| Message ID | 20230112085020.15866-10-avihaih@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vfio/migration: Implement VFIO migration protocol v2 | expand |
On 1/12/23 09:50, Avihai Horon wrote: > Implement the basic mandatory part of VFIO migration protocol v2. > This includes all functionality that is necessary to support > VFIO_MIGRATION_STOP_COPY part of the v2 protocol. > > The two protocols, v1 and v2, will co-exist and in the following patches > v1 protocol code will be removed. > > There are several main differences between v1 and v2 protocols: > - VFIO device state is now represented as a finite state machine instead > of a bitmap. > > - Migration interface with kernel is now done using VFIO_DEVICE_FEATURE > ioctl and normal read() and write() instead of the migration region. > > - Pre-copy is made optional in v2 protocol. Support for pre-copy will be > added later on. > > Detailed information about VFIO migration protocol v2 and its difference > compared to v1 protocol can be found here [1]. > > [1] > https://lore.kernel.org/all/20220224142024.147653-10-yishaih@nvidia.com/ > > Signed-off-by: Avihai Horon <avihaih@nvidia.com> LGTM, Reviewed-by: Cédric Le Goater <clg@redhat.com> Still a small issue below, > --- > include/hw/vfio/vfio-common.h | 5 + > hw/vfio/common.c | 19 +- > hw/vfio/migration.c | 455 +++++++++++++++++++++++++++++++--- > hw/vfio/trace-events | 7 + > 4 files changed, 447 insertions(+), 39 deletions(-) > > diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h > index bbaf72ba00..2ec3346fea 100644 > --- a/include/hw/vfio/vfio-common.h > +++ b/include/hw/vfio/vfio-common.h > @@ -66,6 +66,11 @@ typedef struct VFIOMigration { > int vm_running; > Notifier migration_state; > uint64_t pending_bytes; > + enum vfio_device_mig_state device_state; > + int data_fd; > + void *data_buffer; > + size_t data_buffer_size; > + bool v2; > } VFIOMigration; > > typedef struct VFIOAddressSpace { > diff --git a/hw/vfio/common.c b/hw/vfio/common.c > index 550b2d7ded..dcaa77d2a8 100644 > --- a/hw/vfio/common.c > +++ b/hw/vfio/common.c > @@ -355,10 +355,18 @@ static bool vfio_devices_all_dirty_tracking(VFIOContainer *container) > return false; > } > > - if ((vbasedev->pre_copy_dirty_page_tracking == ON_OFF_AUTO_OFF) && > + if (!migration->v2 && > + (vbasedev->pre_copy_dirty_page_tracking == ON_OFF_AUTO_OFF) && > (migration->device_state_v1 & VFIO_DEVICE_STATE_V1_RUNNING)) { > return false; > } > + > + if (migration->v2 && > + (vbasedev->pre_copy_dirty_page_tracking == ON_OFF_AUTO_OFF) && > + (migration->device_state == VFIO_DEVICE_STATE_RUNNING || > + migration->device_state == VFIO_DEVICE_STATE_RUNNING_P2P)) { > + return false; > + } > } > } > return true; > @@ -385,7 +393,14 @@ static bool vfio_devices_all_running_and_mig_active(VFIOContainer *container) > return false; > } > > - if (migration->device_state_v1 & VFIO_DEVICE_STATE_V1_RUNNING) { > + if (!migration->v2 && > + migration->device_state_v1 & VFIO_DEVICE_STATE_V1_RUNNING) { > + continue; > + } > + > + if (migration->v2 && > + (migration->device_state == VFIO_DEVICE_STATE_RUNNING || > + migration->device_state == VFIO_DEVICE_STATE_RUNNING_P2P)) { > continue; > } else { > return false; > diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c > index 9df859f4d3..08f53189fa 100644 > --- a/hw/vfio/migration.c > +++ b/hw/vfio/migration.c > @@ -10,6 +10,7 @@ > #include "qemu/osdep.h" > #include "qemu/main-loop.h" > #include "qemu/cutils.h" > +#include "qemu/units.h" > #include <linux/vfio.h> > #include <sys/ioctl.h> > > @@ -44,8 +45,103 @@ > #define VFIO_MIG_FLAG_DEV_SETUP_STATE (0xffffffffef100003ULL) > #define VFIO_MIG_FLAG_DEV_DATA_STATE (0xffffffffef100004ULL) > > +/* > + * This is an arbitrary size based on migration of mlx5 devices, where typically > + * total device migration size is on the order of 100s of MB. Testing with > + * larger values, e.g. 128MB and 1GB, did not show a performance improvement. > + */ > +#define VFIO_MIG_DEFAULT_DATA_BUFFER_SIZE (1 * MiB) > + > static int64_t bytes_transferred; > > +static const char *mig_state_to_str(enum vfio_device_mig_state state) > +{ > + switch (state) { > + case VFIO_DEVICE_STATE_ERROR: > + return "ERROR"; > + case VFIO_DEVICE_STATE_STOP: > + return "STOP"; > + case VFIO_DEVICE_STATE_RUNNING: > + return "RUNNING"; > + case VFIO_DEVICE_STATE_STOP_COPY: > + return "STOP_COPY"; > + case VFIO_DEVICE_STATE_RESUMING: > + return "RESUMING"; > + case VFIO_DEVICE_STATE_RUNNING_P2P: > + return "RUNNING_P2P"; > + default: > + return "UNKNOWN STATE"; > + } > +} > + > +static int vfio_migration_set_state(VFIODevice *vbasedev, > + enum vfio_device_mig_state new_state, > + enum vfio_device_mig_state recover_state) > +{ > + VFIOMigration *migration = vbasedev->migration; > + uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) + > + sizeof(struct vfio_device_feature_mig_state), > + sizeof(uint64_t))] = {}; > + struct vfio_device_feature *feature = (struct vfio_device_feature *)buf; > + struct vfio_device_feature_mig_state *mig_state = > + (struct vfio_device_feature_mig_state *)feature->data; > + > + feature->argsz = sizeof(buf); > + feature->flags = > + VFIO_DEVICE_FEATURE_SET | VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE; > + mig_state->device_state = new_state; > + if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) { > + /* Try to set the device in some good state */ > + int err = -errno; > + > + error_report( > + "%s: Failed setting device state to %s, err: %s. Setting device in recover state %s", > + vbasedev->name, mig_state_to_str(new_state), > + strerror(errno), mig_state_to_str(recover_state)); > + > + mig_state->device_state = recover_state; > + if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) { > + err = -errno; > + error_report( > + "%s: Failed setting device in recover state, err: %s. Resetting device", > + vbasedev->name, strerror(errno)); > + > + if (ioctl(vbasedev->fd, VFIO_DEVICE_RESET)) { > + hw_error("%s: Failed resetting device, err: %s", vbasedev->name, > + strerror(errno)); > + } > + > + migration->device_state = VFIO_DEVICE_STATE_RUNNING; > + > + return err; > + } > + > + migration->device_state = recover_state; > + > + return err; > + } > + > + migration->device_state = new_state; > + if (mig_state->data_fd != -1) { > + if (migration->data_fd != -1) { > + /* > + * This can happen if the device is asynchronously reset and > + * terminates a data transfer. > + */ > + error_report("%s: data_fd out of sync", vbasedev->name); > + close(mig_state->data_fd); > + > + return -EBADF; > + } > + > + migration->data_fd = mig_state->data_fd; > + } > + > + trace_vfio_migration_set_state(vbasedev->name, mig_state_to_str(new_state)); > + > + return 0; > +} > + > static inline int vfio_mig_access(VFIODevice *vbasedev, void *val, int count, > off_t off, bool iswrite) > { > @@ -260,6 +356,18 @@ static int vfio_save_buffer(QEMUFile *f, VFIODevice *vbasedev, uint64_t *size) > return ret; > } > > +static int vfio_load_buffer(QEMUFile *f, VFIODevice *vbasedev, > + uint64_t data_size) > +{ > + VFIOMigration *migration = vbasedev->migration; > + int ret; > + > + ret = qemu_file_get_to_fd(f, migration->data_fd, data_size); > + trace_vfio_load_state_device_data(vbasedev->name, data_size, ret); > + > + return ret; > +} > + > static int vfio_v1_load_buffer(QEMUFile *f, VFIODevice *vbasedev, > uint64_t data_size) > { > @@ -394,6 +502,14 @@ static int vfio_load_device_config_state(QEMUFile *f, void *opaque) > return qemu_file_get_error(f); > } > > +static void vfio_migration_cleanup(VFIODevice *vbasedev) > +{ > + VFIOMigration *migration = vbasedev->migration; > + > + close(migration->data_fd); > + migration->data_fd = -1; > +} > + > static void vfio_migration_v1_cleanup(VFIODevice *vbasedev) > { > VFIOMigration *migration = vbasedev->migration; > @@ -403,8 +519,80 @@ static void vfio_migration_v1_cleanup(VFIODevice *vbasedev) > } > } > > +static int vfio_query_stop_copy_size(VFIODevice *vbasedev, > + uint64_t *stop_copy_size) > +{ > + uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) + > + sizeof(struct vfio_device_feature_mig_data_size), > + sizeof(uint64_t))] = {}; > + struct vfio_device_feature *feature = (struct vfio_device_feature *)buf; > + struct vfio_device_feature_mig_data_size *mig_data_size = > + (struct vfio_device_feature_mig_data_size *)feature->data; > + > + feature->argsz = sizeof(buf); > + feature->flags = > + VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_MIG_DATA_SIZE; > + > + if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) { > + return -errno; > + } > + > + *stop_copy_size = mig_data_size->stop_copy_length; > + > + return 0; > +} > + > +/* Returns 1 if end-of-stream is reached, 0 if more data and -1 if error */ > +static int vfio_save_block(QEMUFile *f, VFIOMigration *migration) > +{ > + ssize_t data_size; > + > + data_size = read(migration->data_fd, migration->data_buffer, > + migration->data_buffer_size); > + if (data_size < 0) { > + return -errno; > + } > + if (data_size == 0) { > + return 1; > + } > + > + qemu_put_be64(f, VFIO_MIG_FLAG_DEV_DATA_STATE); > + qemu_put_be64(f, data_size); > + qemu_put_buffer(f, migration->data_buffer, data_size); > + bytes_transferred += data_size; > + > + trace_vfio_save_block(migration->vbasedev->name, data_size); > + > + return qemu_file_get_error(f); > +} > + > /* ---------------------------------------------------------------------- */ > > +static int vfio_save_setup(QEMUFile *f, void *opaque) > +{ > + VFIODevice *vbasedev = opaque; > + VFIOMigration *migration = vbasedev->migration; > + uint64_t stop_copy_size = VFIO_MIG_DEFAULT_DATA_BUFFER_SIZE; > + > + qemu_put_be64(f, VFIO_MIG_FLAG_DEV_SETUP_STATE); > + > + vfio_query_stop_copy_size(vbasedev, &stop_copy_size); > + migration->data_buffer_size = MIN(VFIO_MIG_DEFAULT_DATA_BUFFER_SIZE, > + stop_copy_size); > + migration->data_buffer = g_try_malloc0(migration->data_buffer_size); > + if (!migration->data_buffer) { > + error_report("%s: Failed to allocate migration data buffer", > + vbasedev->name); > + return -ENOMEM; > + } > + > + trace_vfio_save_setup(vbasedev->name, migration->data_buffer_size); > + > + qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE); > + > + return qemu_file_get_error(f); > +} > + > static int vfio_v1_save_setup(QEMUFile *f, void *opaque) > { > VFIODevice *vbasedev = opaque; > @@ -448,6 +636,17 @@ static int vfio_v1_save_setup(QEMUFile *f, void *opaque) > return 0; > } > > +static void vfio_save_cleanup(void *opaque) > +{ > + VFIODevice *vbasedev = opaque; > + VFIOMigration *migration = vbasedev->migration; > + > + g_free(migration->data_buffer); > + migration->data_buffer = NULL; > + vfio_migration_cleanup(vbasedev); > + trace_vfio_save_cleanup(vbasedev->name); > +} > + > static void vfio_v1_save_cleanup(void *opaque) > { > VFIODevice *vbasedev = opaque; > @@ -456,6 +655,31 @@ static void vfio_v1_save_cleanup(void *opaque) > trace_vfio_save_cleanup(vbasedev->name); > } > > +/* > + * Migration size of VFIO devices can be as little as a few KBs or as big as > + * many GBs. This value should be big enough to cover the worst case. > + */ > +#define VFIO_MIG_STOP_COPY_SIZE (100 * GiB) > +static void vfio_save_pending(void *opaque, uint64_t threshold_size, > + uint64_t *res_precopy_only, > + uint64_t *res_compatible, > + uint64_t *res_postcopy_only) > +{ > + VFIODevice *vbasedev = opaque; > + uint64_t stop_copy_size = VFIO_MIG_STOP_COPY_SIZE; > + > + /* > + * If getting pending migration size fails, VFIO_MIG_STOP_COPY_SIZE is > + * reported so downtime limit won't be violated. > + */ > + vfio_query_stop_copy_size(vbasedev, &stop_copy_size); > + *res_precopy_only += stop_copy_size; > + > + trace_vfio_save_pending(vbasedev->name, *res_precopy_only, > + *res_postcopy_only, *res_compatible, > + stop_copy_size); > +} > + > static void vfio_v1_save_pending(void *opaque, uint64_t threshold_size, > uint64_t *res_precopy_only, > uint64_t *res_compatible, > @@ -523,6 +747,41 @@ static int vfio_save_iterate(QEMUFile *f, void *opaque) > return 0; > } > > +static int vfio_save_complete_precopy(QEMUFile *f, void *opaque) > +{ > + VFIODevice *vbasedev = opaque; > + enum vfio_device_mig_state recover_state; > + int ret; > + > + /* We reach here with device state STOP only */ > + recover_state = VFIO_DEVICE_STATE_STOP; > + ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_STOP_COPY, > + recover_state); > + if (ret) { > + return ret; > + } > + > + do { > + ret = vfio_save_block(f, vbasedev->migration); > + if (ret < 0) { > + return ret; > + } > + } while (!ret); > + > + qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE); > + ret = qemu_file_get_error(f); > + if (ret) { > + return ret; > + } > + > + recover_state = VFIO_DEVICE_STATE_ERROR; > + ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_STOP, > + recover_state); > + trace_vfio_save_complete_precopy(vbasedev->name, ret); > + > + return ret; > +} > + > static int vfio_v1_save_complete_precopy(QEMUFile *f, void *opaque) > { > VFIODevice *vbasedev = opaque; > @@ -592,6 +851,14 @@ static void vfio_save_state(QEMUFile *f, void *opaque) > } > } > > +static int vfio_load_setup(QEMUFile *f, void *opaque) > +{ > + VFIODevice *vbasedev = opaque; > + > + return vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_RESUMING, > + vbasedev->migration->device_state); > +} > + > static int vfio_v1_load_setup(QEMUFile *f, void *opaque) > { > VFIODevice *vbasedev = opaque; > @@ -619,6 +886,16 @@ static int vfio_v1_load_setup(QEMUFile *f, void *opaque) > return ret; > } > > +static int vfio_load_cleanup(void *opaque) > +{ > + VFIODevice *vbasedev = opaque; > + > + vfio_migration_cleanup(vbasedev); > + trace_vfio_load_cleanup(vbasedev->name); > + > + return 0; > +} > + > static int vfio_v1_load_cleanup(void *opaque) > { > VFIODevice *vbasedev = opaque; > @@ -661,7 +938,11 @@ static int vfio_load_state(QEMUFile *f, void *opaque, int version_id) > uint64_t data_size = qemu_get_be64(f); > > if (data_size) { > - ret = vfio_v1_load_buffer(f, vbasedev, data_size); > + if (vbasedev->migration->v2) { > + ret = vfio_load_buffer(f, vbasedev, data_size); > + } else { > + ret = vfio_v1_load_buffer(f, vbasedev, data_size); > + } > if (ret < 0) { > return ret; > } > @@ -682,6 +963,17 @@ static int vfio_load_state(QEMUFile *f, void *opaque, int version_id) > return ret; > } > > +static const SaveVMHandlers savevm_vfio_handlers = { > + .save_setup = vfio_save_setup, > + .save_cleanup = vfio_save_cleanup, > + .save_live_pending = vfio_save_pending, > + .save_live_complete_precopy = vfio_save_complete_precopy, > + .save_state = vfio_save_state, > + .load_setup = vfio_load_setup, > + .load_cleanup = vfio_load_cleanup, > + .load_state = vfio_load_state, > +}; > + > static SaveVMHandlers savevm_vfio_v1_handlers = { > .save_setup = vfio_v1_save_setup, > .save_cleanup = vfio_v1_save_cleanup, > @@ -696,6 +988,34 @@ static SaveVMHandlers savevm_vfio_v1_handlers = { > > /* ---------------------------------------------------------------------- */ > > +static void vfio_vmstate_change(void *opaque, bool running, RunState state) > +{ > + VFIODevice *vbasedev = opaque; > + enum vfio_device_mig_state new_state; > + int ret; > + > + if (running) { > + new_state = VFIO_DEVICE_STATE_RUNNING; > + } else { > + new_state = VFIO_DEVICE_STATE_STOP; > + } > + > + ret = vfio_migration_set_state(vbasedev, new_state, > + VFIO_DEVICE_STATE_ERROR); > + if (ret) { > + /* > + * Migration should be aborted in this case, but vm_state_notify() > + * currently does not support reporting failures. > + */ > + if (migrate_get_current()->to_dst_file) { > + qemu_file_set_error(migrate_get_current()->to_dst_file, ret); > + } > + } > + > + trace_vfio_vmstate_change(vbasedev->name, running, RunState_str(state), > + mig_state_to_str(new_state)); > +} > + > static void vfio_v1_vmstate_change(void *opaque, bool running, RunState state) > { > VFIODevice *vbasedev = opaque; > @@ -769,12 +1089,17 @@ static void vfio_migration_state_notifier(Notifier *notifier, void *data) > case MIGRATION_STATUS_CANCELLED: > case MIGRATION_STATUS_FAILED: > bytes_transferred = 0; > - ret = vfio_migration_v1_set_state(vbasedev, > - ~(VFIO_DEVICE_STATE_V1_SAVING | > - VFIO_DEVICE_STATE_V1_RESUMING), > - VFIO_DEVICE_STATE_V1_RUNNING); > - if (ret) { > - error_report("%s: Failed to set state RUNNING", vbasedev->name); > + if (migration->v2) { > + vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_RUNNING, > + VFIO_DEVICE_STATE_ERROR); > + } else { > + ret = vfio_migration_v1_set_state(vbasedev, > + ~(VFIO_DEVICE_STATE_V1_SAVING | > + VFIO_DEVICE_STATE_V1_RESUMING), > + VFIO_DEVICE_STATE_V1_RUNNING); > + if (ret) { > + error_report("%s: Failed to set state RUNNING", vbasedev->name); > + } > } > } > } > @@ -783,12 +1108,42 @@ static void vfio_migration_exit(VFIODevice *vbasedev) > { > VFIOMigration *migration = vbasedev->migration; > > - vfio_region_exit(&migration->region); > - vfio_region_finalize(&migration->region); > + if (!migration->v2) { > + vfio_region_exit(&migration->region); > + vfio_region_finalize(&migration->region); > + } > g_free(vbasedev->migration); > vbasedev->migration = NULL; > } > > +static int vfio_migration_query_flags(VFIODevice *vbasedev, uint64_t *mig_flags) > +{ > + uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) + > + sizeof(struct vfio_device_feature_migration), > + sizeof(uint64_t))] = {}; > + struct vfio_device_feature *feature = (struct vfio_device_feature *)buf; > + struct vfio_device_feature_migration *mig = > + (struct vfio_device_feature_migration *)feature->data; > + > + 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; > + } > + > + *mig_flags = mig->flags; > + > + return 0; > +} > + > static int vfio_migration_init(VFIODevice *vbasedev) > { > int ret; > @@ -797,6 +1152,7 @@ static int vfio_migration_init(VFIODevice *vbasedev) > char id[256] = ""; > g_autofree char *path = NULL, *oid = NULL; > struct vfio_region_info *info; > + uint64_t mig_flags; GCC 12 reports : ../hw/vfio/migration.c: In function ‘vfio_migration_init’: ../hw/vfio/migration.c:1170:25: error: ‘mig_flags’ may be used uninitialized [-Werror=maybe-uninitialized] 1170 | if (!