summary refs log tree commit diff stats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--block/block-backend.c4
-rw-r--r--block/io.c34
-rw-r--r--block/nvme.c18
-rw-r--r--include/block/block-global-state.h5
-rw-r--r--include/block/block_int-common.h5
-rw-r--r--include/sysemu/block-backend-global-state.h2
-rw-r--r--qemu-img.c2
7 files changed, 52 insertions, 18 deletions
diff --git a/block/block-backend.c b/block/block-backend.c
index ae42474891..4f59664397 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -2545,10 +2545,10 @@ static void blk_root_drained_end(BdrvChild *child, int *drained_end_counter)
     }
 }
 
-void blk_register_buf(BlockBackend *blk, void *host, size_t size)
+bool blk_register_buf(BlockBackend *blk, void *host, size_t size, Error **errp)
 {
     GLOBAL_STATE_CODE();
-    bdrv_register_buf(blk_bs(blk), host, size);
+    return bdrv_register_buf(blk_bs(blk), host, size, errp);
 }
 
 void blk_unregister_buf(BlockBackend *blk, void *host, size_t size)
diff --git a/block/io.c b/block/io.c
index 4207648db6..a9673465dd 100644
--- a/block/io.c
+++ b/block/io.c
@@ -3277,17 +3277,45 @@ void bdrv_io_unplug(BlockDriverState *bs)
     }
 }
 
-void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size)
+/* Helper that undoes bdrv_register_buf() when it fails partway through */
+static void bdrv_register_buf_rollback(BlockDriverState *bs,
+                                       void *host,
+                                       size_t size,
+                                       BdrvChild *final_child)
+{
+    BdrvChild *child;
+
+    QLIST_FOREACH(child, &bs->children, next) {
+        if (child == final_child) {
+            break;
+        }
+
+        bdrv_unregister_buf(child->bs, host, size);
+    }
+
+    if (bs->drv && bs->drv->bdrv_unregister_buf) {
+        bs->drv->bdrv_unregister_buf(bs, host, size);
+    }
+}
+
+bool bdrv_register_buf(BlockDriverState *bs, void *host, size_t size,
+                       Error **errp)
 {
     BdrvChild *child;
 
     GLOBAL_STATE_CODE();
     if (bs->drv && bs->drv->bdrv_register_buf) {
-        bs->drv->bdrv_register_buf(bs, host, size);
+        if (!bs->drv->bdrv_register_buf(bs, host, size, errp)) {
+            return false;
+        }
     }
     QLIST_FOREACH(child, &bs->children, next) {
-        bdrv_register_buf(child->bs, host, size);
+        if (!bdrv_register_buf(child->bs, host, size, errp)) {
+            bdrv_register_buf_rollback(bs, host, size, child);
+            return false;
+        }
     }
+    return true;
 }
 
 void bdrv_unregister_buf(BlockDriverState *bs, void *host, size_t size)
diff --git a/block/nvme.c b/block/nvme.c
index 94b76b16f2..656624c585 100644
--- a/block/nvme.c
+++ b/block/nvme.c
@@ -1587,19 +1587,19 @@ static void nvme_aio_unplug(BlockDriverState *bs)
     }
 }
 
-static void nvme_register_buf(BlockDriverState *bs, void *host, size_t size)
+static bool nvme_register_buf(BlockDriverState *bs, void *host, size_t size,
+                              Error **errp)
 {
     int ret;
-    Error *local_err = NULL;
     BDRVNVMeState *s = bs->opaque;
 
-    ret = qemu_vfio_dma_map(s->vfio, host, size, false, NULL, &local_err);
-    if (ret) {
-        /* FIXME: we may run out of IOVA addresses after repeated
-         * bdrv_register_buf/bdrv_unregister_buf, because nvme_vfio_dma_unmap
-         * doesn't reclaim addresses for fixed mappings. */
-        error_reportf_err(local_err, "nvme_register_buf failed: ");
-    }
+    /*
+     * FIXME: we may run out of IOVA addresses after repeated
+     * bdrv_register_buf/bdrv_unregister_buf, because nvme_vfio_dma_unmap
+     * doesn't reclaim addresses for fixed mappings.
+     */
+    ret = qemu_vfio_dma_map(s->vfio, host, size, false, NULL, errp);
+    return ret == 0;
 }
 
 static void nvme_unregister_buf(BlockDriverState *bs, void *host, size_t size)
diff --git a/include/block/block-global-state.h b/include/block/block-global-state.h
index 7901f35863..eba4ed23b4 100644
--- a/include/block/block-global-state.h
+++ b/include/block/block-global-state.h
@@ -246,8 +246,11 @@ void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
  *
  * Buffers must not overlap and they must be unregistered with the same <host,
  * size> values that they were registered with.
+ *
+ * Returns: true on success, false on failure
  */
-void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size);
+bool bdrv_register_buf(BlockDriverState *bs, void *host, size_t size,
+                       Error **errp);
 void bdrv_unregister_buf(BlockDriverState *bs, void *host, size_t size);
 
 void bdrv_cancel_in_flight(BlockDriverState *bs);
diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h
index 19798d0e77..9c569be162 100644
--- a/include/block/block_int-common.h
+++ b/include/block/block_int-common.h
@@ -433,8 +433,11 @@ struct BlockDriver {
      * that it can do IOMMU mapping with VFIO etc., in order to get better
      * performance. In the case of VFIO drivers, this callback is used to do
      * DMA mapping for hot buffers.
+     *
+     * Returns: true on success, false on failure
      */
-    void (*bdrv_register_buf)(BlockDriverState *bs, void *host, size_t size);
+    bool (*bdrv_register_buf)(BlockDriverState *bs, void *host, size_t size,
+                              Error **errp);
     void (*bdrv_unregister_buf)(BlockDriverState *bs, void *host, size_t size);
 
     /*
diff --git a/include/sysemu/block-backend-global-state.h b/include/sysemu/block-backend-global-state.h
index 97f7dad2c3..6858e39cb6 100644
--- a/include/sysemu/block-backend-global-state.h
+++ b/include/sysemu/block-backend-global-state.h
@@ -106,7 +106,7 @@ void blk_io_limits_enable(BlockBackend *blk, const char *group);
 void blk_io_limits_update_group(BlockBackend *blk, const char *group);
 void blk_set_force_allow_inactivate(BlockBackend *blk);
 
-void blk_register_buf(BlockBackend *blk, void *host, size_t size);
+bool blk_register_buf(BlockBackend *blk, void *host, size_t size, Error **errp);
 void blk_unregister_buf(BlockBackend *blk, void *host, size_t size);
 
 const BdrvChild *blk_root(BlockBackend *blk);
diff --git a/qemu-img.c b/qemu-img.c
index 9fe94df650..a3b64c88af 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -4570,7 +4570,7 @@ static int img_bench(int argc, char **argv)
     data.buf = blk_blockalign(blk, buf_size);
     memset(data.buf, pattern, data.nrreq * data.bufsize);
 
-    blk_register_buf(blk, data.buf, buf_size);
+    blk_register_buf(blk, data.buf, buf_size, &error_fatal);
 
     data.qiov = g_new(QEMUIOVector, data.nrreq);
     for (i = 0; i < data.nrreq; i++) {