> +    uint16_t ctrl;
> +    bool msi_64bit, msi_maskbit;
> +    int ret, entries;
> +
> +    if (!msi_supported) {
> +        return 0;
> +    }
> +
> +    if (pread(vdev->fd, &ctrl, sizeof(ctrl),
> +              vdev->config_offset + pos + PCI_CAP_FLAGS) != sizeof(ctrl)) {
> +        return -1;
> +    }
> +    ctrl = le16_to_cpu(ctrl);
> +
> +    msi_64bit = !!(ctrl & PCI_MSI_FLAGS_64BIT);
> +    msi_maskbit = !!(ctrl & PCI_MSI_FLAGS_MASKBIT);
> +    entries = 1 << ((ctrl & PCI_MSI_FLAGS_QMASK) >> 1);
> +
> +    DPRINTF("%04x:%02x:%02x.%x PCI MSI CAP @0x%x\n", vdev->host.domain,
> +            vdev->host.bus, vdev->host.slot, vdev->host.function, pos);
> +
> +    ret = msi_init(&vdev->pdev, pos, entries, msi_64bit, msi_maskbit);
> +    if (ret < 0) {
> +        error_report("vfio: msi_init failed\n");
> +        return ret;
> +    }
> +    vdev->msi_cap_size = 0xa + (msi_maskbit ? 0xa : 0) + (msi_64bit ? 0x4 : 0);
> +
> +    return 0;
> +}
> +
> +/*
> + * We don't have any control over how pci_add_capability() inserts
> + * capabilities into the chain.  In order to setup MSI-X we need a
> + * MemoryRegion for the BAR.  In order to setup the BAR and not
> + * attempt to mmap the MSI-X table area, which VFIO won't allow, we
> + * need to first look for where the MSI-X table lives.  So we
> + * unfortunately split MSI-X setup across two functions.
> + */
> +static int vfio_early_setup_msix(VFIODevice *vdev)
> +{
> +    uint8_t pos;
> +    uint16_t ctrl;
> +    uint32_t table, pba;
> +
> +    pos = pci_find_capability(&vdev->pdev, PCI_CAP_ID_MSIX);
> +    if (!pos) {
> +        return 0;
> +    }
> +
> +    if (pread(vdev->fd, &ctrl, sizeof(ctrl),
> +              vdev->config_offset + pos + PCI_CAP_FLAGS) != sizeof(ctrl)) {
> +        return -1;
> +    }
> +
> +    if (pread(vdev->fd, &table, sizeof(table),
> +              vdev->config_offset + pos + PCI_MSIX_TABLE) != sizeof(table)) {
> +        return -1;
> +    }
> +
> +    if (pread(vdev->fd, &pba, sizeof(pba),
> +              vdev->config_offset + pos + PCI_MSIX_PBA) != sizeof(pba)) {
> +        return -1;
> +    }
> +
> +    ctrl = le16_to_cpu(ctrl);
> +    table = le32_to_cpu(table);
> +    pba = le32_to_cpu(pba);
> +
> +    vdev->msix = g_malloc0(sizeof(*(vdev->msix)));
> +    vdev->msix->table_bar = table & PCI_MSIX_FLAGS_BIRMASK;
> +    vdev->msix->table_offset = table & ~PCI_MSIX_FLAGS_BIRMASK;
> +    vdev->msix->pba_bar = pba & PCI_MSIX_FLAGS_BIRMASK;
> +    vdev->msix->pba_offset = pba & ~PCI_MSIX_FLAGS_BIRMASK;
> +    vdev->msix->entries = (ctrl & PCI_MSIX_FLAGS_QSIZE) + 1;
> +
> +    DPRINTF("%04x:%02x:%02x.%x "
> +            "PCI MSI-X CAP @0x%x, BAR %d, offset 0x%x, entries %d\n",
> +            vdev->host.domain, vdev->host.bus, vdev->host.slot,
> +            vdev->host.function, pos, vdev->msix->table_bar,
> +            vdev->msix->table_offset, vdev->msix->entries);
> +
> +    return 0;
> +}
> +
> +static int vfio_setup_msix(VFIODevice *vdev, int pos)
> +{
> +    int ret;
> +
> +    if (!msi_supported) {
> +        return 0;
> +    }
> +
> +    ret = msix_init(&vdev->pdev, vdev->msix->entries,
> +                    &vdev->bars[vdev->msix->table_bar].mem,
> +                    vdev->msix->table_bar, vdev->msix->table_offset,
> +                    &vdev->bars[vdev->msix->pba_bar].mem,
> +                    vdev->msix->pba_bar, vdev->msix->pba_offset, pos);
> +    if (ret < 0) {
> +        error_report("vfio: msix_init failed\n");
> +        return ret;
> +    }
> +
> +    ret = msix_set_vector_notifiers(&vdev->pdev, vfio_msix_vector_use,
> +                                    vfio_msix_vector_release);
> +    if (ret) {
> +        error_report("vfio: msix_set_vector_notifiers failed %d\n", ret);
> +        msix_uninit(&vdev->pdev, &vdev->bars[vdev->msix->table_bar].mem,
> +                    &vdev->bars[vdev->msix->pba_bar].mem);
> +        return ret;
> +    }
> +
> +    return 0;
> +}
> +
> +static void vfio_teardown_msi(VFIODevice *vdev)
> +{
> +    msi_uninit(&vdev->pdev);
> +
> +    if (vdev->msix) {
> +        /* FIXME: Why can't unset just silently do nothing?? */
> +        if (vdev->pdev.msix_vector_use_notifier &&
> +            vdev->pdev.msix_vector_release_notifier) {
> +            msix_unset_vector_notifiers(&vdev->pdev);
> +        }
> +
> +        msix_uninit(&vdev->pdev, &vdev->bars[vdev->msix->table_bar].mem,
> +                    &vdev->bars[vdev->msix->pba_bar].mem);
> +    }
> +}
> +
> +/*
> + * Resource setup
> + */
> +static void vfio_unmap_bar(VFIODevice *vdev, int nr)
> +{
> +    VFIOBAR *bar = &vdev->bars[nr];
> +
> +    if (!bar->size) {
> +        return;
> +    }
> +
> +    memory_region_del_subregion(&bar->mem, &bar->mmap_mem);
> +    munmap(bar->mmap, memory_region_size(&bar->mmap_mem));
> +
> +    if (vdev->msix && vdev->msix->table_bar == nr) {
> +        memory_region_del_subregion(&bar->mem, &vdev->msix->mmap_mem);
> +        munmap(vdev->msix->mmap, memory_region_size(&vdev->msix->mmap_mem));
> +    }
> +
> +    memory_region_destroy(&bar->mem);
> +}
> +
> +static int vfio_mmap_bar(VFIOBAR *bar, MemoryRegion *mem, MemoryRegion *submem,
> +                         void **map, size_t size, off_t offset,
> +                         const char *name)
> +{
> +    int ret = 0;
> +
> +    if (size && bar->flags & VFIO_REGION_INFO_FLAG_MMAP) {
> +        int prot = 0;
> +
> +        if (bar->flags & VFIO_REGION_INFO_FLAG_READ) {
> +            prot |= PROT_READ;
> +        }
> +
> +        if (bar->flags & VFIO_REGION_INFO_FLAG_WRITE) {
> +            prot |= PROT_WRITE;
> +        }
> +
> +        *map = mmap(NULL, size, prot, MAP_SHARED,
> +                    bar->fd, bar->fd_offset + offset);
> +        if (*map == MAP_FAILED) {
> +            *map = NULL;
> +            ret = -errno;
> +            goto empty_region;
> +        }
> +
> +        memory_region_init_ram_ptr(submem, name, size, *map);
> +    } else {
> +empty_region:
> +        /* Create a zero sized sub-region to make cleanup easy. */
> +        memory_region_init(submem, name, 0);
> +    }
> +
> +    memory_region_add_subregion(mem, offset, submem);
> +
> +    return ret;
> +}
> +
> +static void vfio_map_bar(VFIODevice *vdev, int nr)
> +{
> +    VFIOBAR *bar = &vdev->bars[nr];
> +    unsigned size = bar->size;
> +    char name[64];
> +    uint32_t pci_bar;
> +    uint8_t type;
> +    int ret;
> +
> +    /* Skip both unimplemented BARs and the upper half of 64bit BARS. */
> +    if (!size) {
> +        return;
> +    }
> +
> +    snprintf(name, sizeof(name), "VFIO %04x:%02x:%02x.%x BAR %d",
> +             vdev->host.domain, vdev->host.bus, vdev->host.slot,
> +             vdev->host.function, nr);
> +
> +    /* Determine what type of BAR this is for registration */
> +    ret = pread(vdev->fd, &pci_bar, sizeof(pci_bar),
> +                vdev->config_offset + PCI_BASE_ADDRESS_0 + (4 * nr));
> +    if (ret != sizeof(pci_bar)) {
> +        error_report("vfio: Failed to read BAR %d (%s)\n", nr, strerror(errno));
> +        return;
> +    }
> +
> +    pci_bar = le32_to_cpu(pci_bar);
> +    type = pci_bar & (pci_bar & PCI_BASE_ADDRESS_SPACE_IO ?
> +           ~PCI_BASE_ADDRESS_IO_MASK : ~PCI_BASE_ADDRESS_MEM_MASK);
> +
> +    /* A "slow" read/write mapping underlies all BARs */
> +    memory_region_init_io(&bar->mem, &vfio_bar_ops, bar, name, size);
> +    pci_register_bar(&vdev->pdev, nr, type, &bar->mem);
> +
> +    /*
> +     * We can't mmap areas overlapping the MSIX vector table, so we
> +     * potentially insert a direct-mapped subregion before and after it.
> +     */
> +    if (vdev->msix && vdev->msix->table_bar == nr) {
> +        size = vdev->msix->table_offset & TARGET_PAGE_MASK;
> +    }
> +
> +    strncat(name, " mmap", sizeof(name) - strlen(name) - 1);
> +    if (vfio_mmap_bar(bar, &bar->mem,
> +                      &bar->mmap_mem, &bar->mmap, size, 0, name)) {
> +        error_report("%s unsupported. Performance may be slow\n", name);
> +    }
> +
> +    if (vdev->msix && vdev->msix->table_bar == nr) {
> +        unsigned start;
> +
> +        start = TARGET_PAGE_ALIGN(vdev->msix->table_offset +
> +                                  (vdev->msix->entries * PCI_MSIX_ENTRY_SIZE));
> +
> +        size = start < bar->size ? bar->size - start : 0;
> +        strncat(name, " msix-hi", sizeof(name) - strlen(name) - 1);
> +        /* MSIXInfo contains another MemoryRegion for this mapping */
> +        if (vfio_mmap_bar(bar, &bar->mem, &vdev->msix->mmap_mem,
> +                          &vdev->msix->mmap, size, start, name)) {
> +            error_report("%s unsupported. Performance may be slow\n", name);
> +        }
> +    }
> +
> +    return;
> +}
> +
> +static void vfio_map_bars(VFIODevice *vdev)
> +{
> +    int i;
> +
> +    for (i = 0; i < PCI_ROM_SLOT; i++) {
> +        vfio_map_bar(vdev, i);
> +    }
> +}
> +
> +static void vfio_unmap_bars(VFIODevice *vdev)
> +{
> +    int i;
> +
> +    for (i = 0; i < PCI_ROM_SLOT; i++) {
> +        vfio_unmap_bar(vdev, i);
> +    }
> +}
> +
> +/*
> + * General setup
> + */
> +static uint8_t vfio_std_cap_max_size(PCIDevice *pdev, uint8_t pos)
> +{
> +    uint8_t tmp, next = 0xff;
> +
> +    for (tmp = pdev->config[PCI_CAPABILITY_LIST]; tmp;
> +         tmp = pdev->config[tmp + 1]) {
> +        if (tmp > pos && tmp < next) {
> +            next = tmp;
> +        }
> +    }
> +
> +    return next - pos;
> +}
> +
> +static int vfio_add_std_cap(VFIODevice *vdev, uint8_t pos)
> +{
> +    PCIDevice *pdev = &vdev->pdev;
> +    uint8_t cap_id, next, size;
> +    int ret;
> +
> +    cap_id = pdev->config[pos];
> +    next = pdev->config[pos + 1];
> +
> +    /*
> +     * If it becomes important to configure capabilities to their actual
> +     * size, use this as the default when it's something we don't recognize.
> +     * Since QEMU doesn't actually handle many of the config accesses,
> +     * exact size doesn't seem worthwhile.
> +     */
> +    size = vfio_std_cap_max_size(pdev, pos);
> +
> +    /*
> +     * pci_add_capability always inserts the new capability at the head
> +     * of the chain.  Therefore to end up with a chain that matches the
> +     * physical device, we insert from the end by making this recursive.
> +     * This is also why we pre-caclulate size above as cached config space
> +     * will be changed as we unwind the stack.
> +     */
> +    if (next) {
> +        ret = vfio_add_std_cap(vdev, next);
> +        if (ret) {
> +            return ret;
> +        }
> +    } else {
> +        pdev->config[PCI_CAPABILITY_LIST] = 0; /* Begin the rebuild */
> +    }
> +
> +    switch (cap_id) {
> +    case PCI_CAP_ID_MSI:
> +        ret = vfio_setup_msi(vdev, pos);
> +        break;
> +    case PCI_CAP_ID_MSIX:
> +        ret = vfio_setup_msix(vdev, pos);
> +        break;
> +    default:
> +        ret = pci_add_capability(pdev, cap_id, pos, size);
> +        break;
> +    }
> +
> +    if (ret < 0) {
> +        error_report("vfio: %04x:%02x:%02x.%x Error adding PCI capability "
> +                     "0x%x[0x%x]@0x%x: %d\n", vdev->host.domain,
> +                     vdev->host.bus, vdev->host.slot, vdev->host.function,
> +                     cap_id, size, pos, ret);
> +        return ret;
> +    }
> +
> +    return 0;
> +}
> +
> +static int vfio_add_capabilities(VFIODevice *vdev)
> +{
> +    PCIDevice *pdev = &vdev->pdev;
> +
> +    if (!(pdev->config[PCI_STATUS] & PCI_STATUS_CAP_LIST) ||
> +        !pdev->config[PCI_CAPABILITY_LIST]) {
> +        return 0; /* Nothing to add */
> +    }
> +
> +    return vfio_add_std_cap(vdev, pdev->config[PCI_CAPABILITY_LIST]);
> +}
> +
> +static int vfio_load_rom(VFIODevice *vdev)
> +{
> +    uint64_t size = vdev->rom_size;
> +    const VMStateDescription *vmsd;
> +    char name[32];
> +    off_t off = 0, voff = vdev->rom_offset;
> +    ssize_t bytes;
> +    void *ptr;
> +
> +    /* If loading ROM from file, pci handles it */
> +    if (vdev->pdev.romfile || !vdev->pdev.rom_bar || !size) {
> +        return 0;
> +    }
> +
> +    DPRINTF("%s(%04x:%02x:%02x.%x)\n", __func__, vdev->host.domain,
> +            vdev->host.bus, vdev->host.slot, vdev->host.function);
> +
> +    vmsd = qdev_get_vmsd(DEVICE(&vdev->pdev));
> +
> +    if (vmsd) {
> +        snprintf(name, sizeof(name), "%s.rom", vmsd->name);
> +    } else {
> +        snprintf(name, sizeof(name), "%s.rom",
> +                 object_get_typename(OBJECT(&vdev->pdev)));
> +    }

