Add support for VFIO_DMA_UNMAP_FLAG_ALL flag (#600)

* Add support for VFIO_DMA_UNMAP_FLAG_ALL flag

Signed-off-by: Swapnil Ingle <swapnil.ingle@nutanix.com>
Reviewed-by: John Levon <john.levon@nutanix.com>

1 files changed, 24 insertions, 1 deletions

diff --git a/lib/libvfio-user.c b/lib/libvfio-user.c
index 4e6b81f..3cb30ba 100644
--- a/lib/libvfio-user.c
+++ b/lib/libvfio-user.c
@@ -545,7 +545,8 @@ handle_dma_unmap(vfu_ctx_t *vfu_ctx, vfu_msg_t *msg,
                  struct vfio_user_dma_unmap *dma_unmap)
 {
     size_t out_size;
-    int ret;
+    int ret = 0;
+    bool unmap_all = false;
     char rstr[1024];
 
     assert(vfu_ctx != NULL);
@@ -558,6 +559,12 @@ handle_dma_unmap(vfu_ctx_t *vfu_ctx, vfu_msg_t *msg,
         return ERROR_INT(EINVAL);
     }
 
+    if ((dma_unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) &&
+            (dma_unmap->flags & VFIO_DMA_UNMAP_FLAG_ALL)) {
+        vfu_log(vfu_ctx, LOG_ERR, "invalid DMA flags=%#x", dma_unmap->flags);
+        return ERROR_INT(EINVAL);
+    }
+
     snprintf(rstr, sizeof(rstr), "[%#lx, %#lx) flags=%#x",
              dma_unmap->addr, dma_unmap->addr + dma_unmap->size, dma_unmap->flags);
 
@@ -585,6 +592,13 @@ handle_dma_unmap(vfu_ctx_t *vfu_ctx, vfu_msg_t *msg,
          * the DMA controller.
          */
         out_size += sizeof(*dma_unmap->bitmap) + dma_unmap->bitmap->size;
+    } else if (dma_unmap->flags == VFIO_DMA_UNMAP_FLAG_ALL) {
+        if (dma_unmap->addr || dma_unmap->size) {
+            vfu_log(vfu_ctx, LOG_ERR, "bad addr=%#lx or size=%#lx, expected "
+                    "both to be zero", dma_unmap->addr, dma_unmap->size);
+            return ERROR_INT(EINVAL);
+        }
+        unmap_all = true;
     } else if (dma_unmap->flags != 0) {
         vfu_log(vfu_ctx, LOG_ERR, "bad flags=%#x", dma_unmap->flags);
         return ERROR_INT(ENOTSUP);
@@ -596,6 +610,12 @@ handle_dma_unmap(vfu_ctx_t *vfu_ctx, vfu_msg_t *msg,
     }
     memcpy(msg->out_data, dma_unmap, sizeof(*dma_unmap));
 
+    if (unmap_all) {
+        dma_controller_remove_all_regions(vfu_ctx->dma,
+                                          vfu_ctx->dma_unregister, vfu_ctx);
+        goto out;
+    }
+
     if (dma_unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) {
         memcpy(msg->out_data + sizeof(*dma_unmap), dma_unmap->bitmap, sizeof(*dma_unmap->bitmap));
         ret = dma_controller_dirty_page_get(vfu_ctx->dma,
@@ -621,7 +641,10 @@ handle_dma_unmap(vfu_ctx_t *vfu_ctx, vfu_msg_t *msg,
                 "failed to remove DMA region %s: %m", rstr);
         return ERROR_INT(ret);
     }
+
+out:
     msg->out_size = out_size;
+
     return ret;
 }