On Fri, Jul 12, 2019 at 03:14:03AM +0800, Kirti Wankhede wrote:
>
>
> On 7/11/2019 5:43 PM, Dr. David Alan Gilbert wrote:
> > * Kirti Wankhede (kwankh...@nvidia.com) wrote:
> >> VM state change handler gets called on change in VM's state. This is used
> >> to set
> >> VFIO device state to _RUNNING.
> >> VM state change handler, migration state change handler and log_sync
> >> listener
> >> are called asynchronously, which sometimes lead to data corruption in
> >> migration
> >> region. Initialised mutex that is used to serialize operations on
> >> migration data
> >> region during saving state.
> >>
> >> Signed-off-by: Kirti Wankhede <kwankh...@nvidia.com>
> >> Reviewed-by: Neo Jia <c...@nvidia.com>
> >> ---
> >> hw/vfio/migration.c | 64
> >> +++++++++++++++++++++++++++++++++++++++++++
> >> hw/vfio/trace-events | 2 ++
> >> include/hw/vfio/vfio-common.h | 4 +++
> >> 3 files changed, 70 insertions(+)
> >>
> >> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
> >> index a2cfbd5af2e1..c01f08b659d0 100644
> >> --- a/hw/vfio/migration.c
> >> +++ b/hw/vfio/migration.c
> >> @@ -78,6 +78,60 @@ err:
> >> return ret;
> >> }
> >>
> >> +static int vfio_migration_set_state(VFIODevice *vbasedev, uint32_t state)
> >> +{
> >> + VFIOMigration *migration = vbasedev->migration;
> >> + VFIORegion *region = &migration->region.buffer;
> >> + uint32_t device_state;
> >> + int ret = 0;
> >> +
> >> + device_state = (state & VFIO_DEVICE_STATE_MASK) |
> >> + (vbasedev->device_state & ~VFIO_DEVICE_STATE_MASK);
> >> +
> >> + if ((device_state & VFIO_DEVICE_STATE_MASK) ==
> >> VFIO_DEVICE_STATE_INVALID) {
> >> + return -EINVAL;
> >> + }
> >> +
> >> + ret = pwrite(vbasedev->fd, &device_state, sizeof(device_state),
> >> + region->fd_offset + offsetof(struct
> >> vfio_device_migration_info,
> >> + device_state));
> >> + if (ret < 0) {
> >> + error_report("%s: Failed to set device state %d %s",
> >> + vbasedev->name, ret, strerror(errno));
> >> + return ret;
> >> + }
> >> +
> >> + vbasedev->device_state = device_state;
> >> + trace_vfio_migration_set_state(vbasedev->name, device_state);
> >> + return 0;
> >> +}
> >> +
> >> +static void vfio_vmstate_change(void *opaque, int running, RunState state)
> >> +{
> >> + VFIODevice *vbasedev = opaque;
> >> +
> >> + if ((vbasedev->vm_running != running)) {
> >> + int ret;
> >> + uint32_t dev_state;
> >> +
> >> + if (running) {
> >> + dev_state = VFIO_DEVICE_STATE_RUNNING;
> >> + } else {
> >> + dev_state = (vbasedev->device_state & VFIO_DEVICE_STATE_MASK)
> >> &
> >> + ~VFIO_DEVICE_STATE_RUNNING;
> >> + }
> >> +
> >> + ret = vfio_migration_set_state(vbasedev, dev_state);
> >> + if (ret) {
> >> + error_report("%s: Failed to set device state 0x%x",
> >> + vbasedev->name, dev_state);
> >> + }
> >> + vbasedev->vm_running = running;
> >> + trace_vfio_vmstate_change(vbasedev->name, running,
> >> RunState_str(state),
> >> + dev_state);
> >> + }
> >> +}
> >> +
> >> static int vfio_migration_init(VFIODevice *vbasedev,
> >> struct vfio_region_info *info)
> >> {
> >> @@ -93,6 +147,11 @@ static int vfio_migration_init(VFIODevice *vbasedev,
> >> return ret;
> >> }
> >>
> >> + qemu_mutex_init(&vbasedev->migration->lock);
> >
> > Does this and it's friend below belong in this patch? As far as I can
> > tell you init/deinit the lock here but don't use it which is strange.
> >
>
> This lock is used in
> 0009-vfio-Add-save-state-functions-to-SaveVMHandlers.patch and
> 0011-vfio-Add-function-to-get-dirty-page-list.patch
>
> Hm. I'll move this init/deinit to patch 0009 in next iteration.
>
> Thanks,
> Kirti
>
This lock is used to protect vfio_save_buffer and read dirty page,
right?
if data subregion and bitmap subregion do not reuse "data_offset" in
vfio_device_migration_info.
It seems that this lock can be avoided.
Thanks
Yan
>
> > Dave
> >
> >> + vbasedev->vm_state =
> >> qemu_add_vm_change_state_handler(vfio_vmstate_change,
> >> + vbasedev);
> >> +
> >> return 0;
> >> }
> >>
> >> @@ -135,11 +194,16 @@ void vfio_migration_finalize(VFIODevice *vbasedev)
> >> return;
> >> }
> >>
> >> + if (vbasedev->vm_state) {
> >> + qemu_del_vm_change_state_handler(vbasedev->vm_state);
> >> + }
> >> +
> >> if (vbasedev->migration_blocker) {
> >> migrate_del_blocker(vbasedev->migration_blocker);
> >> error_free(vbasedev->migration_blocker);
> >> }
> >>
> >> + qemu_mutex_destroy(&vbasedev->migration->lock);
> >> vfio_migration_region_exit(vbasedev);
> >> g_free(vbasedev->migration);
> >> }
> >> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
> >> index 191a726a1312..3d15bacd031a 100644
> >> --- a/hw/vfio/trace-events
> >> +++ b/hw/vfio/trace-events
> >> @@ -146,3 +146,5 @@ vfio_display_edid_write_error(void) ""
> >>
> >> # migration.c
> >> vfio_migration_probe(char *name, uint32_t index) " (%s) Region %d"
> >> +vfio_migration_set_state(char *name, uint32_t state) " (%s) state %d"
> >> +vfio_vmstate_change(char *name, int running, const char *reason, uint32_t
> >> dev_state) " (%s) running %d reason %s device state %d"
> >> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> >> index 152da3f8d6f3..f6c70db3a9c1 100644
> >> --- a/include/hw/vfio/vfio-common.h
> >> +++ b/include/hw/vfio/vfio-common.h
> >> @@ -29,6 +29,7 @@
> >> #ifdef CONFIG_LINUX
> >> #include <linux/vfio.h>
> >> #endif
> >> +#include "sysemu/sysemu.h"
> >>
> >> #define VFIO_MSG_PREFIX "vfio %s: "
> >>
> >> @@ -124,6 +125,9 @@ typedef struct VFIODevice {
> >> unsigned int flags;
> >> VFIOMigration *migration;
> >> Error *migration_blocker;
> >> + uint32_t device_state;
> >> + VMChangeStateEntry *vm_state;
> >> + int vm_running;
> >> } VFIODevice;
> >>
> >> struct VFIODeviceOps {
> >> --
> >> 2.7.0
> >>
> > --
> > Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
> >
