From 4542d623c7134bc1738f8a68ccb6dd546f1c264f Mon Sep 17 00:00:00 2001 From: Greg Edwards Date: Wed, 22 Aug 2018 13:21:53 -0600 Subject: vhost/scsi: truncate T10 PI iov_iter to prot_bytes Commands with protection information included were not truncating the protection iov_iter to the number of protection bytes in the command. This resulted in vhost_scsi mis-calculating the size of the protection SGL in vhost_scsi_calc_sgls(), and including both the protection and data SG entries in the protection SGL. Fixes: 09b13fa8c1a1 ("vhost/scsi: Add ANY_LAYOUT support in vhost_scsi_handle_vq") Signed-off-by: Greg Edwards Signed-off-by: Michael S. Tsirkin Fixes: 09b13fa8c1a1093e9458549ac8bb203a7c65c62a Cc: stable@vger.kernel.org Reviewed-by: Paolo Bonzini --- drivers/vhost/scsi.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/vhost') diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index c24bb690680b..e7e3ae13516d 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -964,7 +964,8 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesin); } /* - * Set prot_iter to data_iter, and advance past any + * Set prot_iter to data_iter and truncate it to + * prot_bytes, and advance data_iter past any * preceeding prot_bytes that may be present. * * Also fix up the exp_data_len to reflect only the @@ -973,6 +974,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) if (prot_bytes) { exp_data_len -= prot_bytes; prot_iter = data_iter; + iov_iter_truncate(&prot_iter, prot_bytes); iov_iter_advance(&data_iter, prot_bytes); } tag = vhost64_to_cpu(vq, v_req_pi.tag); -- cgit v1.2.3-59-g8ed1b From 0d02dbd68c47b66367130b696baef7246720791c Mon Sep 17 00:00:00 2001 From: Bijan Mottahedeh Date: Mon, 17 Sep 2018 17:09:47 -0700 Subject: vhost/scsi: Respond to control queue operations The vhost-scsi driver currently does not handle any control queue operations. In particular, vhost_scsi_ctl_handle_kick, merely prints out a debug message but does nothing else. This can cause guest VMs to hang. As part of SCSI recovery from an error, e.g., an I/O timeout, the SCSI midlayer attempts to abort the failed operation. The SCSI virtio driver translates the abort to a SCSI TMF request that gets put on the control queue (virtscsi_abort -> virtscsi_tmf). The SCSI virtio driver then waits indefinitely for this request to be completed, but it never will because vhost-scsi never responds to that request. To avoid a hang, always respond to control queue operations; explicitly reject TMF requests, and return a no-op response to event requests. Signed-off-by: Bijan Mottahedeh Signed-off-by: Michael S. Tsirkin --- drivers/vhost/scsi.c | 190 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 190 insertions(+) (limited to 'drivers/vhost') diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index e7e3ae13516d..1c33d6e39152 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -1050,9 +1050,199 @@ out: mutex_unlock(&vq->mutex); } +static void +vhost_scsi_send_tmf_resp(struct vhost_scsi *vs, + struct vhost_virtqueue *vq, + int head, unsigned int out) +{ + struct virtio_scsi_ctrl_tmf_resp __user *resp; + struct virtio_scsi_ctrl_tmf_resp rsp; + int ret; + + pr_debug("%s\n", __func__); + memset(&rsp, 0, sizeof(rsp)); + rsp.response = VIRTIO_SCSI_S_FUNCTION_REJECTED; + resp = vq->iov[out].iov_base; + ret = __copy_to_user(resp, &rsp, sizeof(rsp)); + if (!ret) + vhost_add_used_and_signal(&vs->dev, vq, head, 0); + else + pr_err("Faulted