Patchwork [2/3] vhost-scsi: new device supporting the tcm_vhost Linux kernel module

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Submitter Nicholas A. Bellinger
Date March 27, 2013, 9:59 p.m.
Message ID <1364421586-29857-3-git-send-email-nab@linux-iscsi.org>
Download mbox | patch
Permalink /patch/231851/
State New
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Nicholas A. Bellinger - March 27, 2013, 9:59 p.m.
From: Paolo Bonzini <pbonzini@redhat.com>

The WWPN specified in configfs is passed to "-device vhost-scsi-pci".
The tgpt field of the SET_ENDPOINT ioctl is obsolete now, so it is not
available from the QEMU command-line.  Instead, I hardcode it to zero.

Changes in V4:
   - Set event_idx=off by default (nab, thanks asias)
   - Disable hotplug feature bit for v3.9 tcm_vhost kernel code, need to
     re-enable in v3.10 (nab)
   - Update to latest qemu.git/master HEAD

Changes in V3:
   - Drop ioeventfd vhost_scsi_properties (asias, thanks stefanha)
   - Add CONFIG_VHOST_SCSI (asias, thanks stefanha)
   - Add hotplug feature bit

Changes in V2:
   - Add backend guest masking support (nab)
   - Bump ABI_VERSION to 1 (nab)
   - Set up set_guest_notifiers (asias)
   - Set up vs->dev.vq_index (asias)
   - Drop vs->vs.vdev.{set,clear}_vhost_endpoint (asias)
   - Drop VIRTIO_CONFIG_S_DRIVER check in vhost_scsi_set_status (asias)

Howto:
   Use the latest seabios, at least commit b44a7be17b
   git clone git://git.seabios.org/seabios.git
   make
   cp out/bios.bin /usr/share/qemu/bios.bin
   qemu -device vhost-scsi-pci,wwpn=naa.6001405bd4e8476d,event_idx=off
...

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Asias He <asias@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 configure                  |   15 +++-
 hw/Makefile.objs           |    5 +-
 hw/s390x/s390-virtio-bus.c |   35 +++++++
 hw/vhost-scsi.c            |  241 ++++++++++++++++++++++++++++++++++++++++++++
 hw/vhost-scsi.h            |   66 ++++++++++++
 hw/virtio-pci.c            |   62 +++++++++++
 hw/virtio-scsi.h           |    2 +
 7 files changed, 424 insertions(+), 2 deletions(-)
 create mode 100644 hw/vhost-scsi.c
 create mode 100644 hw/vhost-scsi.h
Michael S. Tsirkin - March 27, 2013, 10:28 p.m.
On Wed, Mar 27, 2013 at 09:59:45PM +0000, Nicholas A. Bellinger wrote:
> From: Paolo Bonzini <pbonzini@redhat.com>
> 
> The WWPN specified in configfs is passed to "-device vhost-scsi-pci".
> The tgpt field of the SET_ENDPOINT ioctl is obsolete now, so it is not
> available from the QEMU command-line.  Instead, I hardcode it to zero.
> 
> Changes in V4:
>    - Set event_idx=off by default (nab, thanks asias)

Why? What's going on here?

>    - Disable hotplug feature bit for v3.9 tcm_vhost kernel code, need to
>      re-enable in v3.10 (nab)

Userspace needs to support detecting host features
at runtime, based on dev->features.
In particular this applies to event_idx, but also hotplug.
See vhost_net_get_features.

