From: Yishai Hadas Date: Tue, 6 Dec 2022 08:34:32 +0000 (+0200) Subject: vfio/mlx5: Introduce device transitions of PRE_COPY X-Git-Tag: v6.6.17~5909^2~13 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=3319d287f4c04b9deece8ea00e27a70bbe32941b;p=platform%2Fkernel%2Flinux-rpi.git vfio/mlx5: Introduce device transitions of PRE_COPY In order to support PRE_COPY, mlx5 driver is transferring multiple states (images) of the device. e.g.: the source VF can save and transfer multiple states, and the target VF will load them by that order. The device is saving three kinds of states: 1) Initial state - when the device moves to PRE_COPY state. 2) Middle state - during PRE_COPY phase via VFIO_MIG_GET_PRECOPY_INFO. There can be multiple states of this type. 3) Final state - when the device moves to STOP_COPY state. After moving to PRE_COPY state, user is holding the saving migf FD and can use it. For example: user can start transferring data via read() callback. Also, user can switch from PRE_COPY to STOP_COPY whenever he sees it fits. This will invoke saving of final state. This means that mlx5 VFIO device can be switched to STOP_COPY without transferring any data in PRE_COPY state. Therefore, when the device moves to STOP_COPY, mlx5 will store the final state on a dedicated queue entry on the list. Co-developed-by: Shay Drory Signed-off-by: Shay Drory Reviewed-by: Jason Gunthorpe Signed-off-by: Yishai Hadas Link: https://lore.kernel.org/r/20221206083438.37807-9-yishaih@nvidia.com Signed-off-by: Alex Williamson --- diff --git a/drivers/vfio/pci/mlx5/cmd.c b/drivers/vfio/pci/mlx5/cmd.c index 0e36b4c..5fcece2 100644 --- a/drivers/vfio/pci/mlx5/cmd.c +++ b/drivers/vfio/pci/mlx5/cmd.c @@ -14,18 +14,36 @@ _mlx5vf_free_page_tracker_resources(struct mlx5vf_pci_core_device *mvdev); int mlx5vf_cmd_suspend_vhca(struct mlx5vf_pci_core_device *mvdev, u16 op_mod) { + struct mlx5_vf_migration_file *migf = mvdev->saving_migf; u32 out[MLX5_ST_SZ_DW(suspend_vhca_out)] = {}; u32 in[MLX5_ST_SZ_DW(suspend_vhca_in)] = {}; + int err; lockdep_assert_held(&mvdev->state_mutex); if (mvdev->mdev_detach) return -ENOTCONN; + /* + * In case PRE_COPY is used, saving_migf is exposed while the device is + * running. Make sure to run only once there is no active save command. + * Running both in parallel, might end-up with a failure in the save + * command once it will try to turn on 'tracking' on a suspended device. + */ + if (migf) { + err = wait_for_completion_interruptible(&migf->save_comp); + if (err) + return err; + } + MLX5_SET(suspend_vhca_in, in, opcode, MLX5_CMD_OP_SUSPEND_VHCA); MLX5_SET(suspend_vhca_in, in, vhca_id, mvdev->vhca_id); MLX5_SET(suspend_vhca_in, in, op_mod, op_mod); - return mlx5_cmd_exec_inout(mvdev->mdev, suspend_vhca, in, out); + err = mlx5_cmd_exec_inout(mvdev->mdev, suspend_vhca, in, out); + if (migf) + complete(&migf->save_comp); + + return err; } int mlx5vf_cmd_resume_vhca(struct mlx5vf_pci_core_device *mvdev, u16 op_mod) @@ -45,7 +63,7 @@ int mlx5vf_cmd_resume_vhca(struct mlx5vf_pci_core_device *mvdev, u16 op_mod) } int mlx5vf_cmd_query_vhca_migration_state(struct mlx5vf_pci_core_device *mvdev, - size_t *state_size) + size_t *state_size, u8 