(mig_flags & VFIO_MIGRATION_STOP_COPY)) { | ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~ ../hw/vfio/migration.c:1155:14: note: ‘mig_flags’ was declared here 1155 | uint64_t mig_flags; | ^~~~~~~~~ cc1: all warnings being treated as errors You will need a little fix for that. May be it can be done at merge time : - uint64_t mig_flags; + uint64_t mig_flags = 0; Thanks, C. > > if (!vbasedev->ops->vfio_get_object) { > return -EINVAL; > @@ -807,34 +1163,50 @@ static int vfio_migration_init(VFIODevice *vbasedev) > return -EINVAL; > } > > - ret = vfio_get_dev_region_info(vbasedev, > - VFIO_REGION_TYPE_MIGRATION_DEPRECATED, > - VFIO_REGION_SUBTYPE_MIGRATION_DEPRECATED, > - &info); > - if (ret) { > - return ret; > - } > + ret = vfio_migration_query_flags(vbasedev, &mig_flags); > + if (!ret) { > + /* Migration v2 */ > + /* Basic migration functionality must be supported */ > + if (!(mig_flags & VFIO_MIGRATION_STOP_COPY)) { > + return -EOPNOTSUPP; > + } > + vbasedev->migration = g_new0(VFIOMigration, 1); > + vbasedev->migration->device_state = VFIO_DEVICE_STATE_RUNNING; > + vbasedev->migration->data_fd = -1; > + vbasedev->migration->v2 = true; > + } else if (ret == -ENOTTY) { > + /* Migration v1 */ > + ret = vfio_get_dev_region_info(vbasedev, > + VFIO_REGION_TYPE_MIGRATION_DEPRECATED, > + VFIO_REGION_SUBTYPE_MIGRATION_DEPRECATED, > + &info); > + if (ret) { > + return ret; > + } > > - vbasedev->migration = g_new0(VFIOMigration, 1); > - vbasedev->migration->device_state_v1 = VFIO_DEVICE_STATE_V1_RUNNING; > - vbasedev->migration->vm_running = runstate_is_running(); > + vbasedev->migration = g_new0(VFIOMigration, 1); > + vbasedev->migration->device_state_v1 = VFIO_DEVICE_STATE_V1_RUNNING; > + vbasedev->migration->vm_running = runstate_is_running(); > > - ret = vfio_region_setup(obj, vbasedev, &vbasedev->migration->region, > - info->index, "migration"); > - if (ret) { > - error_report("%s: Failed to setup VFIO migration region %d: %s", > - vbasedev->name, info->index, strerror(-ret)); > - goto err; > - } > + ret = vfio_region_setup(obj, vbasedev, &vbasedev->migration->region, > + info->index, "migration"); > + if (ret) { > + error_report("%s: Failed to setup VFIO migration region %d: %s", > + vbasedev->name, info->index, strerror(-ret)); > + goto err; > + } > > - if (!vbasedev->migration->region.size) { > - error_report("%s: Invalid zero-sized VFIO migration region %d", > - vbasedev->name, info->index); > - ret = -EINVAL; > - goto err; > - } > + if (!vbasedev->migration->region.size) { > + error_report("%s: Invalid zero-sized VFIO migration region %d", > + vbasedev->name, info->index); > + ret = -EINVAL; > + goto err; > + } > > - g_free(info); > + g_free(info); > + } else { > + return ret; > + } > > migration = vbasedev->migration; > migration->vbasedev = vbasedev; > @@ -847,11 +1219,20 @@ static int vfio_migration_init(VFIODevice *vbasedev) > } > strpadcpy(id, sizeof(id), path, '\0'); > > - register_savevm_live(id, VMSTATE_INSTANCE_ID_ANY, 1, > - &savevm_vfio_v1_handlers, vbasedev); > + if (migration->v2) { > + register_savevm_live(id, VMSTATE_INSTANCE_ID_ANY, 1, > + &savevm_vfio_handlers, vbasedev); > + > + migration->vm_state = qdev_add_vm_change_state_handler( > + vbasedev->dev, vfio_vmstate_change, vbasedev); > + } else { > + register_savevm_live(id, VMSTATE_INSTANCE_ID_ANY, 1, > + &savevm_vfio_v1_handlers, vbasedev); > + > + migration->vm_state = qdev_add_vm_change_state_handler( > + vbasedev->dev, vfio_v1_vmstate_change, vbasedev); > + } > > - migration->vm_state = qdev_add_vm_change_state_handler( > - vbasedev->dev, vfio_v1_vmstate_change, vbasedev); > migration->migration_state.notify = vfio_migration_state_notifier; > add_migration_state_change_notifier(&migration->migration_state); > return 0; > diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events > index 9eb9aff295..e7b3b4658c 100644 > --- a/hw/vfio/trace-events > +++ b/hw/vfio/trace-events > @@ -149,20 +149,27 @@ vfio_display_edid_write_error(void) "" > > # migration.c > vfio_migration_probe(const char *name) " (%s)" > +vfio_migration_set_state(const char *name, const char *state) " (%s) state %s" > vfio_migration_v1_set_state(const char *name, uint32_t state) " (%s) state %d" > +vfio_vmstate_change(const char *name, int running, const char *reason, const char *dev_state) " (%s) running %d reason %s device state %s" > vfio_v1_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" > +vfio_save_setup(const char *name, uint64_t data_buffer_size) " (%s) data buffer size 0x%"PRIx64 > vfio_v1_save_setup(const char *name) " (%s)" > vfio_save_cleanup(const char *name) " (%s)" > vfio_save_buffer(const char *name, uint64_t data_offset, uint64_t data_size, uint64_t pending) " (%s) Offset 0x%"PRIx64" size 0x%"PRIx64" pending 0x%"PRIx64 > vfio_update_pending(const char *name, uint64_t pending) " (%s) pending 0x%"PRIx64 > vfio_save_device_config_state(const char *name) " (%s)" > +vfio_save_pending(const char *name, uint64_t precopy, uint64_t postcopy, uint64_t compatible, uint64_t stopcopy_size) " (%s) precopy 0x%"PRIx64" postcopy 0x%"PRIx64" compatible 0x%"PRIx64" stopcopy size 0x%"PRIx64 > vfio_v1_save_pending(const char *name, uint64_t precopy, uint64_t postcopy, uint64_t compatible) " (%s) precopy 0x%"PRIx64" postcopy 0x%"PRIx64" compatible 0x%"PRIx64 > vfio_save_iterate(const char *name, int data_size) " (%s) data_size %d" > +vfio_save_complete_precopy(const char *name, int ret) " (%s) ret %d" > vfio_v1_save_complete_precopy(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_v1_load_state_device_data(const char *name, uint64_t data_offset, uint64_t data_size) " (%s) Offset 0x%"PRIx64" size 0x%"PRIx64 > +vfio_load_state_device_data(const char *name, uint64_t data_size, int ret) " (%s) size 0x%"PRIx64" ret %d" > vfio_load_cleanup(const char *name) " (%s)" > vfio_get_dirty_bitmap(int fd, uint64_t iova, uint64_t size, uint64_t bitmap_size, uint64_t start) "container fd=%d, iova=0x%"PRIx64" size= 0x%"PRIx64" bitmap_size=0x%"PRIx64" start=0x%"PRIx64 > vfio_iommu_map_dirty_notify(uint64_t iova_start, uint64_t iova_end) "iommu dirty @ 0x%"PRIx64" - 0x%"PRIx64 > +vfio_save_block(const char *name, int data_size) " (%s) data_size %d"
On 13/01/2023 18:13, Cédric Le Goater wrote: > External email: Use caution opening links or attachments > > > On 1/12/23 09:50, Avihai Horon wrote: >> Implement the basic mandatory part of VFIO migration protocol v2. >> This includes all functionality that is necessary to support >> VFIO_MIGRATION_STOP_COPY part of the v2 protocol. >> >> The two protocols, v1 and v2, will co-exist and in the following patches >> v1 protocol code will be removed. >> >> There are several main differences between v1 and v2 protocols: >> - VFIO device state is now represented as a finite state machine instead >> of a bitmap. >> >> - Migration interface with kernel is now done using VFIO_DEVICE_FEATURE >> ioctl and normal read() and write() instead of the migration region. >> >> - Pre-copy is made optional in v2 protocol. Support for pre-copy will be >> added later on. >> >> Detailed information about VFIO migration protocol v2 and its difference >> compared to v1 protocol can be found here [1]. >> >> [1] >> https://lore.kernel.org/all/20220224142024.147653-10-yishaih@nvidia.com/ >> >> Signed-off-by: Avihai Horon <avihaih@nvidia.com> > > > LGTM, > > Reviewed-by: Cédric Le Goater <clg@redhat.com> > > Still a small issue below, > I have sent v7 with a fix for this. Thanks for reviewing! >> --- >> include/hw/vfio/vfio-common.h | 5 + >> hw/vfio/common.c | 19 +- >> hw/vfio/migration.c | 455 +++++++++++++++++++++++++++++++--- >> hw/vfio/trace-events | 7 + >> 4 files changed, 447 insertions(+), 39 deletions(-) >> >> diff --git a/include/hw/vfio/vfio-common.h >> b/include/hw/vfio/vfio-common.h >> index bbaf72ba00..2ec3346fea 100644 >> --- a/include/hw/vfio/vfio-common.h >> +++ b/include/hw/vfio/vfio-common.h >> @@ -66,6 +66,11 @@ typedef struct VFIOMigration { >> int vm_running; >> Notifier migration_state; >> uint64_t pending_bytes; >> + enum vfio_device_mig_state device_state; >> + int data_fd; >> + void *data_buffer; >> + size_t data_buffer_size; >> + bool v2; >> } VFIOMigration; >> >> typedef struct VFIOAddressSpace { >> diff --git a/hw/vfio/common.c b/hw/vfio/common.c >> index 550b2d7ded..dcaa77d2a8 100644 >> --- a/hw/vfio/common.c >> +++ b/hw/vfio/common.c >> @@ -355,10 +355,18 @@ static bool >> vfio_devices_all_dirty_tracking(VFIOContainer *container) >> return false; >> } >> >> - if ((vbasedev->pre_copy_dirty_page_tracking == >> ON_OFF_AUTO_OFF) && >> + if (!migration->v2 && >> + (vbasedev->pre_copy_dirty_page_tracking == >> ON_OFF_AUTO_OFF) && >> (migration->device_state_v1 & >> VFIO_DEVICE_STATE_V1_RUNNING)) { >> return false; >> } >> + >> + if (migration->v2 && >> + (vbasedev->pre_copy_dirty_page_tracking == >> ON_OFF_AUTO_OFF) && >> + (migration->device_state == >> VFIO_DEVICE_STATE_RUNNING || >> + migration->device_state == >> VFIO_DEVICE_STATE_RUNNING_P2P)) { >> + return false; >> + } >> } >> } >> return true; >> @@ -385,7 +393,14 @@ static bool >> vfio_devices_all_running_and_mig_active(VFIOContainer *container) >> return false; >> } >> >> - if (migration->device_state_v1 & >> VFIO_DEVICE_STATE_V1_RUNNING) { >> + if (!migration->v2 && >> + migration->device_state_v1 & >> VFIO_DEVICE_STATE_V1_RUNNING) { >> + continue; >> + } >> + >> + if (migration->v2 && >> + (migration->device_state == >> VFIO_DEVICE_STATE_RUNNING || >> + migration->device_state == >> VFIO_DEVICE_STATE_RUNNING_P2P)) { >> continue; >> } else { >> return false; >> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c >> index 9df859f4d3..08f53189fa 100644 >> --- a/hw/vfio/migration.c >> +++ b/hw/vfio/migration.c >> @@ -10,6 +10,7 @@ >> #include "qemu/osdep.h" >> #include "qemu/main-loop.h" >> #include "qemu/cutils.h" >> +#include "qemu/units.h" >> #include <linux/vfio.h> >> #include <sys/ioctl.h> >> >> @@ -44,8 +45,103 @@ >> #define VFIO_MIG_FLAG_DEV_SETUP_STATE (0xffffffffef100003ULL) >> #define VFIO_MIG_FLAG_DEV_DATA_STATE (0xffffffffef100004ULL) >> >> +/* >> + * This is an arbitrary size based on migration of mlx5 devices, >> where typically >> + * total device migration size is on the order of 100s of MB. >> Testing with >> + * larger values, e.g. 128MB and 1GB, did not show a performance >> improvement. >> + */ >> +#define VFIO_MIG_DEFAULT_DATA_BUFFER_SIZE (1 * MiB) >> + >> static int64_t bytes_transferred; >> >> +static const char *mig_state_to_str(enum vfio_device_mig_state state) >> +{ >> + switch (state) { >> + case VFIO_DEVICE_STATE_ERROR: >> + return "ERROR"; >> + case VFIO_DEVICE_STATE_STOP: >> + return "STOP"; >> + case VFIO_DEVICE_STATE_RUNNING: >> + return "RUNNING"; >> + case VFIO_DEVICE_STATE_STOP_COPY: >> + return "STOP_COPY"; >> + case VFIO_DEVICE_STATE_RESUMING: >> + return "RESUMING"; >> + case VFIO_DEVICE_STATE_RUNNING_P2P: >> + return "RUNNING_P2P"; >> + default: >> + return "UNKNOWN STATE"; >> + } >> +} >> + >> +static int vfio_migration_set_state(VFIODevice *vbasedev, >> + enum vfio_device_mig_state >> new_state, >> + enum vfio_device_mig_state >> recover_state) >> +{ >> + VFIOMigration *migration = vbasedev->migration; >> + uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) + >> + sizeof(struct >> vfio_device_feature_mig_state), >> + sizeof(uint64_t))] = {}; >> + struct vfio_device_feature *feature = (struct >> vfio_device_feature *)buf; >> + struct vfio_device_feature_mig_state *mig_state = >> + (struct vfio_device_feature_mig_state *)feature->data; >> + >> + feature->argsz = sizeof(buf); >> + feature->flags = >> + VFIO_DEVICE_FEATURE_SET | VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE; >> + mig_state->device_state = new_state; >> + if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) { >> + /* Try to set the device in some good state */ >> + int err = -errno; >> + >> + error_report( >> + "%s: Failed setting device state to %s, err: %s. Setting >> device in recover state %s", >> + vbasedev->name, mig_state_to_str(new_state), >> + strerror(errno), mig_state_to_str(recover_state)); >> + >> + mig_state->device_state = recover_state; >> + if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) { >> + err = -errno; >> + error_report( >> + "%s: Failed setting device in recover state, err: >> %s. Resetting device", >> + vbasedev->name, strerror(errno)); >> + >> + if (ioctl(vbasedev->fd, VFIO_DEVICE_RESET)) { >> + hw_error("%s: Failed resetting device, err: %s", >> vbasedev->name, >> + strerror(errno)); >> + } >> + >> + migration->device_state = VFIO_DEVICE_STATE_RUNNING; >> + >> + return err; >> + } >> + >> + migration->device_state = recover_state; >> + >> + return err; >> + } >> + >> + migration->device_state = new_state; >> + if (mig_state->data_fd != -1) { >> + if (migration->data_fd != -1) { >> + /* >> + * This can happen if the device is asynchronously reset >> and >> + * terminates a data transfer. >> + */ >> + error_report("%s: data_fd out of sync", vbasedev->name); >> + close(mig_state->data_fd); >> + >> + return -EBADF; >> + } >> + >> + migration->data_fd = mig_state->data_fd; >> + } >> + >> + trace_vfio_migration_set_state(vbasedev->name, >> mig_state_to_str(new_state)); >> + >> + return 0; >> +} >> + >> static inline int vfio_mig_access(VFIODevice *vbasedev, void *val, >> int count, >> off_t off, bool iswrite) >> { >> @@ -260,6 +356,18 @@ static int vfio_save_buffer(QEMUFile *f, >> VFIODevice *vbasedev, uint64_t *size) >> return ret; >> } >> >> +static int vfio_load_buffer(QEMUFile *f, VFIODevice *vbasedev, >> + uint64_t data_size) >> +{ >> + VFIOMigration *migration = vbasedev->migration; >> + int ret; >> + >> + ret = qemu_file_get_to_fd(f, migration->data_fd, data_size); >> + trace_vfio_load_state_device_data(vbasedev->name, data_size, ret); >> + >> + return ret; >> +} >> + >> static int vfio_v1_load_buffer(QEMUFile *f, VFIODevice *vbasedev, >> uint64_t data_size) >> { >> @@ -394,6 +502,14 @@ static int >> vfio_load_device_config_state(QEMUFile *f, void *opaque) >> return qemu_file_get_error(f); >> } >> >> +static void vfio_migration_cleanup(VFIODevice *vbasedev) >> +{ >> + VFIOMigration *migration = vbasedev->migration; >> + >> + close(migration->data_fd); >> + migration->data_fd = -1; >> +} >> + >> static void vfio_migration_v1_cleanup(VFIODevice *vbasedev) >> { >> VFIOMigration *migration = vbasedev->migration; >> @@ -403,8 +519,80 @@ static void vfio_migration_v1_cleanup(VFIODevice >> *vbasedev) >> } >> } >> >> +static int vfio_query_stop_copy_size(VFIODevice *vbasedev, >> + uint64_t *stop_copy_size) >> +{ >> + uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) + >> + sizeof(struct >> vfio_device_feature_mig_data_size), >> + sizeof(uint64_t))] = {}; >> + struct vfio_device_feature *feature = (struct >> vfio_device_feature *)buf; >> + struct vfio_device_feature_mig_data_size *mig_data_size = >> + (struct vfio_device_feature_mig_data_size *)feature->data; >> + >> + feature->argsz = sizeof(buf); >> + feature->flags = >> + VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_MIG_DATA_SIZE; >> + >> + if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) { >> + return -errno; >> + } >> + >> + *stop_copy_size = mig_data_size->stop_copy_length; >> + >> + return 0; >> +} >> + >> +/* Returns 1 if end-of-stream is reached, 0 if more data and -1 if >> error */ >> +static int vfio_save_block(QEMUFile *f, VFIOMigration *migration) >> +{ >> + ssize_t data_size; >> + >> + data_size = read(migration->data_fd, migration->data_buffer, >> + migration->data_buffer_size); >> + if (data_size < 0) { >> + return -errno; >> + } >> + if (data_size == 0) { >> + return 1; >> + } >> + >> + qemu_put_be64(f, VFIO_MIG_FLAG_DEV_DATA_STATE); >> + qemu_put_be64(f, data_size); >> + qemu_put_buffer(f, migration->data_buffer, data_size); >> + bytes_transferred += data_size; >> + >> + trace_vfio_save_block(migration->vbasedev->name, data_size); >> + >> + return qemu_file_get_error(f); >> +} >> + >> /* >> ---------------------------------------------------------------------- >> */ >> >> +static int vfio_save_setup(QEMUFile *f, void *opaque) >> +{ >> + VFIODevice *vbasedev = opaque; >> + VFIOMigration *migration = vbasedev->migration; >> + uint64_t stop_copy_size = VFIO_MIG_DEFAULT_DATA_BUFFER_SIZE; >> + >> + qemu_put_be64(f, VFIO_MIG_FLAG_DEV_SETUP_STATE); >> + >> + vfio_query_stop_copy_size(vbasedev, &stop_copy_size); >> + migration->data_buffer_size = >> MIN(VFIO_MIG_DEFAULT_DATA_BUFFER_SIZE, >> + stop_copy_size); >> + migration->data_buffer = >> g_try_malloc0(migration->data_buffer_size); >> + if (!migration->data_buffer) { >> + error_report("%s: Failed to allocate migration data buffer", >> + vbasedev->name); >> + return -ENOMEM; >> + } >> + >> + trace_vfio_save_setup(vbasedev->name, migration->data_buffer_size); >> + >> + qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE); >> + >> + return qemu_file_get_error(f); >> +} >> + >> static int vfio_v1_save_setup(QEMUFile *f, void *opaque) >> { >> VFIODevice *vbasedev = opaque; >> @@ -448,6 +636,17 @@ static int vfio_v1_save_setup(QEMUFile *f, void >> *opaque) >> return 0; >> } >> >> +static void vfio_save_cleanup(void *opaque) >> +{ >> + VFIODevice *vbasedev = opaque; >> + VFIOMigration *migration = vbasedev->migration; >> + >> + g_free(migration->data_buffer); >> + migration->data_buffer = NULL; >> + vfio_migration_cleanup(vbasedev); >> + trace_vfio_save_cleanup(vbasedev->name); >> +} >> + >> static void vfio_v1_save_cleanup(void *opaque) >> { >> VFIODevice *vbasedev = opaque; >> @@ -456,6 +655,31 @@ static void vfio_v1_save_cleanup(void *opaque) >> trace_vfio_save_cleanup(vbasedev->name); >> } >> >> +/* >> + * Migration size of VFIO devices can be as little as a few KBs or >> as big