>    - Update to latest qemu.git/master HEAD
> 
> Changes in V3:
>    - Drop ioeventfd vhost_scsi_properties (asias, thanks stefanha)
>    - Add CONFIG_VHOST_SCSI (asias, thanks stefanha)
>    - Add hotplug feature bit
> 
> Changes in V2:
>    - Add backend guest masking support (nab)
>    - Bump ABI_VERSION to 1 (nab)
>    - Set up set_guest_notifiers (asias)
>    - Set up vs->dev.vq_index (asias)
>    - Drop vs->vs.vdev.{set,clear}_vhost_endpoint (asias)
>    - Drop VIRTIO_CONFIG_S_DRIVER check in vhost_scsi_set_status (asias)
> 
> Howto:
>    Use the latest seabios, at least commit b44a7be17b
>    git clone git://git.seabios.org/seabios.git
>    make
>    cp out/bios.bin /usr/share/qemu/bios.bin
>    qemu -device vhost-scsi-pci,wwpn=naa.6001405bd4e8476d,event_idx=off
> ...
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Asias He <asias@redhat.com>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
> ---
>  configure                  |   15 +++-
>  hw/Makefile.objs           |    5 +-
>  hw/s390x/s390-virtio-bus.c |   35 +++++++
>  hw/vhost-scsi.c            |  241 ++++++++++++++++++++++++++++++++++++++++++++
>  hw/vhost-scsi.h            |   66 ++++++++++++
>  hw/virtio-pci.c            |   62 +++++++++++
>  hw/virtio-scsi.h           |    2 +
>  7 files changed, 424 insertions(+), 2 deletions(-)
>  create mode 100644 hw/vhost-scsi.c
>  create mode 100644 hw/vhost-scsi.h
> 
> diff --git a/configure b/configure
> index f2af714..6b67e35 100755
> --- a/configure
> +++ b/configure
> @@ -169,6 +169,7 @@ libattr=""
>  xfs=""
>  
>  vhost_net="no"
> +vhost_scsi="no"
>  kvm="no"
>  gprof="no"
>  debug_tcg="no"
> @@ -532,6 +533,7 @@ Haiku)
>    usb="linux"
>    kvm="yes"
>    vhost_net="yes"
> +  vhost_scsi="yes"
>    if [ "$cpu" = "i386" -o "$cpu" = "x86_64" ] ; then
>      audio_possible_drivers="$audio_possible_drivers fmod"
>    fi
> @@ -858,6 +860,10 @@ for opt do
>    ;;
>    --enable-vhost-net) vhost_net="yes"
>    ;;
> +  --disable-vhost-scsi) vhost_scsi="no"
> +  ;;
> +  --enable-vhost-scsi) vhost_scsi="yes"
> +  ;;
>    --disable-glx) glx="no"
>    ;;
>    --enable-glx) glx="yes"
> @@ -3078,7 +3084,7 @@ fi
>  # __sync_fetch_and_and requires at least -march=i486. Many toolchains
>  # use i686 as default anyway, but for those that don't, an explicit
>  # specification is necessary
> -if test "$vhost_net" = "yes" && test "$cpu" = "i386"; then
> +if (test "$vhost_net" = "yes" -o "$vhost_scsi" = "yes") && test "$cpu" = "i386"; then
>    cat > $TMPC << EOF
>  static int sfaa(int *ptr)
>  {
> @@ -3424,6 +3430,7 @@ echo "sigev_thread_id   $sigev_thread_id"
>  echo "uuid support      $uuid"
>  echo "libcap-ng support $cap_ng"
>  echo "vhost-net support $vhost_net"
> +echo "vhost-scsi support $vhost_scsi"
>  echo "Trace backend     $trace_backend"
>  echo "Trace output file $trace_file-<pid>"
>  echo "spice support     $spice ($spice_protocol_version/$spice_server_version)"
> @@ -3697,6 +3704,9 @@ fi
>  if test "$virtfs" = "yes" ; then
>    echo "CONFIG_VIRTFS=y" >> $config_host_mak
>  fi
> +if test "$vhost_scsi" = "yes" ; then
> +  echo "CONFIG_VHOST_SCSI=y" >> $config_host_mak
> +fi
>  if test "$blobs" = "yes" ; then
>    echo "INSTALL_BLOBS=yes" >> $config_host_mak
>  fi
> @@ -4175,6 +4185,9 @@ case "$target_arch2" in
>        if test "$vhost_net" = "yes" ; then
>          echo "CONFIG_VHOST_NET=y" >> $config_target_mak
>        fi
> +      if test "$vhost_scsi" = "yes" ; then
> +        echo "CONFIG_VHOST_SCSI=y" >> $config_target_mak
> +      fi
>      fi
>  esac
>  case "$target_arch2" in
> diff --git a/hw/Makefile.objs b/hw/Makefile.objs
> index d0b2ecb..0a38eb5 100644
> --- a/hw/Makefile.objs
> +++ b/hw/Makefile.objs
> @@ -205,8 +205,11 @@ common-obj-$(CONFIG_XEN_BACKEND) += xen_console.o xenfb.o xen_disk.o xen_nic.o
>  obj-$(CONFIG_VIRTIO) += dataplane/
>  obj-$(CONFIG_VIRTIO) += virtio.o virtio-blk.o virtio-balloon.o virtio-net.o
>  obj-$(CONFIG_VIRTIO) += virtio-serial-bus.o virtio-scsi.o
> +ifeq ($(CONFIG_VIRTIO), y)
> +obj-$(CONFIG_LINUX) += vhost-scsi.o
> +endif
>  obj-$(CONFIG_SOFTMMU) += vhost_net.o
> -obj-$(CONFIG_VHOST_NET) += vhost.o
> +obj-$(CONFIG_LINUX) += vhost.o
>  obj-$(CONFIG_REALLY_VIRTFS) += 9pfs/
>  obj-$(CONFIG_VGA) += vga.o
>  
> diff --git a/hw/s390x/s390-virtio-bus.c b/hw/s390x/s390-virtio-bus.c
> index c5d5456..73d93fd 100644
> --- a/hw/s390x/s390-virtio-bus.c
> +++ b/hw/s390x/s390-virtio-bus.c
> @@ -28,6 +28,8 @@
>  #include "hw/virtio-rng.h"
>  #include "hw/virtio-serial.h"
>  #include "hw/virtio-net.h"
> +#include "hw/virtio-scsi.h"
> +#include "hw/vhost-scsi.h"
>  #include "hw/sysbus.h"
>  #include "sysemu/kvm.h"
>  
> @@ -214,6 +216,18 @@ static int s390_virtio_scsi_init(VirtIOS390Device *dev)
>      return s390_virtio_device_init(dev, vdev);
>  }
>  
> +static int s390_vhost_scsi_init(VirtIOS390Device *dev)
> +{
> +    VirtIODevice *vdev;
> +
> +    vdev = vhost_scsi_init((DeviceState *)dev, &dev->scsi);
> +    if (!vdev) {
> +        return -1;
> +    }
> +
> +    return s390_virtio_device_init(dev, vdev);
> +}
> +
>  static int s390_virtio_rng_init(VirtIOS390Device *dev)
>  {
>      VirtIODevice *vdev;
> @@ -537,6 +551,27 @@ static const TypeInfo virtio_s390_device_info = {
>      .abstract = true,
>  };
>  
> +static Property s390_vhost_scsi_properties[] = {
> +    DEFINE_VIRTIO_SCSI_PROPERTIES(VirtIOS390Device, host_features, scsi),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void s390_vhost_scsi_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +    VirtIOS390DeviceClass *k = VIRTIO_S390_DEVICE_CLASS(klass);
> +
> +    k->init = s390_vhost_scsi_init;
> +    dc->props = s390_vhost_scsi_properties;
> +}
> +
> +static const TypeInfo s390_vhost_scsi = {
> +    .name          = "vhost-scsi-s390",
> +    .parent        = TYPE_VIRTIO_S390_DEVICE,
> +    .instance_size = sizeof(VirtIOS390Device),
> +    .class_init    = s390_vhost_scsi_class_init,
> +};
> +
>  static Property s390_virtio_scsi_properties[] = {
>      DEFINE_VIRTIO_SCSI_PROPERTIES(VirtIOS390Device, host_features, scsi),
>      DEFINE_PROP_END_OF_LIST(),
> diff --git a/hw/vhost-scsi.c b/hw/vhost-scsi.c
> new file mode 100644
> index 0000000..70e42fc
> --- /dev/null
> +++ b/hw/vhost-scsi.c
> @@ -0,0 +1,241 @@
> +/*
> + * vhost_scsi host device
> + *
> + * Copyright IBM, Corp. 2011
> + *
> + * Authors:
> + *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>
> + *
> + * Changes for QEMU mainline + tcm_vhost kernel upstream:
> + *  Nicholas Bellinger <nab@risingtidesystems.com>
> + *
> + * This work is licensed under the terms of the GNU LGPL, version 2 or later.
> + * See the COPYING.LIB file in the top-level directory.
> + *
> + */
> +
> +#include <sys/ioctl.h>
> +#include "config.h"
> +#include "qemu/queue.h"
> +#include "monitor/monitor.h"
> +#include "migration/migration.h"
> +#include "vhost-scsi.h"
> +#include "vhost.h"
> +#include "virtio-scsi.h"
> +
> +typedef struct VHostSCSI {
> +    VirtIOSCSICommon vs;
> +
> +    Error *migration_blocker;
> +
> +    struct vhost_dev dev;
> +} VHostSCSI;
> +
> +static int vhost_scsi_set_endpoint(VirtIODevice *vdev)
> +{
> +    VHostSCSI *vs = (VHostSCSI *)vdev;
> +    struct vhost_scsi_target backend;
> +    int ret;
> +
> +    memset(&backend, 0, sizeof(backend));
> +    pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->vs.conf->wwpn);
> +    ret = ioctl(vs->dev.control, VHOST_SCSI_SET_ENDPOINT, &backend);
> +    if (ret < 0) {
> +        return -errno;
> +    }
> +    return 0;
> +}
> +
> +static void vhost_scsi_clear_endpoint(VirtIODevice *vdev)
> +{
> +    VHostSCSI *vs = (VHostSCSI *)vdev;
> +    struct vhost_scsi_target backend;
> +
> +    memset(&backend, 0, sizeof(backend));
> +    pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->vs.conf->wwpn);
> +    ioctl(vs->dev.control, VHOST_SCSI_CLEAR_ENDPOINT, &backend);
> +}
> +
> +static int vhost_scsi_start(VHostSCSI *vs, VirtIODevice *vdev)
> +{
> +    int ret, abi_version;
> +
> +    if (!vdev->binding->set_guest_notifiers) {
> +        error_report("binding does not support guest notifiers");
> +        return -ENOSYS;
> +    }
> +
> +    ret = ioctl(vs->dev.control, VHOST_SCSI_GET_ABI_VERSION, &abi_version);
> +    if (ret < 0) {
> +        return -errno;
> +    }
> +    if (abi_version > VHOST_SCSI_ABI_VERSION) {
> +        error_report("vhost-scsi: The running tcm_vhost kernel abi_version:"
> +                     " %d is greater than vhost_scsi userspace supports: %d, please"
> +                     " upgrade your version of QEMU\n", abi_version,
> +                     VHOST_SCSI_ABI_VERSION);
> +        return -ENOSYS;
> +    }
> +
> +    ret = vhost_dev_enable_notifiers(&vs->dev, vdev);
> +    if (ret < 0) {
> +        return ret;
> +    }
> +
> +    ret = vhost_dev_start(&vs->dev, vdev);
> +    if (ret < 0) {
> +        error_report("Error start vhost dev");
> +        goto err_notifiers;
> +    }
> +
> +    ret = vhost_scsi_set_endpoint(vdev);
> +    if (ret < 0) {
> +        error_report("Error set vhost-scsi endpoint");
> +        goto err_vhost_stop;
> +    }
> +
> +    ret = vdev->binding->set_guest_notifiers(vdev->binding_opaque, vs->dev.nvqs, true);
> +    if (ret < 0) {
> +        error_report("Error binding guest notifier");
> +        goto err_endpoint;
> +    }
> +    return ret;
> +
> +err_endpoint:
> +    vhost_scsi_clear_endpoint(vdev);
> +err_vhost_stop:
> +    vhost_dev_stop(&vs->dev, vdev);
> +err_notifiers:
> +    vhost_dev_disable_notifiers(&vs->dev, vdev);
> +    return ret;
> +}
> +
> +static void vhost_scsi_stop(VHostSCSI *vs, VirtIODevice *vdev)
> +{
> +    int ret = 0;
> +
> +    if (!vdev->binding->set_guest_notifiers) {
> +        ret = vdev->binding->set_guest_notifiers(vdev->binding_opaque,
> +                                                 vs->dev.nvqs, false);
> +        if (ret < 0) {
> +                error_report("vhost guest notifier cleanup failed: %d\n", ret);
> +        }
> +    }
> +    assert(ret >= 0);
> +
> +    vhost_scsi_clear_endpoint(vdev);
> +    vhost_dev_stop(&vs->dev, vdev);
> +    vhost_dev_disable_notifiers(&vs->dev, vdev);
> +}
> +
> +static void vhost_scsi_set_config(VirtIODevice *vdev,
> +                                  const uint8_t *config)
> +{
> +    VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
> +    VHostSCSI *vs = (VHostSCSI *)vdev;
> +
> +    if ((uint32_t) ldl_raw(&scsiconf->sense_size) != vs->vs.sense_size ||
> +        (uint32_t) ldl_raw(&scsiconf->cdb_size) != vs->vs.cdb_size) {
> +        error_report("vhost-scsi does not support changing the sense data and CDB sizes");
> +        exit(1);
> +    }
> +}
> +
> +static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
> +{
> +    VHostSCSI *vs = (VHostSCSI *)vdev;
> +    bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK);
> +
> +    if (vs->dev.started == start) {
> +        return;
> +    }
> +
> +    if (start) {
> +        int ret;
> +
> +        ret = vhost_scsi_start(vs, vdev);
> +        if (ret < 0) {
> +            error_report("virtio-scsi: unable to start vhost: %s\n",
> +                         strerror(-ret));
> +
> +            /* There is no userspace virtio-scsi fallback so exit */
> +            exit(1);
> +        }
> +    } else {
> +        vhost_scsi_stop(vs, vdev);
> +    }
> +}
> +
> +static void vhost_scsi_guest_notifier_mask(VirtIODevice *vdev, int idx,
> +                                           bool mask)
> +{
> +    VHostSCSI *vs = (VHostSCSI *)vdev;
> +
> +    vhost_virtqueue_mask(&vs->dev, vdev, idx, mask);
> +}
> +
> +static bool vhost_scsi_guest_notifier_pending(VirtIODevice *vdev, int idx)
> +{
> +    VHostSCSI *vs = (VHostSCSI *)vdev;
> +
> +    return vhost_virtqueue_pending(&vs->dev, idx);
> +}
> +
> +VirtIODevice *vhost_scsi_init(DeviceState *dev, VirtIOSCSIConf *proxyconf)
> +{
> +    VHostSCSI *vs;
> +    int vhostfd = -1;
> +    int ret;
> +
> +    if (!proxyconf->wwpn) {
> +        error_report("vhost-scsi: missing wwpn\n");
> +        return NULL;
> +    }
> +
> +    if (proxyconf->vhostfd) {
> +        vhostfd = monitor_handle_fd_param(cur_mon, proxyconf->vhostfd);
> +        if (vhostfd == -1) {
> +            error_report("vhost-scsi: unable to parse vhostfd\n");
> +            return NULL;
> +        }
> +    }
> +
> +    vs = (VHostSCSI *)virtio_scsi_init_common(dev, proxyconf,
> +                                              sizeof(VHostSCSI));
> +
> +    vs->vs.vdev.set_config = vhost_scsi_set_config;
> +    vs->vs.vdev.set_status = vhost_scsi_set_status;
> +    vs->vs.vdev.guest_notifier_mask = vhost_scsi_guest_notifier_mask;
> +    vs->vs.vdev.guest_notifier_pending = vhost_scsi_guest_notifier_pending;
> +
> +    vs->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->vs.conf->num_queues;
> +    vs->dev.vqs = g_new(struct vhost_virtqueue, vs->dev.nvqs);
> +    vs->dev.vq_index = 0;
> +
> +    ret = vhost_dev_init(&vs->dev, vhostfd, "/dev/vhost-scsi", true);
> +    if (ret < 0) {
> +        error_report("vhost-scsi: vhost initialization failed: %s\n",
> +                strerror(-ret));
> +        return NULL;
> +    }
> +    vs->dev.backend_features = 0;
> +    vs->dev.acked_features = 0;
> +
> +    error_setg(&vs->migration_blocker,
> +            "vhost-scsi does not support migration");
> +    migrate_add_blocker(vs->migration_blocker);
> +
> +    return &vs->vs.vdev;
> +}
> +
> +void vhost_scsi_exit(VirtIODevice *vdev)
> +{
> +    VHostSCSI *vs = (VHostSCSI *)vdev;
> +    migrate_del_blocker(vs->migration_blocker);
> +    error_free(vs->migration_blocker);
> +
> +    /* This will stop vhost backend. */
> +    vhost_scsi_set_status(vdev, 0);
> +    g_free(vs->dev.vqs);
> +    virtio_cleanup(vdev);
> +}
> diff --git a/hw/vhost-scsi.h b/hw/vhost-scsi.h
> new file mode 100644
> index 0000000..b01f012
> --- /dev/null
> +++ b/hw/vhost-scsi.h
> @@ -0,0 +1,66 @@
> +/*
> + * vhost_scsi host device
> + *
> + * Copyright IBM, Corp. 2011
> + *
> + * Authors:
> + *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>
> + *
> + * This work is licensed under the terms of the GNU LGPL, version 2 or later.
> + * See the COPYING.LIB file in the top-level directory.
> + *
> + */
> +
> +#ifndef VHOST_SCSI_H
> +#define VHOST_SCSI_H
> +
> +#include "qemu-common.h"
> +#include "qdev.h"
> +#include "virtio-scsi.h"
> +
> +/*
> + * Used by QEMU userspace to ensure a consistent vhost-scsi ABI.
> + *
> + * ABI Rev 0: July 2012 version starting point for v3.6-rc merge candidate +
> + *            RFC-v2 vhost-scsi userspace.  Add GET_ABI_VERSION ioctl usage
> + * ABI Rev 1: January 2013. Ignore vhost_tpgt filed in struct vhost_scsi_target.
> + * 	      All the targets under vhost_wwpn can be seen and used by guest.
> + */
> +
> +#define VHOST_SCSI_ABI_VERSION 1
> +
> +/* TODO #include <linux/vhost.h> properly */
> +/* For VHOST_SCSI_SET_ENDPOINT/VHOST_SCSI_CLEAR_ENDPOINT ioctl */
> +struct vhost_scsi_target {
> +    int abi_version;
> +    char vhost_wwpn[224];
> +    unsigned short vhost_tpgt;
> +    unsigned short reserved;
> +};
> +
> +enum vhost_scsi_vq_list {
> +    VHOST_SCSI_VQ_CONTROL = 0,
> +    VHOST_SCSI_VQ_EVENT = 1,
> +    VHOST_SCSI_VQ_NUM_FIXED = 2,
> +};
> +
> +#define VHOST_VIRTIO 0xAF
> +#define VHOST_SCSI_SET_ENDPOINT _IOW(VHOST_VIRTIO, 0x40, struct vhost_scsi_target)
> +#define VHOST_SCSI_CLEAR_ENDPOINT _IOW(VHOST_VIRTIO, 0x41, struct vhost_scsi_target)
> +#define VHOST_SCSI_GET_ABI_VERSION _IOW(VHOST_VIRTIO, 0x42, int)
> +
> +#define DEFINE_VHOST_SCSI_PROPERTIES(_state, _features_field, _conf_field) \
> +    DEFINE_PROP_BIT("indirect_desc", _state, _features_field, VIRTIO_RING_F_INDIRECT_DESC, true), \
> +    DEFINE_PROP_BIT("event_idx", _state, _features_field, VIRTIO_RING_F_EVENT_IDX, false), \

