| Message ID | 1413305610-20494-1-git-send-email-mst@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Tue, 14 Oct 2014 19:55:23 +0300 "Michael S. Tsirkin" <mst@redhat.com> wrote: > Current support for bus master (clearing OK bit) together with the need to > support guests which do not enable PCI bus mastering, leads to extra state in > VIRTIO_PCI_FLAG_BUS_MASTER_BUG bit, which isn't robust in case of cross-version > migration for the case when guests use the device before setting DRIVER_OK. > > Rip out this code, and replace it: > - Modern QEMU doesn't need VIRTIO_PCI_FLAG_BUS_MASTER_BUG > so just drop it for latest machine type. > - For compat machine types, set PCI_COMMAND if DRIVER_OK > is set. > > As this is needed for 2.1 for both pc and ppc, move PC_COMPAT macros from pc.h > to a new common header. > > Cc: Greg Kurz <gkurz@linux.vnet.ibm.com> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- Just a question, see below. Apart from that, it looks good. Reviewed-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Tested-by: Greg Kurz <gkurz@linux.vnet.ibm.com> > hw/virtio/virtio-pci.h | 5 +++++ > include/hw/compat.h | 16 ++++++++++++++++ > include/hw/i386/pc.h | 10 ++-------- > hw/i386/pc_piix.c | 2 +- > hw/i386/pc_q35.c | 2 +- > hw/ppc/spapr.c | 9 ++++++++- > hw/virtio/virtio-pci.c | 29 +++++++++++------------------ > 7 files changed, 44 insertions(+), 29 deletions(-) > create mode 100644 include/hw/compat.h > > diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h > index 1cea157..8873b6d 100644 > --- a/hw/virtio/virtio-pci.h > +++ b/hw/virtio/virtio-pci.h > @@ -53,6 +53,11 @@ typedef struct VirtioBusClass VirtioPCIBusClass; > #define VIRTIO_PCI_BUS_CLASS(klass) \ > OBJECT_CLASS_CHECK(VirtioPCIBusClass, klass, TYPE_VIRTIO_PCI_BUS) > > +/* Need to activate work-arounds for buggy guests at vmstate load. */ > +#define VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION_BIT 0 > +#define VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION \ > + (1 << VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION_BIT) > + > /* Performance improves when virtqueue kick processing is decoupled from the > * vcpu thread using ioeventfd for some devices. */ > #define VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT 1 > diff --git a/include/hw/compat.h b/include/hw/compat.h > new file mode 100644 > index 0000000..47f6ff5 > --- /dev/null > +++ b/include/hw/compat.h > @@ -0,0 +1,16 @@ > +#ifndef HW_COMPAT_H > +#define HW_COMPAT_H > + > +#define HW_COMPAT_2_1 \ > + {\ > + .driver = "intel-hda",\ > + .property = "old_msi_addr",\ > + .value = "on",\ > + },\ > + {\ > + .driver = "virtio-pci",\ > + .property = "virtio-pci-bus-master-bug-migration",\ > + .value = "on",\ > + } > + > +#endif /* HW_COMPAT_H */ > diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h > index bae023a..82ad046 100644 > --- a/include/hw/i386/pc.h > +++ b/include/hw/i386/pc.h > @@ -14,6 +14,7 @@ > #include "sysemu/sysemu.h" > #include "hw/pci/pci.h" > #include "hw/boards.h" > +#include "hw/compat.h" > > #define HPET_INTCAP "hpet-intcap" > > @@ -307,15 +308,8 @@ int e820_add_entry(uint64_t, uint64_t, uint32_t); > int e820_get_num_entries(void); > bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *); > > -#define PC_COMPAT_2_1 \ > - {\ > - .driver = "intel-hda",\ > - .property = "old_msi_addr",\ > - .value = "on",\ > - } > - > #define PC_COMPAT_2_0 \ > - PC_COMPAT_2_1, \ > + HW_COMPAT_2_1, \ > {\ > .driver = "virtio-scsi-pci",\ > .property = "any_layout",\ > diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c > index 553afdd..a1634ab 100644 > --- a/hw/i386/pc_piix.c > +++ b/hw/i386/pc_piix.c > @@ -502,7 +502,7 @@ static QEMUMachine pc_i440fx_machine_v2_1 = { > .name = "pc-i440fx-2.1", > .init = pc_init_pci, > .compat_props = (GlobalProperty[]) { > - PC_COMPAT_2_1, > + HW_COMPAT_2_1, > { /* end of list */ } > }, > }; > diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c > index a199043..f330f7a 100644 > --- a/hw/i386/pc_q35.c > +++ b/hw/i386/pc_q35.c > @@ -365,7 +365,7 @@ static QEMUMachine pc_q35_machine_v2_1 = { > .name = "pc-q35-2.1", > .init = pc_q35_init, > .compat_props = (GlobalProperty[]) { > - PC_COMPAT_2_1, > + HW_COMPAT_2_1, > { /* end of list */ } > }, > }; > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index 2becc9f..8bc597f 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -57,6 +57,8 @@ > #include "trace.h" > #include "hw/nmi.h" > > +#include "hw/compat.h" > + > #include <libfdt.h> > > /* SLOF memory layout: > @@ -1689,10 +1691,15 @@ static const TypeInfo spapr_machine_info = { > static void spapr_machine_2_1_class_init(ObjectClass *oc, void *data) > { > MachineClass *mc = MACHINE_CLASS(oc); > + static GlobalProperty compat_props[] = { > + HW_COMPAT_2_1, > + { /* end of list */ } > + }; > > mc->name = "pseries-2.1"; > mc->desc = "pSeries Logical Partition (PAPR compliant) v2.1"; > - mc->is_default = 0; > + mc->is_default = -1; I could find no other place where we set is_default to -1. What's the point ? > + mc->compat_props = compat_props; > } > > static const TypeInfo spapr_machine_2_1_info = { > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > index a827cd4..a499a3c 100644 > --- a/hw/virtio/virtio-pci.c > +++ b/hw/virtio/virtio-pci.c > @@ -86,9 +86,6 @@ > * 12 is historical, and due to x86 page size. */ > #define VIRTIO_PCI_QUEUE_ADDR_SHIFT 12 > > -/* Flags track per-device state like workarounds for quirks in older guests. */ > -#define VIRTIO_PCI_FLAG_BUS_MASTER_BUG (1 << 0) > - > static void virtio_pci_bus_new(VirtioBusState *bus, size_t bus_size, > VirtIOPCIProxy *dev); > > @@ -323,14 +320,6 @@ static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val) > proxy->pci_dev.config[PCI_COMMAND] | > PCI_COMMAND_MASTER, 1); > } > - > - /* Linux before 2.6.34 sets the device as OK without enabling > - the PCI device bus master bit. In this case we need to disable > - some safety checks. */ > - if ((val & VIRTIO_CONFIG_S_DRIVER_OK) && > - !(proxy->pci_dev.config[PCI_COMMAND] & PCI_COMMAND_MASTER)) { > - proxy->flags |= VIRTIO_PCI_FLAG_BUS_MASTER_BUG; > - } > break; > case VIRTIO_MSI_CONFIG_VECTOR: > msix_vector_unuse(&proxy->pci_dev, vdev->config_vector); > @@ -483,8 +472,7 @@ static void virtio_write_config(PCIDevice *pci_dev, uint32_t address, > pci_default_write_config(pci_dev, address, val, len); > > if (range_covers_byte(address, len, PCI_COMMAND) && > - !(pci_dev->config[PCI_COMMAND] & PCI_COMMAND_MASTER) && > - !(proxy->flags & VIRTIO_PCI_FLAG_BUS_MASTER_BUG)) { > + !