as >> + * many GBs. This value should be big enough to cover the worst case. >> + */ >> +#define VFIO_MIG_STOP_COPY_SIZE (100 * GiB) >> +static void vfio_save_pending(void *opaque, uint64_t threshold_size, >> + uint64_t *res_precopy_only, >> + uint64_t *res_compatible, >> + uint64_t *res_postcopy_only) >> +{ >> + VFIODevice *vbasedev = opaque; >> + uint64_t stop_copy_size = VFIO_MIG_STOP_COPY_SIZE; >> + >> + /* >> + * If getting pending migration size fails, >> VFIO_MIG_STOP_COPY_SIZE is >> + * reported so downtime limit won't be violated. >> + */ >> + vfio_query_stop_copy_size(vbasedev, &stop_copy_size); >> + *res_precopy_only += stop_copy_size; >> + >> + trace_vfio_save_pending(vbasedev->name, *res_precopy_only, >> + *res_postcopy_only, *res_compatible, >> + stop_copy_size); >> +} >> + >> static void vfio_v1_save_pending(void *opaque, uint64_t >> threshold_size, >> uint64_t *res_precopy_only, >> uint64_t *res_compatible, >> @@ -523,6 +747,41 @@ static int vfio_save_iterate(QEMUFile *f, void >> *opaque) >> return 0; >> } >> >> +static int vfio_save_complete_precopy(QEMUFile *f, void *opaque) >> +{ >> + VFIODevice *vbasedev = opaque; >> + enum vfio_device_mig_state recover_state; >> + int ret; >> + >> + /* We reach here with device state STOP only */ >> + recover_state = VFIO_DEVICE_STATE_STOP; >> + ret = vfio_migration_set_state(vbasedev, >> VFIO_DEVICE_STATE_STOP_COPY, >> + recover_state); >> + if (ret) { >> + return ret; >> + } >> + >> + do { >> + ret = vfio_save_block(f, vbasedev->migration); >> + if (ret < 0) { >> + return ret; >> + } >> + } while (!ret); >> + >> + qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE); >> + ret = qemu_file_get_error(f); >> + if (ret) { >> + return ret; >> + } >> + >> + recover_state = VFIO_DEVICE_STATE_ERROR; >> + ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_STOP, >> + recover_state); >> + trace_vfio_save_complete_precopy(vbasedev->name, ret); >> + >> + return ret; >> +} >> + >> static int vfio_v1_save_complete_precopy(QEMUFile *f, void *opaque) >> { >> VFIODevice *vbasedev = opaque; >> @@ -592,6 +851,14 @@ static void vfio_save_state(QEMUFile *f, void >> *opaque) >> } >> } >> >> +static int vfio_load_setup(QEMUFile *f, void *opaque) >> +{ >> + VFIODevice *vbasedev = opaque; >> + >> + return vfio_migration_set_state(vbasedev, >> VFIO_DEVICE_STATE_RESUMING, >> + vbasedev->migration->device_state); >> +} >> + >> static int vfio_v1_load_setup(QEMUFile *f, void *opaque) >> { >> VFIODevice *vbasedev = opaque; >> @@ -619,6 +886,16 @@ static int vfio_v1_load_setup(QEMUFile *f, void >> *opaque) >> return ret; >> } >> >> +static int vfio_load_cleanup(void *opaque) >> +{ >> + VFIODevice *vbasedev = opaque; >> + >> + vfio_migration_cleanup(vbasedev); >> + trace_vfio_load_cleanup(vbasedev->name); >> + >> + return 0; >> +} >> + >> static int vfio_v1_load_cleanup(void *opaque) >> { >> VFIODevice *vbasedev = opaque; >> @@ -661,7 +938,11 @@ static int vfio_load_state(QEMUFile *f, void >> *opaque, int version_id) >> uint64_t data_size = qemu_get_be64(f); >> >> if (data_size) { >> - ret = vfio_v1_load_buffer(f, vbasedev, data_size); >> + if (vbasedev->migration->v2) { >> + ret = vfio_load_buffer(f, vbasedev, data_size); >> + } else { >> + ret = vfio_v1_load_buffer(f, vbasedev, data_size); >> + } >> if (ret < 0) { >> return ret; >> } >> @@ -682,6 +963,17 @@ static int vfio_load_state(QEMUFile *f, void >> *opaque, int version_id) >> return ret; >> } >> >> +static const SaveVMHandlers savevm_vfio_handlers = { >> + .save_setup = vfio_save_setup, >> + .save_cleanup = vfio_save_cleanup, >> + .save_live_pending = vfio_save_pending, >> + .save_live_complete_precopy = vfio_save_complete_precopy, >> + .save_state = vfio_save_state, >> + .load_setup = vfio_load_setup, >> + .load_cleanup = vfio_load_cleanup, >> + .load_state = vfio_load_state, >> +}; >> + >> static SaveVMHandlers savevm_vfio_v1_handlers = { >> .save_setup = vfio_v1_save_setup, >> .save_cleanup = vfio_v1_save_cleanup, >> @@ -696,6 +988,34 @@ static SaveVMHandlers savevm_vfio_v1_handlers = { >> >> /* >> ---------------------------------------------------------------------- >> */ >> >> +static void vfio_vmstate_change(void *opaque, bool running, RunState >> state) >> +{ >> + VFIODevice *vbasedev = opaque; >> + enum vfio_device_mig_state new_state; >> + int ret; >> + >> + if (running) { >> + new_state = VFIO_DEVICE_STATE_RUNNING; >> + } else { >> + new_state = VFIO_DEVICE_STATE_STOP; >> + } >> + >> + ret = vfio_migration_set_state(vbasedev, new_state, >> + VFIO_DEVICE_STATE_ERROR); >> + if (ret) { >> + /* >> + * Migration should be aborted in this case, but >> vm_state_notify() >> + * currently does not support reporting failures. >> + */ >> + if (migrate_get_current()->to_dst_file) { >> + qemu_file_set_error(migrate_get_current()->to_dst_file, ret); >> + } >> + } >> + >> + trace_vfio_vmstate_change(vbasedev->name, running, >> RunState_str(state), >> + mig_state_to_str(new_state)); >> +} >> + >> static void vfio_v1_vmstate_change(void *opaque, bool running, >> RunState state) >> { >> VFIODevice *vbasedev = opaque; >> @@ -769,12 +1089,17 @@ static void >> vfio_migration_state_notifier(Notifier *notifier, void *data) >> case MIGRATION_STATUS_CANCELLED: >> case MIGRATION_STATUS_FAILED: >> bytes_transferred = 0; >> - ret = vfio_migration_v1_set_state(vbasedev, >> - ~(VFIO_DEVICE_STATE_V1_SAVING | >> - VFIO_DEVICE_STATE_V1_RESUMING), >> - VFIO_DEVICE_STATE_V1_RUNNING); >> - if (ret) { >> - error_report("%s: Failed to set state RUNNING", >> vbasedev->name); >> + if (migration->v2) { >> + vfio_migration_set_state(vbasedev, >> VFIO_DEVICE_STATE_RUNNING, >> + VFIO_DEVICE_STATE_ERROR); >> + } else { >> + ret = vfio_migration_v1_set_state(vbasedev, >> + ~(VFIO_DEVICE_STATE_V1_SAVING | >> + VFIO_DEVICE_STATE_V1_RESUMING), >> + VFIO_DEVICE_STATE_V1_RUNNING); >> + if (ret) { >> + error_report("%s: Failed to set state RUNNING", >> vbasedev->name); >> + } >> } >> } >> } >> @@ -783,12 +1108,42 @@ static void vfio_migration_exit(VFIODevice >> *vbasedev) >> { >> VFIOMigration *migration = vbasedev->migration; >> >> - vfio_region_exit(&migration->region); >> - vfio_region_finalize(&migration->region); >> + if (!migration->v2) { >> + vfio_region_exit(&migration->region); >> + vfio_region_finalize(&migration->region); >> + } >> g_free(vbasedev->migration); >> vbasedev->migration = NULL; >> } >> >> +static int vfio_migration_query_flags(VFIODevice *vbasedev, uint64_t >> *mig_flags) >> +{ >> + uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) + >> + sizeof(struct >> vfio_device_feature_migration), >> + sizeof(uint64_t))] = {}; >> + struct vfio_device_feature *feature = (struct >> vfio_device_feature *)buf; >> + struct vfio_device_feature_migration *mig = >> + (struct vfio_device_feature_migration *)feature->data; >> + >> + 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; >> + } >> + >> + *mig_flags = mig->flags; >> + >> + return 0; >> +} >> + >> static int vfio_migration_init(VFIODevice *vbasedev) >> { >> int ret; >> @@ -797,6 +1152,7 @@ static int vfio_migration_init(VFIODevice >> *vbasedev) >> char id[256] = ""; >> g_autofree char *path = NULL, *oid = NULL; >> struct vfio_region_info *info; >> + uint64_t mig_flags; > > GCC 12 reports : > > ../hw/vfio/migration.c: In function ‘vfio_migration_init’: > ../hw/vfio/migration.c:1170:25: error: ‘mig_flags’ may be used > uninitialized [-Werror=maybe-uninitialized] > 1170 | if (!(mig_flags & VFIO_MIGRATION_STOP_COPY)) { > | ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~ > ../hw/vfio/migration.c:1155:14: note: ‘mig_flags’ was declared here > 1155 | uint64_t mig_flags; > | ^~~~~~~~~ > cc1: all warnings being treated as errors > > You will need a little fix for that. May be it can be done at merge > time : > > - uint64_t mig_flags; > + uint64_t mig_flags = 0; > > Thanks, > > C. > >> >> if (!vbasedev->ops->vfio_get_object) { >> return -EINVAL; >> @@ -807,34 +1163,50 @@ static int vfio_migration_init(VFIODevice >> *vbasedev) >> return -EINVAL; >> } >> >> - ret = vfio_get_dev_region_info(vbasedev, >> - VFIO_REGION_TYPE_MIGRATION_DEPRECATED, >> - VFIO_REGION_SUBTYPE_MIGRATION_DEPRECATED, >> - &info); >> - if (ret) { >> - return ret; >> - } >> + ret = vfio_migration_query_flags(vbasedev, &mig_flags); >> + if (!ret) { >> + /* Migration v2 */ >> + /* Basic migration functionality must be supported */ >> + if (!