Not sure where this came from.  You can just hard code this to vfio.rom
or better yet, use the pci-host address and do vfio[%s].rom.

> +    memory_region_init_ram(&vdev->pdev.rom, name, size);
> +    ptr = memory_region_get_ram_ptr(&vdev->pdev.rom);
> +    memset(ptr, 0xff, size);
> +
> +    while (size) {
> +        bytes = pread(vdev->fd, ptr + off, size, voff + off);
> +        if (bytes == 0) {
> +            break; /* expect that we could get back less than the ROM BAR */
> +        } else if (bytes > 0) {
> +            off += bytes;
> +            size -= bytes;
> +        } else {
> +            if (errno == EINTR || errno == EAGAIN) {
> +                continue;
> +            }
> +            error_report("vfio: Error reading device ROM: %s\n",
> +                         strerror(errno));
> +            memory_region_destroy(&vdev->pdev.rom);
> +            return -1;
> +        }
> +    }
> +
> +    pci_register_bar(&vdev->pdev, PCI_ROM_SLOT, 0, &vdev->pdev.rom);
> +    vdev->pdev.has_rom = true;
> +    return 0;
> +}
> +
> +static int vfio_connect_container(VFIOGroup *group)
> +{
> +    VFIOContainer *container;
> +    int ret, fd;
> +
> +    if (group->container) {
> +        return 0;
> +    }
> +
> +    QLIST_FOREACH(container, &container_list, next) {
> +        if (!ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &container->fd)) {
> +            group->container = container;
> +            QLIST_INSERT_HEAD(&container->group_list, group, container_next);
> +            return 0;
> +        }
> +    }
> +
> +    fd = qemu_open("/dev/vfio/vfio", O_RDWR);
> +    if (fd < 0) {
> +        error_report("vfio: failed to open /dev/vfio/vfio: %s\n",
> +                     strerror(errno));
> +        return -1;
> +    }
> +
> +    ret = ioctl(fd, VFIO_GET_API_VERSION);
> +    if (ret != VFIO_API_VERSION) {
> +        error_report("vfio: supported vfio version: %d, "
> +                     "reported version: %d\n", VFIO_API_VERSION, ret);
> +        close(fd);
> +        return -1;
> +    }
> +
> +    container = g_malloc0(sizeof(*container));
> +    container->fd = fd;
> +
> +    if (ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1_IOMMU)) {
> +        ret = ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &fd);
> +        if (ret) {
> +            error_report("vfio: failed to set group container: %s\n",
> +                         strerror(errno));
> +            g_free(container);
> +            close(fd);
> +            return -1;
> +        }
> +
> +        ret = ioctl(fd, VFIO_SET_IOMMU, VFIO_TYPE1_IOMMU);
> +        if (ret) {
> +            error_report("vfio: failed to set iommu for container: %s\n",
> +                         strerror(errno));
> +            g_free(container);
> +            close(fd);
> +            return -1;
> +        }
> +
> +        container->iommu_data.listener = (MemoryListener) {
> +            .begin = vfio_listener_dummy1,
> +            .commit = vfio_listener_dummy1,
> +            .region_add = vfio_listener_region_add,
> +            .region_del = vfio_listener_region_del,
> +            .region_nop = vfio_listener_dummy2,
> +            .log_start = vfio_listener_dummy2,
> +            .log_stop = vfio_listener_dummy2,
> +            .log_sync = vfio_listener_dummy2,
> +            .log_global_start = vfio_listener_dummy1,
> +            .log_global_stop = vfio_listener_dummy1,
> +            .eventfd_add = vfio_listener_dummy3,
> +            .eventfd_del = vfio_listener_dummy3,
> +        };

It would be nicer to move this out to a static structure.

> +        container->iommu_data.release = vfio_listener_release;
> +
> +        memory_listener_register(&container->iommu_data.listener,
> +                                 get_system_memory());
> +    } else {
> +        error_report("vfio: No available IOMMU models\n");
> +        g_free(container);
> +        close(fd);
> +        return -1;
> +    }
> +
> +    QLIST_INIT(&container->group_list);
> +    QLIST_INSERT_HEAD(&container_list, container, next);
> +
> +    group->container = container;
> +    QLIST_INSERT_HEAD(&container->group_list, group, container_next);
> +
> +    return 0;
> +}
> +
> +static void vfio_disconnect_container(VFIOGroup *group)
> +{
> +    VFIOContainer *container = group->container;
> +
> +    if (ioctl(group->fd, VFIO_GROUP_UNSET_CONTAINER, &container->fd)) {
> +        error_report("vfio: error disconnecting group %d from container\n",
> +                     group->groupid);
> +    }

error_report isn't terminal.

