On 01/05/2024 14:50, Joao Martins wrote:
External email: Use caution opening links or attachments On 30/04/2024 06:16, Avihai Horon wrote:Emit VFIO device migration state change QAPI event when a VFIO device changes its migration state. This can be used by management applications to get updates on the current state of the VFIO device for their own purposes. A new per VFIO device capability, "migration-events", is added so events can be enabled only for the required devices. It is disabled by default. Signed-off-by: Avihai Horon <avih...@nvidia.com> --- include/hw/vfio/vfio-common.h | 1 + hw/vfio/migration.c | 44 +++++++++++++++++++++++++++++++++++ hw/vfio/pci.c | 2 ++ 3 files changed, 47 insertions(+) diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h index b9da6c08ef..3ec5f2425e 100644 --- a/include/hw/vfio/vfio-common.h +++ b/include/hw/vfio/vfio-common.h @@ -115,6 +115,7 @@ typedef struct VFIODevice { bool no_mmap; bool ram_block_discard_allowed; OnOffAuto enable_migration; + bool migration_events; VFIODeviceOps *ops; unsigned int num_irqs; unsigned int num_regions; diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c index 06ae40969b..6bbccf6545 100644 --- a/hw/vfio/migration.c +++ b/hw/vfio/migration.c @@ -24,6 +24,7 @@ #include "migration/register.h" #include "migration/blocker.h" #include "qapi/error.h" +#include "qapi/qapi-events-vfio.h" #include "exec/ramlist.h" #include "exec/ram_addr.h" #include "pci.h" @@ -80,6 +81,46 @@ static const char *mig_state_to_str(enum vfio_device_mig_state state) } } +static VFIODeviceMigState +mig_state_to_qapi_state(enum vfio_device_mig_state state) +{ + switch (state) { + case VFIO_DEVICE_STATE_STOP: + return QAPI_VFIO_DEVICE_MIG_STATE_STOP; + case VFIO_DEVICE_STATE_RUNNING: + return QAPI_VFIO_DEVICE_MIG_STATE_RUNNING; + case VFIO_DEVICE_STATE_STOP_COPY: + return QAPI_VFIO_DEVICE_MIG_STATE_STOP_COPY; + case VFIO_DEVICE_STATE_RESUMING: + return QAPI_VFIO_DEVICE_MIG_STATE_RESUMING; + case VFIO_DEVICE_STATE_RUNNING_P2P: + return QAPI_VFIO_DEVICE_MIG_STATE_RUNNING_P2P; + case VFIO_DEVICE_STATE_PRE_COPY: + return QAPI_VFIO_DEVICE_MIG_STATE_PRE_COPY; + case VFIO_DEVICE_STATE_PRE_COPY_P2P: + return QAPI_VFIO_DEVICE_MIG_STATE_PRE_COPY_P2P; + default: + g_assert_not_reached(); + } +} + +static void vfio_migration_send_state_change_event(VFIODevice *vbasedev) +{ + VFIOMigration *migration = vbasedev->migration; + const char *id; + Object *obj; + + if (!vbasedev->migration_events) { + return; + } +Shouldn't this leap frog migrate_events() capability instead of introducing its vfio equivalent i.e. if (!migrate_events()) { return; } ?
I used a per VFIO device cap so the events can be fine tuned for each device (maybe one device should send events while the other not). This gives the most flexibility and I don't think it complicates the configuration (one downside, though, is that it can't be enabled/disabled dynamically during runtime).
I don't think events add much overhead, so if you prefer a global cap, I can change it.
However, I'm not sure overloading the existing migrate_events() is valid?
Applications that don't understand the event string (migration related or not) will just discard it (AIUI)+ obj = vbasedev->ops->vfio_get_object(vbasedev); + id = object_get_canonical_path_component(obj); + + qapi_event_send_vfio_device_mig_state_changed( + id, mig_state_to_qapi_state(migration->device_state)); +} + static int vfio_migration_set_state(VFIODevice *vbasedev, enum vfio_device_mig_state new_state, enum vfio_device_mig_state recover_state) @@ -126,11 +167,13 @@ static int vfio_migration_set_state(VFIODevice *vbasedev, } migration->device_state = recover_state; + vfio_migration_send_state_change_event(vbasedev); return ret; } migration->device_state = new_state; + vfio_migration_send_state_change_event(vbasedev); if (mig_state->data_fd != -1) { if (migration->data_fd != -1) { /* @@ -157,6 +200,7 @@ reset_device: } migration->device_state = VFIO_DEVICE_STATE_RUNNING; + vfio_migration_send_state_change_event(vbasedev); return ret; } diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index 64780d1b79..8840602c50 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -3362,6 +3362,8 @@ static Property vfio_pci_dev_properties[] = { VFIO_FEATURE_ENABLE_IGD_OPREGION_BIT, false), DEFINE_PROP_ON_OFF_AUTO("enable-migration", VFIOPCIDevice, vbasedev.enable_migration, ON_OFF_AUTO_AUTO), + DEFINE_PROP_BOOL("migration-events", VFIOPCIDevice, + vbasedev.migration_events, false), DEFINE_PROP_BOOL("x-no-mmap", VFIOPCIDevice, vbasedev.no_mmap, false), DEFINE_PROP_BOOL("x-balloon-allowed", VFIOPCIDevice, vbasedev.ram_block_discard_allowed, false),
