util/vfio-helpers: Pass Error handle to qemu_vfio_dma_map()

Currently qemu_vfio_dma_map() displays errors on stderr.
When using management interface, this information is simply
lost. Pass qemu_vfio_dma_map() an Error** handle so it can
propagate the error to callers.

Reviewed-by: Fam Zheng <fam@euphon.net>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20210902070025.197072-7-philmd@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

3 files changed, 18 insertions, 16 deletions

diff --git a/block/nvme.c b/block/nvme.c
index 0786c50..80546b0 100644
--- a/block/nvme.c
+++ b/block/nvme.c
@@ -176,12 +176,11 @@ static bool nvme_init_queue(BDRVNVMeState *s, NVMeQueue *q,
         return false;
     }
     memset(q->queue, 0, bytes);
-    r = qemu_vfio_dma_map(s->vfio, q->queue, bytes, false, &q->iova);
+    r = qemu_vfio_dma_map(s->vfio, q->queue, bytes, false, &q->iova, errp);
     if (r) {
-        error_setg(errp, "Cannot map queue");
-        return false;
+        error_prepend(errp, "Cannot map queue: ");
     }
-    return true;
+    return r == 0;
 }
 
 static void nvme_free_queue_pair(NVMeQueuePair *q)
@@ -239,9 +238,9 @@ static NVMeQueuePair *nvme_create_queue_pair(BDRVNVMeState *s,
     qemu_co_queue_init(&q->free_req_queue);
     q->completion_bh = aio_bh_new(aio_context, nvme_process_completion_bh, q);
     r = qemu_vfio_dma_map(s->vfio, q->prp_list_pages, bytes,
-                          false, &prp_list_iova);
+                          false, &prp_list_iova, errp);
     if (r) {
-        error_setg_errno(errp, -r, "Cannot map buffer for DMA");
+        error_prepend(errp, "Cannot map buffer for DMA: ");
         goto fail;
     }
     q->free_req_head = -1;
@@ -534,9 +533,9 @@ static bool nvme_identify(BlockDriverState *bs, int namespace, Error **errp)
         error_setg(errp, "Cannot allocate buffer for identify response");
         goto out;
     }
-    r = qemu_vfio_dma_map(s->vfio, id, id_size, true, &iova);
+    r = qemu_vfio_dma_map(s->vfio, id, id_size, true, &iova, errp);
     if (r) {
-        error_setg(errp, "Cannot map buffer for DMA");
+        error_prepend(errp, "Cannot map buffer for DMA: ");
         goto out;
     }
 
@@ -1032,7 +1031,7 @@ static coroutine_fn int nvme_cmd_map_qiov(BlockDriverState *bs, NvmeCmd *cmd,
 try_map:
         r = qemu_vfio_dma_map(s->vfio,
                               qiov->iov[i].iov_base,
-                              len, true, &iova);
+                              len, true, &iova, NULL);
         if (r == -ENOSPC) {
             /*
              * In addition to the -ENOMEM error, the VFIO_IOMMU_MAP_DMA
@@ -1524,14 +1523,15 @@ static void nvme_aio_unplug(BlockDriverState *bs)
 static void nvme_register_buf(BlockDriverState *bs, void *host, size_t size)
 {
     int ret;
+    Error *local_err = NULL;
     BDRVNVMeState *s = bs->opaque;
 
-    ret = qemu_vfio_dma_map(s->vfio, host, size, false, NULL);
+    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_report("nvme_register_buf failed: %s", strerror(-ret));
+        error_reportf_err(local_err, "nvme_register_buf failed: ");
     }
 }
 
diff --git a/include/qemu/vfio-helpers.h b/include/qemu/vfio-helpers.h
index 4491c8e..bde9495 100644
--- a/include/qemu/vfio-helpers.h
+++ b/include/qemu/vfio-helpers.h
@@ -18,7 +18,7 @@ typedef struct QEMUVFIOState QEMUVFIOState;
 QEMUVFIOState *qemu_vfio_open_pci(const char *device, Error **errp);
 void qemu_vfio_close(QEMUVFIOState *s);
 int qemu_vfio_dma_map(QEMUVFIOState *s, void *host, size_t size,
-                      bool temporary, uint64_t *iova_list);
+                      bool temporary, uint64_t *iova_list, Error **errp);
 int qemu_vfio_dma_reset_temporary(QEMUVFIOState *s);
 void qemu_vfio_dma_unmap(QEMUVFIOState *s, void *host);
 void *qemu_vfio_pci_map_bar(QEMUVFIOState *s, int index,
diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c
index e790922..77cdec8 100644
--- a/util/vfio-helpers.c
+++ b/util/vfio-helpers.c
@@ -463,13 +463,15 @@ static void qemu_vfio_ram_block_added(RAMBlockNotifier *n, void *host,
                                       size_t size, size_t max_size)
 {
     QEMUVFIOState *s = container_of(n, QEMUVFIOState, ram_notifier);
+    Error *local_err = NULL;
     int ret;
 
     trace_qemu_vfio_ram_block_added(s, host, max_size);
-    ret = qemu_vfio_dma_map(s, host, max_size, false, NULL);
+    ret = qemu_vfio_dma_map(s, host, max_size, false, NULL, &local_err);
     if (ret) {
-        error_report("qemu_vfio_dma_map(%p, %zu) failed: %s", host, max_size,
-                     strerror(-ret));
+        error_reportf_err(local_err,
+                          "qemu_vfio_dma_map(%p, %zu) failed: ",
+                          host, max_size);
     }
 }
 
@@ -725,7 +727,7 @@ qemu_vfio_find_temp_iova(QEMUVFIOState *s, size_t size, uint64_t *iova)
  * mapping status within this area is not allowed).
  */
 int qemu_vfio_dma_map(QEMUVFIOState *s, void *host, size_t size,
-                      bool temporary, uint64_t *iova)
+                      bool temporary, uint64_t *iova, Error **errp)
 {
     int ret = 0;
     int index;