From 09d7583294aada625349b6f80f1e1c730b5a5208 Mon Sep 17 00:00:00 2001 From: Bijan Mottahedeh Date: Mon, 17 Sep 2018 17:09:49 -0700 Subject: vhost/scsi: Use common handling code in request queue handler Change the request queue handler to use common handling routines same as the control queue handler. Signed-off-by: Bijan Mottahedeh Signed-off-by: Michael S. Tsirkin --- drivers/vhost/scsi.c | 361 +++++++++++++++++++++++---------------------------- 1 file changed, 164 insertions(+), 197 deletions(-) (limited to 'drivers/vhost') diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index 4cd03a1d7f21..50dffe83714c 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -813,24 +813,120 @@ vhost_scsi_send_bad_target(struct vhost_scsi *vs, pr_err("Faulted on virtio_scsi_cmd_resp\n"); } +static int +vhost_scsi_get_desc(struct vhost_scsi *vs, struct vhost_virtqueue *vq, + struct vhost_scsi_ctx *vc) +{ + int ret = -ENXIO; + + vc->head = vhost_get_vq_desc(vq, vq->iov, + ARRAY_SIZE(vq->iov), &vc->out, &vc->in, + NULL, NULL); + + pr_debug("vhost_get_vq_desc: head: %d, out: %u in: %u\n", + vc->head, vc->out, vc->in); + + /* On error, stop handling until the next kick. */ + if (unlikely(vc->head < 0)) + goto done; + + /* Nothing new? Wait for eventfd to tell us they refilled. */ + if (vc->head == vq->num) { + if (unlikely(vhost_enable_notify(&vs->dev, vq))) { + vhost_disable_notify(&vs->dev, vq); + ret = -EAGAIN; + } + goto done; + } + + /* + * Get the size of request and response buffers. + * FIXME: Not correct for BIDI operation + */ + vc->out_size = iov_length(vq->iov, vc->out); + vc->in_size = iov_length(&vq->iov[vc->out], vc->in); + + /* + * Copy over the virtio-scsi request header, which for a + * ANY_LAYOUT enabled guest may span multiple iovecs, or a + * single iovec may contain both the header + outgoing + * WRITE payloads. + * + * copy_from_iter() will advance out_iter, so that it will + * point at the start of the outgoing WRITE payload, if + * DMA_TO_DEVICE is set. + */ + iov_iter_init(&vc->out_iter, WRITE, vq->iov, vc->out, vc->out_size); + ret = 0; + +done: + return ret; +} + +static int +vhost_scsi_chk_size(struct vhost_virtqueue *vq, struct vhost_scsi_ctx *vc) +{ + if (unlikely(vc->in_size < vc->rsp_size)) { + vq_err(vq, + "Response buf too small, need min %zu bytes got %zu", + vc->rsp_size, vc->in_size); + return -EINVAL; + } else if (unlikely(vc->out_size < vc->req_size)) { + vq_err(vq, + "Request buf too small, need min %zu bytes got %zu", + vc->req_size, vc->out_size); + return -EIO; + } + + return 0; +} + +static int +vhost_scsi_get_req(struct vhost_virtqueue *vq, struct vhost_scsi_ctx *vc, + struct vhost_scsi_tpg **tpgp) +{ + int ret = -EIO; + + if (unlikely(!copy_from_iter_full(vc->req, vc->req_size, + &vc->out_iter))) { + vq_err(vq, "Faulted on copy_from_iter\n"); + } else if (unlikely(*vc->lunp != 1)) { + /* virtio-scsi spec requires byte 0 of the lun to be 1 */ + vq_err(vq, "Illegal virtio-scsi lun: %u\n", *vc->lunp); + } else { + struct vhost_scsi_tpg **vs_tpg, *tpg; + + vs_tpg = vq->private_data; /* validated at handler entry */ + + tpg = READ_ONCE(vs_tpg[*vc->target]); + if (unlikely(!tpg)) { + vq_err(vq, "Target 0x%x does not exist\n", *vc->target); + } else { + if (tpgp) + *tpgp = tpg; + ret = 0; + } + } + + return ret; +} + static void vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) { struct vhost_scsi_tpg **vs_tpg, *tpg; struct virtio_scsi_cmd_req v_req; struct virtio_scsi_cmd_req_pi v_req_pi; + struct vhost_scsi_ctx