on virtio_scsi_ctrl_tmf_resp\n"); +} + +static void +vhost_scsi_send_an_resp(struct vhost_scsi *vs, + struct vhost_virtqueue *vq, + int head, unsigned int out) +{ + struct virtio_scsi_ctrl_an_resp __user *resp; + struct virtio_scsi_ctrl_an_resp rsp; + int ret; + + pr_debug("%s\n", __func__); + memset(&rsp, 0, sizeof(rsp)); /* event_actual = 0 */ + rsp.response = VIRTIO_SCSI_S_OK; + resp = vq->iov[out].iov_base; + ret = __copy_to_user(resp, &rsp, sizeof(rsp)); + if (!ret) + vhost_add_used_and_signal(&vs->dev, vq, head, 0); + else + pr_err("Faulted on virtio_scsi_ctrl_an_resp\n"); +} + +static void +vhost_scsi_ctl_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) +{ + union { + __virtio32 type; + struct virtio_scsi_ctrl_an_req an; + struct virtio_scsi_ctrl_tmf_req tmf; + } v_req; + struct iov_iter out_iter; + unsigned int out = 0, in = 0; + int head; + size_t req_size, rsp_size, typ_size; + size_t out_size, in_size; + u8 *lunp; + void *req; + + mutex_lock(&vq->mutex); + /* + * We can handle the vq only after the endpoint is setup by calling the + * VHOST_SCSI_SET_ENDPOINT ioctl. + */ + if (!vq->private_data) + goto out; + + 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; + } + + /* + * Get the size of request and response buffers. + */ + 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. + */ + iov_iter_init(&out_iter, WRITE, vq->iov, out, out_size); + + req = &v_req.type; + typ_size = sizeof(v_req.type); + + if (unlikely(!copy_from_iter_full(req, typ_size, &out_iter))) { + vq_err(vq, "Faulted on copy_from_iter tmf type\n"); + /* + * The size of the response buffer varies based on + * the request type and must be validated against it. + * Since the request type is not known, don't send + * a response. + */ + continue; + } + + switch (v_req.type) { + case VIRTIO_SCSI_T_TMF: + req = &v_req.tmf; + lunp = &v_req.tmf.lun[0]; + req_size = sizeof(struct virtio_scsi_ctrl_tmf_req); + rsp_size = sizeof(struct virtio_scsi_ctrl_tmf_resp); + break; + case VIRTIO_SCSI_T_AN_QUERY: + case VIRTIO_SCSI_T_AN_SUBSCRIBE: + req = &v_req.an; + lunp = &v_req.an.lun[0]; + req_size = sizeof(struct virtio_scsi_ctrl_an_req); + rsp_size = sizeof(struct virtio_scsi_ctrl_an_resp); + break; + default: + vq_err(vq, "Unknown control request %d", v_req.type); + continue; + } + + /* + * Check for a sane response buffer so we can report early + * errors back to the guest. + */ + if (unlikely(in_size < rsp_size)) { + vq_err(vq, + "Resp buf too small, need min %zu bytes got %zu", + rsp_size, in_size); + /* + * Notifications are disabled at this point; + * continue so they can be eventually enabled + * when processing terminates. + */ + continue; + } + + if (unlikely(out_size < req_size)) { + vq_err(vq, + "Req buf too small, need min %zu bytes got %zu", + req_size, out_size); + vhost_scsi_send_bad_target(vs, vq, head, out); + continue; + } + + req += typ_size; + req_size -= typ_size; + + 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; + } + + if (v_req.type == VIRTIO_SCSI_T_TMF) { + pr_debug("%s tmf %d\n", __func__, v_req.tmf.subtype); + vhost_scsi_send_tmf_resp(vs, vq, head, out); + } else + vhost_scsi_send_an_resp(vs, vq, head, out); + } +out: + mutex_unlock(&vq->mutex); +} + static void vhost_scsi_ctl_handle_kick(struct vhost_work *work) { + struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, + poll.work); + struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev); + pr_debug("%s: The handling func for control queue.