> +
> +    QLIST_REMOVE(group, container_next);
> +    group->container = NULL;
> +
> +    if (QLIST_EMPTY(&container->group_list)) {
> +        if (container->iommu_data.release) {
> +            container->iommu_data.release(container);
> +        }
> +        QLIST_REMOVE(container, next);
> +        DPRINTF("vfio_disconnect_container: close container->fd\n");
> +        close(container->fd);
> +        g_free(container);
> +    }
> +}
> +
> +static VFIOGroup *vfio_get_group(int groupid)
> +{
> +    VFIOGroup *group;
> +    char path[32];
> +    struct vfio_group_status status = { .argsz = sizeof(status) };
> +
> +    QLIST_FOREACH(group, &group_list, next) {
> +        if (group->groupid == groupid) {
> +            return group;
> +        }
> +    }
> +
> +    group = g_malloc0(sizeof(*group));
> +
> +    snprintf(path, sizeof(path), "/dev/vfio/%d", groupid);
> +    group->fd = qemu_open(path, O_RDWR);
> +    if (group->fd < 0) {
> +        error_report("vfio: error opening %s: %s", path, strerror(errno));
> +        g_free(group);
> +        return NULL;
> +    }
> +
> +    if (ioctl(group->fd, VFIO_GROUP_GET_STATUS, &status)) {
> +        error_report("vfio: error getting group status: %s\n",
> +                     strerror(errno));
> +        close(group->fd);
> +        g_free(group);
> +        return NULL;
> +    }
> +
> +    if (!(status.flags & VFIO_GROUP_FLAGS_VIABLE)) {
> +        error_report("vfio: error, group %d is not viable, please ensure "
> +                     "all devices within the iommu_group are bound to their "
> +                     "vfio bus driver.\n", groupid);
> +        close(group->fd);
> +        g_free(group);
> +        return NULL;
> +    }
> +
> +    group->groupid = groupid;
> +    QLIST_INIT(&group->device_list);
> +
> +    if (vfio_connect_container(group)) {
> +        error_report("vfio: failed to setup container for group %d\n", groupid);
> +        close(group->fd);
> +        g_free(group);
> +        return NULL;
> +    }
> +
> +    QLIST_INSERT_HEAD(&group_list, group, next);
> +
> +    return group;
> +}
> +
> +static void vfio_put_group(VFIOGroup *group)
> +{
> +    if (!QLIST_EMPTY(&group->device_list)) {
> +        return;
> +    }
> +
> +    vfio_disconnect_container(group);
> +    QLIST_REMOVE(group, next);
> +    DPRINTF("vfio_put_group: close group->fd\n");
> +    close(group->fd);
> +    g_free(group);
> +}
> +
> +static int vfio_get_device(VFIOGroup *group, const char *name, VFIODevice *vdev)
> +{
> +    struct vfio_device_info dev_info = { .argsz = sizeof(dev_info) };
> +    struct vfio_region_info reg_info = { .argsz = sizeof(reg_info) };
> +    int ret, i;
> +
> +    ret = ioctl(group->fd, VFIO_GROUP_GET_DEVICE_FD, name);
> +    if (ret < 0) {
> +        error_report("vfio: error getting device %s from group %d: %s",
> +                     name, group->groupid, strerror(errno));
> +        error_report("Verify all devices in group %d "
> +                     "are bound to vfio-pci or pci-stub and not already in use",
> +                     group->groupid);
> +        return ret;
> +    }
> +
> +    vdev->fd = ret;
> +    vdev->group = group;
> +    QLIST_INSERT_HEAD(&group->device_list, vdev, next);
> +
> +    /* Sanity check device */
> +    ret = ioctl(vdev->fd, VFIO_DEVICE_GET_INFO, &dev_info);
> +    if (ret) {
> +        error_report("vfio: error getting device info: %s", strerror(errno));
> +        goto error;
> +    }
> +
> +    DPRINTF("Device %s flags: %u, regions: %u, irgs: %u\n", name,
> +            dev_info.flags, dev_info.num_regions, dev_info.num_irqs);
> +
> +    if (!(dev_info.flags & VFIO_DEVICE_FLAGS_PCI)) {
> +        error_report("vfio: Um, this isn't a PCI device");
> +        goto error;
> +    }
> +
> +    vdev->reset_works = !!(dev_info.flags & VFIO_DEVICE_FLAGS_RESET);
> +    if (!vdev->reset_works) {
> +        error_report("Warning, device %s does not support reset\n", name);
> +    }
> +
> +    if (dev_info.num_regions != VFIO_PCI_NUM_REGIONS) {
> +        error_report("vfio: unexpected number of io regions %u",
> +                     dev_info.num_regions);
> +        goto error;
> +    }
> +
> +    if (dev_info.num_irqs != VFIO_PCI_NUM_IRQS) {
> +        error_report("vfio: unexpected number of irqs %u", dev_info.num_irqs);
> +        goto error;
> +    }
> +
> +    for (i = VFIO_PCI_BAR0_REGION_INDEX; i < VFIO_PCI_ROM_REGION_INDEX; i++) {
> +        reg_info.index = i;
> +
> +        ret = ioctl(vdev->fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info);
> +        if (ret) {
> +            error_report("vfio: Error getting region %d info: %s", i,
> +                         strerror(errno));
> +            goto error;
> +        }
> +
> +        DPRINTF("Device %s region %d:\n", name, i);
> +        DPRINTF("  size: 0x%lx, offset: 0x%lx, flags: 0x%lx\n",
> +                (unsigned long)reg_info.size, (unsigned long)reg_info.offset,
> +                (unsigned long)reg_info.flags);
> +
> +        vdev->bars[i].flags = reg_info.flags;
> +        vdev->bars[i].size = reg_info.size;
> +        vdev->bars[i].fd_offset = reg_info.offset;
> +        vdev->bars[i].fd = vdev->fd;
> +        vdev->bars[i].nr = i;
> +    }
> +
> +    reg_info.index = VFIO_PCI_ROM_REGION_INDEX;
> +
> +    ret = ioctl(vdev->fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info);
> +    if (ret) {
> +        error_report("vfio: Error getting ROM info: %s", strerror(errno));
> +        goto error;
> +    }
> +
> +    DPRINTF("Device %s ROM:\n", name);
> +    DPRINTF("  size: 0x%lx, offset: 0x%lx, flags: 0x%lx\n",
> +            (unsigned long)reg_info.size, (unsigned long)reg_info.offset,
> +            (unsigned long)reg_info.flags);
> +
> +    vdev->rom_size = reg_info.size;
> +    vdev->rom_offset = reg_info.offset;
> +
> +    reg_info.index = VFIO_PCI_CONFIG_REGION_INDEX;
> +
> +    ret = ioctl(vdev->fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info);
> +    if (ret) {
> +        error_report("vfio: Error getting config info: %s", strerror(errno));
> +        goto error;
> +    }
> +
> +    DPRINTF("Device %s config:\n", name);
> +    DPRINTF("  size: 0x%lx, offset: 0x%lx, flags: 0x%lx\n",
> +            (unsigned long)reg_info.size, (unsigned long)reg_info.offset,
> +            (unsigned long)reg_info.flags);
> +
> +    vdev->config_size = reg_info.size;
> +    vdev->config_offset = reg_info.offset;
> +
> +error:
> +    if (ret) {
> +        QLIST_REMOVE(vdev, next);
> +        vdev->group = NULL;
> +        close(vdev->fd);
> +    }
> +    return ret;
> +}
> +
> +static void vfio_put_device(VFIODevice *vdev)
> +{
> +    QLIST_REMOVE(vdev, next);
> +    vdev->group = NULL;
> +    DPRINTF("vfio_put_device: close vdev->fd\n");
> +    close(vdev->fd);
> +    if (vdev->msix) {
> +        g_free(vdev->msix);
> +        vdev->msix = NULL;
> +    }
> +}
> +
> +static int vfio_initfn(struct PCIDevice *pdev)

Why struct PCIDevice?

> +{
> +    VFIODevice *pvdev, *vdev = DO_UPCAST(VFIODevice, pdev, pdev);

PCI_DEVICE()

> +    VFIOGroup *group;
> +    char path[PATH_MAX], iommu_group_path[PATH_MAX], *group_name;
> +    ssize_t len;
> +    struct stat st;
> +    int groupid;
> +    int ret;
> +
> +    /* Check that the host device exists */
> +    snprintf(path, sizeof(path),
> +             "/sys/bus/pci/devices/%04x:%02x:%02x.%01x/",
> +             vdev->host.domain, vdev->host.bus, vdev->host.slot,
> +             vdev->host.function);
> +    if (stat(path, &st) < 0) {
> +        error_report("vfio: error: no such host device: %s", path);
> +        return -1;
> +    }
> +
> +    strncat(path, "iommu_group", sizeof(path) - strlen(path) - 1);
> +
> +    len = readlink(path, iommu_group_path, PATH_MAX);
> +    if (len <= 0) {
> +        error_report("vfio: error no iommu_group for device\n");
> +        return -1;
> +    }
> +
> +    iommu_group_path[len] = 0;
> +    group_name = basename(iommu_group_path);
> +
> +    if (sscanf(group_name, "%d", &groupid) != 1) {
> +        error_report("vfio: error reading %s: %s", path, strerror(errno));
> +        return -1;
> +    }
> +
> +    DPRINTF("%s(%04x:%02x:%02x.%x) group %d\n", __func__, vdev->host.domain,
> +            vdev->host.bus, vdev->host.slot, vdev->host.function, groupid);
> +
> +    group = vfio_get_group(groupid);
> +    if (!group) {
> +        error_report("vfio: failed to get group %d", groupid);
> +        return -1;
> +    }
> +
> +    snprintf(path, sizeof(path), "%04x:%02x:%02x.%01x",
> +            vdev->host.domain, vdev->host.bus, vdev->host.slot,
> +            vdev->host.function);
> +
> +    QLIST_FOREACH(pvdev, &group->device_list, next) {
> +        if (pvdev->host.domain == vdev->host.domain &&
> +            pvdev->host.bus == vdev->host.bus &&
> +            pvdev->host.slot == vdev->host.slot &&
> +            pvdev->host.function == vdev->host.function) {
> +
> +            error_report("vfio: error: device %s is already attached\n", path);
> +            vfio_put_group(group);
> +            return -1;
> +        }
> +    }
> +
> +    ret = vfio_get_device(group, path, vdev);
> +    if (ret) {
> +        error_report("vfio: failed to get device %s", path);
> +        vfio_put_group(group);
> +        return -1;
> +    }
> +
> +    /* Get a copy of config space */
> +    assert(pci_config_size(&vdev->pdev) <= vdev->config_size);
> +    ret = pread(vdev->fd, vdev->pdev.config,
> +                pci_config_size(&vdev->pdev), vdev->config_offset);
> +    if (ret < (int)pci_config_size(&vdev->pdev)) {
> +        error_report("vfio: Failed to read device config space\n");
> +        goto out_put;
> +    }
> +
> +    /*
> +     * Clear host resource mapping info.  If we choose not to register a
> +     * BAR, such as might be the case with the option ROM, we can get
> +     * confusing, unwritable, residual addresses from the host here.
> +     */
> +    memset(&vdev->pdev.config[PCI_BASE_ADDRESS_0], 0, 24);
> +    memset(&vdev->pdev.config[PCI_ROM_ADDRESS], 0, 4);
> +
> +    vfio_load_rom(vdev);
> +
> +    if (vfio_early_setup_msix(vdev)) {
> +        goto out_put;
> +    }
> +
> +    vfio_map_bars(vdev);
> +
> +    if (vfio_add_capabilities(vdev)) {
> +        goto out_teardown;
> +    }
> +
> +    if (vfio_pci_read_config(&vdev->pdev, PCI_INTERRUPT_PIN, 1)) {
> +        pci_device_set_intx_routing_notifier(&vdev->pdev, vfio_update_irq);
> +    }
> +
> +    if (vfio_enable_intx(vdev)) {
> +        goto out_teardown;
> +    }
> +
> +    return 0;
> +
> +out_teardown:
> +    pci_device_set_intx_routing_notifier(&vdev->pdev, NULL);
> +    vfio_teardown_msi(vdev);
> +    vfio_unmap_bars(vdev);
> +out_put:
> +    vfio_put_device(vdev);
> +    vfio_put_group(group);
> +    return -1;
> +}
> +
> +static void vfio_exitfn(struct PCIDevice *pdev)
> +{
> +    VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
> +    VFIOGroup *group = vdev->group;
> +
> +    pci_device_set_intx_routing_notifier(&vdev->pdev, NULL);
> +    vfio_disable_interrupts(vdev);
> +    vfio_teardown_msi(vdev);
> +    vfio_unmap_bars(vdev);
> +    vfio_put_device(vdev);
> +    vfio_put_group(group);

You should move this all to the destructor (instance_finalize).