Maybe this works around some bug?
Needs a comment with motivation.

Ideally we won't do this, use DEFINE_VIRTIO_COMMON_FEATURES
so that adding properties to all devices will be easier
in the future.

> +    DEFINE_PROP_STRING("vhostfd", _state, _conf_field.vhostfd), \
> +    DEFINE_PROP_STRING("wwpn", _state, _conf_field.wwpn), \
> +    DEFINE_PROP_UINT32("num_queues", _state, _conf_field.num_queues, 1), \
> +    DEFINE_PROP_UINT32("max_sectors", _state, _conf_field.max_sectors, 0xFFFF), \
> +    DEFINE_PROP_UINT32("cmd_per_lun", _state, _conf_field.cmd_per_lun, 128), \
> +    DEFINE_PROP_BIT("hotplug", _state, _features_field, VIRTIO_SCSI_F_HOTPLUG, true)

Seems unused?

> +
> +VirtIODevice *vhost_scsi_init(DeviceState *dev, VirtIOSCSIConf *proxyconf);
> +void vhost_scsi_exit(VirtIODevice *vdev);
> +
> +
> +#endif
> diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
> index f3ece78..0d67b84 100644
> --- a/hw/virtio-pci.c
> +++ b/hw/virtio-pci.c
> @@ -22,6 +22,7 @@
>  #include "hw/virtio-net.h"
>  #include "hw/virtio-serial.h"
>  #include "hw/virtio-scsi.h"
> +#include "hw/vhost-scsi.h"
>  #include "hw/pci/pci.h"
>  #include "qemu/error-report.h"
>  #include "hw/pci/msi.h"
> @@ -1247,6 +1248,64 @@ static const TypeInfo virtio_scsi_info = {
>      .class_init    = virtio_scsi_class_init,
>  };
>  
> +#ifdef CONFIG_VHOST_SCSI
> +static int vhost_scsi_init_pci(PCIDevice *pci_dev)
> +{
> +    VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
> +    VirtIODevice *vdev;
> +
> +    vdev = vhost_scsi_init(&pci_dev->qdev, &proxy->scsi);
> +    if (!vdev) {
> +        return -EINVAL;
> +    }
> +
> +    vdev->nvectors = proxy->nvectors == DEV_NVECTORS_UNSPECIFIED
> +                                        ? proxy->scsi.num_queues + 3
> +                                        : proxy->nvectors;
> +    virtio_init_pci(proxy, vdev);
> +
> +    /* make the actual value visible */
> +    proxy->nvectors = vdev->nvectors;
> +    return 0;
> +}
> +
> +static void vhost_scsi_exit_pci(PCIDevice *pci_dev)
> +{
> +    VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
> +
> +    vhost_scsi_exit(proxy->vdev);
> +    virtio_exit_pci(pci_dev);
> +}
> +
> +static Property vhost_scsi_properties[] = {
> +    DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, DEV_NVECTORS_UNSPECIFIED),
> +    DEFINE_VHOST_SCSI_PROPERTIES(VirtIOPCIProxy, host_features, scsi),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void vhost_scsi_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
> +
> +    k->init = vhost_scsi_init_pci;
> +    k->exit = vhost_scsi_exit_pci;
> +    k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
> +    k->device_id = PCI_DEVICE_ID_VIRTIO_SCSI;
> +    k->revision = 0x00;
> +    k->class_id = PCI_CLASS_STORAGE_SCSI;
> +    dc->reset = virtio_pci_reset;
> +    dc->props = vhost_scsi_properties;
> +}
> +
> +static const TypeInfo vhost_scsi_info = {
> +    .name          = "vhost-scsi-pci",
> +    .parent        = TYPE_PCI_DEVICE,
> +    .instance_size = sizeof(VirtIOPCIProxy),
> +    .class_init    = vhost_scsi_class_init,
> +};
> +#endif
> +
>  #ifdef CONFIG_VIRTFS
>  static int virtio_9p_init_pci(PCIDevice *pci_dev)
>  {
> @@ -1495,6 +1554,9 @@ static void virtio_pci_register_types(void)
>      type_register_static(&virtio_serial_info);
>      type_register_static(&virtio_balloon_info);
>      type_register_static(&virtio_scsi_info);
> +#ifdef CONFIG_VHOST_SCSI
> +    type_register_static(&vhost_scsi_info);
> +#endif
>      type_register_static(&virtio_rng_info);
>      type_register_static(&virtio_pci_bus_info);
>      type_register_static(&virtio_pci_info);
> diff --git a/hw/virtio-scsi.h b/hw/virtio-scsi.h
> index 2bcf606..356bf38 100644
> --- a/hw/virtio-scsi.h
> +++ b/hw/virtio-scsi.h
> @@ -142,6 +142,8 @@ struct VirtIOSCSIConf {
>      uint32_t num_queues;
>      uint32_t max_sectors;
>      uint32_t cmd_per_lun;
> +    char *vhostfd;
> +    char *wwpn;
>  };
>  
>  typedef struct VirtIOSCSICommon {
> -- 
> 1.7.2.5
Nicholas A. Bellinger - March 27, 2013, 10:45 p.m.
On Thu, 2013-03-28 at 00:28 +0200, Michael S. Tsirkin wrote:
> On Wed, Mar 27, 2013 at 09:59:45PM +0000, Nicholas A. Bellinger wrote:
> > From: Paolo Bonzini <pbonzini@redhat.com>
> > 
> > The WWPN specified in configfs is passed to "-device vhost-scsi-pci".
> > The tgpt field of the SET_ENDPOINT ioctl is obsolete now, so it is not
> > available from the QEMU command-line.  Instead, I hardcode it to zero.
> > 
> > Changes in V4:
> >    - Set event_idx=off by default (nab, thanks asias)
> 
> Why? What's going on here?
> 

Not disabling event_idx by default, or disabling from the command line
ends up resulting in ->handle_kick() not getting called for subsequent
commands..

I spent some time trying to track this down recently with no luck, and
AFAICT it's always been required in order for vhost-scsi to function.

> >    - Disable hotplug feature bit for v3.9 tcm_vhost kernel code, need to
> >      re-enable in v3.10 (nab)
> 
> Userspace needs to support detecting host features
> at runtime, based on dev->features.
> In particular this applies to event_idx, but also hotplug.
> See vhost_net_get_features.

<nod>, will get this fixed up.

> 
> >    - Update to latest qemu.git/master HEAD
> > 
> > Changes in V3:
> >    - Drop ioeventfd vhost_scsi_properties (asias, thanks stefanha)
> >    - Add CONFIG_VHOST_SCSI (asias, thanks stefanha)
> >    - Add hotplug feature bit
> > 
> > Changes in V2:
> >    - Add backend guest masking support (nab)
> >    - Bump ABI_VERSION to 1 (nab)
> >    - Set up set_guest_notifiers (asias)
> >    - Set up vs->dev.vq_index (asias)
> >    - Drop vs->vs.vdev.{set,clear}_vhost_endpoint (asias)
> >    - Drop VIRTIO_CONFIG_S_DRIVER check in vhost_scsi_set_status (asias)
> > 
> > Howto:
> >    Use the latest seabios, at least commit b44a7be17b
> >    git clone git://git.seabios.org/seabios.git
> >    make
> >    cp out/bios.bin /usr/share/qemu/bios.bin
> >    qemu -device vhost-scsi-pci,wwpn=naa.6001405bd4e8476d,event_idx=off
> > ...
> > 
> > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> > Signed-off-by: Asias He <asias@redhat.com>
> > Cc: Michael S. Tsirkin <mst@redhat.com>
> > Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
> > ---
> >  configure                  |   15 +++-
> >  hw/Makefile.objs           |    5 +-
> >  hw/s390x/s390-virtio-bus.c |   35 +++++++
> >  hw/vhost-scsi.c            |  241 ++++++++++++++++++++++++++++++++++++++++++++
> >  hw/vhost-scsi.h            |   66 ++++++++++++
> >  hw/virtio-pci.c            |   62 +++++++++++
> >  hw/virtio-scsi.h           |    2 +
> >  7 files changed, 424 insertions(+), 2 deletions(-)
> >  create mode 100644 hw/vhost-scsi.c
> >  create mode 100644 hw/vhost-scsi.h
> > 

