> -----Original Message-----
> From: Ding, Xuan <xuan.d...@intel.com>
> Sent: Monday, November 15, 2021 8:32 PM
> To: maxime.coque...@redhat.com; Xia, Chenbo <chenbo....@intel.com>
> Cc: dev@dpdk.org; Hu, Jiayu <jiayu...@intel.com>; Wang, YuanX
> <yuanx.w...@intel.com>; He, Xingguang <xingguang...@intel.com>; Ding, Xuan
> <xuan.d...@intel.com>
> Subject: [PATCH v4] vhost: fix physical address mapping
>
> When choosing IOVA as PA mode, IOVA is likely to be discontinuous,
> which requires page by page mapping for DMA devices. To be consistent,
> this patch implements page by page mapping instead of mapping at the
> region granularity for both IOVA as VA and PA mode.
>
> Fixes: 7c61fa08b716 ("vhost: enable IOMMU for async vhost")
>
> Signed-off-by: Xuan Ding <xuan.d...@intel.com>
> ---
> v4:
> * Remove unnessary ENOSUP check.
> * Adjust return type.
>
> v3:
> * Fix commit title.
>
> v2:
> * Fix a format issue.
> ---
> lib/vhost/vhost.h | 1 +
> lib/vhost/vhost_user.c | 111 ++++++++++++++++++++---------------------
> 2 files changed, 54 insertions(+), 58 deletions(-)
>
> diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h
> index 7085e0885c..d246538ca5 100644
> --- a/lib/vhost/vhost.h
> +++ b/lib/vhost/vhost.h
> @@ -355,6 +355,7 @@ struct vring_packed_desc_event {
> struct guest_page {
> uint64_t guest_phys_addr;
> uint64_t host_phys_addr;
This name confused me when doing review: this should be host_iova.
Could you help rename it in the patch?
> + uint64_t host_user_addr;
> uint64_t size;
> };
>
> diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
> index a781346c4d..0a9dc3350f 100644
> --- a/lib/vhost/vhost_user.c
> +++ b/lib/vhost/vhost_user.c
> @@ -143,57 +143,56 @@ get_blk_size(int fd)
> return ret == -1 ? (uint64_t)-1 : (uint64_t)stat.st_blksize;
> }
>
> -static int
> -async_dma_map(struct rte_vhost_mem_region *region, bool do_map)
> +static void
> +async_dma_map(struct virtio_net *dev, bool do_map)
> {
> - uint64_t host_iova;
> int ret = 0;
> -
> - host_iova = rte_mem_virt2iova((void
> *)(uintptr_t)region->host_user_addr);
> + uint32_t i;
> + struct guest_page *page;
> if (do_map) {
> - /* Add mapped region into the default container of DPDK. */
> - ret = rte_vfio_container_dma_map(RTE_VFIO_DEFAULT_CONTAINER_FD,
> - region->host_user_addr,
> - host_iova,
> - region->size);
> - if (ret) {
> - /*
> - * DMA device may bind with kernel driver, in this case,
> - * we don't need to program IOMMU manually. However, if
> no
> - * device is bound with vfio/uio in DPDK, and vfio
> kernel
> - * module is loaded, the API will still be called and
> return
> - * with ENODEV/ENOSUP.
> - *
> - * DPDK vfio only returns ENODEV/ENOSUP in very similar
> - * situations(vfio either unsupported, or supported
> - * but no devices found). Either way, no mappings could
> be
> - * performed. We treat it as normal case in async path.
> - */
> - if (rte_errno == ENODEV || rte_errno == ENOTSUP)
> - return 0;
> -
> - VHOST_LOG_CONFIG(ERR, "DMA engine map failed\n");
> - /* DMA mapping errors won't stop
> VHST_USER_SET_MEM_TABLE. */
> - return 0;
> + for (i = 0; i < dev->nr_guest_pages; i++) {
> + page = &dev->guest_pages[i];
> + ret =
> rte_vfio_container_dma_map(RTE_VFIO_DEFAULT_CONTAINER_FD,
> + page->host_user_addr,
> + page->host_phys_addr,
> + page->size);
> + if (ret) {
> + /*
> + * DMA device may bind with kernel driver, in
> this
> case,
> + * we don't need to program IOMMU manually.
> However,
> if no
> + * device is bound with vfio/uio in DPDK, and
> vfio
> kernel
> + * module is loaded, the API will still be
> called and
> return
> + * with ENODEV.
> + *
> + * DPDK vfio only returns ENODEV in very similar
> situations
> + * (vfio either unsupported, or supported but no
> devices found).
> + * Either way, no mappings could be performed.
> We
> treat it as
> + * normal case in async path. This is a
> workaround.