> +}
> +
> +static void vfio_reset(DeviceState *dev)
> +{
> +    PCIDevice *pdev = DO_UPCAST(PCIDevice, qdev, dev);
> +    VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
> +
> +    if (!vdev->reset_works) {
> +        return;
> +    }
> +
> +    if (ioctl(vdev->fd, VFIO_DEVICE_RESET)) {
> +        error_report("vfio: Error unable to reset physical device "
> +                     "(%04x:%02x:%02x.%x): %s\n", vdev->host.domain,
> +                     vdev->host.bus, vdev->host.slot, vdev->host.function,
> +                     strerror(errno));

%m is thread safe, strerror isn't.

> +    }
> +}
> +
> +static Property vfio_pci_dev_properties[] = {
> +    DEFINE_PROP_PCI_HOST_DEVADDR("host", VFIODevice, host),
> +    /*
> +     * TODO - support passed fds... is this necessary?
> +     * DEFINE_PROP_STRING("vfiofd", VFIODevice, vfiofd_name),
> +     * DEFINE_PROP_STRING("vfiogroupfd, VFIODevice, vfiogroupfd_name),
> +     */
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +
> +static void vfio_pci_dev_class_init(ObjectClass *klass, void *data)
> +{
> +    PCIDeviceClass *dc = PCI_DEVICE_CLASS(klass);
> +
> +    dc->parent_class.reset = vfio_reset;

This is definitely not right.  You want to do:

PCIDeviceClass *pdc = PCI_DEVICE_CLASS(klass);
DeviceClass *dc = DEVICE_CLASS(klass);

dc->reset = vfio_reset;

> +    dc->init = vfio_initfn;
> +    dc->exit = vfio_exitfn;
> +    dc->config_read = vfio_pci_read_config;
> +    dc->config_write = vfio_pci_write_config;
> +    dc->parent_class.props = vfio_pci_dev_properties;

dc->props = vfio_pci_dev_properties;
> +}
> +
> +static TypeInfo vfio_pci_dev_info = {
> +    .name          = "vfio-pci",
> +    .parent        = TYPE_PCI_DEVICE,
> +    .instance_size = sizeof(VFIODevice),
> +    .class_init    = vfio_pci_dev_class_init,
> +};
> +
> +static void register_vfio_pci_dev_type(void)
> +{
> +    type_register_static(&vfio_pci_dev_info);
> +}
> +
> +type_init(register_vfio_pci_dev_type)
> diff --git a/hw/vfio_pci.h b/hw/vfio_pci.h
> new file mode 100644
> index 0000000..0a71bce
> --- /dev/null
> +++ b/hw/vfio_pci.h
> @@ -0,0 +1,101 @@

copyright/license.

> +#ifndef HW_VFIO_PCI_H
> +#define HW_VFIO_PCI_H
> +
> +#include "qemu-common.h"
> +#include "qemu-queue.h"
> +#include "pci.h"
> +#include "event_notifier.h"

This is all private to vfio.c, right?  Perhaps call it vfio_pci_int.h

Regards,

Anthony Liguori

> +
> +typedef struct VFIOBAR {
> +    off_t fd_offset; /* offset of BAR within device fd */
> +    int fd; /* device fd, allows us to pass VFIOBAR as opaque data */
> +    MemoryRegion mem; /* slow, read/write access */
> +    MemoryRegion mmap_mem; /* direct mapped access */
> +    void *mmap;
> +    size_t size;
> +    uint32_t flags; /* VFIO region flags (rd/wr/mmap) */
> +    uint8_t nr; /* cache the BAR number for debug */
> +} VFIOBAR;
> +
> +typedef struct INTx {
> +    bool pending; /* interrupt pending */
> +    bool kvm_accel; /* set when QEMU bypass through KVM enabled */
> +    uint8_t pin; /* which pin to pull for qemu_set_irq */
> +    EventNotifier interrupt; /* eventfd triggered on interrupt */
> +    EventNotifier unmask; /* eventfd for unmask on QEMU bypass */
> +    PCIINTxRoute route; /* routing info for QEMU bypass */
> +} INTx;
> +
> +struct VFIODevice;
> +
> +typedef struct MSIVector {
> +    EventNotifier interrupt; /* eventfd triggered on interrupt */
> +    struct VFIODevice *vdev; /* back pointer to device */
> +    int vector; /* the vector number for this element */
> +    int virq; /* KVM irqchip route for QEMU bypass */
> +    bool use;
> +} MSIVector;
> +
> +enum {
> +    INT_NONE = 0,
> +    INT_INTx = 1,
> +    INT_MSI  = 2,
> +    INT_MSIX = 3,
> +};
> +
> +struct VFIOGroup;
> +
> +typedef struct VFIOContainer {
> +    int fd; /* /dev/vfio/vfio, empowered by the attached groups */
> +    struct {
> +        /* enable abstraction to support various iommu backends */
> +        union {
> +            MemoryListener listener; /* Used by type1 iommu */
> +        };
> +        void (*release)(struct VFIOContainer *);
> +    } iommu_data;
> +    QLIST_HEAD(, VFIOGroup) group_list;
> +    QLIST_ENTRY(VFIOContainer) next;
> +} VFIOContainer;
> +
> +/* Cache of MSI-X setup plus extra mmap and memory region for split BAR map */
> +typedef struct MSIXInfo {
> +    uint8_t table_bar;
> +    uint8_t pba_bar;
> +    uint16_t entries;
> +    uint32_t table_offset;
> +    uint32_t pba_offset;
> +    MemoryRegion mmap_mem;
> +    void *mmap;
> +} MSIXInfo;
> +
> +typedef struct VFIODevice {
> +    PCIDevice pdev;
> +    int fd;
> +    INTx intx;
> +    unsigned int config_size;
> +    off_t config_offset; /* Offset of config space region within device fd */
> +    unsigned int rom_size;
> +    off_t rom_offset; /* Offset of ROM region within device fd */
> +    int msi_cap_size;
> +    MSIVector *msi_vectors;
> +    MSIXInfo *msix;
> +    int nr_vectors; /* Number of MSI/MSIX vectors currently in use */
> +    int interrupt; /* Current interrupt type */
> +    VFIOBAR bars[PCI_NUM_REGIONS - 1]; /* No ROM */
> +    PCIHostDeviceAddress host;
> +    QLIST_ENTRY(VFIODevice) next;
> +    struct VFIOGroup *group;
> +    bool reset_works;
> +} VFIODevice;
> +
> +typedef struct VFIOGroup {
> +    int fd;
> +    int groupid;
> +    VFIOContainer *container;
> +    QLIST_HEAD(, VFIODevice) device_list;
> +    QLIST_ENTRY(VFIOGroup) next;
> +    QLIST_ENTRY(VFIOGroup) container_next;
> +} VFIOGroup;
> +
> +#endif /* HW_VFIO_PCI_H */
>
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

On Mon, 2012-08-13 at 17:18 -0500, Anthony Liguori wrote:
> Alex Williamson <alex.williamson@redhat.com> writes:
> > +static int vfio_load_rom(VFIODevice *vdev)
> > +{
> > +    uint64_t size = vdev->rom_size;
> > +    const VMStateDescription *vmsd;
> > +    char name[32];
> > +    off_t off = 0, voff = vdev->rom_offset;
> > +    ssize_t bytes;
> > +    void *ptr;
> > +
> > +    /* If loading ROM from file, pci handles it */
> > +    if (vdev->pdev.romfile || !vdev->pdev.rom_bar || !size) {
> > +        return 0;
> > +    }
> > +
> > +    DPRINTF("%s(%04x:%02x:%02x.%x)\n", __func__, vdev->host.domain,
> > +            vdev->host.bus, vdev->host.slot, vdev->host.function);
> > +
> > +    vmsd = qdev_get_vmsd(DEVICE(&vdev->pdev));
> > +
> > +    if (vmsd) {
> > +        snprintf(name, sizeof(name), "%s.rom", vmsd->name);
> > +    } else {
> > +        snprintf(name, sizeof(name), "%s.rom",
> > +                 object_get_typename(OBJECT(&vdev->pdev)));
> > +    }
> 
> Not sure where this came from.  You can just hard code this to vfio.rom
> or better yet, use the pci-host address and do vfio[%s].rom.

Ok, assume you mean vfio[%04x:%02x:%02x.%x].rom or should I be calling
object_property_print() to get a %s?