<SNIP>

> > diff --git a/hw/vhost-scsi.h b/hw/vhost-scsi.h
> > new file mode 100644
> > index 0000000..b01f012
> > --- /dev/null
> > +++ b/hw/vhost-scsi.h
> > @@ -0,0 +1,66 @@
> > +/*
> > + * vhost_scsi host device
> > + *
> > + * Copyright IBM, Corp. 2011
> > + *
> > + * Authors:
> > + *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>
> > + *
> > + * This work is licensed under the terms of the GNU LGPL, version 2 or later.
> > + * See the COPYING.LIB file in the top-level directory.
> > + *
> > + */
> > +
> > +#ifndef VHOST_SCSI_H
> > +#define VHOST_SCSI_H
> > +
> > +#include "qemu-common.h"
> > +#include "qdev.h"
> > +#include "virtio-scsi.h"
> > +
> > +/*
> > + * Used by QEMU userspace to ensure a consistent vhost-scsi ABI.
> > + *
> > + * ABI Rev 0: July 2012 version starting point for v3.6-rc merge candidate +
> > + *            RFC-v2 vhost-scsi userspace.  Add GET_ABI_VERSION ioctl usage
> > + * ABI Rev 1: January 2013. Ignore vhost_tpgt filed in struct vhost_scsi_target.
> > + * 	      All the targets under vhost_wwpn can be seen and used by guest.
> > + */
> > +
> > +#define VHOST_SCSI_ABI_VERSION 1
> > +
> > +/* TODO #include <linux/vhost.h> properly */
> > +/* For VHOST_SCSI_SET_ENDPOINT/VHOST_SCSI_CLEAR_ENDPOINT ioctl */
> > +struct vhost_scsi_target {
> > +    int abi_version;
> > +    char vhost_wwpn[224];
> > +    unsigned short vhost_tpgt;
> > +    unsigned short reserved;
> > +};
> > +
> > +enum vhost_scsi_vq_list {
> > +    VHOST_SCSI_VQ_CONTROL = 0,
> > +    VHOST_SCSI_VQ_EVENT = 1,
> > +    VHOST_SCSI_VQ_NUM_FIXED = 2,
> > +};
> > +
> > +#define VHOST_VIRTIO 0xAF
> > +#define VHOST_SCSI_SET_ENDPOINT _IOW(VHOST_VIRTIO, 0x40, struct vhost_scsi_target)
> > +#define VHOST_SCSI_CLEAR_ENDPOINT _IOW(VHOST_VIRTIO, 0x41, struct vhost_scsi_target)
> > +#define VHOST_SCSI_GET_ABI_VERSION _IOW(VHOST_VIRTIO, 0x42, int)
> > +
> > +#define DEFINE_VHOST_SCSI_PROPERTIES(_state, _features_field, _conf_field) \
> > +    DEFINE_PROP_BIT("indirect_desc", _state, _features_field, VIRTIO_RING_F_INDIRECT_DESC, true), \
> > +    DEFINE_PROP_BIT("event_idx", _state, _features_field, VIRTIO_RING_F_EVENT_IDX, false), \
> 
> Maybe this works around some bug?
> Needs a comment with motivation.
> 
> Ideally we won't do this, use DEFINE_VIRTIO_COMMON_FEATURES
> so that adding properties to all devices will be easier
> in the future.

AFAICT vhost-scsi has never worked without event_idx=off, so disabling
it by default here made sense.  ;)

> 
> > +    DEFINE_PROP_STRING("vhostfd", _state, _conf_field.vhostfd), \
> > +    DEFINE_PROP_STRING("wwpn", _state, _conf_field.wwpn), \
> > +    DEFINE_PROP_UINT32("num_queues", _state, _conf_field.num_queues, 1), \
> > +    DEFINE_PROP_UINT32("max_sectors", _state, _conf_field.max_sectors, 0xFFFF), \
> > +    DEFINE_PROP_UINT32("cmd_per_lun", _state, _conf_field.cmd_per_lun, 128), \
> > +    DEFINE_PROP_BIT("hotplug", _state, _features_field, VIRTIO_SCSI_F_HOTPLUG, true)
> 
> Seems unused?

Looks like left-over debug code from Asias..

Dropping this now..

> 
> > +
> > +VirtIODevice *vhost_scsi_init(DeviceState *dev, VirtIOSCSIConf *proxyconf);
> > +void vhost_scsi_exit(VirtIODevice *vdev);
> > +
> > +
> > +#endif
> > diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
> > index f3ece78..0d67b84 100644
> > --- a/hw/virtio-pci.c
> > +++ b/hw/virtio-pci.c
> > @@ -22,6 +22,7 @@
> >  #include "hw/virtio-net.h"
> >  #include "hw/virtio-serial.h"
> >  #include "hw/virtio-scsi.h"
> > +#include "hw/vhost-scsi.h"
> >  #include "hw/pci/pci.h"
> >  #include "qemu/error-report.h"
> >  #include "hw/pci/msi.h"
> > @@ -1247,6 +1248,64 @@ static const TypeInfo virtio_scsi_info = {
> >      .class_init    = virtio_scsi_class_init,
> >  };
> >  
> > +#ifdef CONFIG_VHOST_SCSI
> > +static int vhost_scsi_init_pci(PCIDevice *pci_dev)
> > +{
> > +    VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
> > +    VirtIODevice *vdev;
> > +
> > +    vdev = vhost_scsi_init(&pci_dev->qdev, &proxy->scsi);
> > +    if (!vdev) {
> > +        return -EINVAL;
> > +    }
> > +
> > +    vdev->nvectors = proxy->nvectors == DEV_NVECTORS_UNSPECIFIED
> > +                                        ? proxy->scsi.num_queues + 3
> > +                                        : proxy->nvectors;
> > +    virtio_init_pci(proxy, vdev);
> > +
> > +    /* make the actual value visible */
> > +    proxy->nvectors = vdev->nvectors;
> > +    return 0;
> > +}
> > +
> > +static void vhost_scsi_exit_pci(PCIDevice *pci_dev)
> > +{
> > +    VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
> > +
> > +    vhost_scsi_exit(proxy->vdev);
> > +    virtio_exit_pci(pci_dev);
> > +}
> > +
> > +static Property vhost_scsi_properties[] = {
> > +    DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, DEV_NVECTORS_UNSPECIFIED),
> > +    DEFINE_VHOST_SCSI_PROPERTIES(VirtIOPCIProxy, host_features, scsi),
> > +    DEFINE_PROP_END_OF_LIST(),
> > +};
> > +
> > +static void vhost_scsi_class_init(ObjectClass *klass, void *data)
> > +{
> > +    DeviceClass *dc = DEVICE_CLASS(klass);
> > +    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
> > +
> > +    k->init = vhost_scsi_init_pci;
> > +    k->exit = vhost_scsi_exit_pci;
> > +    k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
> > +    k->device_id = PCI_DEVICE_ID_VIRTIO_SCSI;
> > +    k->revision = 0x00;
> > +    k->class_id = PCI_CLASS_STORAGE_SCSI;
> > +    dc->reset = virtio_pci_reset;
> > +    dc->props = vhost_scsi_properties;
> > +}
> > +
> > +static const TypeInfo vhost_scsi_info = {
> > +    .name          = "vhost-scsi-pci",
> > +    .parent        = TYPE_PCI_DEVICE,
> > +    .instance_size = sizeof(VirtIOPCIProxy),
> > +    .class_init    = vhost_scsi_class_init,
> > +};
> > +#endif
> > +
> >  #ifdef CONFIG_VIRTFS
> >  static int virtio_9p_init_pci(PCIDevice *pci_dev)
> >  {
> > @@ -1495,6 +1554,9 @@ static void virtio_pci_register_types(void)
> >      type_register_static(&virtio_serial_info);
> >      type_register_static(&virtio_balloon_info);
> >      type_register_static(&virtio_scsi_info);
> > +#ifdef CONFIG_VHOST_SCSI
> > +    type_register_static(&vhost_scsi_info);
> > +#endif
> >      type_register_static(&virtio_rng_info);
> >      type_register_static(&virtio_pci_bus_info);
> >      type_register_static(&virtio_pci_info);
> > diff --git a/hw/virtio-scsi.h b/hw/virtio-scsi.h
> > index 2bcf606..356bf38 100644
> > --- a/hw/virtio-scsi.h
> > +++ b/hw/virtio-scsi.h
> > @@ -142,6 +142,8 @@ struct VirtIOSCSIConf {
> >      uint32_t num_queues;
> >      uint32_t max_sectors;
> >      uint32_t cmd_per_lun;
> > +    char *vhostfd;
> > +    char *wwpn;
> >  };
> >  
> >  typedef struct VirtIOSCSICommon {
> > -- 
> > 1.7.2.5
> --
> To unsubscribe from this list: send the line "unsubscribe target-devel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
Michael S. Tsirkin - March 27, 2013, 10:50 p.m.
On Wed, Mar 27, 2013 at 03:45:42PM -0700, Nicholas A. Bellinger wrote:
> On Thu, 2013-03-28 at 00:28 +0200, Michael S. Tsirkin wrote:
> > On Wed, Mar 27, 2013 at 09:59:45PM +0000, Nicholas A. Bellinger wrote:
> > > From: Paolo Bonzini <pbonzini@redhat.com>
> > > 
> > > The WWPN specified in configfs is passed to "-device vhost-scsi-pci".
> > > The tgpt field of the SET_ENDPOINT ioctl is obsolete now, so it is not
> > > available from the QEMU command-line.  Instead, I hardcode it to zero.
> > > 
> > > Changes in V4:
> > >    - Set event_idx=off by default (nab, thanks asias)
> > 
> > Why? What's going on here?
> > 
> 
> Not disabling event_idx by default, or disabling from the command line
> ends up resulting in ->handle_kick() not getting called for subsequent
> commands..
> 
> I spent some time trying to track this down recently with no luck, and
> AFAICT it's always been required in order for vhost-scsi to function.

Hmm this is a bug in kernel then. A better work-around is
to disable EVENT_IDX in kernel. Let's do it for 3.9?
Then when we fix it, things just work for userspace.