(mig_flags & VFIO_MIGRATION_STOP_COPY)) { >> + return -EOPNOTSUPP; >> + } >> + vbasedev->migration = g_new0(VFIOMigration, 1); >> + vbasedev->migration->device_state = VFIO_DEVICE_STATE_RUNNING; >> + vbasedev->migration->data_fd = -1; >> + vbasedev->migration->v2 = true; >> + } else if (ret == -ENOTTY) { >> + /* Migration v1 */ >> + ret = vfio_get_dev_region_info(vbasedev, >> + VFIO_REGION_TYPE_MIGRATION_DEPRECATED, >> + VFIO_REGION_SUBTYPE_MIGRATION_DEPRECATED, >> + &info); >> + if (ret) { >> + return ret; >> + } >> >> - vbasedev->migration = g_new0(VFIOMigration, 1); >> - vbasedev->migration->device_state_v1 = >> VFIO_DEVICE_STATE_V1_RUNNING; >> - vbasedev->migration->vm_running = runstate_is_running(); >> + vbasedev->migration = g_new0(VFIOMigration, 1); >> + vbasedev->migration->device_state_v1 = >> VFIO_DEVICE_STATE_V1_RUNNING; >> + vbasedev->migration->vm_running = runstate_is_running(); >> >> - ret = vfio_region_setup(obj, vbasedev, >> &vbasedev->migration->region, >> - info->index, "migration"); >> - if (ret) { >> - error_report("%s: Failed to setup VFIO migration region %d: >> %s", >> - vbasedev->name, info->index, strerror(-ret)); >> - goto err; >> - } >> + ret = vfio_region_setup(obj, vbasedev, >> &vbasedev->migration->region, >> + info->index, "migration"); >> + if (ret) { >> + error_report("%s: Failed to setup VFIO migration region >> %d: %s", >> + vbasedev->name, info->index, strerror(-ret)); >> + goto err; >> + } >> >> - if (!vbasedev->migration->region.size) { >> - error_report("%s: Invalid zero-sized VFIO migration region %d", >> - vbasedev->name, info->index); >> - ret = -EINVAL; >> - goto err; >> - } >> + if (!vbasedev->migration->region.size) { >> + error_report("%s: Invalid zero-sized VFIO migration >> region %d", >> + vbasedev->name, info->index); >> + ret = -EINVAL; >> + goto err; >> + } >> >> - g_free(info); >> + g_free(info); >> + } else { >> + return ret; >> + } >> >> migration = vbasedev->migration; >> migration->vbasedev = vbasedev; >> @@ -847,11 +1219,20 @@ static int vfio_migration_init(VFIODevice >> *vbasedev) >> } >> strpadcpy(id, sizeof(id), path, '\0'); >> >> - register_savevm_live(id, VMSTATE_INSTANCE_ID_ANY, 1, >> - &savevm_vfio_v1_handlers, vbasedev); >> + if (migration->v2) { >> + register_savevm_live(id, VMSTATE_INSTANCE_ID_ANY, 1, >> + &savevm_vfio_handlers, vbasedev); >> + >> + migration->vm_state = qdev_add_vm_change_state_handler( >> + vbasedev->dev, vfio_vmstate_change, vbasedev); >> + } else { >> + register_savevm_live(id, VMSTATE_INSTANCE_ID_ANY, 1, >> + &savevm_vfio_v1_handlers, vbasedev); >> + >> + migration->vm_state = qdev_add_vm_change_state_handler( >> + vbasedev->dev, vfio_v1_vmstate_change, vbasedev); >> + } >> >> - migration->vm_state = qdev_add_vm_change_state_handler( >> - vbasedev->dev, vfio_v1_vmstate_change, vbasedev); >> migration->migration_state.notify = vfio_migration_state_notifier; >> add_migration_state_change_notifier(&migration->migration_state); >> return 0; >> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events >> index 9eb9aff295..e7b3b4658c 100644 >> --- a/hw/vfio/trace-events >> +++ b/hw/vfio/trace-events >> @@ -149,20 +149,27 @@ vfio_display_edid_write_error(void) "" >> >> # migration.c >> vfio_migration_probe(const char *name) " (%s)" >> +vfio_migration_set_state(const char *name, const char *state) " (%s) >> state %s" >> vfio_migration_v1_set_state(const char *name, uint32_t state) " >> (%s) state %d" >> +vfio_vmstate_change(const char *name, int running, const char >> *reason, const char *dev_state) " (%s) running %d reason %s device >> state %s" >> vfio_v1_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" >> +vfio_save_setup(const char *name, uint64_t data_buffer_size) " (%s) >> data buffer size 0x%"PRIx64 >> vfio_v1_save_setup(const char *name) " (%s)" >> vfio_save_cleanup(const char *name) " (%s)" >> vfio_save_buffer(const char *name, uint64_t data_offset, uint64_t >> data_size, uint64_t pending) " (%s) Offset 0x%"PRIx64" size >> 0x%"PRIx64" pending 0x%"PRIx64 >> vfio_update_pending(const char *name, uint64_t pending) " (%s) >> pending 0x%"PRIx64 >> vfio_save_device_config_state(const char *name) " (%s)" >> +vfio_save_pending(const char *name, uint64_t precopy, uint64_t >> postcopy, uint64_t compatible, uint64_t stopcopy_size) " (%s) precopy >> 0x%"PRIx64" postcopy 0x%"PRIx64" compatible 0x%"PRIx64" stopcopy size >> 0x%"PRIx64 >> vfio_v1_save_pending(const char *name, uint64_t precopy, uint64_t >> postcopy, uint64_t compatible) " (%s) precopy 0x%"PRIx64" postcopy >> 0x%"PRIx64" compatible 0x%"PRIx64 >> vfio_save_iterate(const char *name, int data_size) " (%s) data_size >> %d" >> +vfio_save_complete_precopy(const char *name, int ret) " (%s) ret %d" >> vfio_v1_save_complete_precopy(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_v1_load_state_device_data(const char *name, uint64_t >> data_offset, uint64_t data_size) " (%s) Offset 0x%"PRIx64" size >> 0x%"PRIx64 >> +vfio_load_state_device_data(const char *name, uint64_t data_size, >> int ret) " (%s) size 0x%"PRIx64" ret %d" >> vfio_load_cleanup(const char *name) " (%s)" >> vfio_get_dirty_bitmap(int fd, uint64_t iova, uint64_t size, >> uint64_t bitmap_size, uint64_t start) "container fd=%d, >> iova=0x%"PRIx64" size= 0x%"PRIx64" bitmap_size=0x%"PRIx64" >> start=0x%"PRIx64 >> vfio_iommu_map_dirty_notify(uint64_t iova_start, uint64_t iova_end) >> "iommu dirty @ 0x%"PRIx64" - 0x%"PRIx64 >> +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 bbaf72ba00..2ec3346fea 100644 --- a/include/hw/vfio/vfio-common.h +++ b/include/hw/vfio/vfio-common.h @@ -66,6 +66,11 @@ typedef struct VFIOMigration { int vm_running; Notifier migration_state; uint64_t pending_bytes; + enum vfio_device_mig_state device_state; + int data_fd; + void *data_buffer; + size_t data_buffer_size; + bool v2; } VFIOMigration; typedef struct VFIOAddressSpace { diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 550b2d7ded..dcaa77d2a8 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -355,10 +355,18 @@ static bool vfio_devices_all_dirty_tracking(VFIOContainer *container) return false; } - if ((vbasedev->pre_copy_dirty_page_tracking == ON_OFF_AUTO_OFF) && + if (!migration->v2 && + (vbasedev->pre_copy_dirty_page_tracking == ON_OFF_AUTO_OFF) && (migration->device_state_v1 & VFIO_DEVICE_STATE_V1_RUNNING)) { return false; } + + if (migration->v2 && + (vbasedev->pre_copy_dirty_page_tracking == ON_OFF_AUTO_OFF) && + (migration->device_state == VFIO_DEVICE_STATE_RUNNING || + migration->device_state == VFIO_DEVICE_STATE_RUNNING_P2P)) { + return false; + } } } return true; @@ -385,7 +393,14 @@ static bool vfio_devices_all_running_and_mig_active(VFIOContainer *container) return false; } - if (migration->device_state_v1 & VFIO_DEVICE_STATE_V1_RUNNING) { + if (!migration->v2 && + migration->device_state_v1 & VFIO_DEVICE_STATE_V1_RUNNING) { + continue; + } + + if (migration->v2 && + (migration->device_state == VFIO_DEVICE_STATE_RUNNING || + migration->device_state == VFIO_DEVICE_STATE_RUNNING_P2P)) { continue; } else { return false; diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c index 9df859f4d3..08f53189fa 100644 --- a/hw/vfio/migration.c +++ b/hw/vfio/migration.c @@ -10,6 +10,7 @@ #include "qemu/osdep.h" #include "qemu/main-loop.h" #include "qemu/cutils.h" +#include "qemu/units.h" #include <linux/vfio.h> #include <sys/ioctl.h> @@ -44,8 +45,103 @@ #define VFIO_MIG_FLAG_DEV_SETUP_STATE (0xffffffffef100003ULL) #define VFIO_MIG_FLAG_DEV_DATA_STATE (0xffffffffef100004ULL) +/* + * This is an arbitrary size based on migration of mlx5 devices, where typically + * total device migration size is on the order of 100s of MB. Testing with + * larger values, e.g. 128MB and 1GB, did not show a performance improvement. + */ +#define VFIO_MIG_DEFAULT_DATA_BUFFER_SIZE (1 * MiB) + static int64_t bytes_transferred; +static const char *mig_state_to_str(enum vfio_device_mig_state state) +{ + switch (state) { + case VFIO_DEVICE_STATE_ERROR: + return "ERROR"; + case VFIO_DEVICE_STATE_STOP: + return "STOP"; + case VFIO_DEVICE_STATE_RUNNING: + return "RUNNING"; + case VFIO_DEVICE_STATE_STOP_COPY: + return "STOP_COPY"; + case VFIO_DEVICE_STATE_RESUMING: + return "RESUMING"; + case VFIO_DEVICE_STATE_RUNNING_P2P: + return "RUNNING_P2P"; + default: + return "UNKNOWN STATE"; + } +} + +static int vfio_migration_set_state(VFIODevice *vbasedev, + enum vfio_device_mig_state new_state, + enum vfio_device_mig_state recover_state) +{ + VFIOMigration *migration = vbasedev->migration; + uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) + + sizeof(struct vfio_device_feature_mig_state), + sizeof(uint64_t))] = {}; + struct vfio_device_feature *feature = (struct vfio_device_feature *)buf; + struct vfio_device_feature_mig_state *mig_state = + (struct vfio_device_feature_mig_state *)feature->data; + + feature->argsz = sizeof(buf); + feature->flags = + VFIO_DEVICE_FEATURE_SET | VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE; + mig_state->device_state = new_state; + if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) { + /* Try to set the device in some good state */ + int err = -errno; + + error_report( + "%s: Failed setting device state to %s, err: %s. Setting device in recover state %s", + vbasedev->name, mig_state_to_str(new_state), + strerror(errno), mig_state_to_str(recover_state)); + + mig_state->device_state = recover_state; + if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) { + err = -errno; + error_report( + "%s: Failed setting device in recover state, err: %s. Resetting