> > +    memory_region_init_ram(&vdev->pdev.rom, name, size);
> > +    ptr = memory_region_get_ram_ptr(&vdev->pdev.rom);
> > +    memset(ptr, 0xff, size);
> > +
> > +    while (size) {
> > +        bytes = pread(vdev->fd, ptr + off, size, voff + off);
> > +        if (bytes == 0) {
> > +            break; /* expect that we could get back less than the ROM BAR */
> > +        } else if (bytes > 0) {
> > +            off += bytes;
> > +            size -= bytes;
> > +        } else {
> > +            if (errno == EINTR || errno == EAGAIN) {
> > +                continue;
> > +            }
> > +            error_report("vfio: Error reading device ROM: %s\n",
> > +                         strerror(errno));
> > +            memory_region_destroy(&vdev->pdev.rom);
> > +            return -1;
> > +        }
> > +    }
> > +
> > +    pci_register_bar(&vdev->pdev, PCI_ROM_SLOT, 0, &vdev->pdev.rom);
> > +    vdev->pdev.has_rom = true;
> > +    return 0;
> > +}
> > +
> > +static int vfio_connect_container(VFIOGroup *group)
> > +{
> > +    VFIOContainer *container;
> > +    int ret, fd;
> > +
> > +    if (group->container) {
> > +        return 0;
> > +    }
> > +
> > +    QLIST_FOREACH(container, &container_list, next) {
> > +        if (!ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &container->fd)) {
> > +            group->container = container;
> > +            QLIST_INSERT_HEAD(&container->group_list, group, container_next);
> > +            return 0;
> > +        }
> > +    }
> > +
> > +    fd = qemu_open("/dev/vfio/vfio", O_RDWR);
> > +    if (fd < 0) {
> > +        error_report("vfio: failed to open /dev/vfio/vfio: %s\n",
> > +                     strerror(errno));
> > +        return -1;
> > +    }
> > +
> > +    ret = ioctl(fd, VFIO_GET_API_VERSION);
> > +    if (ret != VFIO_API_VERSION) {
> > +        error_report("vfio: supported vfio version: %d, "
> > +                     "reported version: %d\n", VFIO_API_VERSION, ret);
> > +        close(fd);
> > +        return -1;
> > +    }
> > +
> > +    container = g_malloc0(sizeof(*container));
> > +    container->fd = fd;
> > +
> > +    if (ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1_IOMMU)) {
> > +        ret = ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &fd);
> > +        if (ret) {
> > +            error_report("vfio: failed to set group container: %s\n",
> > +                         strerror(errno));
> > +            g_free(container);
> > +            close(fd);
> > +            return -1;
> > +        }
> > +
> > +        ret = ioctl(fd, VFIO_SET_IOMMU, VFIO_TYPE1_IOMMU);
> > +        if (ret) {
> > +            error_report("vfio: failed to set iommu for container: %s\n",
> > +                         strerror(errno));
> > +            g_free(container);
> > +            close(fd);
> > +            return -1;
> > +        }
> > +
> > +        container->iommu_data.listener = (MemoryListener) {
> > +            .begin = vfio_listener_dummy1,
> > +            .commit = vfio_listener_dummy1,
> > +            .region_add = vfio_listener_region_add,
> > +            .region_del = vfio_listener_region_del,
> > +            .region_nop = vfio_listener_dummy2,
> > +            .log_start = vfio_listener_dummy2,
> > +            .log_stop = vfio_listener_dummy2,
> > +            .log_sync = vfio_listener_dummy2,
> > +            .log_global_start = vfio_listener_dummy1,
> > +            .log_global_stop = vfio_listener_dummy1,
> > +            .eventfd_add = vfio_listener_dummy3,
> > +            .eventfd_del = vfio_listener_dummy3,
> > +        };
> 
> It would be nicer to move this out to a static structure.

Ok

> > +        container->iommu_data.release = vfio_listener_release;
> > +
> > +        memory_listener_register(&container->iommu_data.listener,
> > +                                 get_system_memory());
> > +    } else {
> > +        error_report("vfio: No available IOMMU models\n");
> > +        g_free(container);
> > +        close(fd);
> > +        return -1;
> > +    }
> > +
> > +    QLIST_INIT(&container->group_list);
> > +    QLIST_INSERT_HEAD(&container_list, container, next);
> > +
> > +    group->container = container;
> > +    QLIST_INSERT_HEAD(&container->group_list, group, container_next);
> > +
> > +    return 0;
> > +}
> > +
> > +static void vfio_disconnect_container(VFIOGroup *group)
> > +{
> > +    VFIOContainer *container = group->container;
> > +
> > +    if (ioctl(group->fd, VFIO_GROUP_UNSET_CONTAINER, &container->fd)) {
> > +        error_report("vfio: error disconnecting group %d from container\n",
> > +                     group->groupid);
> > +    }
> 
> error_report isn't terminal.

Not meant to be here, the kernel side will prevent the group from being
re-used.  I suppose there's the question of whether we want to continue
to get further out of sync with the kernel by continuing the below
disconnects though.  Either way seems to be a funky state and I'm not
sure I have a strong preference.  It seems unnecessary to kill the guest
though.

> > +
> > +    QLIST_REMOVE(group, container_next);
> > +    group->container = NULL;
> > +
> > +    if (QLIST_EMPTY(&container->group_list)) {
> > +        if (container->iommu_data.release) {
> > +            container->iommu_data.release(container);
> > +        }
> > +        QLIST_REMOVE(container, next);
> > +        DPRINTF("vfio_disconnect_container: close container->fd\n");
> > +        close(container->fd);
> > +        g_free(container);
> > +    }
> > +}
> > +
> > +static VFIOGroup *vfio_get_group(int groupid)
> > +{
> > +    VFIOGroup *group;
> > +    char path[32];
> > +    struct vfio_group_status status = { .argsz = sizeof(status) };
> > +
> > +    QLIST_FOREACH(group, &group_list, next) {
> > +        if (group->groupid == groupid) {
> > +            return group;
> > +        }
> > +    }
> > +
> > +    group = g_malloc0(sizeof(*group));
> > +
> > +    snprintf(path, sizeof(path), "/dev/vfio/%d", groupid);
> > +    group->fd = qemu_open(path, O_RDWR);
> > +    if (group->fd < 0) {
> > +        error_report("vfio: error opening %s: %s", path, strerror(errno));
> > +        g_free(group);
> > +        return NULL;
> > +    }
> > +
> > +    if (ioctl(group->fd, VFIO_GROUP_GET_STATUS, &status)) {
> > +        error_report("vfio: error getting group status: %s\n",
> > +                     strerror(errno));
> > +        close(group->fd);
> > +        g_free(group);
> > +        return NULL;
> > +    }
> > +
> > +    if (!(status.flags & VFIO_GROUP_FLAGS_VIABLE)) {
> > +        error_report("vfio: error, group %d is not viable, please ensure "
> > +                     "all devices within the iommu_group are bound to their "
> > +                     "vfio bus driver.\n", groupid);
> > +        close(group->fd);
> > +        g_free(group);
> > +        return NULL;
> > +    }
> > +
> > +    group->groupid = groupid;
> > +    QLIST_INIT(&group->device_list);
> > +
> > +    if (vfio_connect_container(group)) {
> > +        error_report("vfio: failed to setup container for group %d\n", groupid);
> > +        close(group->fd);
> > +        g_free(group);
> > +        return NULL;
> > +    }
> > +
> > +    QLIST_INSERT_HEAD(&group_list, group, next);
> > +
> > +    return group;
> > +}
> > +
> > +static void vfio_put_group(VFIOGroup *group)
> > +{
> > +    if (!QLIST_EMPTY(&group->device_list)) {
> > +        return;
> > +    }
> > +
> > +    vfio_disconnect_container(group);
> > +    QLIST_REMOVE(group, next);
> > +    DPRINTF("vfio_put_group: close group->fd\n");
> > +    close(group->fd);
> > +    g_free(group);
> > +}
> > +
> > +static int vfio_get_device(VFIOGroup *group, const char *name, VFIODevice *vdev)
> > +{
> > +    struct vfio_device_info dev_info = { .argsz = sizeof(dev_info) };
> > +    struct vfio_region_info reg_info = { .argsz = sizeof(reg_info) };
> > +    int ret, i;
> > +
> > +    ret = ioctl(group->fd, VFIO_GROUP_GET_DEVICE_FD, name);
> > +    if (ret < 0) {
> > +        error_report("vfio: error getting device %s from group %d: %s",
> > +                     name, group->groupid, strerror(errno));
> > +        error_report("Verify all devices in group %d "
> > +                     "are bound to vfio-pci or pci-stub and not already in use",
> > +                     group->groupid);
> > +        return ret;
> > +    }
> > +
> > +    vdev->fd = ret;
> > +    vdev->group = group;
> > +    QLIST_INSERT_HEAD(&group->device_list, vdev, next);
> > +
> > +    /* Sanity check device */
> > +    ret = ioctl(vdev->fd, VFIO_DEVICE_GET_INFO, &dev_info);
> > +    if (ret) {
> > +        error_report("vfio: error getting device info: %s", strerror(errno));
> > +        goto error;
> > +    }
> > +
> > +    DPRINTF("Device %s flags: %u, regions: %u, irgs: %u\n", name,
> > +            dev_info.flags, dev_info.num_regions, dev_info.num_irqs);
> > +
> > +    if (!(dev_info.flags & VFIO_DEVICE_FLAGS_PCI)) {
> > +        error_report("vfio: Um, this isn't a PCI device");
> > +        goto error;
> > +    }
> > +
> > +    vdev->reset_works = !!(dev_info.flags & VFIO_DEVICE_FLAGS_RESET);
> > +    if (!vdev->reset_works) {
> > +        error_report("Warning, device %s does not support reset\n", name);
> > +    }
> > +
> > +    if (dev_info.num_regions != VFIO_PCI_NUM_REGIONS) {
> > +        error_report("vfio: unexpected number of io regions %u",
> > +                     dev_info.num_regions);
> > +        goto error;
> > +    }
> > +
> > +    if (dev_info.num_irqs != VFIO_PCI_NUM_IRQS) {
> > +        error_report("vfio: unexpected number of irqs %u", dev_info.num_irqs);
> > +        goto error;
> > +    }
> > +
> > +    for (i = VFIO_PCI_BAR0_REGION_INDEX; i < VFIO_PCI_ROM_REGION_INDEX; i++) {
> > +        reg_info.index = i;
> > +
> > +        ret = ioctl(vdev->fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info);
> > +        if (ret) {
> > +            error_report("vfio: Error getting region %d info: %s", i,
> > +                         strerror(errno));
> > +            goto error;
> > +        }
> > +
> > +        DPRINTF("Device %s region %d:\n", name, i);
> > +        DPRINTF("  size: 0x%lx, offset: 0x%lx, flags: 0x%lx\n",
> > +                (unsigned long)reg_info.size, (unsigned long)reg_info.offset,
> > +                (unsigned long)reg_info.flags);
> > +
> > +        vdev->bars[i].flags = reg_info.flags;
> > +        vdev->bars[i].size = reg_info.size;
> > +        vdev->bars[i].fd_offset = reg_info.offset;
> > +        vdev->bars[i].fd = vdev->fd;
> > +        vdev->bars[i].nr = i;
> > +    }
> > +
> > +    reg_info.index = VFIO_PCI_ROM_REGION_INDEX;
> > +
> > +    ret = ioctl(vdev->fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info);
> > +    if (ret) {
> > +        error_report("vfio: Error getting ROM info: %s", strerror(errno));
> > +        goto error;
> > +    }
> > +
> > +    DPRINTF("Device %s ROM:\n", name);
> > +    DPRINTF("  size: 0x%lx, offset: 0x%lx, flags: 0x%lx\n",
> > +            (unsigned long)reg_info.size, (unsigned long)reg_info.offset,
> > +            (unsigned long)reg_info.flags);
> > +
> > +    vdev->rom_size = reg_info.size;
> > +    vdev->rom_offset = reg_info.offset;
> > +
> > +    reg_info.index = VFIO_PCI_CONFIG_REGION_INDEX;
> > +
> > +    ret = ioctl(vdev->fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info);
> > +    if (ret) {
> > +        error_report("vfio: Error getting config info: %s", strerror(errno));
> > +        goto error;
> > +    }
> > +
> > +    DPRINTF("Device %s config:\n", name);
> > +    DPRINTF("  size: 0x%lx, offset: 0x%lx, flags: 0x%lx\n",
> > +            (unsigned long)reg_info.size, (unsigned long)reg_info.offset,
> > +            (unsigned long)reg_info.flags);
> > +
> > +    vdev->config_size = reg_info.size;
> > +    vdev->config_offset = reg_info.offset;
> > +
> > +error:
> > +    if (ret) {
> > +        QLIST_REMOVE(vdev, next);
> > +        vdev->group = NULL;
> > +        close(vdev->fd);
> > +    }
> > +    return ret;
> > +}
> > +
> > +static void vfio_put_device(VFIODevice *vdev)
> > +{
> > +    QLIST_REMOVE(vdev, next);
> > +    vdev->group = NULL;
> > +    DPRINTF("vfio_put_device: close vdev->fd\n");
> > +    close(vdev->fd);
> > +    if (vdev->msix) {
> > +        g_free(vdev->msix);
> > +        vdev->msix = NULL;
> > +    }
> > +}
> > +
> > +static int vfio_initfn(struct PCIDevice *pdev)
> 
> Why struct PCIDevice?

