vdpa: Expose VHOST_F_LOG_ALL on SVQ

SVQ is able to log the dirty bits by itself, so let's use it to not
block migration.

Also, ignore set and clear of VHOST_F_LOG_ALL on set_features if SVQ is
enabled. Even if the device supports it, the reports would be nonsense
because SVQ memory is in the qemu region.

The log region is still allocated. Future changes might skip that, but
this series is already long enough.

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

1 files changed, 35 insertions, 4 deletions

diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 89d59f86f9..c5ed7a3779 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -373,6 +373,16 @@ static bool vhost_vdpa_one_time_request(struct vhost_dev *dev)
     return v->index != 0;
 }
 
+static int vhost_vdpa_get_dev_features(struct vhost_dev *dev,
+                                       uint64_t *features)
+{
+    int ret;
+
+    ret = vhost_vdpa_call(dev, VHOST_GET_FEATURES, features);
+    trace_vhost_vdpa_get_features(dev, *features);
+    return ret;
+}
+
 static int vhost_vdpa_init_svq(struct vhost_dev *hdev, struct vhost_vdpa *v,
                                Error **errp)
 {
@@ -385,7 +395,7 @@ static int vhost_vdpa_init_svq(struct vhost_dev *hdev, struct vhost_vdpa *v,
         return 0;
     }
 
-    r = hdev->vhost_ops->vhost_get_features(hdev, &dev_features);
+    r = vhost_vdpa_get_dev_features(hdev, &dev_features);
     if (r != 0) {
         error_setg_errno(errp, -r, "Can't get vdpa device features");
         return r;
@@ -610,12 +620,29 @@ static int vhost_vdpa_set_mem_table(struct vhost_dev *dev,
 static int vhost_vdpa_set_features(struct vhost_dev *dev,
                                    uint64_t features)
 {
+    struct vhost_vdpa *v = dev->opaque;
     int ret;
 
     if (vhost_vdpa_one_time_request(dev)) {
         return 0;
     }
 
+    if (v->shadow_vqs_enabled) {
+        if ((v->acked_features ^ features) == BIT_ULL(VHOST_F_LOG_ALL)) {
+            /*
+             * QEMU is just trying to enable or disable logging. SVQ handles
+             * this sepparately, so no need to forward this.
+             */
+            v->acked_features = features;
+            return 0;
+        }
+
+        v->acked_features = features;
+
+        /* We must not ack _F_LOG if SVQ is enabled */
+        features &= ~BIT_ULL(VHOST_F_LOG_ALL);
+    }
+
     trace_vhost_vdpa_set_features(dev, features);
     ret = vhost_vdpa_call(dev, VHOST_SET_FEATURES, &features);
     if (ret) {
@@ -1200,10 +1227,14 @@ static int vhost_vdpa_set_vring_call(struct vhost_dev *dev,
 static int vhost_vdpa_get_features(struct vhost_dev *dev,
                                      uint64_t *features)
 {
-    int ret;
+    struct vhost_vdpa *v = dev->opaque;
+    int ret = vhost_vdpa_get_dev_features(dev, features);
+
+    if (ret == 0 && v->shadow_vqs_enabled) {
+        /* Add SVQ logging capabilities */
+        *features |= BIT_ULL(VHOST_F_LOG_ALL);
+    }
 
-    ret = vhost_vdpa_call(dev, VHOST_GET_FEATURES, features);
-    trace_vhost_vdpa_get_features(dev, *features);
     return ret;
 }