vhost/scsi: Enable T10 PI IOV -> SGL memory mapping

This patch updates vhost_scsi_handle_vq() to check for the existance
of virtio_scsi_cmd_req_pi comparing vq->iov[0].iov_len in order to
calculate seperate data + protection SGLs from data_num.

Also update tcm_vhost_submission_work() to pass the pre-allocated
cmd->tvc_prot_sgl[] memory into target_submit_cmd_map_sgls(), and
update vhost_scsi_get_tag() parameters to accept scsi_tag, lun, and
task_attr.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Sagi Grimberg <sagig@dev.mellanox.co.il>
Cc: H. Peter Anvin <hpa@zytor.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 124 insertions, 59 deletions

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index eabcf1875831..667e72d46998 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -169,7 +169,8 @@ enum {
 };
 
 enum {
-        VHOST_SCSI_FEATURES = VHOST_FEATURES | (1ULL << VIRTIO_SCSI_F_HOTPLUG)
+        VHOST_SCSI_FEATURES = VHOST_FEATURES | (1ULL << VIRTIO_SCSI_F_HOTPLUG) |
+                                               (1ULL << VIRTIO_SCSI_F_T10_PI)
 };
 
 #define VHOST_SCSI_MAX_TARGET   256
@@ -720,11 +721,9 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work)
 }
 
 static struct tcm_vhost_cmd *
-vhost_scsi_get_tag(struct vhost_virtqueue *vq,
-                        struct tcm_vhost_tpg *tpg,
-                        struct virtio_scsi_cmd_req *v_req,
-                        u32 exp_data_len,
-                        int data_direction)
+vhost_scsi_get_tag(struct vhost_virtqueue *vq, struct tcm_vhost_tpg *tpg,
+                   unsigned char *cdb, u64 scsi_tag, u16 lun, u8 task_attr,
+                   u32 exp_data_len, int data_direction)
 {
         struct tcm_vhost_cmd *cmd;
         struct tcm_vhost_nexus *tv_nexus;
@@ -756,13 +755,16 @@ vhost_scsi_get_tag(struct vhost_virtqueue *vq,
         cmd->tvc_prot_sgl = prot_sg;
         cmd->tvc_upages = pages;
         cmd->tvc_se_cmd.map_tag = tag;
-        cmd->tvc_tag = v_req->tag;
-        cmd->tvc_task_attr = v_req->task_attr;
+        cmd->tvc_tag = scsi_tag;
+        cmd->tvc_lun = lun;
+        cmd->tvc_task_attr = task_attr;
         cmd->tvc_exp_data_len = exp_data_len;
         cmd->tvc_data_direction = data_direction;
         cmd->tvc_nexus = tv_nexus;
         cmd->inflight = tcm_vhost_get_inflight(vq);
 
+        memcpy(cmd->tvc_cdb, cdb, TCM_VHOST_MAX_CDB_SIZE);
+
         return cmd;
 }
 
@@ -913,18 +915,17 @@ static void tcm_vhost_submission_work(struct work_struct *work)
                 container_of(work, struct tcm_vhost_cmd, work);
         struct tcm_vhost_nexus *tv_nexus;
         struct se_cmd *se_cmd = &cmd->tvc_se_cmd;
-        struct scatterlist *sg_ptr, *sg_bidi_ptr = NULL;
-        int rc, sg_no_bidi = 0;
+        struct scatterlist *sg_ptr, *sg_prot_ptr = NULL;
+        int rc;
 
+        /* FIXME: BIDI operation */
         if (cmd->tvc_sgl_count) {
                 sg_ptr = cmd->tvc_sgl;
-/* FIXME: Fix BIDI operation in tcm_vhost_submission_work() */
-#if 0
-                if (se_cmd->se_cmd_flags & SCF_BIDI) {
-                        sg_bidi_ptr = NULL;
-                        sg_no_bidi = 0;
-                }
-#endif
+
+                if (cmd->tvc_prot_sgl_count)
+                        sg_prot_ptr = cmd->tvc_prot_sgl;
+                else
+                        se_cmd->prot_pto = true;
         } else {
                 sg_ptr = NULL;
         }
@@ -935,7 +936,7 @@ static void tcm_vhost_submission_work(struct work_struct *work)
                         cmd->tvc_lun, cmd->tvc_exp_data_len,
                         cmd->tvc_task_attr, cmd->tvc_data_direction,
                         TARGET_SCF_ACK_KREF, sg_ptr, cmd->tvc_sgl_count,
-                        sg_bidi_ptr, sg_no_bidi, NULL, 0);
+                        NULL, 0, sg_prot_ptr, cmd->tvc_prot_sgl_count);
         if (rc < 0) {
                 transport_send_check_condition_and_sense(se_cmd,
                                 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
@@ -967,12 +968,18 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
 {
         struct tcm_vhost_tpg **vs_tpg;
         struct virtio_scsi_cmd_req v_req;
+        struct virtio_scsi_cmd_req_pi v_req_pi;
         struct tcm_vhost_tpg *tpg;
         struct tcm_vhost_cmd *cmd;
-        u32 exp_data_len, data_first, data_num, data_direction;
+        u64 tag;
+        u32 exp_data_len, data_first, data_num, data_direction, prot_first;
         unsigned out, in, i;
-        int head, ret;
-        u8 target;
+        int head, ret, data_niov, prot_niov, prot_bytes;
+        size_t req_size;
+        u16 lun;
+        u8 *target, *lunp, task_attr;
+        bool hdr_pi;
+        void *req, *cdb;
 