Must have pasted it from somewhere, fixed.

> > +{
> > +    VFIODevice *pvdev, *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
> 
> PCI_DEVICE()

I'm not sure what you're after here, are you perhaps mistaking pdev for
qdev?

> > +    VFIOGroup *group;
> > +    char path[PATH_MAX], iommu_group_path[PATH_MAX], *group_name;
> > +    ssize_t len;
> > +    struct stat st;
> > +    int groupid;
> > +    int ret;
> > +
> > +    /* Check that the host device exists */
> > +    snprintf(path, sizeof(path),
> > +             "/sys/bus/pci/devices/%04x:%02x:%02x.%01x/",
> > +             vdev->host.domain, vdev->host.bus, vdev->host.slot,
> > +             vdev->host.function);
> > +    if (stat(path, &st) < 0) {
> > +        error_report("vfio: error: no such host device: %s", path);
> > +        return -1;
> > +    }
> > +
> > +    strncat(path, "iommu_group", sizeof(path) - strlen(path) - 1);
> > +
> > +    len = readlink(path, iommu_group_path, PATH_MAX);
> > +    if (len <= 0) {
> > +        error_report("vfio: error no iommu_group for device\n");
> > +        return -1;
> > +    }
> > +
> > +    iommu_group_path[len] = 0;
> > +    group_name = basename(iommu_group_path);
> > +
> > +    if (sscanf(group_name, "%d", &groupid) != 1) {
> > +        error_report("vfio: error reading %s: %s", path, strerror(errno));
> > +        return -1;
> > +    }
> > +
> > +    DPRINTF("%s(%04x:%02x:%02x.%x) group %d\n", __func__, vdev->host.domain,
> > +            vdev->host.bus, vdev->host.slot, vdev->host.function, groupid);
> > +
> > +    group = vfio_get_group(groupid);
> > +    if (!group) {
> > +        error_report("vfio: failed to get group %d", groupid);
> > +        return -1;
> > +    }
> > +
> > +    snprintf(path, sizeof(path), "%04x:%02x:%02x.%01x",
> > +            vdev->host.domain, vdev->host.bus, vdev->host.slot,
> > +            vdev->host.function);
> > +
> > +    QLIST_FOREACH(pvdev, &group->device_list, next) {
> > +        if (pvdev->host.domain == vdev->host.domain &&
> > +            pvdev->host.bus == vdev->host.bus &&
> > +            pvdev->host.slot == vdev->host.slot &&
> > +            pvdev->host.function == vdev->host.function) {
> > +
> > +            error_report("vfio: error: device %s is already attached\n", path);
> > +            vfio_put_group(group);
> > +            return -1;
> > +        }
> > +    }
> > +
> > +    ret = vfio_get_device(group, path, vdev);
> > +    if (ret) {
> > +        error_report("vfio: failed to get device %s", path);
> > +        vfio_put_group(group);
> > +        return -1;
> > +    }
> > +
> > +    /* Get a copy of config space */
> > +    assert(pci_config_size(&vdev->pdev) <= vdev->config_size);
> > +    ret = pread(vdev->fd, vdev->pdev.config,
> > +                pci_config_size(&vdev->pdev), vdev->config_offset);
> > +    if (ret < (int)pci_config_size(&vdev->pdev)) {
> > +        error_report("vfio: Failed to read device config space\n");
> > +        goto out_put;
> > +    }
> > +
> > +    /*
> > +     * Clear host resource mapping info.  If we choose not to register a
> > +     * BAR, such as might be the case with the option ROM, we can get
> > +     * confusing, unwritable, residual addresses from the host here.
> > +     */
> > +    memset(&vdev->pdev.config[PCI_BASE_ADDRESS_0], 0, 24);
> > +    memset(&vdev->pdev.config[PCI_ROM_ADDRESS], 0, 4);
> > +
> > +    vfio_load_rom(vdev);
> > +
> > +    if (vfio_early_setup_msix(vdev)) {
> > +        goto out_put;
> > +    }
> > +
> > +    vfio_map_bars(vdev);
> > +
> > +    if (vfio_add_capabilities(vdev)) {
> > +        goto out_teardown;
> > +    }
> > +
> > +    if (vfio_pci_read_config(&vdev->pdev, PCI_INTERRUPT_PIN, 1)) {
> > +        pci_device_set_intx_routing_notifier(&vdev->pdev, vfio_update_irq);
> > +    }
> > +
> > +    if (vfio_enable_intx(vdev)) {
> > +        goto out_teardown;
> > +    }
> > +
> > +    return 0;
> > +
> > +out_teardown:
> > +    pci_device_set_intx_routing_notifier(&vdev->pdev, NULL);
> > +    vfio_teardown_msi(vdev);
> > +    vfio_unmap_bars(vdev);
> > +out_put:
> > +    vfio_put_device(vdev);
> > +    vfio_put_group(group);
> > +    return -1;
> > +}
> > +
> > +static void vfio_exitfn(struct PCIDevice *pdev)
> > +{
> > +    VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
> > +    VFIOGroup *group = vdev->group;
> > +
> > +    pci_device_set_intx_routing_notifier(&vdev->pdev, NULL);
> > +    vfio_disable_interrupts(vdev);
> > +    vfio_teardown_msi(vdev);
> > +    vfio_unmap_bars(vdev);
> > +    vfio_put_device(vdev);
> > +    vfio_put_group(group);
> 
> You should move this all to the destructor (instance_finalize).

Hmm, it looks like if I do that then pci will free my interrupt and
config space out from under me before I get any notice we're killing the
device.  Being a pci device, I think I'm tied to PCIDeviceClass.exit
function, right?

> > +}
> > +
> > +static void vfio_reset(DeviceState *dev)
> > +{
> > +    PCIDevice *pdev = DO_UPCAST(PCIDevice, qdev, dev);
> > +    VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
> > +
> > +    if (!vdev->reset_works) {
> > +        return;
> > +    }
> > +
> > +    if (ioctl(vdev->fd, VFIO_DEVICE_RESET)) {
> > +        error_report("vfio: Error unable to reset physical device "
> > +                     "(%04x:%02x:%02x.%x): %s\n", vdev->host.domain,
> > +                     vdev->host.bus, vdev->host.slot, vdev->host.function,
> > +                     strerror(errno));
> 
> %m is thread safe, strerror isn't.

Neat.  Fixed throughout.

> > +    }
> > +}
> > +
> > +static Property vfio_pci_dev_properties[] = {
> > +    DEFINE_PROP_PCI_HOST_DEVADDR("host", VFIODevice, host),
> > +    /*
> > +     * TODO - support passed fds... is this necessary?
> > +     * DEFINE_PROP_STRING("vfiofd", VFIODevice, vfiofd_name),
> > +     * DEFINE_PROP_STRING("vfiogroupfd, VFIODevice, vfiogroupfd_name),
> > +     */
> > +    DEFINE_PROP_END_OF_LIST(),
> > +};
> > +
> > +
> > +static void vfio_pci_dev_class_init(ObjectClass *klass, void *data)
> > +{
> > +    PCIDeviceClass *dc = PCI_DEVICE_CLASS(klass);
> > +
> > +    dc->parent_class.reset = vfio_reset;
> 
> This is definitely not right.  You want to do:
> 
> PCIDeviceClass *pdc = PCI_DEVICE_CLASS(klass);
> DeviceClass *dc = DEVICE_CLASS(klass);
> 
> dc->reset = vfio_reset;
> 
> > +    dc->init = vfio_initfn;
> > +    dc->exit = vfio_exitfn;
> > +    dc->config_read = vfio_pci_read_config;
> > +    dc->config_write = vfio_pci_write_config;
> > +    dc->parent_class.props = vfio_pci_dev_properties;
> 
> dc->props = vfio_pci_dev_properties;

Ok, fixed.

