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virtio-pci: fix migration for pci bus master

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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>
Reviewed-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
Michael S. Tsirkin 2014-10-14 19:40:06 +03:00
parent 4d5e17a53b
commit 68a27b208a
7 changed files with 62 additions and 44 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
hw/i386/pc_piix.c
View File

@ -474,7 +474,7 @@ 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 */ }
},
};

2
hw/i386/pc_q35.c
View File

@ -370,7 +370,7 @@ 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 */ }
},
};

7
hw/ppc/spapr.c
View File

@ -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->compat_props = compat_props;
}
static const TypeInfo spapr_machine_2_1_info = {

29
hw/virtio/virtio-pci.c
View File

@ -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(),
};

5
hw/virtio/virtio-pci.h
View File

@ -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

35
include/hw/compat.h Normal file
View File

@ -0,0 +1,35 @@
#ifndef HW_COMPAT_H
#define HW_COMPAT_H
#define HW_COMPAT_2_1 \
{\
.driver = "intel-hda",\
.property = "old_msi_addr",\
.value = "on",\
},{\
.driver = "VGA",\
.property = "qemu-extended-regs",\
.value = "off",\
},{\
.driver = "secondary-vga",\
.property = "qemu-extended-regs",\
.value = "off",\
},{\
.driver = "virtio-scsi-pci",\
.property = "any_layout",\
.value = "off",\
},{\
.driver = "usb-mouse",\
.property = "usb_version",\
.value = stringify(1),\
},{\
.driver = "usb-kbd",\
.property = "usb_version",\
.value = stringify(1),\
},{\
.driver = "virtio-pci",\
.property = "virtio-pci-bus-master-bug-migration",\
.value = "on",\
}
#endif /* HW_COMPAT_H */

26
include/hw/i386/pc.h
View File

@ -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"
@ -301,31 +302,8 @@ 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",\
},{\
.driver = "VGA",\
.property = "qemu-extended-regs",\
.value = "off",\
},{\
.driver = "secondary-vga",\
.property = "qemu-extended-regs",\
.value = "off",\
},{\
.driver = "usb-mouse",\
.property = "usb_version",\
.value = stringify(1),\
},{\
.driver = "usb-kbd",\
.property = "usb_version",\
.value = stringify(1),\
}
#define PC_COMPAT_2_0 \
PC_COMPAT_2_1, \
HW_COMPAT_2_1, \
{\
.driver = "virtio-scsi-pci",\
.property = "any_layout",\