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 <bijan.mottahedeh@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Bijan Mottahedeh 2018-09-17 17:09:49 -07:00 committed by Michael S. Tsirkin
parent 3f8ca2e115
commit 09d7583294

View File

@ -813,256 +813,6 @@ vhost_scsi_send_bad_target(struct vhost_scsi *vs,
pr_err("Faulted on virtio_scsi_cmd_resp\n");
}
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_cmd *cmd;
struct iov_iter out_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;
u16 lun;
u8 *target, *lunp, task_attr;
bool t10_pi = vhost_has_feature(vq, VIRTIO_SCSI_F_T10_PI);
void *req, *cdb;
mutex_lock(&vq->mutex);
/*
* We can handle the vq only after the endpoint is setup by calling the
* VHOST_SCSI_SET_ENDPOINT ioctl.
*/
vs_tpg = vq->private_data;
if (!vs_tpg)
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;
}
/*
* 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;
}
/*
* 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];
} else {
req = &v_req;
req_size = sizeof(v_req);
lunp = &v_req.lun[0];
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.
*/
iov_iter_init(&out_iter, WRITE, vq->iov, out, out_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;
}
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 +
* response headers respectively.
*
* For DMA_TO_DEVICE this is out_iter, which is already pointing
* to the right place.
*
* For DMA_FROM_DEVICE, the iovec will be just past the end
* of the virtio-scsi response header in either the same
* or immediately following iovec.
*
* Any associated T10_PI bytes for the outgoing / incoming
* payloads are included in calculation of exp_data_len here.
*/
prot_bytes = 0;
if (out_size > req_size) {
data_direction = DMA_TO_DEVICE;
exp_data_len = out_size - req_size;
data_iter = out_iter;
} else if (in_size > rsp_size) {
data_direction = DMA_FROM_DEVICE;
exp_data_len = in_size - rsp_size;
iov_iter_init(&in_iter, READ, &vq->iov[out], in,
rsp_size + exp_data_len);
iov_iter_advance(&in_iter, rsp_size);
data_iter = in_iter;
} else {
data_direction = DMA_NONE;
exp_data_len = 0;
}
/*
* If T10_PI header + payload is present, setup prot_iter values
* and recalculate data_iter for vhost_scsi_mapal() mapping to
* host scatterlists via get_user_pages_fast().
*/
if (t10_pi) {
if (v_req_pi.pi_bytesout) {
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;
}
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;
}
prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesin);
}
/*
* 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
* actual data payload length.
*/
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);
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 = vhost64_to_cpu(vq, 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;
}
/*
* Check that the received CDB size does not exceeded our
* hardcoded max for vhost-scsi, then get a pre-allocated
* cmd descriptor for the new virtio-scsi tag.
*
* TODO what if cdb was too small for varlen cdb header?
*/
if (unlikely(scsi_command_size(cdb) > VHOST_SCSI_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), VHOST_SCSI_MAX_CDB_SIZE);
vhost_scsi_send_bad_target(vs, vq, head, out);
continue;
}
cmd = vhost_scsi_get_tag(vq, tpg, cdb, tag, lun, task_attr,
exp_data_len + prot_bytes,
data_direction);
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;
}
cmd->tvc_vhost = vs;
cmd->tvc_vq = vq;
cmd->tvc_resp_iov = vq->iov[out];
cmd->tvc_in_iovs = in;
pr_debug("vhost_scsi got command opcode: %#02x, lun: %d\n",
cmd->tvc_cdb[0], cmd->tvc_lun);
pr_debug("cmd: %p exp_data_len: %d, prot_bytes: %d data_direction:"
" %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)) {
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;
}
}
/*
* Save the descriptor from vhost_get_vq_desc() to be used to
* 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;
/*
* Dispatch cmd descriptor for cmwq execution in process
* context provided by vhost_scsi_workqueue. This also ensures
* cmd is executed on the same kworker CPU as this vhost
* thread to gain positive L2 cache locality effects.
