From: Feng Liu <[email protected]> Add support for sending admin command through admin virtqueue interface. Abort any inflight admin commands once device reset completes.
To enforce the below statement from the specification [1], the admin queue is activated for the upper layer users only post of setting status to DRIVER_OK. [1] The driver MUST NOT send any buffer available notifications to the device before setting DRIVER_OK. Signed-off-by: Feng Liu <[email protected]> Reviewed-by: Parav Pandit <[email protected]> Signed-off-by: Yishai Hadas <[email protected]> --- drivers/virtio/virtio_pci_common.h | 3 + drivers/virtio/virtio_pci_modern.c | 174 +++++++++++++++++++++++++++++ include/linux/virtio.h | 8 ++ include/uapi/linux/virtio_pci.h | 22 ++++ 4 files changed, 207 insertions(+) diff --git a/drivers/virtio/virtio_pci_common.h b/drivers/virtio/virtio_pci_common.h index e03af0966a4b..a21b9ba01a60 100644 --- a/drivers/virtio/virtio_pci_common.h +++ b/drivers/virtio/virtio_pci_common.h @@ -44,9 +44,12 @@ struct virtio_pci_vq_info { struct virtio_pci_admin_vq { /* Virtqueue info associated with this admin queue. */ struct virtio_pci_vq_info info; + struct completion flush_done; + refcount_t refcount; /* Name of the admin queue: avq.$index. */ char name[10]; u16 vq_index; + bool abort; }; /* Our device structure */ diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c index 01c5ba346471..cc159a8e6c70 100644 --- a/drivers/virtio/virtio_pci_modern.c +++ b/drivers/virtio/virtio_pci_modern.c @@ -36,6 +36,58 @@ static bool vp_is_avq(struct virtio_device *vdev, unsigned int index) return index == vp_dev->admin_vq.vq_index; } +static bool vp_modern_avq_get(struct virtio_pci_admin_vq *admin_vq) +{ + return refcount_inc_not_zero(&admin_vq->refcount); +} + +static void vp_modern_avq_put(struct virtio_pci_admin_vq *admin_vq) +{ + if (refcount_dec_and_test(&admin_vq->refcount)) + complete(&admin_vq->flush_done); +} + +static bool vp_modern_avq_is_abort(const struct virtio_pci_admin_vq *admin_vq) +{ + return READ_ONCE(admin_vq->abort); +} + +static void +vp_modern_avq_set_abort(struct virtio_pci_admin_vq *admin_vq, bool abort) +{ + /* Mark the AVQ to abort, so that inflight commands can be aborted. */ + WRITE_ONCE(admin_vq->abort, abort); +} + +static void vp_modern_avq_activate(struct virtio_device *vdev) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + struct virtio_pci_admin_vq *admin_vq = &vp_dev->admin_vq; + + if (!virtio_has_feature(vdev, VIRTIO_F_ADMIN_VQ)) + return; + + init_completion(&admin_vq->flush_done); + refcount_set(&admin_vq->refcount, 1); + vp_modern_avq_set_abort(admin_vq, false); +} + +static void vp_modern_avq_deactivate(struct virtio_device *vdev) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + struct virtio_pci_admin_vq *admin_vq = &vp_dev->admin_vq; + + if (!virtio_has_feature(vdev, VIRTIO_F_ADMIN_VQ)) + return; + + vp_modern_avq_set_abort(admin_vq, true); + /* Balance with refcount_set() during vp_modern_avq_activate */ + vp_modern_avq_put(admin_vq); + + /* Wait for all the inflight admin commands to be aborted */ + wait_for_completion(&vp_dev->admin_vq.flush_done); +} + static void vp_transport_features(struct virtio_device *vdev, u64 features) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); @@ -172,6 +224,8 @@ static void vp_set_status(struct virtio_device *vdev, u8 status) /* We should never be setting status to 0. */ BUG_ON(status == 0); vp_modern_set_status(&vp_dev->mdev, status); + if (status & VIRTIO_CONFIG_S_DRIVER_OK) + vp_modern_avq_activate(vdev); } static void vp_reset(struct virtio_device *vdev) @@ -188,6 +242,9 @@ static void vp_reset(struct virtio_device *vdev) */ while (vp_modern_get_status(mdev)) msleep(1); + + vp_modern_avq_deactivate(vdev); + /* Flush pending VQ/configuration callbacks. */ vp_synchronize_vectors(vdev); } @@ -505,6 +562,121 @@ static bool vp_get_shm_region(struct virtio_device *vdev, return true; } +static int virtqueue_exec_admin_cmd(struct virtio_pci_admin_vq *admin_vq, + struct scatterlist **sgs, + unsigned int out_num, + unsigned int in_num, + void *data, + gfp_t gfp) +{ + struct virtqueue *vq; + int ret, len; + + if (!vp_modern_avq_get(admin_vq)) + return -EIO; + + vq = admin_vq->info.vq; + + ret = virtqueue_add_sgs(vq, sgs, out_num, in_num, data, gfp); + if (ret < 0) + goto out; + + if (unlikely(!virtqueue_kick(vq))) { + ret = -EIO; + goto out; + } + + while (!virtqueue_get_buf(vq, &len) && + !virtqueue_is_broken(vq) && + !vp_modern_avq_is_abort(admin_vq)) + cpu_relax(); + + if (vp_modern_avq_is_abort(admin_vq)) { + ret = -EIO; + goto out; + } +out: + vp_modern_avq_put(admin_vq); + return ret; +} + +#define VIRTIO_AVQ_SGS_MAX 4 + +static int vp_modern_admin_cmd_exec(struct virtio_device *vdev, + struct virtio_admin_cmd *cmd) +{ + struct scatterlist *sgs[VIRTIO_AVQ_SGS_MAX], hdr, stat; + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + struct virtio_admin_cmd_status *va_status; + unsigned int out_num = 0, in_num = 0; + struct virtio_admin_cmd_hdr *va_hdr; + struct virtqueue *avq; + u16 status; + int ret; + + avq = virtio_has_feature(vdev, VIRTIO_F_ADMIN_VQ) ? + vp_dev->admin_vq.info.vq : NULL; + if (!avq) + return -EOPNOTSUPP; + + va_status = kzalloc(sizeof(*va_status), GFP_KERNEL); + if (!va_status) + return -ENOMEM; + + va_hdr = kzalloc(sizeof(*va_hdr), GFP_KERNEL); + if (!va_hdr) { + ret = -ENOMEM; + goto err_alloc; + } + + va_hdr->opcode = cmd->opcode; + va_hdr->group_type = cmd->group_type; + va_hdr->group_member_id = cmd->group_member_id; + + /* Add header */ + sg_init_one(&hdr, va_hdr, sizeof(*va_hdr)); + sgs[out_num] = &hdr; + out_num++; + + if (cmd->data_sg) { + sgs[out_num] = cmd->data_sg; + out_num++; + } + + /* Add return status */ + sg_init_one(&stat, va_status, sizeof(*va_status)); + sgs[out_num + in_num] = &stat; + in_num++; + + if (cmd->result_sg) { + sgs[out_num + in_num] = cmd->result_sg; + in_num++; + } + + ret = virtqueue_exec_admin_cmd(&vp_dev->admin_vq, sgs, + out_num, in_num, + sgs, GFP_KERNEL); + if (ret) { + dev_err(&vdev->dev, + "Failed to execute command on admin vq: %d\n.", ret); + goto err_cmd_exec; + } + + status = le16_to_cpu(va_status->status); + if (status != VIRTIO_ADMIN_STATUS_OK) { + dev_err(&vdev->dev, + "admin command error: status(%#x) qualifier(%#x)\n", + status, le16_to_cpu(va_status->status_qualifier)); + ret = -status; + } + +err_cmd_exec: + kfree(va_hdr); +err_alloc: + kfree(va_status); + return ret; +} + static int vp_modern_create_avq(struct virtio_device *vdev) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); @@ -530,6 +702,7 @@ static int vp_modern_create_avq(struct virtio_device *vdev) return PTR_ERR(vq); } + refcount_set(&vp_dev->admin_vq.refcount, 0); vp_dev->admin_vq.info.vq = vq; vp_modern_set_queue_enable(&vp_dev->mdev, avq->info.vq->index, true); return 0; @@ -542,6 +715,7 @@ static void vp_modern_destroy_avq(struct virtio_device *vdev) if (!virtio_has_feature(vdev, VIRTIO_F_ADMIN_VQ)) return; + WARN_ON(refcount_read(&vp_dev->admin_vq.refcount)); vp_dev->del_vq(&vp_dev->admin_vq.info); } diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 4cc614a38376..b0201747a263 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -103,6 +103,14 @@ int virtqueue_resize(struct virtqueue *vq, u32 num, int virtqueue_reset(struct virtqueue *vq, void (*recycle)(struct virtqueue *vq, void *buf)); +struct virtio_admin_cmd { + __le16 opcode; + __le16 group_type; + __le64 group_member_id; + struct scatterlist *data_sg; + struct scatterlist *result_sg; +}; + /** * struct virtio_device - representation of a device using virtio * @index: unique position on the virtio bus diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h index f703afc7ad31..68eacc9676dc 100644 --- a/include/uapi/linux/virtio_pci.h +++ b/include/uapi/linux/virtio_pci.h @@ -207,4 +207,26 @@ struct virtio_pci_cfg_cap { #endif /* VIRTIO_PCI_NO_MODERN */ +/* Admin command status. */ +#define VIRTIO_ADMIN_STATUS_OK 0 + +struct __packed virtio_admin_cmd_hdr { + __le16 opcode; + /* + * 1 - SR-IOV + * 2-65535 - reserved + */ + __le16 group_type; + /* Unused, reserved for future extensions. */ + __u8 reserved1[12]; + __le64 group_member_id; +}; + +struct __packed virtio_admin_cmd_status { + __le16 status; + __le16 status_qualifier; + /* Unused, reserved for future extensions. */ + __u8 reserved2[4]; +}; + #endif -- 2.27.0 _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