         mutex_lock(&vq->mutex);
         /*
@@ -1003,7 +1010,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
                         break;
                 }
 
-/* FIXME: BIDI operation */
+                /* FIXME: BIDI operation */
                 if (out == 1 && in == 1) {
                         data_direction = DMA_NONE;
                         data_first = 0;
@@ -1033,29 +1040,38 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
                         break;
                 }
 
-                if (unlikely(vq->iov[0].iov_len != sizeof(v_req))) {
-                        vq_err(vq, "Expecting virtio_scsi_cmd_req, got %zu"
-                                " bytes\n", vq->iov[0].iov_len);
+                if (vs->dev.acked_features & VIRTIO_SCSI_F_T10_PI) {
+                        req = &v_req_pi;
+                        lunp = &v_req_pi.lun[0];
+                        target = &v_req_pi.lun[1];
+                        req_size = sizeof(v_req_pi);
+                        hdr_pi = true;
+                } else {
+                        req = &v_req;
+                        lunp = &v_req.lun[0];
+                        target = &v_req.lun[1];
+                        req_size = sizeof(v_req);
+                        hdr_pi = false;
+                }
+
+                if (unlikely(vq->iov[0].iov_len < req_size)) {
+                        pr_err("Expecting virtio-scsi header: %zu, got %zu\n",
+                               req_size, vq->iov[0].iov_len);
                         break;
                 }
-                pr_debug("Calling __copy_from_user: vq->iov[0].iov_base: %p,"
-                        " len: %zu\n", vq->iov[0].iov_base, sizeof(v_req));
-                ret = __copy_from_user(&v_req, vq->iov[0].iov_base,
-                                sizeof(v_req));
+                ret = memcpy_fromiovecend(req, &vq->iov[0], 0, req_size);
                 if (unlikely(ret)) {
                         vq_err(vq, "Faulted on virtio_scsi_cmd_req\n");
                         break;
                 }
 
                 /* virtio-scsi spec requires byte 0 of the lun to be 1 */
-                if (unlikely(v_req.lun[0] != 1)) {
+                if (unlikely(*lunp != 1)) {
                         vhost_scsi_send_bad_target(vs, vq, head, out);
                         continue;
                 }
 
-                /* Extract the tpgt */
-                target = v_req.lun[1];
-                tpg = ACCESS_ONCE(vs_tpg[target]);
+                tpg = ACCESS_ONCE(vs_tpg[*target]);
 
                 /* Target does not exist, fail the request */
                 if (unlikely(!tpg)) {
@@ -1063,17 +1079,78 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
                         continue;
                 }
 
+                data_niov = data_num;
+                prot_niov = prot_first = prot_bytes = 0;
+                /*
+                 * Determine if any protection information iovecs are preceeding
+                 * the actual data payload, and adjust data_first + data_niov
+                 * values accordingly for vhost_scsi_map_iov_to_sgl() below.
+                 *
+                 * Also extract virtio_scsi header bits for vhost_scsi_get_tag()
+                 */
+                if (hdr_pi) {
+                        if (v_req_pi.pi_bytesout) {
+                                if (data_direction != DMA_TO_DEVICE) {
+                                        vq_err(vq, "Received non zero do_pi_niov"
+                                                ", but wrong data_direction\n");
+                                        goto err_cmd;
+                                }
+                                prot_bytes = v_req_pi.pi_bytesout;
+                        } else if (v_req_pi.pi_bytesin) {
+                                if (data_direction != DMA_FROM_DEVICE) {
+                                        vq_err(vq, "Received non zero di_pi_niov"
+                                                ", but wrong data_direction\n");
+                                        goto err_cmd;
+                                }
+                                prot_bytes = v_req_pi.pi_bytesin;
+                        }
+                        if (prot_bytes) {
+                                int tmp = 0;
+
+                                for (i = 0; i < data_num; i++) {
+                                        tmp += vq->iov[data_first + i].iov_len;
+                                        prot_niov++;
+                                        if (tmp >= prot_bytes)
+                                                break;
+                                }
+                                prot_first = data_first;
+                                data_first += prot_niov;
+                                data_niov = data_num - prot_niov;
+                        }
+                        tag = v_req_pi.tag;
+                        task_attr = v_req_pi.task_attr;
+                        cdb = &v_req_pi.cdb[0];
+                        lun = ((v_req_pi.lun[2] << 8) | v_req_pi.lun[3]) & 0x3FFF;
+                } else {
+                        tag = v_req.tag;
+                        task_attr = v_req.task_attr;
+                        cdb = &v_req.cdb[0];
+                        lun = ((v_req.lun[2] << 8) | v_req.lun[3]) & 0x3FFF;
+                }
                 exp_data_len = 0;
-                for (i = 0; i < data_num; i++)
+                for (i = 0; i < data_niov; i++)
                         exp_data_len += vq->iov[data_first + i].iov_len;
+                /*
+                 * Check that the recieved CDB size does not exceeded our
+                 * hardcoded max for vhost-scsi
+                 *
+                 * TODO what if cdb was too small for varlen cdb header?
+                 */
+                if (unlikely(scsi_command_size(cdb) > TCM_VHOST_MAX_CDB_SIZE)) {
+                        vq_err(vq, "Received SCSI CDB with command_size: %d that"
+                                " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
+                                scsi_command_size(cdb), TCM_VHOST_MAX_CDB_SIZE);
+                        goto err_cmd;
+                }
 
