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path: root/drivers/scsi/virtio_scsi.c
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Diffstat (limited to 'drivers/scsi/virtio_scsi.c')
-rw-r--r--drivers/scsi/virtio_scsi.c199
1 files changed, 110 insertions, 89 deletions
diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index db3b494e592..308256b5e4c 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;
@@ -73,17 +75,12 @@ struct virtio_scsi_vq {
* queue, and also lets the driver optimize the IRQ affinity for the virtqueues
* (each virtqueue's affinity is set to the CPU that "owns" the queue).
*
- * An interesting effect of this policy is that only writes to req_vq need to
- * take the tgt_lock. Read can be done outside the lock because:
+ * tgt_lock is held to serialize reading and writing req_vq. Reading req_vq
+ * could be done locklessly, but we do not do it yet.
*
- * - writes of req_vq only occur when atomic_inc_return(&tgt->reqs) returns 1.
- * In that case, no other CPU is reading req_vq: even if they were in
- * virtscsi_queuecommand_multi, they would be spinning on tgt_lock.
- *
- * - reads of req_vq only occur when the target is not idle (reqs != 0).
- * A CPU that enters virtscsi_queuecommand_multi will not modify req_vq.
- *
- * Similarly, decrements of reqs are never concurrent with writes of req_vq.
+ * Decrements of reqs are never concurrent with writes of req_vq: before the
+ * decrement reqs will be != 0; after the decrement the virtqueue completion
+ * routine will not use the req_vq so it can be changed by a new request.
* Thus they can happen outside the tgt_lock, provided of course we make reqs
* an atomic_t.
*/
@@ -204,7 +201,6 @@ static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf)
set_driver_byte(sc, DRIVER_SENSE);
}
- mempool_free(cmd, virtscsi_cmd_pool);
sc->scsi_done(sc);
atomic_dec(&tgt->reqs);
@@ -238,49 +234,25 @@ static void virtscsi_req_done(struct virtqueue *vq)
int index = vq->index - VIRTIO_SCSI_VQ_BASE;
struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index];
- /*
- * Read req_vq before decrementing the reqs field in
- * virtscsi_complete_cmd.
- *
- * With barriers:
- *
- * CPU #0 virtscsi_queuecommand_multi (CPU #1)
- * ------------------------------------------------------------
- * lock vq_lock
- * read req_vq
- * read reqs (reqs = 1)
- * write reqs (reqs = 0)
- * increment reqs (reqs = 1)
- * write req_vq
- *
- * Possible reordering without barriers:
- *
- * CPU #0 virtscsi_queuecommand_multi (CPU #1)
- * ------------------------------------------------------------
- * lock vq_lock
- * read reqs (reqs = 1)
- * write reqs (reqs = 0)
- * increment reqs (reqs = 1)
- * write req_vq
- * read (wrong) req_vq
- *
- * We do not need a full smp_rmb, because req_vq is required to get
- * to tgt->reqs: tgt is &vscsi->tgt[sc->device->id], where sc is stored
- * in the virtqueue as the user token.
- */
- smp_read_barrier_depends();
-
virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd);
};
+static void virtscsi_poll_requests(struct virtio_scsi *vscsi)
+{
+ int i, num_vqs;
+
+ num_vqs = vscsi->num_queues;
+ for (i = 0; i < num_vqs; i++)
+ virtscsi_vq_done(vscsi, &vscsi->req_vqs[i],
+ virtscsi_complete_cmd);
+}
+
static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf)
{
struct virtio_scsi_cmd *cmd = buf;
if (cmd->comp)
complete_all(cmd->comp);
- else
- mempool_free(cmd, virtscsi_cmd_pool);
}
static void virtscsi_ctrl_done(struct virtqueue *vq)
@@ -291,6 +263,8 @@ static void virtscsi_ctrl_done(struct virtqueue *vq)
virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free);
};
+static void virtscsi_handle_event(struct work_struct *work);
+
static int virtscsi_kick_event(struct virtio_scsi *vscsi,
struct virtio_scsi_event_node *event_node)
{
@@ -298,6 +272,7 @@ static int virtscsi_kick_event(struct virtio_scsi *vscsi,
struct scatterlist sg;
unsigned long flags;
+ INIT_WORK(&event_node->work, virtscsi_handle_event);
sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
@@ -415,7 +390,6 @@ static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf)
{
struct virtio_scsi_event_node *event_node = buf;
- INIT_WORK(&event_node->work, virtscsi_handle_event);
schedule_work(&event_node->work);
}
@@ -433,14 +407,13 @@ static void virtscsi_event_done(struct virtqueue *vq)