> > +}
> > +
> > +static TypeInfo vfio_pci_dev_info = {
> > +    .name          = "vfio-pci",
> > +    .parent        = TYPE_PCI_DEVICE,
> > +    .instance_size = sizeof(VFIODevice),
> > +    .class_init    = vfio_pci_dev_class_init,
> > +};
> > +
> > +static void register_vfio_pci_dev_type(void)
> > +{
> > +    type_register_static(&vfio_pci_dev_info);
> > +}
> > +
> > +type_init(register_vfio_pci_dev_type)
> > diff --git a/hw/vfio_pci.h b/hw/vfio_pci.h
> > new file mode 100644
> > index 0000000..0a71bce
> > --- /dev/null
> > +++ b/hw/vfio_pci.h
> > @@ -0,0 +1,101 @@
> 
> copyright/license.
> 
> > +#ifndef HW_VFIO_PCI_H
> > +#define HW_VFIO_PCI_H
> > +
> > +#include "qemu-common.h"
> > +#include "qemu-queue.h"
> > +#include "pci.h"
> > +#include "event_notifier.h"
> 
> This is all private to vfio.c, right?  Perhaps call it vfio_pci_int.h

Yes, it is private.  Ok, renamed.  Thanks for the review,

Alex

On Tue, Jul 31, 2012 at 11:18:15PM -0600, Alex Williamson wrote:
> This adds the core of the QEMU VFIO-based PCI device assignment driver.
> To make use of this driver, enable CONFIG_VFIO, CONFIG_VFIO_IOMMU_TYPE1,
> and CONFIG_VFIO_PCI in your host Linux kernel config.  Load the vfio-pci
> module.  To assign device 0000:05:00.0 to a guest, do the following:
> 
> for dev in $(ls /sys/bus/pci/devices/0000:05:00.0/iommu_group/devices); do
>     vendor=$(cat /sys/bus/pci/devices/$dev/vendor)
>     device=$(cat /sys/bus/pci/devices/$dev/device)
>     if [ -e /sys/bus/pci/devices/$dev/driver ]; then
>         echo $dev > /sys/bus/pci/devices/$dev/driver/unbind
>     fi
>     echo $vendor $device > /sys/bus/pci/drivers/vfio-pci/new_id
> done

Both vfio-pci and the old driver successfully match the $vendor:$device.
What happens when another $vendor:$device PCI adapter is hotplugged into
the host?

Is there a way to bind vfio-pci on a per-adapter basis instead of a
per-$vendor:$device?

Stefan

On Tue, 2012-08-14 at 08:12 +0100, Stefan Hajnoczi wrote:
> On Tue, Jul 31, 2012 at 11:18:15PM -0600, Alex Williamson wrote:
> > This adds the core of the QEMU VFIO-based PCI device assignment driver.
> > To make use of this driver, enable CONFIG_VFIO, CONFIG_VFIO_IOMMU_TYPE1,
> > and CONFIG_VFIO_PCI in your host Linux kernel config.  Load the vfio-pci
> > module.  To assign device 0000:05:00.0 to a guest, do the following:
> > 
> > for dev in $(ls /sys/bus/pci/devices/0000:05:00.0/iommu_group/devices); do
> >     vendor=$(cat /sys/bus/pci/devices/$dev/vendor)
> >     device=$(cat /sys/bus/pci/devices/$dev/device)
> >     if [ -e /sys/bus/pci/devices/$dev/driver ]; then
> >         echo $dev > /sys/bus/pci/devices/$dev/driver/unbind
> >     fi
> >     echo $vendor $device > /sys/bus/pci/drivers/vfio-pci/new_id
> > done
> 
> Both vfio-pci and the old driver successfully match the $vendor:$device.
> What happens when another $vendor:$device PCI adapter is hotplugged into
> the host?
> 
> Is there a way to bind vfio-pci on a per-adapter basis instead of a
> per-$vendor:$device?

There's also a remove_id sysfs entry so we can be a little more
strategic, this was just an example.  We can also re-order new_id vs
unbind so that we need to manually unbind->bind the device.  There's
still an opportunity to race with a hotplug during this interaction
though.  I think this is the best Linux currently offers for dynamic
driver binding though.  Thanks,

Alex

On 08/01/2012 08:18 AM, Alex Williamson wrote:
> This adds the core of the QEMU VFIO-based PCI device assignment driver.
> To make use of this driver, enable CONFIG_VFIO, CONFIG_VFIO_IOMMU_TYPE1,
> and CONFIG_VFIO_PCI in your host Linux kernel config.  Load the vfio-pci
> module.  To assign device 0000:05:00.0 to a guest, do the following:
> 
> for dev in $(ls /sys/bus/pci/devices/0000:05:00.0/iommu_group/devices); do
>     vendor=$(cat /sys/bus/pci/devices/$dev/vendor)
>     device=$(cat /sys/bus/pci/devices/$dev/device)
>     if [ -e /sys/bus/pci/devices/$dev/driver ]; then
>         echo $dev > /sys/bus/pci/devices/$dev/driver/unbind
>     fi
>     echo $vendor $device > /sys/bus/pci/drivers/vfio-pci/new_id
> done
> 
> See Documentation/vfio.txt in the Linux kernel tree for further
> description of IOMMU groups and VFIO.
> 
> Then launch qemu including the option:
> 
> -device vfio-pci,host=0000:05:00.0
> 
> Support for legacy PCI interrupts (INTx) is not yet included and will
> be added in a future update.  Both MSI and MSI-X are supported here.


> +
> +static void vfio_update_irq(PCIDevice *pdev)
> +{
> +    VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
> +    PCIINTxRoute route;
> +
> +    if (vdev->interrupt != INT_INTx) {
> +        return;
> +    }
> +
> +    route = pci_device_route_intx_to_irq(&vdev->pdev, vdev->intx.pin);
> +    if (!memcmp(&route, &vdev->intx.route, sizeof(route))) {
> +        return; /* Nothing changed */
> +    }

You can't memcmp() structures, the compiler may add uninitialized holes
that will miscompare.  It's probably harmless here since it's an
optimization.

Unrelated nit: memcmp() doesn't return a boolean or a count, so
!memcmp() is really unintuitive, at least to me.

> +
> +static int vfio_enable_intx(VFIODevice *vdev)
> +{
> +    struct vfio_irq_set_fd irq_set_fd = {
> +        .irq_set = {
> +            .argsz = sizeof(irq_set_fd),
> +            .flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER,
> +            .index = VFIO_PCI_INTX_IRQ_INDEX,
> +            .start = 0,
> +            .count = 1,
> +        },
> +    };
> +    uint8_t pin = vfio_pci_read_config(&vdev->pdev, PCI_INTERRUPT_PIN, 1);
> +
> +    if (!pin) {
> +        return 0;
> +    }
> +
> +    vfio_disable_interrupts(vdev);
> +
> +    vdev->intx.pin = pin - 1; /* Pin A (1) -> irq[0] */
> +    vdev->intx.route = pci_device_route_intx_to_irq(&vdev->pdev,
> +                                                    vdev->intx.pin);
> +    /* TBD - Enable QEMU eoi notifier */
> +
> +    if (event_notifier_init(&vdev->intx.interrupt, 0)) {
> +        error_report("vfio: Error: event_notifier_init failed\n");
> +        return -1;

return -error is better.

> +    }
> +
> +    irq_set_fd.fd = event_notifier_get_fd(&vdev->intx.interrupt);
> +    qemu_set_fd_handler(irq_set_fd.fd, vfio_intx_interrupt, NULL, vdev);
> +
> +    if (ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, &irq_set_fd)) {
> +        error_report("vfio: Error: Failed to setup INTx fd: %s\n",
> +                     strerror(errno));
> +        return -1;
> +    }
> +
> +    vfio_enable_intx_kvm(vdev);
> +
> +    vdev->interrupt = INT_INTx;
> +
> +    DPRINTF("%s(%04x:%02x:%02x.%x)\n", __func__, vdev->host.domain,
> +            vdev->host.bus, vdev->host.slot, vdev->host.function);
> +
> +    return 0;
> +}
> +
> +
> +
> +/* XXX This should move to msi.c */

Well?

> +static MSIMessage msi_get_msg(PCIDevice *pdev, unsigned int vector)
> +{
> +    uint16_t flags = pci_get_word(pdev->config + pdev->msi_cap + PCI_MSI_FLAGS);
> +    bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;
> +    MSIMessage msg;
> +
> +    if (msi64bit) {
> +        msg.address = pci_get_quad(pdev->config +
> +                                   pdev->msi_cap + PCI_MSI_ADDRESS_LO);
> +    } else {
> +        msg.address = pci_get_long(pdev->config +
> +                                   pdev->msi_cap + PCI_MSI_ADDRESS_LO);
> +    }
> +
> +    msg.data = pci_get_word(pdev->config + pdev->msi_cap +
> +                            (msi64bit ? PCI_MSI_DATA_64 : PCI_MSI_DATA_32));
> +    msg.data += vector;
> +
> +    return msg;
> +}
> +
> +
> +/*
> + * IO Port/MMIO - Beware of the endians, VFIO is always little endian
> + */
> +static void vfio_bar_write(void *opaque, target_phys_addr_t addr,
> +                           uint64_t data, unsigned size)
> +{
> +    VFIOBAR *bar = opaque;
> +    uint8_t buf[8];
> +
> +    switch (size) {
> +    case 1:
> +        *buf = data & 0xff;
> +        break;
> +    case 2:
> +        *(uint16_t *)buf = cpu_to_le16(data);
> +        break;
> +    case 4:
> +        *(uint32_t *)buf = cpu_to_le32(data);
> +        break;

This works accidentally on machines that require alignment, since
there's no requirement from the compiler to align buf.  You can use a
union to align it.

> +    default:
> +        hw_error("vfio: unsupported write size, %d bytes\n", size);
> +        break;
> +    }
> +
> +    if (pwrite(bar->fd, buf, size, bar->fd_offset + addr) != size) {
> +        error_report("%s(,0x%"PRIx64", 0x%"PRIx64", %d) failed: %s\n",
> +                     __func__, addr, data, size, strerror(errno));
> +    }
> +
> +    DPRINTF("%s(BAR%d+0x%"PRIx64", 0x%"PRIx64", %d)\n",
> +            __func__, bar->nr, addr, data, size);
> +}
> +
> +
> +static void vfio_listener_region_add(MemoryListener *listener,
> +                                     MemoryRegionSection *section)
> +{
> +    VFIOContainer *container = container_of(listener, VFIOContainer,
> +                                            iommu_data.listener);
> +    target_phys_addr_t iova, end;
> +    void *vaddr;
> +    int ret;
> +
> +    if (vfio_listener_skipped_section(section)) {
> +        DPRINTF("vfio: SKIPPING region_add %016lx - %016lx\n",
> +                section->offset_within_address_space,
> +                section->offset_within_address_space + section->size - 1);
> +        return;
> +    }
> +
> +    if (unlikely((section->offset_within_address_space & ~TARGET_PAGE_MASK) !=
> +                 (section->offset_within_region & ~TARGET_PAGE_MASK))) {
> +        error_report("%s received unaligned region\n", __func__);

Is it really an error?  I think you can just add the condition to
skipped_section.

