From e31885dd901e80d5bd528c1cbedde07ebbf051b2 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Sat, 22 Feb 2014 18:34:43 -0800 Subject: [PATCH] vhost/scsi: Add T10 PI IOV -> SGL memory mapping logic 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 Cc: Paolo Bonzini Cc: Martin K. Petersen Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Sagi Grimberg Cc: H. Peter Anvin Acked-by: Michael S. Tsirkin Signed-off-by: Nicholas Bellinger --- 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 30402e618078..eabcf1875831 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 = -- 2.20.1