device", + vbasedev->name, strerror(errno)); + + if (ioctl(vbasedev->fd, VFIO_DEVICE_RESET)) { + hw_error("%s: Failed resetting device, err: %s", vbasedev->name, + strerror(errno)); + } + + migration->device_state = VFIO_DEVICE_STATE_RUNNING; + + return err; + } + + migration->device_state = recover_state; + + return err; + } + + migration->device_state = new_state; + if (mig_state->data_fd != -1) { + if (migration->data_fd != -1) { + /* + * This can happen if the device is asynchronously reset and + * terminates a data transfer. + */ + error_report("%s: data_fd out of sync", vbasedev->name); + close(mig_state->data_fd); + + return -EBADF; + } + + migration->data_fd = mig_state->data_fd; + } + + trace_vfio_migration_set_state(vbasedev->name, mig_state_to_str(new_state)); + + return 0; +} + static inline int vfio_mig_access(VFIODevice *vbasedev, void *val, int count, off_t off, bool iswrite) { @@ -260,6 +356,18 @@ static int vfio_save_buffer(QEMUFile *f, VFIODevice *vbasedev, uint64_t *size) return ret; } +static int vfio_load_buffer(QEMUFile *f, VFIODevice *vbasedev, + uint64_t data_size) +{ + VFIOMigration *migration = vbasedev->migration; + int ret; + + ret = qemu_file_get_to_fd(f, migration->data_fd, data_size); + trace_vfio_load_state_device_data(vbasedev->name, data_size, ret); + + return ret; +} + static int vfio_v1_load_buffer(QEMUFile *f, VFIODevice *vbasedev, uint64_t data_size) { @@ -394,6 +502,14 @@ static int vfio_load_device_config_state(QEMUFile *f, void *opaque) return qemu_file_get_error(f); } +static void vfio_migration_cleanup(VFIODevice *vbasedev) +{ + VFIOMigration *migration = vbasedev->migration; + + close(migration->data_fd); + migration->data_fd = -1; +} + static void vfio_migration_v1_cleanup(VFIODevice *vbasedev) { VFIOMigration *migration = vbasedev->migration; @@ -403,8 +519,80 @@ static void vfio_migration_v1_cleanup(VFIODevice *vbasedev) } } +static int vfio_query_stop_copy_size(VFIODevice *vbasedev, + uint64_t *stop_copy_size) +{ + uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) + + sizeof(struct vfio_device_feature_mig_data_size), + sizeof(uint64_t))] = {}; + struct vfio_device_feature *feature = (struct vfio_device_feature *)buf; + struct vfio_device_feature_mig_data_size *mig_data_size = + (struct vfio_device_feature_mig_data_size *)feature->data; + + feature->argsz = sizeof(buf); + feature->flags = + VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_MIG_DATA_SIZE; + + if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) { + return -errno; + } + + *stop_copy_size = mig_data_size->stop_copy_length; + + return 0; +} + +/* Returns 1 if end-of-stream is reached, 0 if more data and -1 if error */ +static int vfio_save_block(QEMUFile *f, VFIOMigration *migration) +{ + ssize_t data_size; + + data_size = read(migration->data_fd, migration->data_buffer, + migration->data_buffer_size); + if (data_size < 0) { + return -errno; + } + if (data_size == 0) { + return 1; + } + + qemu_put_be64(f, VFIO_MIG_FLAG_DEV_DATA_STATE); + qemu_put_be64(f, data_size); + qemu_put_buffer(f, migration->data_buffer, data_size); + bytes_transferred += data_size; + + trace_vfio_save_block(migration->vbasedev->name, data_size); + + return qemu_file_get_error(f); +} + /* ---------------------------------------------------------------------- */ +static int vfio_save_setup(QEMUFile *f, void *opaque) +{ + VFIODevice *vbasedev = opaque; + VFIOMigration *migration = vbasedev->migration; + uint64_t stop_copy_size = VFIO_MIG_DEFAULT_DATA_BUFFER_SIZE; + + qemu_put_be64(f, VFIO_MIG_FLAG_DEV_SETUP_STATE); + + vfio_query_stop_copy_size(vbasedev, &stop_copy_size); + migration->data_buffer_size = MIN(VFIO_MIG_DEFAULT_DATA_BUFFER_SIZE, + stop_copy_size); + migration->data_buffer = g_try_malloc0(migration->data_buffer_size); + if (!migration->data_buffer) { + error_report("%s: Failed to allocate migration data buffer", + vbasedev->name); + return -ENOMEM; + } + + trace_vfio_save_setup(vbasedev->name, migration->data_buffer_size); + + qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE); + + return qemu_file_get_error(f); +} + static int vfio_v1_save_setup(QEMUFile *f, void *opaque) { VFIODevice *vbasedev = opaque; @@ -448,6 +636,17 @@ static int vfio_v1_save_setup(QEMUFile *f, void *opaque) return 0; } +static void vfio_save_cleanup(void *opaque) +{ + VFIODevice *vbasedev = opaque; + VFIOMigration *migration = vbasedev->migration; + + g_free(migration->data_buffer); + migration->data_buffer = NULL; + vfio_migration_cleanup(vbasedev); + trace_vfio_save_cleanup(vbasedev->name); +} + static void vfio_v1_save_cleanup(void *opaque) { VFIODevice *vbasedev = opaque; @@ -456,6 +655,31 @@ static void vfio_v1_save_cleanup(void *opaque) trace_vfio_save_cleanup(vbasedev->name); } +/* + * Migration size of VFIO devices can be as little as a few KBs or as big as + * many GBs. This value should be big enough to cover the worst case. + */ +#define VFIO_MIG_STOP_COPY_SIZE (100 * GiB) +static void vfio_save_pending(void *opaque, uint64_t threshold_size, + uint64_t *res_precopy_only, + uint64_t *res_compatible, + uint64_t *res_postcopy_only) +{ + VFIODevice *vbasedev = opaque; + uint64_t stop_copy_size = VFIO_MIG_STOP_COPY_SIZE; + + /* + * If getting pending migration size fails, VFIO_MIG_STOP_COPY_SIZE is + * reported so downtime limit won't be violated. + */ + vfio_query_stop_copy_size(vbasedev, &stop_copy_size); + *res_precopy_only += stop_copy_size; + + trace_vfio_save_pending(vbasedev->name, *res_precopy_only, + *res_postcopy_only, *res_compatible, + stop_copy_size); +} + static void vfio_v1_save_pending(void *opaque, uint64_t threshold_size, uint64_t *res_precopy_only, uint64_t *res_compatible, @@ -523,6 +747,41 @@ static int vfio_save_iterate(QEMUFile *f, void *opaque) return 0; } +static int vfio_save_complete_precopy(QEMUFile *f, void *opaque) +{ + VFIODevice *vbasedev = opaque; + enum vfio_device_mig_state recover_state; + int ret; + + /* We reach here with device state STOP only */ + recover_state = VFIO_DEVICE_STATE_STOP; + ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_STOP_COPY, + recover_state); + if (ret) { + return ret; + } + + do { + ret = vfio_save_block(f, vbasedev->migration); + if (ret < 0) { + return ret; + } + } while (!ret); + + qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE); + ret = qemu_file_get_error(f); + if (ret) { + return ret; + } + + recover_state = VFIO_DEVICE_STATE_ERROR; + ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_STOP, + recover_state); + trace_vfio_save_complete_precopy(vbasedev->name, ret); + + return ret; +} + static int vfio_v1_save_complete_precopy(QEMUFile *f, void *opaque) { VFIODevice *vbasedev = opaque; @@ -592,6 +851,14 @@ static void vfio_save_state(QEMUFile *f, void *opaque) } } +static int vfio_load_setup(QEMUFile *f, void *opaque) +{ + VFIODevice *vbasedev = opaque; + + return vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_RESUMING, + vbasedev->migration->device_state); +} + static int vfio_v1_load_setup(QEMUFile *f, void *opaque) { VFIODevice *vbasedev = opaque; @@ -619,6 +886,16 @@ static int vfio_v1_load_setup(QEMUFile *f, void *opaque) return ret; } +static int vfio_load_cleanup(void *opaque) +{ + VFIODevice *vbasedev = opaque; + + vfio_migration_cleanup(vbasedev); + trace_vfio_load_cleanup(vbasedev->name); + + return 0; +} + static int vfio_v1_load_cleanup(void *opaque) { VFIODevice *vbasedev = opaque; @@ -661,7 +938,11 @@ static int vfio_load_state(QEMUFile *f, void *opaque, int version_id) uint64_t data_size = qemu_get_be64(f); if (data_size) { - ret = vfio_v1_load_buffer(f, vbasedev, data_size); + if (vbasedev->migration->v2) { + ret = vfio_load_buffer(f, vbasedev, data_size); + } else { + ret = vfio_v1_load_buffer(f, vbasedev, data_size); + } if (ret < 0) { return ret; } @@ -682,6 +963,17 @@ static int vfio_load_state(QEMUFile *f, void *opaque, int version_id) return ret; } +static const SaveVMHandlers savevm_vfio_handlers = { + .save_setup = vfio_save_setup, + .save_cleanup = vfio_save_cleanup, + .save_live_pending = vfio_save_pending, + .save_live_complete_precopy = vfio_save_complete_precopy, + .save_state = vfio_save_state, + .load_setup = vfio_load_setup, + .load_cleanup = vfio_load_cleanup, + .load_state = vfio_load_state, +}; + static SaveVMHandlers savevm_vfio_v1_handlers = { .save_setup = vfio_v1_save_setup, .save_cleanup = vfio_v1_save_cleanup, @@ -696,6 +988,34 @@ static SaveVMHandlers savevm_vfio_v1_handlers = { /* ---------------------------------------------------------------------- */ +static void vfio_vmstate_change(void *opaque, bool running, RunState state) +{ + VFIODevice *vbasedev = opaque; + enum vfio_device_mig_state new_state; + int ret; + + if (running) { + new_state = VFIO_DEVICE_STATE_RUNNING; + } else { + new_state = VFIO_DEVICE_STATE_STOP; + } + + ret = vfio_migration_set_state(vbasedev, new_state, + VFIO_DEVICE_STATE_ERROR); + if (ret) { + /* + * Migration should be aborted in this case, but vm_state_notify() + * currently