query_flags) { u32 out[MLX5_ST_SZ_DW(query_vhca_migration_state_out)] = {}; u32 in[MLX5_ST_SZ_DW(query_vhca_migration_state_in)] = {}; @@ -59,6 +77,8 @@ int mlx5vf_cmd_query_vhca_migration_state(struct mlx5vf_pci_core_device *mvdev, MLX5_CMD_OP_QUERY_VHCA_MIGRATION_STATE); MLX5_SET(query_vhca_migration_state_in, in, vhca_id, mvdev->vhca_id); MLX5_SET(query_vhca_migration_state_in, in, op_mod, 0); + MLX5_SET(query_vhca_migration_state_in, in, incremental, + query_flags & MLX5VF_QUERY_INC); ret = mlx5_cmd_exec_inout(mvdev->mdev, query_vhca_migration_state, in, out); @@ -342,6 +362,56 @@ end: return ERR_PTR(ret); } +void mlx5vf_put_data_buffer(struct mlx5_vhca_data_buffer *buf) +{ + spin_lock_irq(&buf->migf->list_lock); + list_add_tail(&buf->buf_elm, &buf->migf->avail_list); + spin_unlock_irq(&buf->migf->list_lock); +} + +struct mlx5_vhca_data_buffer * +mlx5vf_get_data_buffer(struct mlx5_vf_migration_file *migf, + size_t length, enum dma_data_direction dma_dir) +{ + struct mlx5_vhca_data_buffer *buf, *temp_buf; + struct list_head free_list; + + lockdep_assert_held(&migf->mvdev->state_mutex); + if (migf->mvdev->mdev_detach) + return ERR_PTR(-ENOTCONN); + + INIT_LIST_HEAD(&free_list); + + spin_lock_irq(&migf->list_lock); + list_for_each_entry_safe(buf, temp_buf, &migf->avail_list, buf_elm) { + if (buf->dma_dir == dma_dir) { + list_del_init(&buf->buf_elm); + if (buf->allocated_length >= length) { + spin_unlock_irq(&migf->list_lock); + goto found; + } + /* + * Prevent holding redundant buffers. Put in a free + * list and call at the end not under the spin lock + * (&migf->list_lock) to mlx5vf_free_data_buffer which + * might sleep. + */ + list_add(&buf->buf_elm, &free_list); + } + } + spin_unlock_irq(&migf->list_lock); + buf = mlx5vf_alloc_data_buffer(migf, length, dma_dir); + +found: + while ((temp_buf = list_first_entry_or_null(&free_list, + struct mlx5_vhca_data_buffer, buf_elm))) { + list_del(&temp_buf->buf_elm); + mlx5vf_free_data_buffer(temp_buf); + } + + return buf; +} + void mlx5vf_mig_file_cleanup_cb(struct work_struct *_work) { struct mlx5vf_async_data *async_data = container_of(_work, @@ -351,7 +421,7 @@ void mlx5vf_mig_file_cleanup_cb(struct work_struct *_work) mutex_lock(&migf->lock); if (async_data->status) { - migf->buf = async_data->buf; + mlx5vf_put_data_buffer(async_data->buf); migf->state = MLX5_MIGF_STATE_ERROR; wake_up_interruptible(&migf->poll_wait); } @@ -369,15 +439,19 @@ static void mlx5vf_save_callback(int status, struct mlx5_async_work *context) struct mlx5_vf_migration_file, async_data); if (!status) { + size_t image_size; unsigned long flags; - async_data->buf->length = - MLX5_GET(save_vhca_state_out, async_data->out, - actual_image_size); + image_size = MLX5_GET(save_vhca_state_out, async_data->out, + actual_image_size); + async_data->buf->length = image_size; + async_data->buf->start_pos = migf->max_pos; + migf->max_pos += async_data->buf->length; spin_lock_irqsave(&migf->list_lock, flags); list_add_tail(&async_data->buf->buf_elm, &migf->buf_list); spin_unlock_irqrestore(&migf->list_lock, flags); - migf->state = MLX5_MIGF_STATE_COMPLETE; + if (async_data->last_chunk) + migf->state = MLX5_MIGF_STATE_COMPLETE; wake_up_interruptible(&migf->poll_wait); } @@ -391,7 +465,8 @@ static void mlx5vf_save_callback(int status, struct mlx5_async_work *context) int mlx5vf_cmd_save_vhca_state(struct mlx5vf_pci_core_device *mvdev, struct mlx5_vf_migration_file *migf, - struct mlx5_vhca_data_buffer *buf) + struct mlx5_vhca_data_buffer *buf, bool inc, + bool track) { u32 out_size = MLX5_ST_SZ_BYTES(save_vhca_state_out); u32 in[MLX5_ST_SZ_DW(save_vhca_state_in)] = {}; @@ -412,9 +487,12 @@ int mlx5vf_cmd_save_vhca_state(struct mlx5vf_pci_core_device *mvdev, MLX5_SET(save_vhca_state_in, in, vhca_id, mvdev->vhca_id); MLX5_SET(save_vhca_state_in, in, mkey, buf->mkey); MLX5_SET(save_vhca_state_in, in, size, buf->allocated_length); + MLX5_SET(save_vhca_state_in, in, incremental, inc); + MLX5_SET(save_vhca_state_in, in, set_track, track); async_data = &migf->async_data; async_data->buf = buf; + async_data->last_chunk = !track; async_data->out = kvzalloc(out_size, GFP_KERNEL); if (!async_data->out) { err = -ENOMEM; @@ -497,6 +575,8 @@ void mlx5fv_cmd_clean_migf_resources(struct mlx5_vf_migration_file *migf) migf->buf = NULL; } + list_splice(&migf->avail_list, &migf->buf_list); + while ((entry = list_first_entry_or_null(&migf->buf_list, struct mlx5_vhca_data_buffer, buf_elm))) { list_del(&entry->buf_elm); diff --git a/drivers/vfio/pci/mlx5/cmd.h b/drivers/vfio/pci/mlx5/cmd.h index 6e59468..34e61c7 100644 --- a/drivers/vfio/pci/mlx5/cmd.h +++ b/drivers/vfio/pci/mlx5/cmd.h @@ -38,6 +38,7 @@ struct mlx5vf_async_data { struct work_struct work; struct mlx5_vhca_data_buffer *buf; int status; + u8 last_chunk:1; void *out; }; @@ -47,9 +48,11 @@ struct mlx5_vf_migration_file { enum mlx5_vf_migf_state state; u32 pdn; + loff_t max_pos; struct mlx5_vhca_data_buffer *buf; spinlock_t list_lock; struct list_head buf_list; + struct list_head avail_list; struct mlx5vf_pci_core_device *mvdev; wait_queue_head_t poll_wait; struct completion save_comp; @@ -129,10 +132,14 @@ struct mlx5vf_pci_core_device { struct mlx5_core_dev *mdev; }; +enum { + MLX5VF_QUERY_INC = (1UL << 0), +}; + int mlx5vf_cmd_suspend_vhca(struct mlx5vf_pci_core_device *mvdev, u16 op_mod); int mlx5vf_cmd_resume_vhca(struct mlx5vf_pci_core_device *mvdev, u16 op_mod); int mlx5vf_cmd_query_vhca_migration_state(struct mlx5vf_pci_core_device *mvdev, - size_t *state_size); + size_t *state_size, u8 query_flags); void mlx5vf_cmd_set_migratable(struct mlx5vf_pci_core_device *mvdev, const struct vfio_migration_ops *mig_ops, const struct vfio_log_ops *log_ops); @@ -140,7 +147,8 @@ void mlx5vf_cmd_remove_migratable(struct mlx5vf_pci_core_device *mvdev); void mlx5vf_cmd_close_migratable(struct mlx5vf_pci_core_device *mvdev); int mlx5vf_cmd_save_vhca_state(struct mlx5vf_pci_core_device *mvdev, struct mlx5_vf_migration_file *migf, - struct mlx5_vhca_data_buffer *buf); + struct mlx5_vhca_data_buffer *buf, bool inc, + bool track); int mlx5vf_cmd_load_vhca_state(struct mlx5vf_pci_core_device *mvdev, struct mlx5_vf_migration_file *migf, struct mlx5_vhca_data_buffer *buf); @@ -151,6 +159,10 @@ struct mlx5_vhca_data_buffer * mlx5vf_alloc_data_buffer(struct mlx5_vf_migration_file *migf, size_t length, enum dma_data_direction