> > >    - Disable hotplug feature bit for v3.9 tcm_vhost kernel code, need to
> > >      re-enable in v3.10 (nab)
> > 
> > Userspace needs to support detecting host features
> > at runtime, based on dev->features.
> > In particular this applies to event_idx, but also hotplug.
> > See vhost_net_get_features.
> 
> <nod>, will get this fixed up.
> 
> > 
> > >    - Update to latest qemu.git/master HEAD
> > > 
> > > Changes in V3:
> > >    - Drop ioeventfd vhost_scsi_properties (asias, thanks stefanha)
> > >    - Add CONFIG_VHOST_SCSI (asias, thanks stefanha)
> > >    - Add hotplug feature bit
> > > 
> > > Changes in V2:
> > >    - Add backend guest masking support (nab)
> > >    - Bump ABI_VERSION to 1 (nab)
> > >    - Set up set_guest_notifiers (asias)
> > >    - Set up vs->dev.vq_index (asias)
> > >    - Drop vs->vs.vdev.{set,clear}_vhost_endpoint (asias)
> > >    - Drop VIRTIO_CONFIG_S_DRIVER check in vhost_scsi_set_status (asias)
> > > 
> > > Howto:
> > >    Use the latest seabios, at least commit b44a7be17b
> > >    git clone git://git.seabios.org/seabios.git
> > >    make
> > >    cp out/bios.bin /usr/share/qemu/bios.bin
> > >    qemu -device vhost-scsi-pci,wwpn=naa.6001405bd4e8476d,event_idx=off
> > > ...
> > > 
> > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> > > Signed-off-by: Asias He <asias@redhat.com>
> > > Cc: Michael S. Tsirkin <mst@redhat.com>
> > > Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
> > > ---
> > >  configure                  |   15 +++-
> > >  hw/Makefile.objs           |    5 +-
> > >  hw/s390x/s390-virtio-bus.c |   35 +++++++
> > >  hw/vhost-scsi.c            |  241 ++++++++++++++++++++++++++++++++++++++++++++
> > >  hw/vhost-scsi.h            |   66 ++++++++++++
> > >  hw/virtio-pci.c            |   62 +++++++++++
> > >  hw/virtio-scsi.h           |    2 +
> > >  7 files changed, 424 insertions(+), 2 deletions(-)
> > >  create mode 100644 hw/vhost-scsi.c
> > >  create mode 100644 hw/vhost-scsi.h
> > > 
> 
> <SNIP>
> 
> > > diff --git a/hw/vhost-scsi.h b/hw/vhost-scsi.h
> > > new file mode 100644
> > > index 0000000..b01f012
> > > --- /dev/null
> > > +++ b/hw/vhost-scsi.h
> > > @@ -0,0 +1,66 @@
> > > +/*
> > > + * vhost_scsi host device
> > > + *
> > > + * Copyright IBM, Corp. 2011
> > > + *
> > > + * Authors:
> > > + *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>
> > > + *
> > > + * This work is licensed under the terms of the GNU LGPL, version 2 or later.
> > > + * See the COPYING.LIB file in the top-level directory.
> > > + *
> > > + */
> > > +
> > > +#ifndef VHOST_SCSI_H
> > > +#define VHOST_SCSI_H
> > > +
> > > +#include "qemu-common.h"
> > > +#include "qdev.h"
> > > +#include "virtio-scsi.h"
> > > +
> > > +/*
> > > + * Used by QEMU userspace to ensure a consistent vhost-scsi ABI.
> > > + *
> > > + * ABI Rev 0: July 2012 version starting point for v3.6-rc merge candidate +
> > > + *            RFC-v2 vhost-scsi userspace.  Add GET_ABI_VERSION ioctl usage
> > > + * ABI Rev 1: January 2013. Ignore vhost_tpgt filed in struct vhost_scsi_target.
> > > + * 	      All the targets under vhost_wwpn can be seen and used by guest.
> > > + */
> > > +
> > > +#define VHOST_SCSI_ABI_VERSION 1
> > > +
> > > +/* TODO #include <linux/vhost.h> properly */
> > > +/* For VHOST_SCSI_SET_ENDPOINT/VHOST_SCSI_CLEAR_ENDPOINT ioctl */
> > > +struct vhost_scsi_target {
> > > +    int abi_version;
> > > +    char vhost_wwpn[224];
> > > +    unsigned short vhost_tpgt;
> > > +    unsigned short reserved;
> > > +};
> > > +
> > > +enum vhost_scsi_vq_list {
> > > +    VHOST_SCSI_VQ_CONTROL = 0,
> > > +    VHOST_SCSI_VQ_EVENT = 1,
> > > +    VHOST_SCSI_VQ_NUM_FIXED = 2,
> > > +};
> > > +
> > > +#define VHOST_VIRTIO 0xAF
> > > +#define VHOST_SCSI_SET_ENDPOINT _IOW(VHOST_VIRTIO, 0x40, struct vhost_scsi_target)
> > > +#define VHOST_SCSI_CLEAR_ENDPOINT _IOW(VHOST_VIRTIO, 0x41, struct vhost_scsi_target)
> > > +#define VHOST_SCSI_GET_ABI_VERSION _IOW(VHOST_VIRTIO, 0x42, int)
> > > +
> > > +#define DEFINE_VHOST_SCSI_PROPERTIES(_state, _features_field, _conf_field) \
> > > +    DEFINE_PROP_BIT("indirect_desc", _state, _features_field, VIRTIO_RING_F_INDIRECT_DESC, true), \
> > > +    DEFINE_PROP_BIT("event_idx", _state, _features_field, VIRTIO_RING_F_EVENT_IDX, false), \
> > 
> > Maybe this works around some bug?
> > Needs a comment with motivation.
> > 
> > Ideally we won't do this, use DEFINE_VIRTIO_COMMON_FEATURES
> > so that adding properties to all devices will be easier
> > in the future.
> 
> AFAICT vhost-scsi has never worked without event_idx=off, so disabling
> it by default here made sense.  ;)
> 
> > 
> > > +    DEFINE_PROP_STRING("vhostfd", _state, _conf_field.vhostfd), \
> > > +    DEFINE_PROP_STRING("wwpn", _state, _conf_field.wwpn), \
> > > +    DEFINE_PROP_UINT32("num_queues", _state, _conf_field.num_queues, 1), \
> > > +    DEFINE_PROP_UINT32("max_sectors", _state, _conf_field.max_sectors, 0xFFFF), \
> > > +    DEFINE_PROP_UINT32("cmd_per_lun", _state, _conf_field.cmd_per_lun, 128), \
> > > +    DEFINE_PROP_BIT("hotplug", _state, _features_field, VIRTIO_SCSI_F_HOTPLUG, true)
> > 
> > Seems unused?
> 
> Looks like left-over debug code from Asias..
> 
> Dropping this now..
> 
> > 
> > > +
> > > +VirtIODevice *vhost_scsi_init(DeviceState *dev, VirtIOSCSIConf *proxyconf);
> > > +void vhost_scsi_exit(VirtIODevice *vdev);
> > > +
> > > +
> > > +#endif
> > > diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
> > > index f3ece78..0d67b84 100644
> > > --- a/hw/virtio-pci.c
> > > +++ b/hw/virtio-pci.c
> > > @@ -22,6 +22,7 @@
> > >  #include "hw/virtio-net.h"
> > >  #include "hw/virtio-serial.h"
> > >  #include "hw/virtio-scsi.h"
> > > +#include "hw/vhost-scsi.h"
> > >  #include "hw/pci/pci.h"
> > >  #include "qemu/error-report.h"
> > >  #include "hw/pci/msi.h"
> > > @@ -1247,6 +1248,64 @@ static const TypeInfo virtio_scsi_info = {
> > >      .class_init    = virtio_scsi_class_init,
> > >  };
> > >  
> > > +#ifdef CONFIG_VHOST_SCSI
> > > +static int vhost_scsi_init_pci(PCIDevice *pci_dev)
> > > +{
> > > +    VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
> > > +    VirtIODevice *vdev;
> > > +
> > > +    vdev = vhost_scsi_init(&pci_dev->qdev, &proxy->scsi);
> > > +    if (!vdev) {
> > > +        return -EINVAL;
> > > +    }
> > > +
> > > +    vdev->nvectors = proxy->nvectors == DEV_NVECTORS_UNSPECIFIED
> > > +                                        ? proxy->scsi.num_queues + 3
> > > +                                        : proxy->nvectors;
> > > +    virtio_init_pci(proxy, vdev);
> > > +
> > > +    /* make the actual value visible */
> > > +    proxy->nvectors = vdev->nvectors;
> > > +    return 0;
> > > +}
> > > +
> > > +static void vhost_scsi_exit_pci(PCIDevice *pci_dev)
> > > +{
> > > +    VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
> > > +
> > > +    vhost_scsi_exit(proxy->vdev);
> > > +    virtio_exit_pci(pci_dev);
> > > +}
> > > +
> > > +static Property vhost_scsi_properties[] = {
> > > +    DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, DEV_NVECTORS_UNSPECIFIED),
> > > +    DEFINE_VHOST_SCSI_PROPERTIES(VirtIOPCIProxy, host_features, scsi),
> > > +    DEFINE_PROP_END_OF_LIST(),
> > > +};
> > > +
> > > +static void vhost_scsi_class_init(ObjectClass *klass, void *data)
> > > +{
> > > +    DeviceClass *dc = DEVICE_CLASS(klass);
> > > +    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
> > > +
> > > +    k->init = vhost_scsi_init_pci;
> > > +    k->exit = vhost_scsi_exit_pci;
> > > +    k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
> > > +    k->device_id = PCI_DEVICE_ID_VIRTIO_SCSI;
> > > +    k->revision = 0x00;
> > > +    k->class_id = PCI_CLASS_STORAGE_SCSI;
> > > +    dc->reset = virtio_pci_reset;
> > > +    dc->props = vhost_scsi_properties;
> > > +}
> > > +
> > > +static const TypeInfo vhost_scsi_info = {
> > > +    .name          = "vhost-scsi-pci",
> > > +    .parent        = TYPE_PCI_DEVICE,
> > > +    .instance_size = sizeof(VirtIOPCIProxy),
> > > +    .class_init    = vhost_scsi_class_init,
> > > +};
> > > +#endif
> > > +
> > >  #ifdef CONFIG_VIRTFS
> > >  static int virtio_9p_init_pci(PCIDevice *pci_dev)
> > >  {
> > > @@ -1495,6 +1554,9 @@ static void virtio_pci_register_types(void)
> > >      type_register_static(&virtio_serial_info);
> > >      type_register_static(&virtio_balloon_info);
> > >      type_register_static(&virtio_scsi_info);
> > > +#ifdef CONFIG_VHOST_SCSI
> > > +    type_register_static(&vhost_scsi_info);
> > > +#endif
> > >      type_register_static(&virtio_rng_info);
> > >      type_register_static(&virtio_pci_bus_info);
> > >      type_register_static(&virtio_pci_info);
> > > diff --git a/hw/virtio-scsi.h b/hw/virtio-scsi.h
> > > index 2bcf606..356bf38 100644
> > > --- a/hw/virtio-scsi.h
> > > +++ b/hw/virtio-scsi.h
> > > @@ -142,6 +142,8 @@ struct VirtIOSCSIConf {
> > >      uint32_t num_queues;
> > >      uint32_t max_sectors;
> > >      uint32_t cmd_per_lun;
> > > +    char *vhostfd;
> > > +    char *wwpn;
> > >  };
> > >  
> > >  typedef struct VirtIOSCSICommon {
> > > -- 
> > > 1.7.2.5
> > --
> > To unsubscribe from this list: send the line "unsubscribe target-devel" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
Michael S. Tsirkin - March 27, 2013, 10:53 p.m.
On Thu, Mar 28, 2013 at 12:50:21AM +0200, Michael S. Tsirkin wrote:
> On Wed, Mar 27, 2013 at 03:45:42PM -0700, Nicholas A. Bellinger wrote:
> > On Thu, 2013-03-28 at 00:28 +0200, Michael S. Tsirkin wrote:
> > > On Wed, Mar 27, 2013 at 09:59:45PM +0000, Nicholas A. Bellinger wrote:
> > > > From: Paolo Bonzini <pbonzini@redhat.com>
> > > > 
> > > > The WWPN specified in configfs is passed to "-device vhost-scsi-pci".
> > > > The tgpt field of the SET_ENDPOINT ioctl is obsolete now, so it is not
> > > > available from the QEMU command-line.  Instead, I hardcode it to zero.
> > > > 
> > > > Changes in V4:
> > > >    - Set event_idx=off by default (nab, thanks asias)
> > > 
> > > Why? What's going on here?
> > > 
> > 
> > Not disabling event_idx by default, or disabling from the command line
> > ends up resulting in ->handle_kick() not getting called for subsequent
> > commands..
> > 
> > I spent some time trying to track this down recently with no luck, and
> > AFAICT it's always been required in order for vhost-scsi to function.
> 
> Hmm this is a bug in kernel then. A better work-around is
> to disable EVENT_IDX in kernel. Let's do it for 3.9?