*/
INIT_WORK(&cmd->work, vhost_scsi_submission_work);
queue_work(vhost_scsi_workqueue, &cmd->work);
}
out:
mutex_unlock(&vq->mutex);
}
static int
vhost_scsi_get_desc(struct vhost_scsi *vs, struct vhost_virtqueue *vq,
struct vhost_scsi_ctx *vc)
@ -1091,6 +841,7 @@ vhost_scsi_get_desc(struct vhost_scsi *vs, struct vhost_virtqueue *vq,
/*
* 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);
@ -1137,20 +888,20 @@ vhost_scsi_get_req(struct vhost_virtqueue *vq, struct vhost_scsi_ctx *vc,
int ret = -EIO;
if (unlikely(!copy_from_iter_full(vc->req, vc->req_size,
&vc->out_iter)))
&vc->out_iter))) {
vq_err(vq, "Faulted on copy_from_iter\n");
else if (unlikely(*vc->lunp != 1))
} 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 {
} 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))
if (unlikely(!tpg)) {
vq_err(vq, "Target 0x%x does not exist\n", *vc->target);
else {
} else {
if (tpgp)
*tpgp = tpg;
ret = 0;
@ -1161,9 +912,225 @@ vhost_scsi_get_req(struct vhost_virtqueue *vq, struct vhost_scsi_ctx *vc,
}
static void
vhost_scsi_send_tmf_resp(struct vhost_scsi *vs,
struct vhost_virtqueue *vq,
struct vhost_scsi_ctx *vc)
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 in_iter, prot_iter, data_iter;
u64 tag;
u32 exp_data_len, data_direction;
int ret, prot_bytes;
u16 lun;
u8 task_attr;
bool t10_pi = vhost_has_feature(vq, VIRTIO_SCSI_F_T10_PI);
void *cdb;
mutex_lock(&vq->mutex);
/*
* We can handle the vq only after the endpoint is setup by calling the
* VHOST_SCSI_SET_ENDPOINT ioctl.
*/
vs_tpg = vq->private_data;
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 (;;) {
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) {
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 {
vc.req = &v_req;
vc.req_size = sizeof(v_req);
vc.lunp = &v_req.lun[0];
vc.target = &v_req.lun[1];
}
/*
* Validate the size of request and response buffers.
* Check for a sane response buffer so we can report
* early errors back to the guest.
*/
ret = vhost_scsi_chk_size(vq, &vc);
if (ret)
goto err;
ret = vhost_scsi_get_req(vq, &vc, &tpg);
if (ret)
goto err;
ret = -EIO; /* bad target on any error from here on */
/*
* Determine data_direction by calculating the total outgoing
* iovec sizes + incoming iovec sizes vs. virtio-scsi request +
* response headers respectively.
*
* For DMA_TO_DEVICE this is out_iter, which is already pointing
* to the right place.
*
* For DMA_FROM_DEVICE, the iovec will be just past the end
* of the virtio-scsi response header in either the same
* or immediately following iovec.
*
* Any associated T10_PI bytes for the outgoing / incoming
* payloads are included in calculation of exp_data_len here.
*/
prot_bytes = 0;
if (vc.out_size > vc.req_size) {
data_direction = DMA_TO_DEVICE;
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 = vc.in_size - vc.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;
exp_data_len = 0;
}
/*
* If T10_PI header + payload is present, setup prot_iter values
* and recalculate data_iter for vhost_scsi_mapal() mapping to
* host scatterlists via get_user_pages_fast().
*/
if (t10_pi) {
if (v_req_pi.pi_bytesout) {
if (data_direction != DMA_TO_DEVICE) {
vq_err(vq, "Received non zero pi_bytesout,"
" but wrong data_direction\n");
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");
goto err;
}
prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesin);
}
/*
* 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
* actual data payload length.
*/
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);
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 = vhost64_to_cpu(vq, 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;
}
/*
* Check that the received CDB size does not exceeded our
* hardcoded max for vhost-scsi, then get a pre-allocated
* cmd descriptor for the new virtio-scsi tag.
*
* TODO what if cdb was too small for varlen cdb header?
*/
if (unlikely(scsi_command_size(cdb) > VHOST_SCSI_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), VHOST_SCSI_MAX_CDB_SIZE);
goto err;
}
cmd = vhost_scsi_get_tag(vq, tpg, cdb, tag, lun, task_attr,
exp_data_len + prot_bytes,
data_direction);
if (IS_ERR(cmd)) {
vq_err(vq, "vhost_scsi_get_tag failed %ld\n",
PTR_ERR(cmd));
goto err;
}
cmd->tvc_vhost = vs;
cmd->tvc_vq = vq;
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);
pr_debug("cmd: %p exp_data_len: %d, prot_bytes: %d data_direction:"
" %d\n", cmd, exp_data_len, prot_bytes, data_direction);
if (data_direction != DMA_NONE) {
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);
goto err;
}
}
/*
* Save the descriptor from vhost_get_vq_desc() to be used to
* complete the virtio-scsi request in TCM callback context via
* vhost_scsi_queue_data_in() and vhost_scsi_queue_status()
*/
cmd->tvc_vq_desc = vc.head;
/*
* Dispatch cmd descriptor for cmwq execution in process
* context provided by vhost_scsi_workqueue. This also ensures
* cmd is executed on the same kworker CPU as this vhost
* thread to gain positive L2 cache locality effects.
*/
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 void
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: