vdpa: Export vhost_vdpa_dma_map and unmap calls

Shadow CVQ will copy buffers on qemu VA, so we avoid TOCTOU attacks from
the guest that could set a different state in qemu device model and vdpa
device.

To do so, it needs to be able to map these new buffers to the device.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

hw/virtio/vhost-vdpa.c

@@ -71,8 +71,8 @@ static bool vhost_vdpa_listener_skipped_section(MemoryRegionSection *section,
     return false;
 }
 
-static int vhost_vdpa_dma_map(struct vhost_vdpa *v, hwaddr iova, hwaddr size,
-                              void *vaddr, bool readonly)
+int vhost_vdpa_dma_map(struct vhost_vdpa *v, hwaddr iova, hwaddr size,
+                       void *vaddr, bool readonly)
 {
     struct vhost_msg_v2 msg = {};
     int fd = v->device_fd;
@@ -97,8 +97,7 @@ static int vhost_vdpa_dma_map(struct vhost_vdpa *v, hwaddr iova, hwaddr size,
     return ret;
 }
 
-static int vhost_vdpa_dma_unmap(struct vhost_vdpa *v, hwaddr iova,
-                                hwaddr size)
+int vhost_vdpa_dma_unmap(struct vhost_vdpa *v, hwaddr iova, hwaddr size)
 {
     struct vhost_msg_v2 msg = {};
     int fd = v->device_fd;

include/hw/virtio/vhost-vdpa.h

@@ -39,4 +39,8 @@ typedef struct vhost_vdpa {
     VhostVDPAHostNotifier notifier[VIRTIO_QUEUE_MAX];
 } VhostVDPA;
 
+int vhost_vdpa_dma_map(struct vhost_vdpa *v, hwaddr iova, hwaddr size,
+                       void *vaddr, bool readonly);
+int vhost_vdpa_dma_unmap(struct vhost_vdpa *v, hwaddr iova, hwaddr size);
+
 #endif