From 8bbcb64a71d84627b0171a205a5f3586eaa1e081 Mon Sep 17 00:00:00 2001 From: Avihai Horon Date: Wed, 28 Jun 2023 10:31:12 +0300 Subject: [PATCH] vfio/migration: Make VFIO migration non-experimental MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The major parts of VFIO migration are supported today in QEMU. This includes basic VFIO migration, device dirty page tracking and precopy support. Thus, at this point in time, it seems appropriate to make VFIO migration non-experimental: remove the x prefix from enable_migration property, change it to ON_OFF_AUTO and let the default value be AUTO. In addition, make the following adjustments: 1. When enable_migration is ON and migration is not supported, fail VFIO device realization. 2. When enable_migration is AUTO (i.e., not explicitly enabled), require device dirty tracking support. This is because device dirty tracking is currently the only method to do dirty page tracking, which is essential for migrating in a reasonable downtime. Setting enable_migration to ON will not require device dirty tracking. 3. Make migration error and blocker messages more elaborate. 4. Remove error prints in vfio_migration_query_flags(). 5. Rename trace_vfio_migration_probe() to trace_vfio_migration_realize(). Signed-off-by: Avihai Horon Reviewed-by: Joao Martins Reviewed-by: Cédric Le Goater Reviewed-by: Alex Williamson Signed-off-by: Cédric Le Goater --- hw/vfio/common.c | 16 ++++++- hw/vfio/migration.c | 79 +++++++++++++++++++++++------------ hw/vfio/pci.c | 4 +- hw/vfio/trace-events | 2 +- include/hw/vfio/vfio-common.h | 6 +-- 5 files changed, 73 insertions(+), 34 deletions(-) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 28ec9e999c..77e2ee0e5c 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -381,7 +381,7 @@ static unsigned int vfio_migratable_device_num(void) return device_num; } -int vfio_block_multiple_devices_migration(Error **errp) +int vfio_block_multiple_devices_migration(VFIODevice *vbasedev, Error **errp) { int ret; @@ -390,6 +390,12 @@ int vfio_block_multiple_devices_migration(Error **errp) return 0; } + if (vbasedev->enable_migration == ON_OFF_AUTO_ON) { + error_setg(errp, "Migration is currently not supported with multiple " + "VFIO devices"); + return -EINVAL; + } + error_setg(&multiple_devices_migration_blocker, "Migration is currently not supported with multiple " "VFIO devices"); @@ -427,7 +433,7 @@ static bool vfio_viommu_preset(void) return false; } -int vfio_block_giommu_migration(Error **errp) +int vfio_block_giommu_migration(VFIODevice *vbasedev, Error **errp) { int ret; @@ -436,6 +442,12 @@ int vfio_block_giommu_migration(Error **errp) return 0; } + if (vbasedev->enable_migration == ON_OFF_AUTO_ON) { + error_setg(errp, + "Migration is currently not supported with vIOMMU enabled"); + return -EINVAL; + } + error_setg(&giommu_migration_blocker, "Migration is currently not supported with vIOMMU enabled"); ret = migrate_add_blocker(giommu_migration_blocker, errp); diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c index 7cf143926c..1db7d52ab2 100644 --- a/hw/vfio/migration.c +++ b/hw/vfio/migration.c @@ -724,14 +724,6 @@ static int vfio_migration_query_flags(VFIODevice *vbasedev, uint64_t *mig_flags) feature->argsz = sizeof(buf); feature->flags = VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_MIGRATION; if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) { - if (errno == ENOTTY) { - error_report("%s: VFIO migration is not supported in kernel", - vbasedev->name); - } else { - error_report("%s: Failed to query VFIO migration support, err: %s", - vbasedev->name, strerror(errno)); - } - return -errno; } @@ -810,6 +802,27 @@ static int vfio_migration_init(VFIODevice *vbasedev) return 0; } +static int vfio_block_migration(VFIODevice *vbasedev, Error *err, Error **errp) +{ + int ret; + + if (vbasedev->enable_migration == ON_OFF_AUTO_ON) { + error_propagate(errp, err); + return -EINVAL; + } + + vbasedev->migration_blocker = error_copy(err); + error_free(err); + + ret = migrate_add_blocker(vbasedev->migration_blocker, errp); + if (ret < 0) { + error_free(vbasedev->migration_blocker); + vbasedev->migration_blocker = NULL; + } + + return ret; +} + /* ---------------------------------------------------------------------- */ int64_t vfio_mig_bytes_transferred(void) @@ -824,40 +837,54 @@ void vfio_reset_bytes_transferred(void) int vfio_migration_realize(VFIODevice *vbasedev, Error **errp) { - int ret = -ENOTSUP; + Error *err = NULL; + int ret; - if (!vbasedev->enable_migration) { - goto add_blocker; + if (vbasedev->enable_migration == ON_OFF_AUTO_OFF) { + error_setg(&err, "%s: Migration is disabled for VFIO device", + vbasedev->name); + return vfio_block_migration(vbasedev, err, errp); } ret = vfio_migration_init(vbasedev); if (ret) { - goto add_blocker; + if (ret == -ENOTTY) { + error_setg(&err, "%s: VFIO migration is not supported in kernel", + vbasedev->name); + } else { + error_setg(&err, + "%s: Migration couldn't be initialized for VFIO device, " + "err: %d (%s)", + vbasedev->name, ret, strerror(-ret)); + } + + return vfio_block_migration(vbasedev, err, errp); } - ret = vfio_block_multiple_devices_migration(errp); + if (!vbasedev->dirty_pages_supported) { + if (vbasedev->enable_migration == ON_OFF_AUTO_AUTO) { + error_setg(&err, + "%s: VFIO device doesn't support device dirty tracking", + vbasedev->name); + return vfio_block_migration(vbasedev, err, errp); + } + + warn_report("%s: VFIO device doesn't support device dirty tracking", + vbasedev->name); + } + + ret = vfio_block_multiple_devices_migration(vbasedev, errp); if (ret) { return ret; } - ret = vfio_block_giommu_migration(errp); + ret = vfio_block_giommu_migration(vbasedev, errp); if (ret) { return ret; } - trace_vfio_migration_probe(vbasedev->name); + trace_vfio_migration_realize(vbasedev->name); return 0; - -add_blocker: - error_setg(&vbasedev->migration_blocker, - "VFIO device doesn't support migration"); - - ret = migrate_add_blocker(vbasedev->migration_blocker, errp); - if (ret < 0) { - error_free(vbasedev->migration_blocker); - vbasedev->migration_blocker = NULL; - } - return ret; } void vfio_migration_exit(VFIODevice *vbasedev) diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index 8fb2c53a63..73e19a04b2 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -3347,8 +3347,8 @@ static Property vfio_pci_dev_properties[] = { VFIO_FEATURE_ENABLE_REQ_BIT, true), DEFINE_PROP_BIT("x-igd-opregion", VFIOPCIDevice, features, VFIO_FEATURE_ENABLE_IGD_OPREGION_BIT, false), - DEFINE_PROP_BOOL("x-enable-migration", VFIOPCIDevice, - vbasedev.enable_migration, false), + DEFINE_PROP_ON_OFF_AUTO("enable-migration", VFIOPCIDevice, + vbasedev.enable_migration, ON_OFF_AUTO_AUTO), DEFINE_PROP_BOOL("x-no-mmap", VFIOPCIDevice, vbasedev.no_mmap, false), DEFINE_PROP_BOOL("x-balloon-allowed", VFIOPCIDevice, vbasedev.ram_block_discard_allowed, false), diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events index e328d644d2..ee7509e68e 100644 --- a/hw/vfio/trace-events +++ b/hw/vfio/trace-events @@ -155,7 +155,7 @@ vfio_load_cleanup(const char *name) " (%s)" vfio_load_device_config_state(const char *name) " (%s)" vfio_load_state(const char *name, uint64_t data) " (%s) data 0x%"PRIx64 vfio_load_state_device_data(const char *name, uint64_t data_size, int ret) " (%s) size 0x%"PRIx64" ret %d" -vfio_migration_probe(const char *name) " (%s)" +vfio_migration_realize(const char *name) " (%s)" vfio_migration_set_state(const char *name, const char *state) " (%s) state %s" vfio_migration_state_notifier(const char *name, const char *state) " (%s) state %s" vfio_save_block(const char *name, int data_size) " (%s) data_size %d" diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h index 1d19c6f251..93429b9abb 100644 --- a/include/hw/vfio/vfio-common.h +++ b/include/hw/vfio/vfio-common.h @@ -139,7 +139,7 @@ typedef struct VFIODevice { bool needs_reset; bool no_mmap; bool ram_block_discard_allowed; - bool enable_migration; + OnOffAuto enable_migration; VFIODeviceOps *ops; unsigned int num_irqs; unsigned int num_regions; @@ -225,9 +225,9 @@ typedef QLIST_HEAD(VFIOGroupList, VFIOGroup) VFIOGroupList; extern VFIOGroupList vfio_group_list; bool vfio_mig_active(void); -int vfio_block_multiple_devices_migration(Error **errp); +int vfio_block_multiple_devices_migration(VFIODevice *vbasedev, Error **errp); void vfio_unblock_multiple_devices_migration(void); -int vfio_block_giommu_migration(Error **errp); +int vfio_block_giommu_migration(VFIODevice *vbasedev, Error **errp); int64_t vfio_mig_bytes_transferred(void); void vfio_reset_bytes_transferred(void);