From: Nicholas Bellinger <n...@linux-iscsi.org>
This patch adds vhost_scsi_map_iov_to_prot() to perform the mapping of
T10 data integrity memory between virtio iov + struct scatterlist using
get_user_pages_fast() following existing code.
As with vhost_scsi_map_iov_to_sgl(), this does sanity checks against the
total prot_sgl_count vs. pre-allocated SGLs, and loops across protection
iovs using vhost_scsi_map_to_sgl() to perform the actual memory mapping.
Also update tcm_vhost_release_cmd() to release associated tvc_prot_sgl[]
struct page.
Cc: Michael S. Tsirkin <m...@redhat.com>
Cc: Paolo Bonzini <pbonz...@redhat.com>
Cc: Martin K. Petersen <martin.peter...@oracle.com>
Cc: Christoph Hellwig <h...@lst.de>
Cc: Hannes Reinecke <h...@suse.de>
Cc: Sagi Grimberg <sa...@dev.mellanox.co.il>
Cc: H. Peter Anvin <h...@zytor.com>
Signed-off-by: Nicholas Bellinger <n...@linux-iscsi.org>
---
drivers/vhost/scsi.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 47 insertions(+), 1 deletion(-)
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 30402e6..eabcf18 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -80,6 +80,7 @@ struct tcm_vhost_cmd {
u64 tvc_tag;
/* The number of scatterlists associated with this cmd */
u32 tvc_sgl_count;
+ u32 tvc_prot_sgl_count;
/* Saved unpacked SCSI LUN for tcm_vhost_submission_work() */
u32 tvc_lun;
/* Pointer to the SGL formatted memory from virtio-scsi */
@@ -458,12 +459,16 @@ static void tcm_vhost_release_cmd(struct se_cmd *se_cmd)
struct tcm_vhost_cmd *tv_cmd = container_of(se_cmd,
struct tcm_vhost_cmd, tvc_se_cmd);
struct se_session *se_sess = se_cmd->se_sess;
+ int i;
if (tv_cmd->tvc_sgl_count) {
- u32 i;
for (i = 0; i < tv_cmd->tvc_sgl_count; i++)
put_page(sg_page(&tv_cmd->tvc_sgl[i]));
}
+ if (tv_cmd->tvc_prot_sgl_count) {
+ for (i = 0; i < tv_cmd->tvc_prot_sgl_count; i++)
+ put_page(sg_page(&tv_cmd->tvc_prot_sgl[i]));
+ }
tcm_vhost_put_inflight(tv_cmd->inflight);
percpu_ida_free(&se_sess->sess_tag_pool, se_cmd->map_tag);
@@ -861,6 +866,47 @@ vhost_scsi_map_iov_to_sgl(struct tcm_vhost_cmd *cmd,
return 0;
}
+static int
+vhost_scsi_map_iov_to_prot(struct tcm_vhost_cmd *cmd,
+ struct iovec *iov,
+ int niov,
+ bool write)
+{
+ struct scatterlist *prot_sg = cmd->tvc_prot_sgl;
+ unsigned int prot_sgl_count = 0;
+ int ret, i;
+
+ for (i = 0; i < niov; i++)
+ prot_sgl_count += iov_num_pages(&iov[i]);
+
+ if (prot_sgl_count > TCM_VHOST_PREALLOC_PROT_SGLS) {
+ pr_err("vhost_scsi_map_iov_to_prot() sgl_count: %u greater than"
+ " preallocated TCM_VHOST_PREALLOC_PROT_SGLS: %u\n",
+ prot_sgl_count, TCM_VHOST_PREALLOC_PROT_SGLS);
+ return -ENOBUFS;
+ }
+
+ pr_debug("%s prot_sg %p prot_sgl_count %u\n", __func__,
+ prot_sg, prot_sgl_count);
+ sg_init_table(prot_sg, prot_sgl_count);
+ cmd->tvc_prot_sgl_count = prot_sgl_count;
+
+ for (i = 0; i < niov; i++) {
+ ret = vhost_scsi_map_to_sgl(cmd, prot_sg, prot_sgl_count,
&iov[i],
+ cmd->tvc_upages, write);
+ if (ret < 0) {
+ for (i = 0; i < cmd->tvc_prot_sgl_count; i++)
+ put_page(sg_page(&cmd->tvc_prot_sgl[i]));
+
+ cmd->tvc_prot_sgl_count = 0;
+ return ret;
+ }
+ prot_sg += ret;
+ prot_sgl_count -= ret;
+ }
+ return 0;
+}
+
static void tcm_vhost_submission_work(struct work_struct *work)
{
struct tcm_vhost_cmd *cmd =
--
1.7.10.4
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