\n", __func__); + vhost_scsi_ctl_handle_vq(vs, vq); } static void -- cgit v1.2.3-59-g8ed1b From 3f8ca2e115e55af4c15d97dda635e948d2e380be Mon Sep 17 00:00:00 2001 From: Bijan Mottahedeh Date: Mon, 17 Sep 2018 17:09:48 -0700 Subject: vhost/scsi: Extract common handling code from control queue handler Prepare to change the request queue handler to use common handling routines. Signed-off-by: Bijan Mottahedeh Signed-off-by: Michael S. Tsirkin --- drivers/vhost/scsi.c | 271 ++++++++++++++++++++++++++++++++------------------- 1 file changed, 172 insertions(+), 99 deletions(-) (limited to 'drivers/vhost') diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index 1c33d6e39152..4cd03a1d7f21 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -203,6 +203,19 @@ struct vhost_scsi { int vs_events_nr; /* num of pending events, protected by vq->mutex */ }; +/* + * Context for processing request and control queue operations. + */ +struct vhost_scsi_ctx { + int head; + unsigned int out, in; + size_t req_size, rsp_size; + size_t out_size, in_size; + u8 *target, *lunp; + void *req; + struct iov_iter out_iter; +}; + static struct workqueue_struct *vhost_scsi_workqueue; /* Global spinlock to protect vhost_scsi TPG list for vhost IOCTL access */ @@ -1050,10 +1063,107 @@ 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, - int head, unsigned int out) + struct vhost_virtqueue *vq, + struct vhost_scsi_ctx *vc) { struct virtio_scsi_ctrl_tmf_resp __user *resp; struct virtio_scsi_ctrl_tmf_resp rsp; @@ -1062,18 +1172,18 @@ vhost_scsi_send_tmf_resp(struct vhost_scsi *vs, pr_debug("%s\n", __func__); memset(&rsp, 0, sizeof(rsp)); rsp.response = VIRTIO_SCSI_S_FUNCTION_REJECTED; - resp = vq->iov[out].iov_base; + resp = vq->iov[vc->out].iov_base; ret = __copy_to_user(resp, &rsp, sizeof(rsp)); if (!ret) - vhost_add_used_and_signal(&vs->dev, vq, head, 0); + vhost_add_used_and_signal(&vs->dev, vq, vc->head, 0); else pr_err("Faulted on virtio_scsi_ctrl_tmf_resp\n"); } static void vhost_scsi_send_an_resp(struct vhost_scsi *vs, - struct vhost_virtqueue *vq, - int head, unsigned int out) + struct vhost_virtqueue *vq, + struct vhost_scsi_ctx *vc) { struct virtio_scsi_ctrl_an_resp __user *resp; struct virtio_scsi_ctrl_an_resp rsp; @@ -1082,10 +1192,10 @@ vhost_scsi_send_an_resp(struct vhost_scsi *vs, pr_debug("%s\n", __func__); memset(&rsp, 0, sizeof(rsp)); /* event_actual = 0 */ rsp.response = VIRTIO_SCSI_S_OK; - resp = vq->iov[out].iov_base; + resp = vq->iov[vc->out].iov_base; ret = __copy_to_user(resp, &rsp, sizeof(rsp)); if (!ret) - vhost_add_used_and_signal(&vs->dev, vq, head, 0); + vhost_add_used_and_signal(&vs->dev, vq, vc->head, 0); else pr_err("Faulted on virtio_scsi_ctrl_an_resp\n"); } @@ -1098,13 +1208,9 @@ vhost_scsi_ctl_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) struct virtio_scsi_ctrl_an_req an; struct virtio_scsi_ctrl_tmf_req tmf; } v_req; - struct iov_iter out_iter; - unsigned int out = 0, in = 0; - int head; - size_t req_size, rsp_size, typ_size; - size_t out_size, in_size; - u8 *lunp; - void *req; + struct vhost_scsi_ctx vc; + size_t typ_size; + int ret; mutex_lock(&vq->mutex); /* @@ -1114,52 +1220,28 @@ vhost_scsi_ctl_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) if (!vq->private_data) goto out; + memset(&vc, 0, sizeof(vc)); + 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; - } + ret = vhost_scsi_get_desc(vs, vq, &vc); + if (ret) + goto