vdpa: add vhost_vdpa->suspended parameter

This allows vhost_vdpa to track if it is safe to get the vring base from
the device or not.  If it is not, vhost can fall back to fetch idx from
the guest buffer again.

No functional change intended in this patch, later patches will use this
field.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Message-Id: <20230303172445.1089785-6-eperezma@redhat.com>
Tested-by: Lei Yang <leiyang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 1550b1e26ae170a68d078b97a34f0e68b1433467..517e3cdc8dd2dfa33bbd720123a8acf24213a1da 100644 (file)
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -1193,6 +1193,14 @@ static int vhost_vdpa_get_vring_base(struct vhost_dev *dev,
         return 0;
     }
 
+    if (!v->suspended) {
+        /*
+         * Cannot trust in value returned by device, let vhost recover used
+         * idx from guest.
+         */
+        return -1;
+    }
+
     ret = vhost_vdpa_call(dev, VHOST_GET_VRING_BASE, ring);
     trace_vhost_vdpa_get_vring_base(dev, ring->index, ring->num);
     return ret;

diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
index 7997f09a8df52e6ab4f24244f72844a190bb0dbb..4a7d3966742839c0654ff4387e50f630fa1106ea 100644 (file)
--- a/include/hw/virtio/vhost-vdpa.h
+++ b/include/hw/virtio/vhost-vdpa.h
@@ -42,6 +42,8 @@ typedef struct vhost_vdpa {
     bool shadow_vqs_enabled;
     /* Vdpa must send shadow addresses as IOTLB key for data queues, not GPA */
     bool shadow_data;
+    /* Device suspended successfully */
+    bool suspended;
     /* IOVA mapping used by the Shadow Virtqueue */
     VhostIOVATree *iova_tree;
     GPtrArray *shadow_vqs;