On Sun, 18 Oct 2020 02:05:03 +0530
Kirti Wankhede <kwankh...@nvidia.com> wrote:
> On 9/26/2020 1:50 AM, Alex Williamson wrote:
> > On Wed, 23 Sep 2020 04:54:08 +0530
> > Kirti Wankhede <kwankh...@nvidia.com> wrote:
> >
> >> Added migration state change notifier to get notification on migration
> >> state
> >> change. These states are translated to VFIO device state and conveyed to
> >> vendor
> >> driver.
> >>
> >> Signed-off-by: Kirti Wankhede <kwankh...@nvidia.com>
> >> Reviewed-by: Neo Jia <c...@nvidia.com>
> >> Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> >> ---
> >> hw/vfio/migration.c | 29 +++++++++++++++++++++++++++++
> >> hw/vfio/trace-events | 5 +++--
> >> include/hw/vfio/vfio-common.h | 1 +
> >> 3 files changed, 33 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
> >> index a30d628ba963..f650fe9fc3c8 100644
> >> --- a/hw/vfio/migration.c
> >> +++ b/hw/vfio/migration.c
> >> @@ -199,6 +199,28 @@ static void vfio_vmstate_change(void *opaque, int
> >> running, RunState state)
> >> }
> >> }
> >>
> >> +static void vfio_migration_state_notifier(Notifier *notifier, void *data)
> >> +{
> >> + MigrationState *s = data;
> >> + VFIODevice *vbasedev = container_of(notifier, VFIODevice,
> >> migration_state);
> >> + int ret;
> >> +
> >> + trace_vfio_migration_state_notifier(vbasedev->name,
> >> + MigrationStatus_str(s->state));
> >> +
> >> + switch (s->state) {
> >> + case MIGRATION_STATUS_CANCELLING:
> >> + case MIGRATION_STATUS_CANCELLED:
> >> + case MIGRATION_STATUS_FAILED:
> >> + ret = vfio_migration_set_state(vbasedev,
> >> + ~(VFIO_DEVICE_STATE_SAVING |
> >> VFIO_DEVICE_STATE_RESUMING),
> >> + VFIO_DEVICE_STATE_RUNNING);
> >> + if (ret) {
> >> + error_report("%s: Failed to set state RUNNING",
> >> vbasedev->name);
> >> + }
> >
> > Here again the caller assumes success means the device has entered the
> > desired state, but as implemented it only means the device is in some
> > non-error state.
> >
> >> + }
> >> +}
> >> +
> >> static int vfio_migration_init(VFIODevice *vbasedev,
> >> struct vfio_region_info *info)
> >> {
> >> @@ -221,6 +243,8 @@ static int vfio_migration_init(VFIODevice *vbasedev,
> >>
> >> vbasedev->vm_state =
> >> qemu_add_vm_change_state_handler(vfio_vmstate_change,
> >> vbasedev);
> >> + vbasedev->migration_state.notify = vfio_migration_state_notifier;
> >> + add_migration_state_change_notifier(&vbasedev->migration_state);
> >> return ret;
> >> }
> >>
> >> @@ -263,6 +287,11 @@ add_blocker:
> >>
> >> void vfio_migration_finalize(VFIODevice *vbasedev)
> >> {
> >> +
> >> + if (vbasedev->migration_state.notify) {
> >> +
> >> remove_migration_state_change_notifier(&vbasedev->migration_state);
> >> + }
> >> +
> >> if (vbasedev->vm_state) {
> >> qemu_del_vm_change_state_handler(vbasedev->vm_state);
> >> }
> >> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
> >> index 6524734bf7b4..bcb3fa7314d7 100644
> >> --- a/hw/vfio/trace-events
> >> +++ b/hw/vfio/trace-events
> >> @@ -149,5 +149,6 @@ vfio_display_edid_write_error(void) ""
> >>
> >> # migration.c
> >> vfio_migration_probe(const 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"
> >> +vfio_migration_set_state(const char *name, uint32_t state) " (%s) state
> >> %d"
> >> +vfio_vmstate_change(const char *name, int running, const char *reason,
> >> uint32_t dev_state) " (%s) running %d reason %s device state %d"
> >> +vfio_migration_state_notifier(const char *name, const char *state) " (%s)
> >> state %s"
> >> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> >> index 25e3b1a3b90a..49c7c7a0e29a 100644
> >> --- a/include/hw/vfio/vfio-common.h
> >> +++ b/include/hw/vfio/vfio-common.h
> >> @@ -123,6 +123,7 @@ typedef struct VFIODevice {
> >> VMChangeStateEntry *vm_state;
> >> uint32_t device_state;
> >> int vm_running;
> >> + Notifier migration_state;
> >
> > Can this live in VFIOMigration? Thanks,
> >
>
> No, callback vfio_migration_state_notifier() has notifier argument and
> to reach its corresponding device structure as below, its should be in
> VFIODevice.
>
> VFIODevice *vbasedev = container_of(notifier, VFIODevice, migration_state);
An alternative would be to place migration_state within VFIOMigration,
along with a pointer back to vbasedev (like we do in VFIORegion) then
the notifier could use container_of to get the VFIOMigration structure,
from which we could get to the VFIODevice via the vbasedev pointer.
This would better compartmentalize the migration related data into a
single structure. Thanks,
Alex