vc; struct vhost_scsi_cmd *cmd; - struct iov_iter out_iter, in_iter, prot_iter, data_iter; + struct iov_iter in_iter, prot_iter, data_iter; u64 tag; u32 exp_data_len, data_direction; - unsigned int out = 0, in = 0; - int head, ret, prot_bytes; - size_t req_size, rsp_size = sizeof(struct virtio_scsi_cmd_resp); - size_t out_size, in_size; + int ret, prot_bytes; u16 lun; - u8 *target, *lunp, task_attr; + u8 task_attr; bool t10_pi = vhost_has_feature(vq, VIRTIO_SCSI_F_T10_PI); - void *req, *cdb; + void *cdb; mutex_lock(&vq->mutex); /* @@ -841,85 +937,47 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) if (!vs_tpg) goto out; + memset(&vc, 0, sizeof(vc)); + vc.rsp_size = sizeof(struct virtio_scsi_cmd_resp); + vhost_disable_notify(&vs->dev, vq); for (;;) { - head = vhost_get_vq_desc(vq, vq->iov, - ARRAY_SIZE(vq->iov), &out, &in, - NULL, NULL); - pr_debug("vhost_get_vq_desc: head: %d, out: %u in: %u\n", - head, out, in); - /* On error, stop handling until the next kick. */ - if (unlikely(head < 0)) - break; - /* Nothing new? Wait for eventfd to tell us they refilled. */ - if (head == vq->num) { - if (unlikely(vhost_enable_notify(&vs->dev, vq))) { - vhost_disable_notify(&vs->dev, vq); - continue; - } - break; - } - /* - * Check for a sane response buffer so we can report early - * errors back to the guest. - */ - if (unlikely(vq->iov[out].iov_len < rsp_size)) { - vq_err(vq, "Expecting at least virtio_scsi_cmd_resp" - " size, got %zu bytes\n", vq->iov[out].iov_len); - break; - } + ret = vhost_scsi_get_desc(vs, vq, &vc); + if (ret) + goto err; + /* * Setup pointers and values based upon different virtio-scsi * request header if T10_PI is enabled in KVM guest. */ if (t10_pi) { - req = &v_req_pi; - req_size = sizeof(v_req_pi); - lunp = &v_req_pi.lun[0]; - target = &v_req_pi.lun[1]; + vc.req = &v_req_pi; + vc.req_size = sizeof(v_req_pi); + vc.lunp = &v_req_pi.lun[0]; + vc.target = &v_req_pi.lun[1]; } else { - req = &v_req; - req_size = sizeof(v_req); - lunp = &v_req.lun[0]; - target = &v_req.lun[1]; + vc.req = &v_req; + vc.req_size = sizeof(v_req); + vc.lunp = &v_req.lun[0]; + vc.target = &v_req.lun[1]; } - /* - * FIXME: Not correct for BIDI operation - */ - out_size = iov_length(vq->iov, out); - in_size = iov_length(&vq->iov[out], in); /* - * Copy over the virtio-scsi request header, which for a - * ANY_LAYOUT enabled guest may span multiple iovecs, or a - * single iovec may contain both the header + outgoing - * WRITE payloads. - * - * copy_from_iter() will advance out_iter, so that it will - * point at the start of the outgoing WRITE payload, if - * DMA_TO_DEVICE is set. + * Validate the size of request and response buffers. + * Check for a sane response buffer so we can report + * early errors back to the guest. */ - iov_iter_init(&out_iter, WRITE, vq->iov, out, out_size); + ret = vhost_scsi_chk_size(vq, &vc); + if (ret) + goto err; - if (unlikely(!copy_from_iter_full(req, req_size, &out_iter))) { - vq_err(vq, "Faulted on copy_from_iter\n"); - vhost_scsi_send_bad_target(vs, vq, head, out); - continue; - } - /* virtio-scsi spec requires byte 0 of the lun to be 1 */ - if (unlikely(*lunp != 1)) { - vq_err(vq, "Illegal virtio-scsi lun: %u\n", *lunp); - vhost_scsi_send_bad_target(vs, vq, head, out); - continue; - } + ret = vhost_scsi_get_req(vq, &vc, &tpg); + if (ret) + goto err; + + ret = -EIO; /* bad target on any error from here on */ - tpg = READ_ONCE(vs_tpg[*target]); - if (unlikely(!tpg)) { - /* Target does not exist, fail the request */ - vhost_scsi_send_bad_target(vs, vq, head, out); - continue; - } /* * Determine data_direction by calculating the total outgoing * iovec sizes + incoming iovec sizes vs. virtio-scsi request + @@ -937,17 +995,17 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) */ prot_bytes = 0; - if (out_size > req_size) { + if (vc.out_size > vc.req_size) { data_direction = DMA_TO_DEVICE; - exp_data_len = out_size - req_size; - data_iter = out_iter; - } else if (in_size > rsp_size) { + exp_data_len = vc.out_size - vc.req_size; + data_iter = vc.out_iter; + } else if (vc.in_size > vc.rsp_size) { data_direction = DMA_FROM_DEVICE; - exp_data_len = in_size - rsp_size; + exp_data_len = vc.in_size - vc.rsp_size; - iov_iter_init(&in_iter, READ, &vq->iov[out], in, - rsp_size + exp_data_len); - iov_iter_advance(&in_iter, rsp_size); + iov_iter_init(&in_iter, READ, &vq->iov[vc.out], vc.in, + vc.rsp_size + exp_data_len); + iov_iter_advance(&in_iter, vc.rsp_size); data_iter = in_iter; } else { data_direction = DMA_NONE; @@ -963,16 +1021,14 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) if (data_direction != DMA_TO_DEVICE) { vq_err(vq, "Received non zero pi_bytesout," " but wrong data_direction\n"); - vhost_scsi_send_bad_target(vs, vq, head, out); - continue; + goto err; } prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesout); } else if (v_req_pi.pi_bytesin) { if (data_direction != DMA_FROM_DEVICE) { vq_err(vq, "Received non zero pi_bytesin," " but wrong data_direction\n"); - vhost_scsi_send_bad_target(vs, vq, head, out); - continue; + goto err; } prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesin); } @@ -1011,8 +1067,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) vq_err(vq, "Received SCSI CDB with command_size: %d that" " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n", scsi_command_size(cdb), VHOST_SCSI_MAX_CDB_SIZE); - vhost_scsi_send_bad_target(vs, vq, head, out); - continue; + goto err; } cmd = vhost_scsi_get_tag(vq, tpg, cdb, tag, lun, task_attr, exp_data_len + prot_bytes, @@ -1020,13 +1075,12 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) if (IS_ERR(cmd)) { vq_err(vq, "vhost_scsi_get_tag failed %ld\n", PTR_ERR(cmd)); - vhost_scsi_send_bad_target(vs, vq, head, out); - continue; + goto err; } cmd->tvc_vhost = vs; cmd->tvc_vq = vq; - cmd->tvc_resp_iov = vq->iov[out]; - cmd->tvc_in_iovs = in; + cmd->tvc_resp_iov = vq->iov[vc.out]; + cmd->tvc_in_iovs = vc.in; pr_debug("vhost_scsi got command opcode: %#02x, lun: %d\n", cmd->tvc_cdb[0], cmd->tvc_lun); @@ -1034,14 +1088,12 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) " %d\n", cmd, exp_data_len, prot_bytes, data_direction); if (data_direction != DMA_NONE) { - ret = vhost_scsi_mapal(cmd, - prot_bytes, &prot_iter, - exp_data_len, &data_iter); - if (unlikely(ret)) { + if (unlikely(vhost_scsi_mapal(cmd, prot_bytes, + &prot_iter, exp_data_len, + &data_iter))) { vq_err(vq, "Failed to map iov to sgl\n"); vhost_scsi_release_cmd(&cmd->tvc_se_cmd); - vhost_scsi_send_bad_target(vs, vq, head, out); - continue; + goto err; } } /* @@ -1049,7 +1101,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) * complete the virtio-scsi request in TCM callback context via * vhost_scsi_queue_data_in() and vhost_scsi_queue_status() */ - cmd->tvc_vq_desc = head; + cmd->tvc_vq_desc = vc.head; /* * Dispatch cmd descriptor for cmwq execution in process * context provided by vhost_scsi_workqueue. This also ensures @@ -1058,112 +1110,27 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) */ INIT_WORK(&cmd->work, vhost_scsi_submission_work); queue_work(vhost_scsi_workqueue, &cmd->work); + ret = 0; +err: + /* + * ENXIO: No more requests, or read error, wait for next kick + * EINVAL: Invalid response buffer, drop the request + * EIO: Respond with bad target + * EAGAIN: Pending request + */ + if (ret == -ENXIO) + break; + else if (ret == -EIO) + vhost_scsi_send_bad_target(vs, vq, vc.head, vc.out); } out: mutex_unlock(&vq->mutex); } -static int -vhost_scsi_get_desc(struct vhost_scsi *vs, struct vhost_virtqueue *vq, - struct vhost_scsi_ctx *vc) -{ - int ret = -ENXIO; - - vc->head = vhost_get_vq_desc(vq, vq->iov, - ARRAY_SIZE(vq->iov), &vc->out, &vc->in, - NULL, NULL); - - pr_debug("vhost_get_vq_desc: head: %d, out: %u in: %u\n", - vc->head, vc->out, vc->in); - - /* On error, stop handling until the next kick. */ - if (unlikely(vc->head < 0)) - goto done; - - /* Nothing new? Wait for eventfd to tell us they refilled. */ - if (vc->head == vq->num) { - if (unlikely(vhost_enable_notify(&vs->dev, vq))) { - vhost_disable_notify(&vs->dev, vq); - ret = -EAGAIN; - } - goto done; - } - - /* - * Get the size of request and response buffers. - */ - vc->out_size = iov_length(vq->iov, vc->out); - vc->in_size = iov_length(&vq->iov[vc->out], vc->in); - - /* - * Copy over the virtio-scsi request header, which for a - * ANY_LAYOUT enabled guest may span multiple iovecs, or a - * single iovec may contain both the header + outgoing - * WRITE payloads. - * - * copy_from_iter() will advance out_iter, so that it will - * point at the start of the outgoing WRITE payload, if - * DMA_TO_DEVICE is set. - */ - iov_iter_init(&vc->out_iter, WRITE, vq->iov, vc->out, vc->out_size); - ret = 0; - -done: - return ret; -} - -static int -vhost_scsi_chk_size(struct vhost_virtqueue *vq, struct vhost_scsi_ctx *vc) -{ - if (unlikely(vc->in_size < vc->rsp_size)) { - vq_err(vq, - "Response buf too small, need min %zu bytes got %zu", - vc->rsp_size, vc->in_size); - return -EINVAL; - } else if (unlikely(vc->out_size < vc->req_size)) { - vq_err(vq, - "Request buf too small, need min %zu bytes got %zu", - vc->req_size, vc->out_size); - return -EIO; - } - - return 0; -} - -static int -vhost_scsi_get_req(struct vhost_virtqueue *vq, struct vhost_scsi_ctx *vc, - struct vhost_scsi_tpg **tpgp) -{ - int ret = -EIO; - - if (unlikely(!copy_from_iter_full(vc->req, vc->req_size, - &vc->out_iter))) - vq_err(vq, "Faulted on copy_from_iter\n"); - else if (unlikely(*vc->lunp != 1)) - /* virtio-scsi spec requires byte 0 of the lun to be 1 */ - vq_err(vq, "Illegal virtio-scsi lun: %u\n", *vc->lunp); - else { - struct vhost_scsi_tpg **vs_tpg, *tpg; - - vs_tpg = vq->private_data; /* validated at handler entry */ - - tpg = READ_ONCE(vs_tpg[*vc->target]); - if (unlikely(!tpg)) - vq_err(vq, "Target 0x%x does not exist\n", *vc->target); - else { - if (tpgp) - *tpgp = tpg; - ret = 0; - } - } - - return ret; -} - static void -vhost_scsi_send_tmf_resp(struct vhost_scsi *vs, - struct vhost_virtqueue *vq, - struct vhost_scsi_ctx *vc) +vhost_scsi_send_tmf_reject(struct vhost_scsi *vs, + struct vhost_virtqueue *vq, + struct vhost_scsi_ctx *vc) { struct virtio_scsi_ctrl_tmf_resp __user *resp; struct virtio_scsi_ctrl_tmf_resp rsp; @@ -1289,7 +1256,7 @@ vhost_scsi_ctl_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) goto err; if (v_req.type == VIRTIO_SCSI_T_TMF) - vhost_scsi_send_tmf_resp(vs, vq, &vc); + vhost_scsi_send_tmf_reject(vs, vq, &vc); else vhost_scsi_send_an_resp(vs, vq, &vc); err: -- cgit v1.2.3-59-g8ed1b