X-Git-Url: http://git.monstr.eu/?a=blobdiff_plain;f=drivers%2Fvhost%2Fscsi.c;fp=drivers%2Fvhost%2Fscsi.c;h=324e4b3846fa3e929350ac699c0721a1146ed3c4;hb=5ced58bfa132c8ba0f9c893eb621595a84cfee12;hp=c83f7f043470d687b32d92f6dfe864b1e93964c3;hpb=9ad1a29cb0991e3145996cdce691525e8ac65db7;p=linux-2.6-microblaze.git diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index c83f7f043470..324e4b3846fa 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -25,6 +25,8 @@ #include #include #include +#include +#include #include #include #include @@ -75,6 +77,9 @@ struct vhost_scsi_cmd { u32 tvc_prot_sgl_count; /* Saved unpacked SCSI LUN for vhost_scsi_target_queue_cmd() */ u32 tvc_lun; + u32 copied_iov:1; + const void *saved_iter_addr; + struct iov_iter saved_iter; /* Pointer to the SGL formatted memory from virtio-scsi */ struct scatterlist *tvc_sgl; struct scatterlist *tvc_prot_sgl; @@ -328,8 +333,13 @@ static void vhost_scsi_release_cmd_res(struct se_cmd *se_cmd) int i; if (tv_cmd->tvc_sgl_count) { - for (i = 0; i < tv_cmd->tvc_sgl_count; i++) - put_page(sg_page(&tv_cmd->tvc_sgl[i])); + for (i = 0; i < tv_cmd->tvc_sgl_count; i++) { + if (tv_cmd->copied_iov) + __free_page(sg_page(&tv_cmd->tvc_sgl[i])); + else + put_page(sg_page(&tv_cmd->tvc_sgl[i])); + } + kfree(tv_cmd->saved_iter_addr); } if (tv_cmd->tvc_prot_sgl_count) { for (i = 0; i < tv_cmd->tvc_prot_sgl_count; i++) @@ -504,6 +514,28 @@ static void vhost_scsi_evt_work(struct vhost_work *work) mutex_unlock(&vq->mutex); } +static int vhost_scsi_copy_sgl_to_iov(struct vhost_scsi_cmd *cmd) +{ + struct iov_iter *iter = &cmd->saved_iter; + struct scatterlist *sg = cmd->tvc_sgl; + struct page *page; + size_t len; + int i; + + for (i = 0; i < cmd->tvc_sgl_count; i++) { + page = sg_page(&sg[i]); + len = sg[i].length; + + if (copy_page_to_iter(page, 0, len, iter) != len) { + pr_err("Could not copy data while handling misaligned cmd. Error %zu\n", + len); + return -1; + } + } + + return 0; +} + /* Fill in status and signal that we are done processing this command * * This is scheduled in the vhost work queue so we are called with the owner @@ -527,15 +559,20 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work) pr_debug("%s tv_cmd %p resid %u status %#02x\n", __func__, cmd, se_cmd->residual_count, se_cmd->scsi_status); - memset(&v_rsp, 0, sizeof(v_rsp)); - v_rsp.resid = cpu_to_vhost32(cmd->tvc_vq, se_cmd->residual_count); - /* TODO is status_qualifier field needed? */ - v_rsp.status = se_cmd->scsi_status; - v_rsp.sense_len = cpu_to_vhost32(cmd->tvc_vq, - se_cmd->scsi_sense_length); - memcpy(v_rsp.sense, cmd->tvc_sense_buf, - se_cmd->scsi_sense_length); + + if (cmd->saved_iter_addr && vhost_scsi_copy_sgl_to_iov(cmd)) { + v_rsp.response = VIRTIO_SCSI_S_BAD_TARGET; + } else { + v_rsp.resid = cpu_to_vhost32(cmd->tvc_vq, + se_cmd->residual_count); + /* TODO is status_qualifier field needed? */ + v_rsp.status = se_cmd->scsi_status; + v_rsp.sense_len = cpu_to_vhost32(cmd->tvc_vq, + se_cmd->scsi_sense_length); + memcpy(v_rsp.sense, cmd->tvc_sense_buf, + se_cmd->scsi_sense_length); + } iov_iter_init(&iov_iter, ITER_DEST, cmd->tvc_resp_iov, cmd->tvc_in_iovs, sizeof(v_rsp)); @@ -613,12 +650,12 @@ static int vhost_scsi_map_to_sgl(struct vhost_scsi_cmd *cmd, struct iov_iter *iter, struct scatterlist *sgl, - bool write) + bool is_prot) { struct page **pages = cmd->tvc_upages; struct scatterlist *sg = sgl; - ssize_t bytes; - size_t offset; + ssize_t bytes, mapped_bytes; + size_t offset, mapped_offset; unsigned int npages = 0; bytes = iov_iter_get_pages2(iter, pages, LONG_MAX, @@ -627,13 +664,53 @@ vhost_scsi_map_to_sgl(struct vhost_scsi_cmd *cmd, if (bytes <= 0) return bytes < 0 ? bytes : -EFAULT; + mapped_bytes = bytes; + mapped_offset = offset; + while (bytes) { unsigned n = min_t(unsigned, PAGE_SIZE - offset, bytes); + /* + * The block layer requires bios/requests to be a multiple of + * 512 bytes, but Windows can send us vecs that are misaligned. + * This can result in bios and later requests with misaligned + * sizes if we have to break up a cmd/scatterlist into multiple + * bios. + * + * We currently only break up a command into multiple bios if + * we hit the vec/seg limit, so check if our sgl_count is + * greater than the max and if a vec in the cmd has a + * misaligned offset/size. + */ + if (!is_prot && + (offset & (SECTOR_SIZE - 1) || n & (SECTOR_SIZE - 1)) && + cmd->tvc_sgl_count > BIO_MAX_VECS) { + WARN_ONCE(true, + "vhost-scsi detected misaligned IO. Performance may be degraded."); + goto revert_iter_get_pages; + } + sg_set_page(sg++, pages[npages++], n, offset); bytes -= n; offset = 0; } + return npages; + +revert_iter_get_pages: + iov_iter_revert(iter, mapped_bytes); + + npages = 0; + while (mapped_bytes) { + unsigned int n = min_t(unsigned int, PAGE_SIZE - mapped_offset, + mapped_bytes); + + put_page(pages[npages++]); + + mapped_bytes -= n; + mapped_offset = 0; + } + + return -EINVAL; } static int @@ -657,25 +734,80 @@ vhost_scsi_calc_sgls(struct iov_iter *iter, size_t bytes, int max_sgls) } static int -vhost_scsi_iov_to_sgl(struct vhost_scsi_cmd *cmd, bool write, - struct iov_iter *iter, - struct scatterlist *sg, int sg_count) +vhost_scsi_copy_iov_to_sgl(struct vhost_scsi_cmd *cmd, struct iov_iter *iter, + struct scatterlist *sg, int sg_count) +{ + size_t len = iov_iter_count(iter); + unsigned int nbytes = 0; + struct page *page; + int i; + + if (cmd->tvc_data_direction == DMA_FROM_DEVICE) { + cmd->saved_iter_addr = dup_iter(&cmd->saved_iter, iter, + GFP_KERNEL); + if (!cmd->saved_iter_addr) + return -ENOMEM; + } + + for (i = 0; i < sg_count; i++) { + page = alloc_page(GFP_KERNEL); + if (!page) { + i--; + goto err; + } + + nbytes = min_t(unsigned int, PAGE_SIZE, len); + sg_set_page(&sg[i], page, nbytes, 0); + + if (cmd->tvc_data_direction == DMA_TO_DEVICE && + copy_page_from_iter(page, 0, nbytes, iter) != nbytes) + goto err; + + len -= nbytes; + } + + cmd->copied_iov = 1; + return 0; + +err: + pr_err("Could not read %u bytes while handling misaligned cmd\n", + nbytes); + + for (; i >= 0; i--) + __free_page(sg_page(&sg[i])); + kfree(cmd->saved_iter_addr); + return -ENOMEM; +} + +static int +vhost_scsi_iov_to_sgl(struct vhost_scsi_cmd *cmd, struct iov_iter *iter, + struct scatterlist *sg, int sg_count, bool is_prot) { struct scatterlist *p = sg; + size_t revert_bytes; int ret; while (iov_iter_count(iter)) { - ret = vhost_scsi_map_to_sgl(cmd, iter, sg, write); + ret = vhost_scsi_map_to_sgl(cmd, iter, sg, is_prot); if (ret < 0) { + revert_bytes = 0; + while (p < sg) { - struct page *page = sg_page(p++); - if (page) + struct page *page = sg_page(p); + + if (page) { put_page(page); + revert_bytes += p->length; + } + p++; } + + iov_iter_revert(iter, revert_bytes); return ret; } sg += ret; } + return 0; } @@ -685,7 +817,6 @@ vhost_scsi_mapal(struct vhost_scsi_cmd *cmd, size_t data_bytes, struct iov_iter *data_iter) { int sgl_count, ret; - bool write = (cmd->tvc_data_direction == DMA_FROM_DEVICE); if (prot_bytes) { sgl_count = vhost_scsi_calc_sgls(prot_iter, prot_bytes, @@ -698,9 +829,8 @@ vhost_scsi_mapal(struct vhost_scsi_cmd *cmd, pr_debug("%s prot_sg %p prot_sgl_count %u\n", __func__, cmd->tvc_prot_sgl, cmd->tvc_prot_sgl_count); - ret = vhost_scsi_iov_to_sgl(cmd, write, prot_iter, - cmd->tvc_prot_sgl, - cmd->tvc_prot_sgl_count); + ret = vhost_scsi_iov_to_sgl(cmd, prot_iter, cmd->tvc_prot_sgl, + cmd->tvc_prot_sgl_count, true); if (ret < 0) { cmd->tvc_prot_sgl_count = 0; return ret; @@ -716,8 +846,14 @@ vhost_scsi_mapal(struct vhost_scsi_cmd *cmd, pr_debug("%s data_sg %p data_sgl_count %u\n", __func__, cmd->tvc_sgl, cmd->tvc_sgl_count); - ret = vhost_scsi_iov_to_sgl(cmd, write, data_iter, - cmd->tvc_sgl, cmd->tvc_sgl_count); + ret = vhost_scsi_iov_to_sgl(cmd, data_iter, cmd->tvc_sgl, + cmd->tvc_sgl_count, false); + if (ret == -EINVAL) { + sg_init_table(cmd->tvc_sgl, cmd->tvc_sgl_count); + ret = vhost_scsi_copy_iov_to_sgl(cmd, data_iter, cmd->tvc_sgl, + cmd->tvc_sgl_count); + } + if (ret < 0) { cmd->tvc_sgl_count = 0; return ret;