* @cmd : command structure
* @req_size : size of the request buffer
* @resp_size : size of the response buffer
- * @gfp : flags to use for memory allocations
*/
static int virtscsi_add_cmd(struct virtqueue *vq,
struct virtio_scsi_cmd *cmd,
- size_t req_size, size_t resp_size, gfp_t gfp)
+ size_t req_size, size_t resp_size)
{
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;
@@ -458,30 +431,38 @@ 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);
+ return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC);
}
static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq,
struct virtio_scsi_cmd *cmd,
- size_t req_size, size_t resp_size, gfp_t gfp)
+ size_t req_size, size_t resp_size)
{
unsigned long flags;
int err;
bool needs_kick = false;
spin_lock_irqsave(&vq->vq_lock, flags);
- err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size, gfp);
+ err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size);
if (!err)
needs_kick = virtqueue_kick_prepare(vq->vq);
@@ -492,14 +473,46 @@ 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;
-
struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
+ struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc);
+ int req_size;
+
BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
/* TODO: check feature bit and fail if unsupported? */
@@ -508,36 +521,24 @@ static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
dev_dbg(&sc->device->sdev_gendev,
"cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
- ret = SCSI_MLQUEUE_HOST_BUSY;
- cmd = mempool_alloc(virtscsi_cmd_pool, GFP_ATOMIC);
- if (!cmd)
- goto out;
-
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,
- GFP_ATOMIC) == 0)
- ret = 0;
- else
- mempool_free(cmd, virtscsi_cmd_pool);
+ 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);
+ }
-out:
- return ret;
+ if (virtscsi_kick_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd)) != 0)
+ return SCSI_MLQUEUE_HOST_BUSY;
+ return 0;
}
static int virtscsi_queuecommand_single(struct Scsi_Host *sh,
@@ -560,12 +561,8 @@ static struct virtio_scsi_vq *virtscsi_pick_vq(struct virtio_scsi *vscsi,
spin_lock_irqsave(&tgt->tgt_lock, flags);
- /*
- * The memory barrier after atomic_inc_return matches
- * the smp_read_barrier_depends() in virtscsi_req_done.
- */
if (atomic_inc_return(&tgt->reqs) > 1)
- vq = ACCESS_ONCE(tgt->req_vq);
+ vq = tgt->req_vq;
else {
queue_num = smp_processor_id();
while (unlikely(queue_num >= vscsi->num_queues))
@@ -596,8 +593,7 @@ static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
cmd->comp = &comp;
if (virtscsi_kick_cmd(&vscsi->ctrl_vq, cmd,
- sizeof cmd->req.tmf, sizeof cmd->resp.tmf,
- GFP_NOIO) < 0)
+ sizeof cmd->req.tmf, sizeof cmd->resp.tmf) < 0)
goto out;
wait_for_completion(&comp);
@@ -605,6 +601,18 @@ static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED)
ret = SUCCESS;
+ /*
+ * The spec guarantees that all requests related to the TMF have
+ * been completed, but the callback might not have run yet if
+ * we're using independent interrupts (e.g. MSI). Poll the
+ * virtqueues once.
+ *
+ * In the abort case, sc->scsi_done will do nothing, because
+ * the block layer must have detected a timeout and as a result
+ * REQ_ATOM_COMPLETE has been set.
+ */
+ virtscsi_poll_requests(vscsi);
+
out:
mempool_free(cmd, virtscsi_cmd_pool);
return ret;
@@ -683,6 +691,7 @@ static struct scsi_host_template virtscsi_host_template_single = {
.name = "Virtio SCSI HBA",
.proc_name = "virtio_scsi",
.this_id = -1,
+ .cmd_size = sizeof(struct virtio_scsi_cmd),
.queuecommand = virtscsi_queuecommand_single,
.eh_abort_handler = virtscsi_abort,
.eh_device_reset_handler = virtscsi_device_reset,
@@ -699,6 +708,7 @@ static struct scsi_host_template virtscsi_host_template_multi = {
.name = "Virtio SCSI HBA",
.proc_name = "virtio_scsi",
.this_id = -1,
+ .cmd_size = sizeof(struct virtio_scsi_cmd),
.queuecommand = virtscsi_queuecommand_multi,
.eh_abort_handler = virtscsi_abort,
.eh_device_reset_handler = virtscsi_device_reset,
@@ -875,7 +885,7 @@ 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;
@@ -925,6 +935,16 @@ 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;
@@ -994,6 +1014,7 @@ 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 = {
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-03-23 22:22:00 +0000