(pci_dev->config[PCI_COMMAND] & PCI_COMMAND_MASTER)) { > virtio_pci_stop_ioeventfd(proxy); > virtio_set_status(vdev, vdev->status & ~VIRTIO_CONFIG_S_DRIVER_OK); > } > @@ -895,11 +883,15 @@ static void virtio_pci_vmstate_change(DeviceState *d, bool running) > VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); > > if (running) { > - /* Try to find out if the guest has bus master disabled, but is > - in ready state. Then we have a buggy guest OS. */ > - if ((vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) && > + /* Old QEMU versions did not set bus master enable on status write. > + * Detect DRIVER set and enable it. > + */ > + if ((proxy->flags & VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION) && > + (vdev->status & VIRTIO_CONFIG_S_DRIVER) && > !(proxy->pci_dev.config[PCI_COMMAND] & PCI_COMMAND_MASTER)) { > - proxy->flags |= VIRTIO_PCI_FLAG_BUS_MASTER_BUG; > + pci_default_write_config(&proxy->pci_dev, PCI_COMMAND, > + proxy->pci_dev.config[PCI_COMMAND] | > + PCI_COMMAND_MASTER, 1); > } > virtio_pci_start_ioeventfd(proxy); > } else { > @@ -1040,10 +1032,11 @@ static void virtio_pci_reset(DeviceState *qdev) > virtio_pci_stop_ioeventfd(proxy); > virtio_bus_reset(bus); > msix_unuse_all_vectors(&proxy->pci_dev); > - proxy->flags &= ~VIRTIO_PCI_FLAG_BUS_MASTER_BUG; > } > > static Property virtio_pci_properties[] = { > + DEFINE_PROP_BIT("virtio-pci-bus-master-bug-migration", VirtIOPCIProxy, flags, > + VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION_BIT, false), > DEFINE_VIRTIO_COMMON_FEATURES(VirtIOPCIProxy, host_features), > DEFINE_PROP_END_OF_LIST(), > };
On Wed, Oct 15, 2014 at 05:34:25PM +0200, Greg Kurz wrote: > On Tue, 14 Oct 2014 19:55:23 +0300 > "Michael S. Tsirkin" <mst@redhat.com> wrote: > > Current support for bus master (clearing OK bit) together with the need to > > support guests which do not enable PCI bus mastering, leads to extra state in > > VIRTIO_PCI_FLAG_BUS_MASTER_BUG bit, which isn't robust in case of cross-version > > migration for the case when guests use the device before setting DRIVER_OK. > > > > Rip out this code, and replace it: > > - Modern QEMU doesn't need VIRTIO_PCI_FLAG_BUS_MASTER_BUG > > so just drop it for latest machine type. > > - For compat machine types, set PCI_COMMAND if DRIVER_OK > > is set. > > > > As this is needed for 2.1 for both pc and ppc, move PC_COMPAT macros from pc.h > > to a new common header. > > > > Cc: Greg Kurz <gkurz@linux.vnet.ibm.com> > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > > --- > > Just a question, see below. > > Apart from that, it looks good. > > Reviewed-by: Greg Kurz <gkurz@linux.vnet.ibm.com> > Tested-by: Greg Kurz <gkurz@linux.vnet.ibm.com> > > > hw/virtio/virtio-pci.h | 5 +++++ > > include/hw/compat.h | 16 ++++++++++++++++ > > include/hw/i386/pc.h | 10 ++-------- > > hw/i386/pc_piix.c | 2 +- > > hw/i386/pc_q35.c | 2 +- > > hw/ppc/spapr.c | 9 ++++++++- > > hw/virtio/virtio-pci.c | 29 +++++++++++------------------ > > 7 files changed, 44 insertions(+), 29 deletions(-) > > create mode 100644 include/hw/compat.h > > > > diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h > > index 1cea157..8873b6d 100644 > > --- a/hw/virtio/virtio-pci.h > > +++ b/hw/virtio/virtio-pci.h > > @@ -53,6 +53,11 @@ typedef struct VirtioBusClass VirtioPCIBusClass; > > #define VIRTIO_PCI_BUS_CLASS(klass) \ > > OBJECT_CLASS_CHECK(VirtioPCIBusClass, klass, TYPE_VIRTIO_PCI_BUS) > > > > +/* Need to activate work-arounds for buggy guests at vmstate load. */ > > +#define VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION_BIT 0 > > +#define VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION \ > > + (1 << VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION_BIT) > > + > > /* Performance improves when virtqueue kick processing is decoupled from the > > * vcpu thread using ioeventfd for some devices. */ > > #define VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT 1 > > diff --git a/include/hw/compat.h b/include/hw/compat.h > > new file mode 100644 > > index 0000000..47f6ff5 > > --- /dev/null > > +++ b/include/hw/compat.h > > @@ -0,0 +1,16 @@ > > +#ifndef HW_COMPAT_H > > +#define HW_COMPAT_H > > + > > +#define HW_COMPAT_2_1 \ > > + {\ > > + .driver = "intel-hda",\ > > + .property = "old_msi_addr",\ > > + .value = "on",\ > > + },\ > > + {\ > > + .driver = "virtio-pci",\ > > + .property = "virtio-pci-bus-master-bug-migration",\ > > + .value = "on",\ > > + } > > + > > +#endif /* HW_COMPAT_H */ > > diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h > > index bae023a..82ad046 100644 > > --- a/include/hw/i386/pc.h > > +++ b/include/hw/i386/pc.h > > @@ -14,6 +14,7 @@ > > #include "sysemu/sysemu.h" > > #include "hw/pci/pci.h" > > #include "hw/boards.h" > > +#include "hw/compat.h" > > > > #define HPET_INTCAP "hpet-intcap" > > > > @@ -307,15 +308,8 @@ int e820_add_entry(uint64_t, uint64_t, uint32_t); > > int e820_get_num_entries(void); > > bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *); > > > > -#define PC_COMPAT_2_1 \ > > - {\ > > - .driver = "intel-hda",\ > > - .property = "old_msi_addr",\ > > - .value = "on",\ > > - } > > - > > #define PC_COMPAT_2_0 \ > > - PC_COMPAT_2_1, \ > > + HW_COMPAT_2_1, \ > > {\ > > .driver = "virtio-scsi-pci",\ > > .property = "any_layout",\ > > diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c > > index 553afdd..a1634ab 100644 > > --- a/hw/i386/pc_piix.c > > +++ b/hw/i386/pc_piix.c > > @@ -502,7 +502,7 @@ static QEMUMachine pc_i440fx_machine_v2_1 = { > > .name = "pc-i440fx-2.1", > > .init = pc_init_pci, > > .compat_props = (GlobalProperty[]) { > > - PC_COMPAT_2_1, > > + HW_COMPAT_2_1, > > { /* end of list */ } > > }, > > }; > > diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c > > index a199043..f330f7a 100644 > > --- a/hw/i386/pc_q35.c > > +++ b/hw/i386/pc_q35.c > > @@ -365,7 +365,7 @@ static QEMUMachine pc_q35_machine_v2_1 = { > > .name = "pc-q35-2.1", > > .init = pc_q35_init, > > .compat_props = (GlobalProperty[]) { > > - PC_COMPAT_2_1, > > + HW_COMPAT_2_1, > > { /* end of list */ } > > }, > > }; > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > > index 2becc9f..8bc597f 100644 > > --- a/hw/ppc/spapr.c > > +++ b/hw/ppc/spapr.c > > @@ -57,6 +57,8 @@ > > #include "trace.h" > > #include "hw/nmi.h" > > > > +#include "hw/compat.h" > > + > > #include <libfdt.h> > > > > /* SLOF memory layout: > > @@ -1689,10 +1691,15 @@ static const TypeInfo spapr_machine_info = { > > static void spapr_machine_2_1_class_init(ObjectClass *oc, void *data) > > { > > MachineClass *mc = MACHINE_CLASS(oc); > > + static GlobalProperty compat_props[] = { > > + HW_COMPAT_2_1, > > + { /* end of list */ } > > + }; > > > > mc->name = "pseries-2.1"; > > mc->desc = "pSeries Logical Partition (PAPR compliant) v2.1"; > > - mc->is_default = 0; > > + mc->is_default = -1; > > I could find no other place where we set is_default to -1. What's the point ? Leftover from unrelated code changes. I'll drop this, good catch! > > + mc->compat_props = compat_props; > > } > > > > static const TypeInfo spapr_machine_2_1_info = { > > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > > index a827cd4..a499a3c 100644 > > --- a/hw/virtio/virtio-pci.c > > +++ b/hw/virtio/virtio-pci.c > > @@ -86,9 +86,6 @@ > > * 12 is historical, and due to x86 page size. */ > > #define VIRTIO_PCI_QUEUE_ADDR_SHIFT 12 > > > > -/* Flags track per-device state like workarounds for quirks in older guests. */ > > -#define VIRTIO_PCI_FLAG_BUS_MASTER_BUG (1 << 0) > > - > > static void virtio_pci_bus_new(VirtioBusState *bus, size_t bus_size, > > VirtIOPCIProxy *dev); > > > > @@ -323,14 +320,6 @@ static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val) > > proxy->pci_dev.config[PCI_COMMAND] | > > PCI_COMMAND_MASTER, 1); > > } > > - > > - /* Linux before 2.6.34 sets the device as OK without enabling > > - the PCI device bus master bit. In this case we need to disable > > - some safety checks. */ > > - if ((val & VIRTIO_CONFIG_S_DRIVER_OK) && > > - !(proxy->pci_dev.config[PCI_COMMAND] & PCI_COMMAND_MASTER)) { > > - proxy->flags |= VIRTIO_PCI_FLAG_BUS_MASTER_BUG; > > - } > > break; > > case VIRTIO_MSI_CONFIG_VECTOR: > > msix_vector_unuse(&proxy->pci_dev, vdev->config_vector); > > @@ -483,8 +472,7 @@ static void virtio_write_config(PCIDevice *pci_dev, uint32_t address, > > pci_default_write_config(pci_dev, address, val, len); > > > > if (range_covers_byte(address, len, PCI_COMMAND) && > > - !(pci_dev->config[PCI_COMMAND] & PCI_COMMAND_MASTER) && > > - !(proxy->flags & VIRTIO_PCI_FLAG_BUS_MASTER_BUG)) { > > + !(pci_dev->config[PCI_COMMAND] & PCI_COMMAND_MASTER)) { > > virtio_pci_stop_ioeventfd(proxy); > > virtio_set_status(vdev, vdev->status & ~VIRTIO_CONFIG_S_DRIVER_OK); > > } > > @@ -895,11 +883,15 @@ static void virtio_pci_vmstate_change(DeviceState *d, bool running) > > VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); > > > > if (running) { > > - /* Try to find out if the guest has bus master disabled, but is > > - in ready state. Then we have a buggy guest OS. */ > > - if ((vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) && > > + /* Old QEMU versions did not set bus master enable on status write. > > + * Detect DRIVER set and enable it. > > + */ > > + if ((proxy->flags & VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION) && > > + (vdev->status & VIRTIO_CONFIG_S_DRIVER) && > > !(proxy->pci_dev.config[PCI_COMMAND] & PCI_COMMAND_MASTER)) { > > - proxy->flags |= VIRTIO_PCI_FLAG_BUS_MASTER_BUG; > > + pci_default_write_config(&proxy->pci_dev, PCI_COMMAND, > > + proxy->pci_dev.config[PCI_COMMAND] | > > + PCI_COMMAND_MASTER, 1); > > } > > virtio_pci_start_ioeventfd(proxy); > > } else { > > @@ -1040,10 +1032,11 @@ static void virtio_pci_reset(DeviceState *qdev) > > virtio_pci_stop_ioeventfd(proxy); > > virtio_bus_reset(bus); > > msix_unuse_all_vectors(&proxy->pci_dev); > > - proxy->flags &= ~VIRTIO_PCI_FLAG_BUS_MASTER_BUG; > > } > > > > static Property virtio_pci_properties[] = { > > + DEFINE_PROP_BIT("virtio-pci-bus-master-bug-migration", VirtIOPCIProxy, flags, > > + VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION_BIT, false), > > DEFINE_VIRTIO_COMMON_FEATURES(VirtIOPCIProxy, host_features), > > DEFINE_PROP_END_OF_LIST(), > > };
diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h index 1cea157..8873b6d 100644 --- a/hw/virtio/virtio-pci.h +++ b/hw/virtio/virtio-pci.h @@ -53,6 +53,11 @@ typedef struct VirtioBusClass VirtioPCIBusClass; #define VIRTIO_PCI_BUS_CLASS(klass) \ OBJECT_CLASS_CHECK(VirtioPCIBusClass, klass, TYPE_VIRTIO_PCI_BUS) +/* Need to activate work-arounds for buggy guests at vmstate load. */ +#define VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION_BIT 0 +#define VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION \ + (1 << VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION_BIT) + /* Performance improves when virtqueue kick processing is decoupled from the * vcpu thread using ioeventfd for some devices. */ #define VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT 1 diff --git a/include/hw/compat.h b/include/hw/compat.h new file mode 100644 index 0000000..47f6ff5 --- /dev/null +++ b/include/hw/compat.h @@ -0,0 +1,16 @@ +#ifndef HW_COMPAT_H +#define HW_COMPAT_H + +#define HW_COMPAT_2_1 \ + {\ + .driver = "intel-hda",\ + .property = "old_msi_addr",\ + .value = "on",\ + },\ + {\ + .driver = "virtio-pci",\ + .property = "virtio-pci-bus-master-bug-migration",\ + .value = "on",\ + } + +#endif /* HW_COMPAT_H */ diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h index bae023a..82ad046 100644 --- a/include/hw/i386/pc.h +++ b/include/hw/i386/pc.h @@ -14,6 +14,7 @@ #include "sysemu/sysemu.h" #include "hw/pci/pci.h" #include "hw/boards.h" +#include "hw/compat.h" #define HPET_INTCAP "hpet-intcap" @@ -307,15 +308,8 @@ int e820_add_entry(uint64_t, uint64_t, uint32_t); int e820_get_num_entries(void); bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *); -#define PC_COMPAT_2_1 \ - {\ - .driver = "intel-hda",\ - .property = "old_msi_addr",\ - .value = "on",\ - } - #define PC_COMPAT_2_0 \ - PC_COMPAT_2_1, \ + HW_COMPAT_2_1, \ {\ .driver = "virtio-scsi-pci",\ .property = "any_layout",\ diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c index 553afdd..a1634ab 100644 --- a/hw/i386/pc_piix.c +++ b/hw/i386/pc_piix.c @@ -502,7 +502,7 @@ static QEMUMachine pc_i440fx_machine_v2_1 = { .name = "pc-i440fx-2.1", .init = pc_init_pci, .compat_props = (GlobalProperty[]) { - PC_COMPAT_2_1, + HW_COMPAT_2_1, { /* end of list */ } }, }; diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c index a199043..f330f7a 100644 --- a/hw/i386/pc_q35.c +++ b/hw/i386/pc_q35.c @@ -365,7 +365,7 @@ static QEMUMachine pc_q35_machine_v2_1 = { .name = "pc-q35-2.1", .init = pc_q35_init, .compat_props = (GlobalProperty[]) { - PC_COMPAT_2_1, + HW_COMPAT_2_1, { /* end of list */ } }, }; diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index 2becc9f..8bc597f 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -57,6 +57,8 @@ #include "trace.h" #include "hw/nmi.h" +#include "hw/compat.h" + #include <libfdt.h> /* SLOF memory layout: @@ -1689,10 +1691,15 @@ static const TypeInfo spapr_machine_info = { static void spapr_machine_2_1_class_init(ObjectClass *oc, void *data) { MachineClass *mc = MACHINE_CLASS(oc); + static GlobalProperty compat_props[] = { + HW_COMPAT_2_1, + { /* end of list */ } + }; mc->name = "pseries-2.1"; mc->desc = "pSeries Logical Partition (PAPR compliant) v2.1"; - mc->is_default = 0; + mc->is_default = -1; + mc->compat_props = compat_props; } static const TypeInfo spapr_machine_2_1_info = { diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index a827cd4..a499a3c 100644 --- a/hw/virtio/virtio-pci.c +++ b/hw/virtio/virtio-pci.c @@ -86,9 +86,6 @@ * 12 is historical, and due to x86 page size. */ #define VIRTIO_PCI_QUEUE_ADDR_SHIFT 12 -/* Flags track per-device state like workarounds for quirks in older guests. */ -#define VIRTIO_PCI_FLAG_BUS_MASTER_BUG (1 << 0) - static void virtio_pci_bus_new(VirtioBusState *bus, size_t bus_size, VirtIOPCIProxy *dev); @@ -323,14 +320,6 @@ static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val) proxy->pci_dev.config[PCI_COMMAND] | PCI_COMMAND_MASTER, 1); } - - /* Linux before 2.6.34 sets the device as OK without enabling - the PCI device bus master bit. In this case we need to disable - some safety checks. */ - if ((val & VIRTIO_CONFIG_S_DRIVER_OK) && - !