dma_dir); void mlx5vf_free_data_buffer(struct mlx5_vhca_data_buffer *buf); +struct mlx5_vhca_data_buffer * +mlx5vf_get_data_buffer(struct mlx5_vf_migration_file *migf, + size_t length, enum dma_data_direction dma_dir); +void mlx5vf_put_data_buffer(struct mlx5_vhca_data_buffer *buf); int mlx5vf_add_migration_pages(struct mlx5_vhca_data_buffer *buf, unsigned int npages); void mlx5vf_state_mutex_unlock(struct mlx5vf_pci_core_device *mvdev); diff --git a/drivers/vfio/pci/mlx5/main.c b/drivers/vfio/pci/mlx5/main.c index ca16425..9cabba4 100644 --- a/drivers/vfio/pci/mlx5/main.c +++ b/drivers/vfio/pci/mlx5/main.c @@ -195,6 +195,7 @@ static ssize_t mlx5vf_buf_read(struct mlx5_vhca_data_buffer *vhca_buf, if (*pos >= vhca_buf->start_pos + vhca_buf->length) { spin_lock_irq(&vhca_buf->migf->list_lock); list_del_init(&vhca_buf->buf_elm); + list_add_tail(&vhca_buf->buf_elm, &vhca_buf->migf->avail_list); spin_unlock_irq(&vhca_buf->migf->list_lock); } @@ -283,6 +284,16 @@ static __poll_t mlx5vf_save_poll(struct file *filp, return pollflags; } +/* + * FD is exposed and user can use it after receiving an error. + * Mark migf in error, and wake the user. + */ +static void mlx5vf_mark_err(struct mlx5_vf_migration_file *migf) +{ + migf->state = MLX5_MIGF_STATE_ERROR; + wake_up_interruptible(&migf->poll_wait); +} + static const struct file_operations mlx5vf_save_fops = { .owner = THIS_MODULE, .read = mlx5vf_save_read, @@ -291,8 +302,42 @@ static const struct file_operations mlx5vf_save_fops = { .llseek = no_llseek, }; +static int mlx5vf_pci_save_device_inc_data(struct mlx5vf_pci_core_device *mvdev) +{ + struct mlx5_vf_migration_file *migf = mvdev->saving_migf; + struct mlx5_vhca_data_buffer *buf; + size_t length; + int ret; + + if (migf->state == MLX5_MIGF_STATE_ERROR) + return -ENODEV; + + ret = mlx5vf_cmd_query_vhca_migration_state(mvdev, &length, + MLX5VF_QUERY_INC); + if (ret) + goto err; + + buf = mlx5vf_get_data_buffer(migf, length, DMA_FROM_DEVICE); + if (IS_ERR(buf)) { + ret = PTR_ERR(buf); + goto err; + } + + ret = mlx5vf_cmd_save_vhca_state(mvdev, migf, buf, true, false); + if (ret) + goto err_save; + + return 0; + +err_save: + mlx5vf_put_data_buffer(buf); +err: + mlx5vf_mark_err(migf); + return ret; +} + static struct mlx5_vf_migration_file * -mlx5vf_pci_save_device_data(struct mlx5vf_pci_core_device *mvdev) +mlx5vf_pci_save_device_data(struct mlx5vf_pci_core_device *mvdev, bool track) { struct mlx5_vf_migration_file *migf; struct mlx5_vhca_data_buffer *buf; @@ -328,8 +373,9 @@ mlx5vf_pci_save_device_data(struct mlx5vf_pci_core_device *mvdev) mlx5_cmd_init_async_ctx(mvdev->mdev, &migf->async_ctx); INIT_WORK(&migf->async_data.work, mlx5vf_mig_file_cleanup_cb); INIT_LIST_HEAD(&migf->buf_list); + INIT_LIST_HEAD(&migf->avail_list); spin_lock_init(&migf->list_lock); - ret = mlx5vf_cmd_query_vhca_migration_state(mvdev, &length); + ret = mlx5vf_cmd_query_vhca_migration_state(mvdev, &length, 0); if (ret) goto out_pd; @@ -339,7 +385,7 @@ mlx5vf_pci_save_device_data(struct mlx5vf_pci_core_device *mvdev) goto out_pd; } - ret = mlx5vf_cmd_save_vhca_state(mvdev, migf, buf); + ret = mlx5vf_cmd_save_vhca_state(mvdev, migf, buf, false, track); if (ret) goto