diff options
| -rw-r--r-- | docs/devel/migration/vfio.rst | 15 | ||||
| -rw-r--r-- | hw/vfio/migration-multifd.c | 18 | ||||
| -rw-r--r-- | hw/vfio/pci.c | 7 | ||||
| -rw-r--r-- | include/hw/vfio/vfio-common.h | 2 |
4 files changed, 41 insertions, 1 deletions
diff --git a/docs/devel/migration/vfio.rst b/docs/devel/migration/vfio.rst index a803a09bc1..673e354754 100644 --- a/docs/devel/migration/vfio.rst +++ b/docs/devel/migration/vfio.rst @@ -232,3 +232,18 @@ Postcopy ======== Postcopy migration is currently not supported for VFIO devices. + +Multifd +======= + +Starting from QEMU version 10.0 there's a possibility to transfer VFIO device +_STOP_COPY state via multifd channels. This helps reduce downtime - especially +with multiple VFIO devices or with devices having a large migration state. +As an additional benefit, setting the VFIO device to _STOP_COPY state and +saving its config space is also parallelized (run in a separate thread) in +such migration mode. + +The multifd VFIO device state transfer is controlled by +"x-migration-multifd-transfer" VFIO device property. This property defaults to +AUTO, which means that VFIO device state transfer via multifd channels is +attempted in configurations that otherwise support it. diff --git a/hw/vfio/migration-multifd.c b/hw/vfio/migration-multifd.c index bfb9a72fa4..aacddc503b 100644 --- a/hw/vfio/migration-multifd.c +++ b/hw/vfio/migration-multifd.c @@ -476,18 +476,34 @@ bool vfio_multifd_transfer_supported(void) bool vfio_multifd_transfer_enabled(VFIODevice *vbasedev) { - return false; + VFIOMigration *migration = vbasedev->migration; + + return migration->multifd_transfer; } bool vfio_multifd_setup(VFIODevice *vbasedev, bool alloc_multifd, Error **errp) { VFIOMigration *migration = vbasedev->migration; + if (vbasedev->migration_multifd_transfer == ON_OFF_AUTO_AUTO) { + migration->multifd_transfer = vfio_multifd_transfer_supported(); + } else { + migration->multifd_transfer = + vbasedev->migration_multifd_transfer == ON_OFF_AUTO_ON; + } + if (!vfio_multifd_transfer_enabled(vbasedev)) { /* Nothing further to check or do */ return true; } + if (!vfio_multifd_transfer_supported()) { + error_setg(errp, + "%s: Multifd device transfer requested but unsupported in the current config", + vbasedev->name); + return false; + } + if (alloc_multifd) { assert(!migration->multifd); migration->multifd = vfio_multifd_new(); diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index c1cee280ae..1bbf15cea3 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -3381,6 +3381,9 @@ static const 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_ON_OFF_AUTO("x-migration-multifd-transfer", VFIOPCIDevice, + vbasedev.migration_multifd_transfer, + 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), @@ -3553,6 +3556,10 @@ static void vfio_pci_dev_class_init(ObjectClass *klass, void *data) "Skip config space check for Vendor Specific Capability. " "Setting to false will enforce strict checking of VSC content " "(DEBUG)"); + object_class_property_set_description(klass, /* 10.0 */ + "x-migration-multifd-transfer", + "Transfer this device state via " + "multifd channels when live migrating it"); } static const TypeInfo vfio_pci_dev_info = { diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h index 961931d9f4..04b123a6c9 100644 --- a/include/hw/vfio/vfio-common.h +++ b/include/hw/vfio/vfio-common.h @@ -91,6 +91,7 @@ typedef struct VFIOMigration { uint64_t mig_flags; uint64_t precopy_init_size; uint64_t precopy_dirty_size; + bool multifd_transfer; VFIOMultifd *multifd; bool initial_data_sent; @@ -153,6 +154,7 @@ typedef struct VFIODevice { bool no_mmap; bool ram_block_discard_allowed; OnOffAuto enable_migration; + OnOffAuto migration_multifd_transfer; bool migration_events; VFIODeviceOps *ops; unsigned int num_irqs; |