virtio-scsi: Enable DIF/DIX modes in SCSI host LLD

This patch updates virtscsi_probe() to setup necessary Scsi_Host
level protection resources. (currently hardcoded to 1)

It changes virtscsi_add_cmd() to attach outgoing / incoming
protection SGLs preceeding the data payload, and is using the
new virtio_scsi_cmd_req_pi->pi_bytes[out,in] field to signal
to signal to vhost/scsi bytes to expect for protection data.

(Add missing #include <linux/blkdev.h> for blk_integrity - sfr + nab)

Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Michael S. Tsirkin <mst@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>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 69 insertions, 18 deletions

diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 16bfd50cd3fe..1c326b63ca55 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -23,6 +23,7 @@
 #include <linux/virtio_config.h>
 #include <linux/virtio_scsi.h>
 #include <linux/cpu.h>
+#include <linux/blkdev.h>
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_device.h>
 #include <scsi/scsi_cmnd.h>
@@ -37,6 +38,7 @@ struct virtio_scsi_cmd {
         struct completion *comp;
         union {
                 struct virtio_scsi_cmd_req       cmd;
+                struct virtio_scsi_cmd_req_pi    cmd_pi;
                 struct virtio_scsi_ctrl_tmf_req  tmf;
                 struct virtio_scsi_ctrl_an_req   an;
         } req;
@@ -440,7 +442,7 @@ static int virtscsi_add_cmd(struct virtqueue *vq,
                             size_t req_size, size_t resp_size, gfp_t gfp)
 {
         struct scsi_cmnd *sc = cmd->sc;
-        struct scatterlist *sgs[4], req, resp;
+        struct scatterlist *sgs[6], req, resp;
         struct sg_table *out, *in;
         unsigned out_num = 0, in_num = 0;
 
@@ -458,16 +460,24 @@ static int virtscsi_add_cmd(struct virtqueue *vq,
         sgs[out_num++] = &req;
 
         /* Data-out buffer.  */
-        if (out)
+        if (out) {
+                /* Place WRITE protection SGLs before Data OUT payload */
+                if (scsi_prot_sg_count(sc))
+                        sgs[out_num++] = scsi_prot_sglist(sc);
                 sgs[out_num++] = out->sgl;
+        }
 
         /* Response header.  */
         sg_init_one(&resp, &cmd->resp, resp_size);
         sgs[out_num + in_num++] = &resp;
 
         /* Data-in buffer */
-        if (in)
+        if (in) {
+                /* Place READ protection SGLs before Data IN payload */
+                if (scsi_prot_sg_count(sc))
+                        sgs[out_num + in_num++] = scsi_prot_sglist(sc);
                 sgs[out_num + in_num++] = in->sgl;
+        }
 
         return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, gfp);
 }
@@ -492,12 +502,44 @@ static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq,
         return err;
 }
 
+static void virtio_scsi_init_hdr(struct virtio_scsi_cmd_req *cmd,
+                                 struct scsi_cmnd *sc)
+{
+        cmd->lun[0] = 1;
+        cmd->lun[1] = sc->device->id;
+        cmd->lun[2] = (sc->device->lun >> 8) | 0x40;
+        cmd->lun[3] = sc->device->lun & 0xff;
+        cmd->tag = (unsigned long)sc;
+        cmd->task_attr = VIRTIO_SCSI_S_SIMPLE;
+        cmd->prio = 0;
+        cmd->crn = 0;
+}
+
+static void virtio_scsi_init_hdr_pi(struct virtio_scsi_cmd_req_pi *cmd_pi,
+                                    struct scsi_cmnd *sc)
+{
+        struct request *rq = sc->request;
+        struct blk_integrity *bi;
+
+        virtio_scsi_init_hdr((struct virtio_scsi_cmd_req *)cmd_pi, sc);
+
+        if (!rq || !scsi_prot_sg_count(sc))
+                return;
+
+        bi = blk_get_integrity(rq->rq_disk);
+
+        if (sc->sc_data_direction == DMA_TO_DEVICE)
+                cmd_pi->pi_bytesout = blk_rq_sectors(rq) * bi->tuple_size;
+        else if (sc->sc_data_direction == DMA_FROM_DEVICE)
+                cmd_pi->pi_bytesin = blk_rq_sectors(rq) * bi->tuple_size;
+}
+
 static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
                                  struct virtio_scsi_vq *req_vq,
                                  struct scsi_cmnd *sc)
 {
         struct virtio_scsi_cmd *cmd;
-        int ret;
+        int ret, req_size;
 
         struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
         BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
@@ -515,22 +557,20 @@ static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
 
         memset(cmd, 0, sizeof(*cmd));
         cmd->sc = sc;
-        cmd->req.cmd = (struct virtio_scsi_cmd_req){
-                .lun[0] = 1,
-                .lun[1] = sc->device->id,
-                .lun[2] = (sc->device->lun >> 8) | 0x40,
-                .lun[3] = sc->device->lun & 0xff,
-                .tag = (unsigned long)sc,
-                .task_attr = VIRTIO_SCSI_S_SIMPLE,
-                .prio = 0,
-                .crn = 0,
-        };
 
         BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
-        memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
 
-        if (virtscsi_kick_cmd(req_vq, cmd,
-                              sizeof cmd->req.cmd, sizeof cmd->resp.cmd,
+        if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) {
+                virtio_scsi_init_hdr_pi(&cmd->req.cmd_pi, sc);
+                memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len);
+                req_size = sizeof(cmd->req.cmd_pi);
+        } else {
+                virtio_scsi_init_hdr(&cmd->req.cmd, sc);
+                memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
+                req_size = sizeof(cmd->req.cmd);
+        }
+
+        if (virtscsi_kick_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd),
                               GFP_ATOMIC) == 0)
                 ret = 0;
         else
@@ -871,7 +911,7 @@ static int virtscsi_probe(struct virtio_device *vdev)
 {
         struct Scsi_Host *shost;
         struct virtio_scsi *vscsi;
-        int err;
+        int err, host_prot;
         u32 sg_elems, num_targets;
         u32 cmd_per_lun;
         u32 num_queues;
@@ -921,6 +961,16 @@ static int virtscsi_probe(struct virtio_device *vdev)
         shost->max_id = num_targets;
         shost->max_channel = 0;
         shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
+
+        if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) {
+                host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
+                            SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
+                            SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
+
+                scsi_host_set_prot(shost, host_prot);
+                scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC);
+        }
+
         err = scsi_add_host(shost, &vdev->dev);
         if (err)
                 goto scsi_add_host_failed;
@@ -990,6 +1040,7 @@ static struct virtio_device_id id_table[] = {
 static unsigned int features[] = {
         VIRTIO_SCSI_F_HOTPLUG,
         VIRTIO_SCSI_F_CHANGE,
+        VIRTIO_SCSI_F_T10_PI,
 };
 
 static struct virtio_driver virtio_scsi_driver = {