out_save; return migf; @@ -462,6 +508,7 @@ mlx5vf_pci_resume_device_data(struct mlx5vf_pci_core_device *mvdev) stream_open(migf->filp->f_inode, migf->filp); mutex_init(&migf->lock); INIT_LIST_HEAD(&migf->buf_list); + INIT_LIST_HEAD(&migf->avail_list); spin_lock_init(&migf->list_lock); return migf; out_pd: @@ -514,7 +561,8 @@ mlx5vf_pci_step_device_state_locked(struct mlx5vf_pci_core_device *mvdev, return NULL; } - if (cur == VFIO_DEVICE_STATE_RUNNING && new == VFIO_DEVICE_STATE_RUNNING_P2P) { + if ((cur == VFIO_DEVICE_STATE_RUNNING && new == VFIO_DEVICE_STATE_RUNNING_P2P) || + (cur == VFIO_DEVICE_STATE_PRE_COPY && new == VFIO_DEVICE_STATE_PRE_COPY_P2P)) { ret = mlx5vf_cmd_suspend_vhca(mvdev, MLX5_SUSPEND_VHCA_IN_OP_MOD_SUSPEND_INITIATOR); if (ret) @@ -522,7 +570,8 @@ mlx5vf_pci_step_device_state_locked(struct mlx5vf_pci_core_device *mvdev, return NULL; } - if (cur == VFIO_DEVICE_STATE_RUNNING_P2P && new == VFIO_DEVICE_STATE_RUNNING) { + if ((cur == VFIO_DEVICE_STATE_RUNNING_P2P && new == VFIO_DEVICE_STATE_RUNNING) || + (cur == VFIO_DEVICE_STATE_PRE_COPY_P2P && new == VFIO_DEVICE_STATE_PRE_COPY)) { ret = mlx5vf_cmd_resume_vhca(mvdev, MLX5_RESUME_VHCA_IN_OP_MOD_RESUME_INITIATOR); if (ret) @@ -533,7 +582,7 @@ mlx5vf_pci_step_device_state_locked(struct mlx5vf_pci_core_device *mvdev, if (cur == VFIO_DEVICE_STATE_STOP && new == VFIO_DEVICE_STATE_STOP_COPY) { struct mlx5_vf_migration_file *migf; - migf = mlx5vf_pci_save_device_data(mvdev); + migf = mlx5vf_pci_save_device_data(mvdev, false); if (IS_ERR(migf)) return ERR_CAST(migf); get_file(migf->filp); @@ -541,7 +590,10 @@ mlx5vf_pci_step_device_state_locked(struct mlx5vf_pci_core_device *mvdev, return migf->filp; } - if ((cur == VFIO_DEVICE_STATE_STOP_COPY && new == VFIO_DEVICE_STATE_STOP)) { + if ((cur == VFIO_DEVICE_STATE_STOP_COPY && new == VFIO_DEVICE_STATE_STOP) || + (cur == VFIO_DEVICE_STATE_PRE_COPY && new == VFIO_DEVICE_STATE_RUNNING) || + (cur == VFIO_DEVICE_STATE_PRE_COPY_P2P && + new == VFIO_DEVICE_STATE_RUNNING_P2P)) { mlx5vf_disable_fds(mvdev); return NULL; } @@ -567,6 +619,28 @@ mlx5vf_pci_step_device_state_locked(struct mlx5vf_pci_core_device *mvdev, return NULL; } + if ((cur == VFIO_DEVICE_STATE_RUNNING && new == VFIO_DEVICE_STATE_PRE_COPY) || + (cur == VFIO_DEVICE_STATE_RUNNING_P2P && + new == VFIO_DEVICE_STATE_PRE_COPY_P2P)) { + struct mlx5_vf_migration_file *migf; + + migf = mlx5vf_pci_save_device_data(mvdev, true); + if (IS_ERR(migf)) + return ERR_CAST(migf); + get_file(migf->filp); + mvdev->saving_migf = migf; + return migf->filp; + } + + if (cur == VFIO_DEVICE_STATE_PRE_COPY_P2P && new == VFIO_DEVICE_STATE_STOP_COPY) { + ret = mlx5vf_cmd_suspend_vhca(mvdev, + MLX5_SUSPEND_VHCA_IN_OP_MOD_SUSPEND_RESPONDER); + if (ret) + return ERR_PTR(ret); + ret = mlx5vf_pci_save_device_inc_data(mvdev); + return ret ? ERR_PTR(ret) : NULL; + } + /* * vfio_mig_get_next_state() does not use arcs other than the above */ @@ -635,7 +709,7 @@ static int mlx5vf_pci_get_data_size(struct vfio_device *vdev, mutex_lock(&mvdev->state_mutex); ret = mlx5vf_cmd_query_vhca_migration_state(mvdev, - &state_size); + &state_size, 0); if (!ret) *stop_copy_length = state_size; mlx5vf_state_mutex_unlock(mvdev);