-                cmd = vhost_scsi_get_tag(vq, tpg, &v_req,
+                cmd = vhost_scsi_get_tag(vq, tpg, cdb, tag, lun, task_attr,
                                          exp_data_len, data_direction);
                 if (IS_ERR(cmd)) {
                         vq_err(vq, "vhost_scsi_get_tag failed %ld\n",
                                         PTR_ERR(cmd));
                         goto err_cmd;
                 }
+
                 pr_debug("Allocated tv_cmd: %p exp_data_len: %d, data_direction"
                         ": %d\n", cmd, exp_data_len, data_direction);
 
@@ -1081,40 +1158,28 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
                 cmd->tvc_vq = vq;
                 cmd->tvc_resp = vq->iov[out].iov_base;
 
-                /*
-                 * Copy in the recieved CDB descriptor into cmd->tvc_cdb
-                 * that will be used by tcm_vhost_new_cmd_map() and down into
-                 * target_setup_cmd_from_cdb()
-                 */
-                memcpy(cmd->tvc_cdb, v_req.cdb, TCM_VHOST_MAX_CDB_SIZE);
-                /*
-                 * Check that the recieved CDB size does not exceeded our
-                 * hardcoded max for tcm_vhost
-                 */
-                /* TODO what if cdb was too small for varlen cdb header? */
-                if (unlikely(scsi_command_size(cmd->tvc_cdb) >
-                                        TCM_VHOST_MAX_CDB_SIZE)) {
-                        vq_err(vq, "Received SCSI CDB with command_size: %d that"
-                                " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
-                                scsi_command_size(cmd->tvc_cdb),
-                                TCM_VHOST_MAX_CDB_SIZE);
-                        goto err_free;
-                }
-                cmd->tvc_lun = ((v_req.lun[2] << 8) | v_req.lun[3]) & 0x3FFF;
-
                 pr_debug("vhost_scsi got command opcode: %#02x, lun: %d\n",
                         cmd->tvc_cdb[0], cmd->tvc_lun);
 
+                if (prot_niov) {
+                        ret = vhost_scsi_map_iov_to_prot(cmd,
+                                        &vq->iov[prot_first], prot_niov,
+                                        data_direction == DMA_FROM_DEVICE);
+                        if (unlikely(ret)) {
+                                vq_err(vq, "Failed to map iov to"
+                                        " prot_sgl\n");
+                                goto err_free;
+                        }
+                }
                 if (data_direction != DMA_NONE) {
                         ret = vhost_scsi_map_iov_to_sgl(cmd,
-                                        &vq->iov[data_first], data_num,
+                                        &vq->iov[data_first], data_niov,
                                         data_direction == DMA_FROM_DEVICE);
                         if (unlikely(ret)) {
                                 vq_err(vq, "Failed to map iov to sgl\n");
                                 goto err_free;
                         }
                 }
-
                 /*
                  * Save the descriptor from vhost_get_vq_desc() to be used to
                  * complete the virtio-scsi request in TCM callback context via
@@ -1788,7 +1853,7 @@ static int tcm_vhost_make_nexus(struct tcm_vhost_tpg *tpg,
         tv_nexus->tvn_se_sess = transport_init_session_tags(
                                         TCM_VHOST_DEFAULT_TAGS,
                                         sizeof(struct tcm_vhost_cmd),
-                                        TARGET_PROT_NORMAL);
+                                        TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS);
         if (IS_ERR(tv_nexus->tvn_se_sess)) {
                 mutex_unlock(&tpg->tv_tpg_mutex);
                 kfree(tv_nexus);