(proxy->pci_dev.config[PCI_COMMAND] & PCI_COMMAND_MASTER)) { - proxy->flags |= VIRTIO_PCI_FLAG_BUS_MASTER_BUG; - } break; case VIRTIO_MSI_CONFIG_VECTOR: msix_vector_unuse(&proxy->pci_dev, vdev->config_vector); @@ -483,8 +472,7 @@ static void virtio_write_config(PCIDevice *pci_dev, uint32_t address, pci_default_write_config(pci_dev, address, val, len); if (range_covers_byte(address, len, PCI_COMMAND) && - !(pci_dev->config[PCI_COMMAND] & PCI_COMMAND_MASTER) && - !(proxy->flags & VIRTIO_PCI_FLAG_BUS_MASTER_BUG)) { + !(pci_dev->config[PCI_COMMAND] & PCI_COMMAND_MASTER)) { virtio_pci_stop_ioeventfd(proxy); virtio_set_status(vdev, vdev->status & ~VIRTIO_CONFIG_S_DRIVER_OK); } @@ -895,11 +883,15 @@ static void virtio_pci_vmstate_change(DeviceState *d, bool running) VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); if (running) { - /* Try to find out if the guest has bus master disabled, but is - in ready state. Then we have a buggy guest OS. */ - if ((vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) && + /* Old QEMU versions did not set bus master enable on status write. + * Detect DRIVER set and enable it. + */ + if ((proxy->flags & VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION) && + (vdev->status & VIRTIO_CONFIG_S_DRIVER) && !(proxy->pci_dev.config[PCI_COMMAND] & PCI_COMMAND_MASTER)) { - proxy->flags |= VIRTIO_PCI_FLAG_BUS_MASTER_BUG; + pci_default_write_config(&proxy->pci_dev, PCI_COMMAND, + proxy->pci_dev.config[PCI_COMMAND] | + PCI_COMMAND_MASTER, 1); } virtio_pci_start_ioeventfd(proxy); } else { @@ -1040,10 +1032,11 @@ static void virtio_pci_reset(DeviceState *qdev) virtio_pci_stop_ioeventfd(proxy); virtio_bus_reset(bus); msix_unuse_all_vectors(&proxy->pci_dev); - proxy->flags &= ~VIRTIO_PCI_FLAG_BUS_MASTER_BUG; } static Property virtio_pci_properties[] = { + DEFINE_PROP_BIT("virtio-pci-bus-master-bug-migration", VirtIOPCIProxy, flags, + VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION_BIT, false), DEFINE_VIRTIO_COMMON_FEATURES(VirtIOPCIProxy, host_features), DEFINE_PROP_END_OF_LIST(), };
Current support for bus master (clearing OK bit) together with the need to support guests which do not enable PCI bus mastering, leads to extra state in VIRTIO_PCI_FLAG_BUS_MASTER_BUG bit, which isn't robust in case of cross-version migration for the case when guests use the device before setting DRIVER_OK. Rip out this code, and replace it: - Modern QEMU doesn't need VIRTIO_PCI_FLAG_BUS_MASTER_BUG so just drop it for latest machine type. - For compat machine types, set PCI_COMMAND if DRIVER_OK is set. As this is needed for 2.1 for both pc and ppc, move PC_COMPAT macros from pc.h to a new common header. Cc: Greg Kurz <gkurz@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- hw/virtio/virtio-pci.h | 5 +++++ include/hw/compat.h | 16 ++++++++++++++++ include/hw/i386/pc.h | 10 ++-------- hw/i386/pc_piix.c | 2 +- hw/i386/pc_q35.c | 2 +- hw/ppc/spapr.c | 9 ++++++++- hw/virtio/virtio-pci.c | 29 +++++++++++------------------ 7 files changed, 44 insertions(+), 29 deletions(-) create mode 100644 include/hw/compat.h