does not support reporting failures. + */ + if (migrate_get_current()->to_dst_file) { + qemu_file_set_error(migrate_get_current()->to_dst_file, ret); + } + } + + trace_vfio_vmstate_change(vbasedev->name, running, RunState_str(state), + mig_state_to_str(new_state)); +} + static void vfio_v1_vmstate_change(void *opaque, bool running, RunState state) { VFIODevice *vbasedev = opaque; @@ -769,12 +1089,17 @@ static void vfio_migration_state_notifier(Notifier *notifier, void *data) case MIGRATION_STATUS_CANCELLED: case MIGRATION_STATUS_FAILED: bytes_transferred = 0; - ret = vfio_migration_v1_set_state(vbasedev, - ~(VFIO_DEVICE_STATE_V1_SAVING | - VFIO_DEVICE_STATE_V1_RESUMING), - VFIO_DEVICE_STATE_V1_RUNNING); - if (ret) { - error_report("%s: Failed to set state RUNNING", vbasedev->name); + if (migration->v2) { + vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_RUNNING, + VFIO_DEVICE_STATE_ERROR); + } else { + ret = vfio_migration_v1_set_state(vbasedev, + ~(VFIO_DEVICE_STATE_V1_SAVING | + VFIO_DEVICE_STATE_V1_RESUMING), + VFIO_DEVICE_STATE_V1_RUNNING); + if (ret) { + error_report("%s: Failed to set state RUNNING", vbasedev->name); + } } } } @@ -783,12 +1108,42 @@ static void vfio_migration_exit(VFIODevice *vbasedev) { VFIOMigration *migration = vbasedev->migration; - vfio_region_exit(&migration->region); - vfio_region_finalize(&migration->region); + if (!migration->v2) { + vfio_region_exit(&migration->region); + vfio_region_finalize(&migration->region); + } g_free(vbasedev->migration); vbasedev->migration = NULL; } +static int vfio_migration_query_flags(VFIODevice *vbasedev, uint64_t *mig_flags) +{ + uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) + + sizeof(struct vfio_device_feature_migration), + sizeof(uint64_t))] = {}; + struct vfio_device_feature *feature = (struct vfio_device_feature *)buf; + struct vfio_device_feature_migration *mig = + (struct vfio_device_feature_migration *)feature->data; + + 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; + } + + *mig_flags = mig->flags; + + return 0; +} + static int vfio_migration_init(VFIODevice *vbasedev) { int ret; @@ -797,6 +1152,7 @@ static int vfio_migration_init(VFIODevice *vbasedev) char id[256] = ""; g_autofree char *path = NULL, *oid = NULL; struct vfio_region_info *info; + uint64_t mig_flags; if (!vbasedev->ops->vfio_get_object) { return -EINVAL; @@ -807,34 +1163,50 @@ static int vfio_migration_init(VFIODevice *vbasedev) return -EINVAL; } - ret = vfio_get_dev_region_info(vbasedev, - VFIO_REGION_TYPE_MIGRATION_DEPRECATED, - VFIO_REGION_SUBTYPE_MIGRATION_DEPRECATED, - &info); - if (ret) { - return ret; - } + ret = vfio_migration_query_flags(vbasedev, &mig_flags); + if (!ret) { + /* Migration v2 */ + /* Basic migration functionality must be supported */ + if (!(mig_flags & VFIO_MIGRATION_STOP_COPY)) { + return -EOPNOTSUPP; + } + vbasedev->migration = g_new0(VFIOMigration, 1); + vbasedev->migration->device_state = VFIO_DEVICE_STATE_RUNNING; + vbasedev->migration->data_fd = -1; + vbasedev->migration->v2 = true; + } else if (ret == -ENOTTY) { + /* Migration v1 */ + ret = vfio_get_dev_region_info(vbasedev, + VFIO_REGION_TYPE_MIGRATION_DEPRECATED, + VFIO_REGION_SUBTYPE_MIGRATION_DEPRECATED, + &info); + if (ret) { + return ret; + } - vbasedev->migration = g_new0(VFIOMigration, 1); - vbasedev->migration->device_state_v1 = VFIO_DEVICE_STATE_V1_RUNNING; - vbasedev->migration->vm_running = runstate_is_running(); + vbasedev->migration = g_new0(VFIOMigration, 1); + vbasedev->migration->device_state_v1 = VFIO_DEVICE_STATE_V1_RUNNING; + vbasedev->migration->vm_running = runstate_is_running(); - ret = vfio_region_setup(obj, vbasedev, &vbasedev->migration->region, - info->index, "migration"); - if (ret) { - error_report("%s: Failed to setup VFIO migration region %d: %s", - vbasedev->name, info->index, strerror(-ret)); - goto err; - } + ret = vfio_region_setup(obj, vbasedev, &vbasedev->migration->region, + info->index, "migration"); + if (ret) { + error_report("%s: Failed to setup VFIO migration region %d: %s", + vbasedev->name, info->index, strerror(-ret)); + goto err; + } - if (!vbasedev->migration->region.size) { - error_report("%s: Invalid zero-sized VFIO migration region %d", - vbasedev->name, info->index); - ret = -EINVAL; - goto err; - } + if (!vbasedev->migration->region.size) { + error_report("%s: Invalid zero-sized VFIO migration region %d", + vbasedev->name, info->index); + ret = -EINVAL; + goto err; + } - g_free(info); + g_free(info); + } else { + return ret; + } migration = vbasedev->migration; migration->vbasedev = vbasedev; @@ -847,11 +1219,20 @@ static int vfio_migration_init(VFIODevice *vbasedev) } strpadcpy(id, sizeof(id), path, '\0'); - register_savevm_live(id, VMSTATE_INSTANCE_ID_ANY, 1, - &savevm_vfio_v1_handlers, vbasedev); + if (migration->v2) { + register_savevm_live(id, VMSTATE_INSTANCE_ID_ANY, 1, + &savevm_vfio_handlers, vbasedev); + + migration->vm_state = qdev_add_vm_change_state_handler( + vbasedev->dev, vfio_vmstate_change, vbasedev); + } else { + register_savevm_live(id, VMSTATE_INSTANCE_ID_ANY, 1, + &savevm_vfio_v1_handlers, vbasedev); + + migration->vm_state = qdev_add_vm_change_state_handler( + vbasedev->dev, vfio_v1_vmstate_change, vbasedev); + } - migration->vm_state = qdev_add_vm_change_state_handler( - vbasedev->dev, vfio_v1_vmstate_change, vbasedev); migration->migration_state.notify = vfio_migration_state_notifier; add_migration_state_change_notifier(&migration->migration_state); return 0; diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events index 9eb9aff295..e7b3b4658c 100644 --- a/hw/vfio/trace-events +++ b/hw/vfio/trace-events @@ -149,20 +149,27 @@ vfio_display_edid_write_error(void) "" # migration.c vfio_migration_probe(const char *name) " (%s)" +vfio_migration_set_state(const char *name, const char *state) " (%s) state %s" vfio_migration_v1_set_state(const char *name, uint32_t state) " (%s) state %d" +vfio_vmstate_change(const char *name, int running, const char *reason, const char *dev_state) " (%s) running %d reason %s device state %s" vfio_v1_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" +vfio_save_setup(const char *name, uint64_t data_buffer_size) " (%s) data buffer size 0x%"PRIx64 vfio_v1_save_setup(const char *name) " (%s)" vfio_save_cleanup(const char *name) " (%s)" vfio_save_buffer(const char *name, uint64_t data_offset, uint64_t data_size, uint64_t pending) " (%s) Offset 0x%"PRIx64" size 0x%"PRIx64" pending 0x%"PRIx64 vfio_update_pending(const char *name, uint64_t pending) " (%s) pending 0x%"PRIx64 vfio_save_device_config_state(const char *name) " (%s)" +vfio_save_pending(const char *name, uint64_t precopy, uint64_t postcopy, uint64_t compatible, uint64_t stopcopy_size) " (%s) precopy 0x%"PRIx64" postcopy 0x%"PRIx64" compatible 0x%"PRIx64" stopcopy size 0x%"PRIx64 vfio_v1_save_pending(const char *name, uint64_t precopy, uint64_t postcopy, uint64_t compatible) " (%s) precopy 0x%"PRIx64" postcopy 0x%"PRIx64" compatible 0x%"PRIx64 vfio_save_iterate(const char *name, int data_size) " (%s) data_size %d" +vfio_save_complete_precopy(const char *name, int ret) " (%s) ret %d" vfio_v1_save_complete_precopy(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_v1_load_state_device_data(const char *name, uint64_t data_offset, uint64_t data_size) " (%s) Offset 0x%"PRIx64" size 0x%"PRIx64 +vfio_load_state_device_data(const char *name, uint64_t data_size, int ret) " (%s) size 0x%"PRIx64" ret %d" vfio_load_cleanup(const char *name) " (%s)" vfio_get_dirty_bitmap(int fd, uint64_t iova, uint64_t size, uint64_t bitmap_size, uint64_t start) "container fd=%d, iova=0x%"PRIx64" size= 0x%"PRIx64" bitmap_size=0x%"PRIx64" start=0x%"PRIx64 vfio_iommu_map_dirty_notify(uint64_t iova_start, uint64_t iova_end) "iommu dirty @ 0x%"PRIx64" - 0x%"PRIx64 +vfio_save_block(const char *name, int data_size) " (%s) data_size %d"
Implement the basic mandatory part of VFIO migration protocol v2. This includes all functionality that is necessary to support VFIO_MIGRATION_STOP_COPY part of the v2 protocol. The two protocols, v1 and v2, will co-exist and in the following patches v1 protocol code will be removed. There are several main differences between v1 and v2 protocols: - VFIO device state is now represented as a finite state machine instead of a bitmap. - Migration interface with kernel is now done using VFIO_DEVICE_FEATURE ioctl and normal read() and write() instead of the migration region. - Pre-copy is made optional in v2 protocol. Support for pre-copy will be added later on. Detailed information about VFIO migration protocol v2 and its difference compared to v1 protocol can be found here [1]. [1] https://lore.kernel.org/all/20220224142024.147653-10-yishaih@nvidia.com/ Signed-off-by: Avihai Horon <avihaih@nvidia.com> --- include/hw/vfio/vfio-common.h | 5 + hw/vfio/common.c | 19 +- hw/vfio/migration.c | 455 +++++++++++++++++++++++++++++++--- hw/vfio/trace-events | 7 + 4 files changed, 447 insertions(+), 39 deletions(-)