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>

diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 02832d6..baca589 100644 (file)
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -1773,6 +1773,7 @@ config SCSI_BFA_FC
 config SCSI_VIRTIO
        tristate "virtio-scsi support"
        depends on VIRTIO
+       select BLK_DEV_INTEGRITY
        help
           This is the virtual HBA driver for virtio.  If the kernel will
           be used in a virtual machine, say Y or M.

diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 16bfd50..1c326b6 100644 (file)
--- 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 = {