> +        return;
> +    }
> +
> +

On Tue, 2012-08-14 at 18:53 +0300, Avi Kivity wrote:
> On 08/01/2012 08:18 AM, Alex Williamson wrote:
> > This adds the core of the QEMU VFIO-based PCI device assignment driver.
> > To make use of this driver, enable CONFIG_VFIO, CONFIG_VFIO_IOMMU_TYPE1,
> > and CONFIG_VFIO_PCI in your host Linux kernel config.  Load the vfio-pci
> > module.  To assign device 0000:05:00.0 to a guest, do the following:
> > 
> > for dev in $(ls /sys/bus/pci/devices/0000:05:00.0/iommu_group/devices); do
> >     vendor=$(cat /sys/bus/pci/devices/$dev/vendor)
> >     device=$(cat /sys/bus/pci/devices/$dev/device)
> >     if [ -e /sys/bus/pci/devices/$dev/driver ]; then
> >         echo $dev > /sys/bus/pci/devices/$dev/driver/unbind
> >     fi
> >     echo $vendor $device > /sys/bus/pci/drivers/vfio-pci/new_id
> > done
> > 
> > See Documentation/vfio.txt in the Linux kernel tree for further
> > description of IOMMU groups and VFIO.
> > 
> > Then launch qemu including the option:
> > 
> > -device vfio-pci,host=0000:05:00.0
> > 
> > Support for legacy PCI interrupts (INTx) is not yet included and will
> > be added in a future update.  Both MSI and MSI-X are supported here.
> 
> 
> > +
> > +static void vfio_update_irq(PCIDevice *pdev)
> > +{
> > +    VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
> > +    PCIINTxRoute route;
> > +
> > +    if (vdev->interrupt != INT_INTx) {
> > +        return;
> > +    }
> > +
> > +    route = pci_device_route_intx_to_irq(&vdev->pdev, vdev->intx.pin);
> > +    if (!memcmp(&route, &vdev->intx.route, sizeof(route))) {
> > +        return; /* Nothing changed */
> > +    }
> 
> You can't memcmp() structures, the compiler may add uninitialized holes
> that will miscompare.  It's probably harmless here since it's an
> optimization.

Added this helper function:

/* TODO: Move this helper out to generic PCI code */
static bool vfio_intx_route_changed(PCIINTxRoute *old, PCIINTxRoute *new)
{
    return old->mode != new->mode || old->irq != new->irq;
}


> Unrelated nit: memcmp() doesn't return a boolean or a count, so
> !memcmp() is really unintuitive, at least to me.

I figure we're all pretty used to it growing up on !strcmp though.

> > +
> > +static int vfio_enable_intx(VFIODevice *vdev)
> > +{
> > +    struct vfio_irq_set_fd irq_set_fd = {
> > +        .irq_set = {
> > +            .argsz = sizeof(irq_set_fd),
> > +            .flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER,
> > +            .index = VFIO_PCI_INTX_IRQ_INDEX,
> > +            .start = 0,
> > +            .count = 1,
> > +        },
> > +    };
> > +    uint8_t pin = vfio_pci_read_config(&vdev->pdev, PCI_INTERRUPT_PIN, 1);
> > +
> > +    if (!pin) {
> > +        return 0;
> > +    }
> > +
> > +    vfio_disable_interrupts(vdev);
> > +
> > +    vdev->intx.pin = pin - 1; /* Pin A (1) -> irq[0] */
> > +    vdev->intx.route = pci_device_route_intx_to_irq(&vdev->pdev,
> > +                                                    vdev->intx.pin);
> > +    /* TBD - Enable QEMU eoi notifier */
> > +
> > +    if (event_notifier_init(&vdev->intx.interrupt, 0)) {
> > +        error_report("vfio: Error: event_notifier_init failed\n");
> > +        return -1;
> 
> return -error is better.

Here we probably want to return the return value of
event_notifier_init(), but there are lots of cases where we could return
-errno.  Fixed them.

> > +    }
> > +
> > +    irq_set_fd.fd = event_notifier_get_fd(&vdev->intx.interrupt);
> > +    qemu_set_fd_handler(irq_set_fd.fd, vfio_intx_interrupt, NULL, vdev);
> > +
> > +    if (ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, &irq_set_fd)) {
> > +        error_report("vfio: Error: Failed to setup INTx fd: %s\n",
> > +                     strerror(errno));
> > +        return -1;
> > +    }
> > +
> > +    vfio_enable_intx_kvm(vdev);
> > +
> > +    vdev->interrupt = INT_INTx;
> > +
> > +    DPRINTF("%s(%04x:%02x:%02x.%x)\n", __func__, vdev->host.domain,
> > +            vdev->host.bus, vdev->host.slot, vdev->host.function);
> > +
> > +    return 0;
> > +}
> > +
> > +
> > +
> > +/* XXX This should move to msi.c */
> 
> Well?

Just marking a todo item.  I'll change it formally to TODO.  I think
there are a few interfaces to msi.c that probably needs some rethinking
for device assignment.  When they're small like this it seems easier to
have the user in tree first.
> 
> > +static MSIMessage msi_get_msg(PCIDevice *pdev, unsigned int vector)
> > +{
> > +    uint16_t flags = pci_get_word(pdev->config + pdev->msi_cap + PCI_MSI_FLAGS);
> > +    bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;
> > +    MSIMessage msg;
> > +
> > +    if (msi64bit) {
> > +        msg.address = pci_get_quad(pdev->config +
> > +                                   pdev->msi_cap + PCI_MSI_ADDRESS_LO);
> > +    } else {
> > +        msg.address = pci_get_long(pdev->config +
> > +                                   pdev->msi_cap + PCI_MSI_ADDRESS_LO);
> > +    }
> > +
> > +    msg.data = pci_get_word(pdev->config + pdev->msi_cap +
> > +                            (msi64bit ? PCI_MSI_DATA_64 : PCI_MSI_DATA_32));
> > +    msg.data += vector;
> > +
> > +    return msg;
> > +}
> > +
> > +
> > +/*
> > + * IO Port/MMIO - Beware of the endians, VFIO is always little endian
> > + */
> > +static void vfio_bar_write(void *opaque, target_phys_addr_t addr,
> > +                           uint64_t data, unsigned size)
> > +{
> > +    VFIOBAR *bar = opaque;
> > +    uint8_t buf[8];
> > +
> > +    switch (size) {
> > +    case 1:
> > +        *buf = data & 0xff;
> > +        break;
> > +    case 2:
> > +        *(uint16_t *)buf = cpu_to_le16(data);
> > +        break;
> > +    case 4:
> > +        *(uint32_t *)buf = cpu_to_le32(data);
> > +        break;
> 
> This works accidentally on machines that require alignment, since
> there's no requirement from the compiler to align buf.  You can use a
> union to align it.

Good catch, fixed.

> > +    default:
> > +        hw_error("vfio: unsupported write size, %d bytes\n", size);
> > +        break;
> > +    }
> > +
> > +    if (pwrite(bar->fd, buf, size, bar->fd_offset + addr) != size) {
> > +        error_report("%s(,0x%"PRIx64", 0x%"PRIx64", %d) failed: %s\n",
> > +                     __func__, addr, data, size, strerror(errno));
> > +    }
> > +
> > +    DPRINTF("%s(BAR%d+0x%"PRIx64", 0x%"PRIx64", %d)\n",
> > +            __func__, bar->nr, addr, data, size);
> > +}
> > +
> > +
> > +static void vfio_listener_region_add(MemoryListener *listener,
> > +                                     MemoryRegionSection *section)
> > +{
> > +    VFIOContainer *container = container_of(listener, VFIOContainer,
> > +                                            iommu_data.listener);
> > +    target_phys_addr_t iova, end;
> > +    void *vaddr;
> > +    int ret;
> > +
> > +    if (vfio_listener_skipped_section(section)) {
> > +        DPRINTF("vfio: SKIPPING region_add %016lx - %016lx\n",
> > +                section->offset_within_address_space,
> > +                section->offset_within_address_space + section->size - 1);
> > +        return;
> > +    }
> > +
> > +    if (unlikely((section->offset_within_address_space & ~TARGET_PAGE_MASK) !=
> > +                 (section->offset_within_region & ~TARGET_PAGE_MASK))) {
> > +        error_report("%s received unaligned region\n", __func__);
> 
> Is it really an error?  I think you can just add the condition to
> skipped_section.

I had left this in as paranoia for myself that I wanted to see if this
actually happens.  I want to assume that our TARGET_PAGE_ALIGNED
offset_within_address_space results in an aligned ram pointer.  If one
is aligned different from the other we're kinda screwed trying to map it
into the iommu.  So far I haven't seen it.  Thanks for the feedback,

Alex

On 08/14/2012 08:23 PM, Alex Williamson wrote:
> 
>> Unrelated nit: memcmp() doesn't return a boolean or a count, so
>> !memcmp() is really unintuitive, at least to me.
> 
> I figure we're all pretty used to it growing up on !strcmp though.

I hate that one too.

>> > +
>> > +/* XXX This should move to msi.c */
>> 
>> Well?
> 
> Just marking a todo item.  I'll change it formally to TODO.  I think
> there are a few interfaces to msi.c that probably needs some rethinking
> for device assignment.  When they're small like this it seems easier to
> have the user in tree first.

I prefer them in the right place but I don't insist.

>> > +
>> > +    if (unlikely((section->offset_within_address_space & ~TARGET_PAGE_MASK) !=
>> > +                 (section->offset_within_region & ~TARGET_PAGE_MASK))) {
>> > +        error_report("%s received unaligned region\n", __func__);
>> 
>> Is it really an error?  I think you can just add the condition to
>> skipped_section.
> 
> I had left this in as paranoia for myself that I wanted to see if this
> actually happens.  I want to assume that our TARGET_PAGE_ALIGNED
> offset_within_address_space results in an aligned ram pointer.  If one
> is aligned different from the other we're kinda screwed trying to map it
> into the iommu.  So far I haven't seen it.  Thanks for the feedback,

We could have a sub-page RAM region (perhaps inserted as a mapped BAR
from some emulated device, or from vfio if/when it grows that capability).

But you're right, it really is an error, we can't just ignore it.  So
the current code is right.