err; /* - * Get the size of request and response buffers. + * Get the request type first in order to setup + * other parameters dependent on the type. */ - 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. - */ - iov_iter_init(&out_iter, WRITE, vq->iov, out, out_size); - - req = &v_req.type; + vc.req = &v_req.type; typ_size = sizeof(v_req.type); - if (unlikely(!copy_from_iter_full(req, typ_size, &out_iter))) { + if (unlikely(!copy_from_iter_full(vc.req, typ_size, + &vc.out_iter))) { vq_err(vq, "Faulted on copy_from_iter tmf type\n"); /* - * The size of the response buffer varies based on - * the request type and must be validated against it. + * The size of the response buffer depends on the + * request type and must be validated against it. * Since the request type is not known, don't send * a response. */ @@ -1168,17 +1250,19 @@ vhost_scsi_ctl_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) switch (v_req.type) { case VIRTIO_SCSI_T_TMF: - req = &v_req.tmf; - lunp = &v_req.tmf.lun[0]; - req_size = sizeof(struct virtio_scsi_ctrl_tmf_req); - rsp_size = sizeof(struct virtio_scsi_ctrl_tmf_resp); + vc.req = &v_req.tmf; + vc.req_size = sizeof(struct virtio_scsi_ctrl_tmf_req); + vc.rsp_size = sizeof(struct virtio_scsi_ctrl_tmf_resp); + vc.lunp = &v_req.tmf.lun[0]; + vc.target = &v_req.tmf.lun[1]; break; case VIRTIO_SCSI_T_AN_QUERY: case VIRTIO_SCSI_T_AN_SUBSCRIBE: - req = &v_req.an; - lunp = &v_req.an.lun[0]; - req_size = sizeof(struct virtio_scsi_ctrl_an_req); - rsp_size = sizeof(struct virtio_scsi_ctrl_an_resp); + vc.req = &v_req.an; + vc.req_size = sizeof(struct virtio_scsi_ctrl_an_req); + vc.rsp_size = sizeof(struct virtio_scsi_ctrl_an_resp); + vc.lunp = &v_req.an.lun[0]; + vc.target = NULL; break; default: vq_err(vq, "Unknown control request %d", v_req.type); @@ -1186,50 +1270,39 @@ vhost_scsi_ctl_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) } /* - * Check for a sane response buffer so we can report early - * errors back to the guest. + * Validate the size of request and response buffers. + * Check for a sane response buffer so we can report + * early errors back to the guest. */ - if (unlikely(in_size < rsp_size)) { - vq_err(vq, - "Resp buf too small, need min %zu bytes got %zu", - rsp_size, in_size); - /* - * Notifications are disabled at this point; - * continue so they can be eventually enabled - * when processing terminates. - */ - continue; - } + ret = vhost_scsi_chk_size(vq, &vc); + if (ret) + goto err; - if (unlikely(out_size < req_size)) { - vq_err(vq, - "Req buf too small, need min %zu bytes got %zu", - req_size, out_size); - vhost_scsi_send_bad_target(vs, vq, head, out); - continue; - } - - req += typ_size; - req_size -= typ_size; - - 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; - } + /* + * Get the rest of the request now that its size is known. + */ + vc.req += typ_size; + vc.req_size -= typ_size; - /* 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, NULL); + if (ret) + goto err; - if (v_req.type == VIRTIO_SCSI_T_TMF) { - pr_debug("%s tmf %d\n", __func__, v_req.tmf.subtype); - vhost_scsi_send_tmf_resp(vs, vq, head, out); - } else - vhost_scsi_send_an_resp(vs, vq, head, out); + if (v_req.type == VIRTIO_SCSI_T_TMF) + vhost_scsi_send_tmf_resp(vs, vq, &vc); + else + vhost_scsi_send_an_resp(vs, vq, &vc); +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); -- cgit v1.2.3-59-g8ed1b 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