vhost: remove async DMA map status

Async DMA map status flag was added to prevent the unnecessary unmap
when DMA devices bound to kernel driver. This brings maintenance cost
for a lot of code. This patch removes the DMA map status by using
rte_errno instead.

This patch relies on the following patch to fix a partial
unmap check in vfio unmapping API.
[1] https://www.mail-archive.com/dev@dpdk.org/msg226464.html

Signed-off-by: Xuan Ding <xuan.ding@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h
index 6c6a2da..71fddf3 100644 (file)
--- a/lib/vhost/vhost.h
+++ b/lib/vhost/vhost.h
@@ -370,9 +370,6 @@ struct virtio_net {
        uint32_t                nr_vring;
        int                     async_copy;
 
-       /* Record the dma map status for each region. */
-       bool                    *async_map_status;
-
        int                     extbuf;
        int                     linearbuf;
        struct vhost_virtqueue  *virtqueue[VHOST_MAX_QUEUE_PAIRS * 2];

diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
index 720d1c1..9489d03 100644 (file)
--- a/lib/vhost/vhost_user.c
+++ b/lib/vhost/vhost_user.c
@@ -144,7 +144,7 @@ get_blk_size(int fd)
 }
 
 static int
-async_dma_map(struct rte_vhost_mem_region *region, bool *dma_map_success, bool do_map)
+async_dma_map(struct rte_vhost_mem_region *region, bool do_map)
 {
        uint64_t host_iova;
        int ret = 0;
@@ -156,8 +156,6 @@ async_dma_map(struct rte_vhost_mem_region *region, bool *dma_map_success, bool d
                                                 region->host_user_addr,
                                                 host_iova,
                                                 region->size);
-               *dma_map_success = ret == 0;
-
                if (ret) {
                        /*
                         * DMA device may bind with kernel driver, in this case,
@@ -175,26 +173,24 @@ async_dma_map(struct rte_vhost_mem_region *region, bool *dma_map_success, bool d
                                return 0;
 
                        VHOST_LOG_CONFIG(ERR, "DMA engine map failed\n");
-                       return ret;
-
+                       /* DMA mapping errors won't stop VHST_USER_SET_MEM_TABLE. */
+                       return 0;
                }
 
        } else {
-               /* No need to do vfio unmap if the map failed. */
-               if (!*dma_map_success)
-                       return 0;
-
                /* 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;
                }
-               /* Clear the flag once the unmap succeeds. */
-               *dma_map_success = 0;
        }
 
        return ret;
@@ -213,7 +209,7 @@ free_mem_region(struct virtio_net *dev)
                reg = &dev->mem->regions[i];
                if (reg->host_user_addr) {
                        if (dev->async_copy && rte_vfio_is_enabled("vfio"))
-                               async_dma_map(reg, &dev->async_map_status[i], false);
+                               async_dma_map(reg, false);
 
                        munmap(reg->mmap_addr, reg->mmap_size);
                        close(reg->fd);
@@ -228,11 +224,6 @@ vhost_backend_cleanup(struct virtio_net *dev)
                free_mem_region(dev);
                rte_free(dev->mem);
                dev->mem = NULL;
-
-               if (dev->async_map_status) {
-                       rte_free(dev->async_map_status);
-                       dev->async_map_status = NULL;
-               }
        }
 
        rte_free(dev->guest_pages);
@@ -688,19 +679,6 @@ out_dev_realloc:
        }
        dev->mem = mem;
 
-       if (dev->async_copy && rte_vfio_is_enabled("vfio")) {
-               if (dev->async_map_status == NULL) {
-                       dev->async_map_status = rte_zmalloc_socket("async-dma-map-status",
-                                       sizeof(bool) * dev->mem->nregions, 0, node);
-                       if (!dev->async_map_status) {
-                               VHOST_LOG_CONFIG(ERR,
-                                       "(%d) failed to realloc dma mapping status on node\n",
-                                       dev->vid);
-                               return dev;
-                       }
-               }
-       }
-
        gp = rte_realloc_socket(dev->guest_pages, dev->max_guest_pages * sizeof(*gp),
                        RTE_CACHE_LINE_SIZE, node);
        if (!gp) {
@@ -1231,7 +1209,6 @@ vhost_user_postcopy_register(struct virtio_net *dev, int main_fd,
 static int
 vhost_user_mmap_region(struct virtio_net *dev,
                struct rte_vhost_mem_region *region,
-               uint32_t region_index,
                uint64_t mmap_offset)
 {
        void *mmap_addr;
@@ -1294,16 +1271,14 @@ vhost_user_mmap_region(struct virtio_net *dev,
 
        if (dev->async_copy) {
                if (add_guest_pages(dev, region, alignment) < 0) {
-                       VHOST_LOG_CONFIG(ERR,
-                                       "adding guest pages to region failed.\n");
+                       VHOST_LOG_CONFIG(ERR, "adding guest pages to region failed.\n");
                        return -1;
                }
 
                if (rte_vfio_is_enabled("vfio")) {
-                       ret = async_dma_map(region, &dev->async_map_status[region_index], true);
+                       ret = async_dma_map(region, true);
                        if (ret) {
-                               VHOST_LOG_CONFIG(ERR, "Configure IOMMU for DMA "
-                                                       "engine failed\n");
+                               VHOST_LOG_CONFIG(ERR, "Configure IOMMU for DMA engine failed\n");
                                return -1;
                        }
                }
@@ -1381,11 +1356,6 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
                free_mem_region(dev);
                rte_free(dev->mem);
                dev->mem = NULL;
-
-               if (dev->async_map_status) {
-                       rte_free(dev->async_map_status);
-                       dev->async_map_status = NULL;
-               }
        }
 
        /* Flush IOTLB cache as previous HVAs are now invalid */
@@ -1426,17 +1396,6 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
                goto free_guest_pages;
        }
 
-       if (dev->async_copy) {
-               dev->async_map_status = rte_zmalloc_socket("async-dma-map-status",
-                                       sizeof(bool) * memory->nregions, 0, numa_node);
-               if (!dev->async_map_status) {
-                       VHOST_LOG_CONFIG(ERR,
-                               "(%d) failed to allocate memory for dma mapping status\n",
-                               dev->vid);
-                       goto free_mem_table;
-               }
-       }
-
        for (i = 0; i < memory->nregions; i++) {
                reg = &dev->mem->regions[i];
 
@@ -1453,7 +1412,7 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
 
                mmap_offset = memory->regions[i].mmap_offset;
 
-               if (vhost_user_mmap_region(dev, reg, i, mmap_offset) < 0) {
+               if (vhost_user_mmap_region(dev, reg, mmap_offset) < 0) {
                        VHOST_LOG_CONFIG(ERR, "Failed to mmap region %u\n", i);
                        goto free_mem_table;
                }
@@ -1501,10 +1460,7 @@ free_mem_table:
        free_mem_region(dev);
        rte_free(dev->mem);
        dev->mem = NULL;
-       if (dev->async_map_status) {
-               rte_free(dev->async_map_status);
-               dev->async_map_status = NULL;
-       }
+
 free_guest_pages:
        rte_free(dev->guest_pages);
        dev->guest_pages = NULL;