But before we do, can you check that SET_FEATURES is
called with this bit set if you enable event_idx?
If not that's your bug then ...
Nicholas A. Bellinger - March 27, 2013, 11:24 p.m.
On Thu, 2013-03-28 at 00:53 +0200, Michael S. Tsirkin wrote:
> On Thu, Mar 28, 2013 at 12:50:21AM +0200, Michael S. Tsirkin wrote:
> > On Wed, Mar 27, 2013 at 03:45:42PM -0700, Nicholas A. Bellinger wrote:
> > > On Thu, 2013-03-28 at 00:28 +0200, Michael S. Tsirkin wrote:
> > > > On Wed, Mar 27, 2013 at 09:59:45PM +0000, Nicholas A. Bellinger wrote:
> > > > > From: Paolo Bonzini <pbonzini@redhat.com>
> > > > > 
> > > > > The WWPN specified in configfs is passed to "-device vhost-scsi-pci".
> > > > > The tgpt field of the SET_ENDPOINT ioctl is obsolete now, so it is not
> > > > > available from the QEMU command-line.  Instead, I hardcode it to zero.
> > > > > 
> > > > > Changes in V4:
> > > > >    - Set event_idx=off by default (nab, thanks asias)
> > > > 
> > > > Why? What's going on here?
> > > > 
> > > 
> > > Not disabling event_idx by default, or disabling from the command line
> > > ends up resulting in ->handle_kick() not getting called for subsequent
> > > commands..
> > > 
> > > I spent some time trying to track this down recently with no luck, and
> > > AFAICT it's always been required in order for vhost-scsi to function.
> > 
> > Hmm this is a bug in kernel then. A better work-around is
> > to disable EVENT_IDX in kernel. Let's do it for 3.9?
> 
> But before we do, can you check that SET_FEATURES is
> called with this bit set if you enable event_idx?
> If not that's your bug then ...
> 

Ok, SET_FEATURES is currently not setting any bits at all based upon
vhost_dev->features, so it looks like a vhost-scsi-pci bug..
Michael S. Tsirkin - March 28, 2013, 6:19 a.m.
On Wed, Mar 27, 2013 at 04:24:22PM -0700, Nicholas A. Bellinger wrote:
> On Thu, 2013-03-28 at 00:53 +0200, Michael S. Tsirkin wrote:
> > On Thu, Mar 28, 2013 at 12:50:21AM +0200, Michael S. Tsirkin wrote:
> > > On Wed, Mar 27, 2013 at 03:45:42PM -0700, Nicholas A. Bellinger wrote:
> > > > On Thu, 2013-03-28 at 00:28 +0200, Michael S. Tsirkin wrote:
> > > > > On Wed, Mar 27, 2013 at 09:59:45PM +0000, Nicholas A. Bellinger wrote:
> > > > > > From: Paolo Bonzini <pbonzini@redhat.com>
> > > > > > 
> > > > > > The WWPN specified in configfs is passed to "-device vhost-scsi-pci".
> > > > > > The tgpt field of the SET_ENDPOINT ioctl is obsolete now, so it is not
> > > > > > available from the QEMU command-line.  Instead, I hardcode it to zero.
> > > > > > 
> > > > > > Changes in V4:
> > > > > >    - Set event_idx=off by default (nab, thanks asias)
> > > > > 
> > > > > Why? What's going on here?
> > > > > 
> > > > 
> > > > Not disabling event_idx by default, or disabling from the command line
> > > > ends up resulting in ->handle_kick() not getting called for subsequent
> > > > commands..
> > > > 
> > > > I spent some time trying to track this down recently with no luck, and
> > > > AFAICT it's always been required in order for vhost-scsi to function.
> > > 
> > > Hmm this is a bug in kernel then. A better work-around is
> > > to disable EVENT_IDX in kernel. Let's do it for 3.9?
> > 
> > But before we do, can you check that SET_FEATURES is
> > called with this bit set if you enable event_idx?
> > If not that's your bug then ...
> > 
> 
> Ok, SET_FEATURES is currently not setting any bits at all based upon
> vhost_dev->features, so it looks like a vhost-scsi-pci bug..
> 
> 

If you call SET_FEATURES, does it start working even without
disabling EVENT_IDX in kernel?
Nicholas A. Bellinger - March 28, 2013, 6:28 a.m.
On Thu, 2013-03-28 at 08:19 +0200, Michael S. Tsirkin wrote:
> On Wed, Mar 27, 2013 at 04:24:22PM -0700, Nicholas A. Bellinger wrote:
> > On Thu, 2013-03-28 at 00:53 +0200, Michael S. Tsirkin wrote:
> > > On Thu, Mar 28, 2013 at 12:50:21AM +0200, Michael S. Tsirkin wrote:
> > > > On Wed, Mar 27, 2013 at 03:45:42PM -0700, Nicholas A. Bellinger wrote:
> > > > > On Thu, 2013-03-28 at 00:28 +0200, Michael S. Tsirkin wrote:
> > > > > > On Wed, Mar 27, 2013 at 09:59:45PM +0000, Nicholas A. Bellinger wrote:
> > > > > > > From: Paolo Bonzini <pbonzini@redhat.com>
> > > > > > > 
> > > > > > > The WWPN specified in configfs is passed to "-device vhost-scsi-pci".
> > > > > > > The tgpt field of the SET_ENDPOINT ioctl is obsolete now, so it is not
> > > > > > > available from the QEMU command-line.  Instead, I hardcode it to zero.
> > > > > > > 
> > > > > > > Changes in V4:
> > > > > > >    - Set event_idx=off by default (nab, thanks asias)
> > > > > > 
> > > > > > Why? What's going on here?
> > > > > > 
> > > > > 
> > > > > Not disabling event_idx by default, or disabling from the command line
> > > > > ends up resulting in ->handle_kick() not getting called for subsequent
> > > > > commands..
> > > > > 
> > > > > I spent some time trying to track this down recently with no luck, and
> > > > > AFAICT it's always been required in order for vhost-scsi to function.
> > > > 
> > > > Hmm this is a bug in kernel then. A better work-around is
> > > > to disable EVENT_IDX in kernel. Let's do it for 3.9?
> > > 
> > > But before we do, can you check that SET_FEATURES is
> > > called with this bit set if you enable event_idx?
> > > If not that's your bug then ...
> > > 
> > 
> > Ok, SET_FEATURES is currently not setting any bits at all based upon
> > vhost_dev->features, so it looks like a vhost-scsi-pci bug..
> > 
> > 
> 
> If you call SET_FEATURES, does it start working even without
> disabling EVENT_IDX in kernel?
> 

Unfortunately, no.  The same strangeness persists unless event_idx=off
is passed, or EVENT_IDX is disabled in the kernel and stripped off with
the vhost_scsi_get_features() patch.
Michael S. Tsirkin - March 28, 2013, 4:54 p.m.
On Wed, Mar 27, 2013 at 11:28:56PM -0700, Nicholas A. Bellinger wrote:
> On Thu, 2013-03-28 at 08:19 +0200, Michael S. Tsirkin wrote:
> > On Wed, Mar 27, 2013 at 04:24:22PM -0700, Nicholas A. Bellinger wrote:
> > > On Thu, 2013-03-28 at 00:53 +0200, Michael S. Tsirkin wrote:
> > > > On Thu, Mar 28, 2013 at 12:50:21AM +0200, Michael S. Tsirkin wrote:
> > > > > On Wed, Mar 27, 2013 at 03:45:42PM -0700, Nicholas A. Bellinger wrote:
> > > > > > On Thu, 2013-03-28 at 00:28 +0200, Michael S. Tsirkin wrote:
> > > > > > > On Wed, Mar 27, 2013 at 09:59:45PM +0000, Nicholas A. Bellinger wrote:
> > > > > > > > From: Paolo Bonzini <pbonzini@redhat.com>
> > > > > > > > 
> > > > > > > > The WWPN specified in configfs is passed to "-device vhost-scsi-pci".
> > > > > > > > The tgpt field of the SET_ENDPOINT ioctl is obsolete now, so it is not
> > > > > > > > available from the QEMU command-line.  Instead, I hardcode it to zero.
> > > > > > > > 
> > > > > > > > Changes in V4:
> > > > > > > >    - Set event_idx=off by default (nab, thanks asias)
> > > > > > > 
> > > > > > > Why? What's going on here?
> > > > > > > 
> > > > > > 
> > > > > > Not disabling event_idx by default, or disabling from the command line
> > > > > > ends up resulting in ->handle_kick() not getting called for subsequent
> > > > > > commands..
> > > > > > 
> > > > > > I spent some time trying to track this down recently with no luck, and
> > > > > > AFAICT it's always been required in order for vhost-scsi to function.
> > > > > 
> > > > > Hmm this is a bug in kernel then. A better work-around is
> > > > > to disable EVENT_IDX in kernel. Let's do it for 3.9?
> > > > 
> > > > But before we do, can you check that SET_FEATURES is
> > > > called with this bit set if you enable event_idx?
> > > > If not that's your bug then ...
> > > > 
> > > 
> > > Ok, SET_FEATURES is currently not setting any bits at all based upon
> > > vhost_dev->features, so it looks like a vhost-scsi-pci bug..
> > > 
> > > 
> > 
> > If you call SET_FEATURES, does it start working even without
> > disabling EVENT_IDX in kernel?
> > 
> 
> Unfortunately, no.  The same strangeness persists unless event_idx=off
> is passed, or EVENT_IDX is disabled in the kernel and stripped off with
> the vhost_scsi_get_features() patch.
> 


I think it's important to fix it (usually exposes other bugs)
but I agree, lets get it working without first.