> + */
> + if (rte_errno == ENODEV)
> + return;
> +
> + /* DMA mapping errors won't stop
> VHST_USER_SET_MEM_TABLE. */
A comment in v3 is missed:
VHST -> VHOST
Thanks,
Chenbo
> + VHOST_LOG_CONFIG(ERR, "DMA engine map
> failed\n");
> + }
> }
>
> } else {
> - /* Remove mapped region from the default container of DPDK. */
> - ret =
> rte_vfio_container_dma_unmap(RTE_VFIO_DEFAULT_CONTAINER_FD,
> - region->host_user_addr,
> - host_iova,
> - region->size);
> - if (ret) {
> - /* like DMA map, ignore the kernel driver case when
> unmap.
> */
> - if (rte_errno == EINVAL)
> - return 0;
> -
> - VHOST_LOG_CONFIG(ERR, "DMA engine unmap failed\n");
> - return ret;
> + for (i = 0; i < dev->nr_guest_pages; i++) {
> + page = &dev->guest_pages[i];
> + ret =
> rte_vfio_container_dma_unmap(RTE_VFIO_DEFAULT_CONTAINER_FD,
> + page->host_user_addr,
> + page->host_phys_addr,
> + page->size);
> + if (ret) {
> + /* like DMA map, ignore the kernel driver case
> when
> unmap. */
> + if (rte_errno == EINVAL)
> + return;
> +
> + VHOST_LOG_CONFIG(ERR, "DMA engine unmap
> failed\n");
> + }
> }
> }
> -
> - return ret;
> }
>
> static void
> @@ -205,12 +204,12 @@ free_mem_region(struct virtio_net *dev)
> if (!dev || !dev->mem)
> return;
>
> + if (dev->async_copy && rte_vfio_is_enabled("vfio"))
> + async_dma_map(dev, false);
> +
> for (i = 0; i < dev->mem->nregions; i++) {
> reg = &dev->mem->regions[i];
> if (reg->host_user_addr) {
> - if (dev->async_copy && rte_vfio_is_enabled("vfio"))
> - async_dma_map(reg, false);
> -
> munmap(reg->mmap_addr, reg->mmap_size);
> close(reg->fd);
> }
> @@ -978,7 +977,7 @@ vhost_user_set_vring_base(struct virtio_net **pdev,
>
> static int
> add_one_guest_page(struct virtio_net *dev, uint64_t guest_phys_addr,
> - uint64_t host_phys_addr, uint64_t size)
> + uint64_t host_phys_addr, uint64_t host_user_addr, uint64_t
> size)
> {
> struct guest_page *page, *last_page;
> struct guest_page *old_pages;
> @@ -1009,6 +1008,7 @@ add_one_guest_page(struct virtio_net *dev, uint64_t
> guest_phys_addr,
> page = &dev->guest_pages[dev->nr_guest_pages++];
> page->guest_phys_addr = guest_phys_addr;
> page->host_phys_addr = host_phys_addr;
> + page->host_user_addr = host_user_addr;
> page->size = size;
>
> return 0;
> @@ -1028,7 +1028,8 @@ add_guest_pages(struct virtio_net *dev, struct
> rte_vhost_mem_region *reg,
> size = page_size - (guest_phys_addr & (page_size - 1));
> size = RTE_MIN(size, reg_size);
>
> - if (add_one_guest_page(dev, guest_phys_addr, host_phys_addr, size) < 0)
> + if (add_one_guest_page(dev, guest_phys_addr, host_phys_addr,
> + host_user_addr, size) < 0)
> return -1;
>
> host_user_addr += size;
> @@ -1040,7 +1041,7 @@ add_guest_pages(struct virtio_net *dev, struct
> rte_vhost_mem_region *reg,
> host_phys_addr = rte_mem_virt2iova((void *)(uintptr_t)
> host_user_addr);
> if (add_one_guest_page(dev, guest_phys_addr, host_phys_addr,
> - size) < 0)
> + host_user_addr, size) < 0)
> return -1;
>
> host_user_addr += size;
> @@ -1215,7 +1216,6 @@ vhost_user_mmap_region(struct virtio_net *dev,
> uint64_t mmap_size;
> uint64_t alignment;
> int populate;
> - int ret;
>
> /* Check for memory_size + mmap_offset overflow */
> if (mmap_offset >= -region->size) {
> @@ -1274,14 +1274,6 @@ vhost_user_mmap_region(struct virtio_net *dev,
> VHOST_LOG_CONFIG(ERR, "adding guest pages to region
> failed.\n");
> return -1;
> }
> -
> - if (rte_vfio_is_enabled("vfio")) {
> - ret = async_dma_map(region, true);
> - if (ret) {
> - VHOST_LOG_CONFIG(ERR, "Configure IOMMU for DMA
> engine
> failed\n");
> - return -1;
> - }
> - }
> }
>
> VHOST_LOG_CONFIG(INFO,
> @@ -1420,6 +1412,9 @@ vhost_user_set_mem_table(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
> dev->mem->nregions++;
> }
>
> + if (dev->async_copy && rte_vfio_is_enabled("vfio"))
> + async_dma_map(dev, true);
> +
> if (vhost_user_postcopy_register(dev, main_fd, msg) < 0)
> goto free_mem_table;
>
> --
> 2.17.1
