vfio-pci: skip reset during cpr

Do not reset a vfio-pci device during CPR, and do not complain if the
kernel's PCI config space changes for non-emulated bits between the
vmstate save and load, which can happen due to ongoing interrupt activity.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/1749569991-25171-12-git-send-email-steven.sistare@oracle.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
This commit is contained in:
Steve Sistare 2025-06-10 08:39:24 -07:00 committed by Cédric Le Goater
parent 24c156dcd9
commit 031fbb7110
3 changed files with 40 additions and 0 deletions

View file

@ -8,6 +8,8 @@
#include "qemu/osdep.h"
#include "hw/vfio/vfio-device.h"
#include "hw/vfio/vfio-cpr.h"
#include "hw/vfio/pci.h"
#include "migration/cpr.h"
#include "qapi/error.h"
#include "system/runstate.h"
@ -37,3 +39,32 @@ void vfio_cpr_unregister_container(VFIOContainerBase *bcontainer)
{
migration_remove_notifier(&bcontainer->cpr_reboot_notifier);
}
/*
* The kernel may change non-emulated config bits. Exclude them from the
* changed-bits check in get_pci_config_device.
*/
static int vfio_cpr_pci_pre_load(void *opaque)
{
VFIOPCIDevice *vdev = opaque;
PCIDevice *pdev = &vdev->pdev;
int size = MIN(pci_config_size(pdev), vdev->config_size);
int i;
for (i = 0; i < size; i++) {
pdev->cmask[i] &= vdev->emulated_config_bits[i];
}
return 0;
}
const VMStateDescription vfio_cpr_pci_vmstate = {
.name = "vfio-cpr-pci",
.version_id = 0,
.minimum_version_id = 0,
.pre_load = vfio_cpr_pci_pre_load,
.needed = cpr_incoming_needed,
.fields = (VMStateField[]) {
VMSTATE_END_OF_LIST()
}
};

View file

@ -30,6 +30,7 @@
#include "hw/qdev-properties.h"
#include "hw/qdev-properties-system.h"
#include "migration/vmstate.h"
#include "migration/cpr.h"
#include "qobject/qdict.h"
#include "qemu/error-report.h"
#include "qemu/main-loop.h"
@ -3354,6 +3355,11 @@ static void vfio_pci_reset(DeviceState *dev)
{
VFIOPCIDevice *vdev = VFIO_PCI_BASE(dev);
/* Do not reset the device during qemu_system_reset prior to cpr load */
if (cpr_is_incoming()) {
return;
}
trace_vfio_pci_reset(vdev->vbasedev.name);
vfio_pci_pre_reset(vdev);
@ -3530,6 +3536,7 @@ static void vfio_pci_dev_class_init(ObjectClass *klass, const void *data)
#ifdef CONFIG_IOMMUFD
object_class_property_add_str(klass, "fd", NULL, vfio_pci_set_fd);
#endif
dc->vmsd = &vfio_cpr_pci_vmstate;
dc->desc = "VFIO-based PCI device assignment";
pdc->realize = vfio_pci_realize;