Patch

diff --git a/configure b/configure
index f2af714..6b67e35 100755
--- a/configure
+++ b/configure
@@ -169,6 +169,7 @@  libattr=""
 xfs=""
 
 vhost_net="no"
+vhost_scsi="no"
 kvm="no"
 gprof="no"
 debug_tcg="no"
@@ -532,6 +533,7 @@  Haiku)
   usb="linux"
   kvm="yes"
   vhost_net="yes"
+  vhost_scsi="yes"
   if [ "$cpu" = "i386" -o "$cpu" = "x86_64" ] ; then
     audio_possible_drivers="$audio_possible_drivers fmod"
   fi
@@ -858,6 +860,10 @@  for opt do
   ;;
   --enable-vhost-net) vhost_net="yes"
   ;;
+  --disable-vhost-scsi) vhost_scsi="no"
+  ;;
+  --enable-vhost-scsi) vhost_scsi="yes"
+  ;;
   --disable-glx) glx="no"
   ;;
   --enable-glx) glx="yes"
@@ -3078,7 +3084,7 @@  fi
 # __sync_fetch_and_and requires at least -march=i486. Many toolchains
 # use i686 as default anyway, but for those that don't, an explicit
 # specification is necessary
-if test "$vhost_net" = "yes" && test "$cpu" = "i386"; then
+if (test "$vhost_net" = "yes" -o "$vhost_scsi" = "yes") && test "$cpu" = "i386"; then
   cat > $TMPC << EOF
 static int sfaa(int *ptr)
 {
@@ -3424,6 +3430,7 @@  echo "sigev_thread_id   $sigev_thread_id"
 echo "uuid support      $uuid"
 echo "libcap-ng support $cap_ng"
 echo "vhost-net support $vhost_net"
+echo "vhost-scsi support $vhost_scsi"
 echo "Trace backend     $trace_backend"
 echo "Trace output file $trace_file-<pid>"
 echo "spice support     $spice ($spice_protocol_version/$spice_server_version)"
@@ -3697,6 +3704,9 @@  fi
 if test "$virtfs" = "yes" ; then
   echo "CONFIG_VIRTFS=y" >> $config_host_mak
 fi
+if test "$vhost_scsi" = "yes" ; then
+  echo "CONFIG_VHOST_SCSI=y" >> $config_host_mak
+fi
 if test "$blobs" = "yes" ; then
   echo "INSTALL_BLOBS=yes" >> $config_host_mak
 fi
@@ -4175,6 +4185,9 @@  case "$target_arch2" in
       if test "$vhost_net" = "yes" ; then
         echo "CONFIG_VHOST_NET=y" >> $config_target_mak
       fi
+      if test "$vhost_scsi" = "yes" ; then
+        echo "CONFIG_VHOST_SCSI=y" >> $config_target_mak
+      fi
     fi
 esac
 case "$target_arch2" in
diff --git a/hw/Makefile.objs b/hw/Makefile.objs
index d0b2ecb..0a38eb5 100644
--- a/hw/Makefile.objs
+++ b/hw/Makefile.objs
@@ -205,8 +205,11 @@  common-obj-$(CONFIG_XEN_BACKEND) += xen_console.o xenfb.o xen_disk.o xen_nic.o
 obj-$(CONFIG_VIRTIO) += dataplane/
 obj-$(CONFIG_VIRTIO) += virtio.o virtio-blk.o virtio-balloon.o virtio-net.o
 obj-$(CONFIG_VIRTIO) += virtio-serial-bus.o virtio-scsi.o
+ifeq ($(CONFIG_VIRTIO), y)
+obj-$(CONFIG_LINUX) += vhost-scsi.o
+endif
 obj-$(CONFIG_SOFTMMU) += vhost_net.o
-obj-$(CONFIG_VHOST_NET) += vhost.o
+obj-$(CONFIG_LINUX) += vhost.o
 obj-$(CONFIG_REALLY_VIRTFS) += 9pfs/
 obj-$(CONFIG_VGA) += vga.o
 
diff --git a/hw/s390x/s390-virtio-bus.c b/hw/s390x/s390-virtio-bus.c
index c5d5456..73d93fd 100644
--- a/hw/s390x/s390-virtio-bus.c
+++ b/hw/s390x/s390-virtio-bus.c
@@ -28,6 +28,8 @@ 
 #include "hw/virtio-rng.h"
 #include "hw/virtio-serial.h"
 #include "hw/virtio-net.h"
+#include "hw/virtio-scsi.h"
+#include "hw/vhost-scsi.h"
 #include "hw/sysbus.h"
 #include "sysemu/kvm.h"
 
@@ -214,6 +216,18 @@  static int s390_virtio_scsi_init(VirtIOS390Device *dev)
     return s390_virtio_device_init(dev, vdev);
 }
 
+static int s390_vhost_scsi_init(VirtIOS390Device *dev)
+{
+    VirtIODevice *vdev;
+
+    vdev = vhost_scsi_init((DeviceState *)dev, &dev->scsi);
+    if (!vdev) {
+        return -1;
+    }
+
+    return s390_virtio_device_init(dev, vdev);
+}
+
 static int s390_virtio_rng_init(VirtIOS390Device *dev)
 {
     VirtIODevice *vdev;
@@ -537,6 +551,27 @@  static const TypeInfo virtio_s390_device_info = {
     .abstract = true,
 };
 
