diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c
index 02d9ed0bd4..41e71af08a 100644
--- a/hw/display/cirrus_vga.c
+++ b/hw/display/cirrus_vga.c
@@ -640,10 +640,16 @@ static void cirrus_invalidate_region(CirrusVGAState * s, int off_begin,
     }
 
     for (y = 0; y < lines; y++) {
-        off_cur = off_begin;
+        off_cur = off_begin & s->cirrus_addr_mask;
         off_cur_end = ((off_cur + bytesperline - 1) & s->cirrus_addr_mask) + 1;
-        assert(off_cur_end >= off_cur);
-        memory_region_set_dirty(&s->vga.vram, off_cur, off_cur_end - off_cur);
+        if (off_cur_end >= off_cur) {
+            memory_region_set_dirty(&s->vga.vram, off_cur, off_cur_end - off_cur);
+        } else {
+            /* wraparound */
+            memory_region_set_dirty(&s->vga.vram, off_cur,
+                                    s->cirrus_addr_mask + 1 - off_cur);
+            memory_region_set_dirty(&s->vga.vram, 0, off_cur_end);
+        }
         off_begin += off_pitch;
     }
 }
diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c
index 5f0dd7c150..90be4e3ed7 100644
--- a/hw/display/virtio-gpu.c
+++ b/hw/display/virtio-gpu.c
@@ -646,9 +646,9 @@ int virtio_gpu_create_mapping_iov(VirtIOGPU *g,
         uint64_t a = le64_to_cpu(ents[i].addr);
         uint32_t l = le32_to_cpu(ents[i].length);
         hwaddr len = l;
-        (*iov)[i].iov_len = l;
         (*iov)[i].iov_base = dma_memory_map(VIRTIO_DEVICE(g)->dma_as,
                                             a, &len, DMA_DIRECTION_TO_DEVICE);
+        (*iov)[i].iov_len = len;
         if (addr) {
             (*addr)[i] = a;
         }
@@ -656,6 +656,9 @@ int virtio_gpu_create_mapping_iov(VirtIOGPU *g,
             qemu_log_mask(LOG_GUEST_ERROR, "%s: failed to map MMIO memory for"
                           " resource %d element %d\n",
                           __func__, ab->resource_id, i);
+            if ((*iov)[i].iov_base) {
+                i++; /* cleanup the 'i'th map */
+            }
             virtio_gpu_cleanup_mapping_iov(g, *iov, i);
             g_free(ents);
             *iov = NULL;