+static Property s390_vhost_scsi_properties[] = {
+    DEFINE_VIRTIO_SCSI_PROPERTIES(VirtIOS390Device, host_features, scsi),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void s390_vhost_scsi_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtIOS390DeviceClass *k = VIRTIO_S390_DEVICE_CLASS(klass);
+
+    k->init = s390_vhost_scsi_init;
+    dc->props = s390_vhost_scsi_properties;
+}
+
+static const TypeInfo s390_vhost_scsi = {
+    .name          = "vhost-scsi-s390",
+    .parent        = TYPE_VIRTIO_S390_DEVICE,
+    .instance_size = sizeof(VirtIOS390Device),
+    .class_init    = s390_vhost_scsi_class_init,
+};
+
 static Property s390_virtio_scsi_properties[] = {
     DEFINE_VIRTIO_SCSI_PROPERTIES(VirtIOS390Device, host_features, scsi),
     DEFINE_PROP_END_OF_LIST(),
diff --git a/hw/vhost-scsi.c b/hw/vhost-scsi.c
new file mode 100644
index 0000000..70e42fc
--- /dev/null
+++ b/hw/vhost-scsi.c
@@ -0,0 +1,241 @@ 
+/*
+ * vhost_scsi host device
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>
+ *
+ * Changes for QEMU mainline + tcm_vhost kernel upstream:
+ *  Nicholas Bellinger <nab@risingtidesystems.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#include <sys/ioctl.h>
+#include "config.h"
+#include "qemu/queue.h"
+#include "monitor/monitor.h"
+#include "migration/migration.h"
+#include "vhost-scsi.h"
+#include "vhost.h"
+#include "virtio-scsi.h"
+
+typedef struct VHostSCSI {
+    VirtIOSCSICommon vs;
+
+    Error *migration_blocker;
+
+    struct vhost_dev dev;
+} VHostSCSI;
+
+static int vhost_scsi_set_endpoint(VirtIODevice *vdev)
+{
+    VHostSCSI *vs = (VHostSCSI *)vdev;
+    struct vhost_scsi_target backend;
+    int ret;
+
+    memset(&backend, 0, sizeof(backend));
+    pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->vs.conf->wwpn);
+    ret = ioctl(vs->dev.control, VHOST_SCSI_SET_ENDPOINT, &backend);
+    if (ret < 0) {
+        return -errno;
+    }
+    return 0;
+}
+
+static void vhost_scsi_clear_endpoint(VirtIODevice *vdev)
+{
+    VHostSCSI *vs = (VHostSCSI *)vdev;
+    struct vhost_scsi_target backend;
+
+    memset(&backend, 0, sizeof(backend));
+    pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->vs.conf->wwpn);
+    ioctl(vs->dev.control, VHOST_SCSI_CLEAR_ENDPOINT, &backend);
+}
+
+static int vhost_scsi_start(VHostSCSI *vs, VirtIODevice *vdev)
+{
+    int ret, abi_version;
+
+    if (!vdev->binding->set_guest_notifiers) {
+        error_report("binding does not support guest notifiers");
+        return -ENOSYS;
+    }
+
+    ret = ioctl(vs->dev.control, VHOST_SCSI_GET_ABI_VERSION, &abi_version);
+    if (ret < 0) {
+        return -errno;
+    }
+    if (abi_version > VHOST_SCSI_ABI_VERSION) {
+        error_report("vhost-scsi: The running tcm_vhost kernel abi_version:"
+                     " %d is greater than vhost_scsi userspace supports: %d, please"
+                     " upgrade your version of QEMU\n", abi_version,
+                     VHOST_SCSI_ABI_VERSION);
+        return -ENOSYS;
+    }
+
+    ret = vhost_dev_enable_notifiers(&vs->dev, vdev);
+    if (ret < 0) {
+        return ret;
+    }
+
+    ret = vhost_dev_start(&vs->dev, vdev);
+    if (ret < 0) {
+        error_report("Error start vhost dev");
+        goto err_notifiers;
+    }
+
+    ret = vhost_scsi_set_endpoint(vdev);
+    if (ret < 0) {
+        error_report("Error set vhost-scsi endpoint");
+        goto err_vhost_stop;
+    }
+
+    ret = vdev->binding->set_guest_notifiers(vdev->binding_opaque, vs->dev.nvqs, true);
+    if (ret < 0) {
+        error_report("Error binding guest notifier");
+        goto err_endpoint;
+    }
+    return ret;
+
+err_endpoint:
+    vhost_scsi_clear_endpoint(vdev);
+err_vhost_stop:
+    vhost_dev_stop(&vs->dev, vdev);
+err_notifiers:
+    vhost_dev_disable_notifiers(&vs->dev, vdev);
+    return ret;
+}
+
+static void vhost_scsi_stop(VHostSCSI *vs, VirtIODevice *vdev)
+{
+    int ret = 0;
+
+    if (!vdev->binding->set_guest_notifiers) {
+        ret = vdev->binding->set_guest_notifiers(vdev->binding_opaque,
+                                                 vs->dev.nvqs, false);
+        if (ret < 0) {
+                error_report("vhost guest notifier cleanup failed: %d\n", ret);
+        }
+    }
+    assert(ret >= 0);
+
+    vhost_scsi_clear_endpoint(vdev);
+    vhost_dev_stop(&vs->dev, vdev);
+    vhost_dev_disable_notifiers(&vs->dev, vdev);
+}
+
+static void vhost_scsi_set_config(VirtIODevice *vdev,
+                                  const uint8_t *config)
+{
+    VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
+    VHostSCSI *vs = (VHostSCSI *)vdev;
+
+    if ((uint32_t) ldl_raw(&scsiconf->sense_size) != vs->vs.sense_size ||
+        (uint32_t) ldl_raw(&scsiconf->cdb_size) != vs->vs.cdb_size) {
+        error_report("vhost-scsi does not support changing the sense data and CDB sizes");
+        exit(1);
+    }
+}
+
+static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
+{
+    VHostSCSI *vs = (VHostSCSI *)vdev;
+    bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK);
+
+    if (vs->dev.started == start) {
+        return;
+    }
+
+    if (start) {
+        int ret;
+
+        ret = vhost_scsi_start(vs, vdev);
+        if (ret < 0) {
+            error_report("virtio-scsi: unable to start vhost: %s\n",
+                         strerror(-ret));
+
+            /* There is no userspace virtio-scsi fallback so exit */
+            exit(1);
+        }
+    } else {
+        vhost_scsi_stop(vs, vdev);
+    }
+}
+
+static void vhost_scsi_guest_notifier_mask(VirtIODevice *vdev, int idx,
+                                           bool mask)
+{
+    VHostSCSI *vs = (VHostSCSI *)vdev;
+
+    vhost_virtqueue_mask(&vs->dev, vdev, idx, mask);
+}
+
+static bool vhost_scsi_guest_notifier_pending(VirtIODevice *vdev, int idx)
+{
+    VHostSCSI *vs = (VHostSCSI *)vdev;
+
+    return vhost_virtqueue_pending(&vs->dev, idx);
+}
+
+VirtIODevice *vhost_scsi_init(DeviceState *dev, VirtIOSCSIConf *proxyconf)
+{
+    VHostSCSI *vs;
+    int vhostfd = -1;
+    int ret;
+
+    if (!proxyconf->wwpn) {
+        error_report("vhost-scsi: missing wwpn\n");
+        return NULL;
+    }
+
+    if (proxyconf->vhostfd) {
+        vhostfd = monitor_handle_fd_param(cur_mon, proxyconf->vhostfd);
+        if (vhostfd == -1) {
+            error_report("vhost-scsi: unable to parse vhostfd\n");
+            return NULL;
+        }
+    }
+
+    vs = (VHostSCSI *)virtio_scsi_init_common(dev, proxyconf,
+                                              sizeof(VHostSCSI));
+
+    vs->vs.vdev.set_config = vhost_scsi_set_config;
+    vs->vs.vdev.set_status = vhost_scsi_set_status;
+    vs->vs.vdev.guest_notifier_mask = vhost_scsi_guest_notifier_mask;
+    vs->vs.vdev.guest_notifier_pending = vhost_scsi_guest_notifier_pending;
+
+    vs->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->vs.conf->num_queues;
+    vs->dev.vqs = g_new(struct vhost_virtqueue, vs->dev.nvqs);
+    vs->dev.vq_index = 0;
+
+    ret = vhost_dev_init(&vs->dev, vhostfd, "/dev/vhost-scsi", true);
+    if (ret < 0) {
+        error_report("vhost-scsi: vhost initialization failed: %s\n",
+                strerror(-ret));
+        return NULL;
+    }
+    vs->dev.backend_features = 0;
+    vs->dev.acked_features = 0;
+
+    error_setg(&vs->migration_blocker,
+            "vhost-scsi does not support migration");
+    migrate_add_blocker(vs->migration_blocker);
+
+    return &vs->vs.vdev;
+}
+
+void vhost_scsi_exit(VirtIODevice *vdev)
+{
+    VHostSCSI *vs = (VHostSCSI *)vdev;
+    migrate_del_blocker(vs->migration_blocker);
+    error_free(vs->migration_blocker);
+
+    /* This will stop vhost backend. */
+    vhost_scsi_set_status(vdev, 0);
+    g_free(vs->dev.vqs);
+    virtio_cleanup(vdev);
+}
diff --git a/hw/vhost-scsi.h b/hw/vhost-scsi.h
new file mode 100644
index 0000000..b01f012
--- /dev/null
+++ b/hw/vhost-scsi.h
@@ -0,0 +1,66 @@ 
+/*
+ * vhost_scsi host device
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#ifndef VHOST_SCSI_H
+#define VHOST_SCSI_H
+
+#include "qemu-common.h"
+#include "qdev.h"
+#include "virtio-scsi.h"
+
+/*
+ * Used by QEMU userspace to ensure a consistent vhost-scsi ABI.
+ *
+ * ABI Rev 0: July 2012 version starting point for v3.6-rc merge candidate +
+ *            RFC-v2 vhost-scsi userspace.  Add GET_ABI_VERSION ioctl usage
+ * ABI Rev 1: January 2013. Ignore vhost_tpgt filed in struct vhost_scsi_target.
+ * 	      All the targets under vhost_wwpn can be seen and used by guest.
+ */
+
+#define VHOST_SCSI_ABI_VERSION 1
+
+/* TODO #include <linux/vhost.h> properly */
+/* For VHOST_SCSI_SET_ENDPOINT/VHOST_SCSI_CLEAR_ENDPOINT ioctl */
+struct vhost_scsi_target {
+    int abi_version;
+    char vhost_wwpn[224];
+    unsigned short vhost_tpgt;
+    unsigned short reserved;
+};
+
+enum vhost_scsi_vq_list {
+    VHOST_SCSI_VQ_CONTROL = 0,
+    VHOST_SCSI_VQ_EVENT = 1,
+    VHOST_SCSI_VQ_NUM_FIXED = 2,
+};
+
+#define VHOST_VIRTIO 0xAF
+#define VHOST_SCSI_SET_ENDPOINT _IOW(VHOST_VIRTIO, 0x40, struct vhost_scsi_target)
+#define VHOST_SCSI_CLEAR_ENDPOINT _IOW(VHOST_VIRTIO, 0x41, struct vhost_scsi_target)
+#define VHOST_SCSI_GET_ABI_VERSION _IOW(VHOST_VIRTIO, 0x42, int)
+
+#define DEFINE_VHOST_SCSI_PROPERTIES(_state, _features_field, _conf_field) \
+    DEFINE_PROP_BIT("indirect_desc", _state, _features_field, VIRTIO_RING_F_INDIRECT_DESC, true), \
+    DEFINE_PROP_BIT("event_idx", _state, _features_field, VIRTIO_RING_F_EVENT_IDX, false), \
+    DEFINE_PROP_STRING("vhostfd", _state, _conf_field.vhostfd), \
+    DEFINE_PROP_STRING("wwpn", _state, _conf_field.wwpn), \
+    DEFINE_PROP_UINT32("num_queues", _state, _conf_field.num_queues, 1), \
+    DEFINE_PROP_UINT32("max_sectors", _state, _conf_field.max_sectors, 0xFFFF), \
+    DEFINE_PROP_UINT32("cmd_per_lun", _state, _conf_field.cmd_per_lun, 128), \
+    DEFINE_PROP_BIT("hotplug", _state, _features_field, VIRTIO_SCSI_F_HOTPLUG, true)
+
+VirtIODevice *vhost_scsi_init(DeviceState *dev, VirtIOSCSIConf *proxyconf);
+void vhost_scsi_exit(VirtIODevice *vdev);
+
+
+#endif
diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
index f3ece78..0d67b84 100644
--- a/hw/virtio-pci.c
+++ b/hw/virtio-pci.c
@@ -22,6 +22,7 @@ 
 #include "hw/virtio-net.h"
 #include "hw/virtio-serial.h"
 #include "hw/virtio-scsi.h"
+#include "hw/vhost-scsi.h"
 #include "hw/pci/pci.h"
 #include "qemu/error-report.h"
 #include "hw/pci/msi.h"
@@ -1247,6 +1248,64 @@  static const TypeInfo virtio_scsi_info = {
     .class_init    = virtio_scsi_class_init,
 };
 
+#ifdef CONFIG_VHOST_SCSI
+static int vhost_scsi_init_pci(PCIDevice *pci_dev)
+{
+    VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
+    VirtIODevice *vdev;
+
+    vdev = vhost_scsi_init(&pci_dev->qdev, &proxy->scsi);
+    if (!vdev) {
+        return -EINVAL;
+    }
+
+    vdev->nvectors = proxy->nvectors == DEV_NVECTORS_UNSPECIFIED
+                                        ? proxy->scsi.num_queues + 3
+                                        : proxy->nvectors;
+    virtio_init_pci(proxy, vdev);
+
+    /* make the actual value visible */
+    proxy->nvectors = vdev->nvectors;
+    return 0;
+}
+
+static void vhost_scsi_exit_pci(PCIDevice *pci_dev)
+{
+    VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
+
+    vhost_scsi_exit(proxy->vdev);
+    virtio_exit_pci(pci_dev);
+}
+
+static Property vhost_scsi_properties[] = {
+    DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, DEV_NVECTORS_UNSPECIFIED),
+    DEFINE_VHOST_SCSI_PROPERTIES(VirtIOPCIProxy, host_features, scsi),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void vhost_scsi_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
+
+    k->init = vhost_scsi_init_pci;
+    k->exit = vhost_scsi_exit_pci;
+    k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
+    k->device_id = PCI_DEVICE_ID_VIRTIO_SCSI;
+    k->revision = 0x00;
+    k->class_id = PCI_CLASS_STORAGE_SCSI;
+    dc->reset = virtio_pci_reset;
+    dc->props = vhost_scsi_properties;
+}
+
+static const TypeInfo vhost_scsi_info = {
+    .name          = "vhost-scsi-pci",
+    .parent        = TYPE_PCI_DEVICE,
+    .instance_size = sizeof(VirtIOPCIProxy),
+    .class_init    = vhost_scsi_class_init,
+};
+#endif
+
 #ifdef CONFIG_VIRTFS
 static int virtio_9p_init_pci(PCIDevice *pci_dev)
 {
@@ -1495,6 +1554,9 @@  static void virtio_pci_register_types(void)
     type_register_static(&virtio_serial_info);
     type_register_static(&virtio_balloon_info);
     type_register_static(&virtio_scsi_info);
+#ifdef CONFIG_VHOST_SCSI
+    type_register_static(&vhost_scsi_info);
+#endif
     type_register_static(&virtio_rng_info);
     type_register_static(&virtio_pci_bus_info);
     type_register_static(&virtio_pci_info);
diff --git a/hw/virtio-scsi.h b/hw/virtio-scsi.h
index 2bcf606..356bf38 100644
--- a/hw/virtio-scsi.h
+++ b/hw/virtio-scsi.h
@@ -142,6 +142,8 @@  struct VirtIOSCSIConf {
     uint32_t num_queues;
     uint32_t max_sectors;
     uint32_t cmd_per_lun;
+    char *vhostfd;
+    char *wwpn;
 };
 
 typedef struct VirtIOSCSICommon {