3 files changed, 61 insertions, 0 deletions

diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c
index 55cb5414ef..519328445c 100644
--- a/hw/virtio/vhost-shadow-virtqueue.c
+++ b/hw/virtio/vhost-shadow-virtqueue.c
@@ -11,10 +11,54 @@
 #include "hw/virtio/vhost-shadow-virtqueue.h"
 
 #include "qemu/error-report.h"
+#include "qapi/error.h"
 #include "qemu/main-loop.h"
 #include "linux-headers/linux/vhost.h"
 
 /**
+ * Validate the transport device features that both guests can use with the SVQ
+ * and SVQs can use with the device.
+ *
+ * @dev_features: The features
+ * @errp: Error pointer
+ */
+bool vhost_svq_valid_features(uint64_t features, Error **errp)
+{
+    bool ok = true;
+    uint64_t svq_features = features;
+
+    for (uint64_t b = VIRTIO_TRANSPORT_F_START; b <= VIRTIO_TRANSPORT_F_END;
+         ++b) {
+        switch (b) {
+        case VIRTIO_F_ANY_LAYOUT:
+            continue;
+
+        case VIRTIO_F_ACCESS_PLATFORM:
+            /* SVQ trust in the host's IOMMU to translate addresses */
+        case VIRTIO_F_VERSION_1:
+            /* SVQ trust that the guest vring is little endian */
+            if (!(svq_features & BIT_ULL(b))) {
+                svq_features |= BIT_ULL(b);
+                ok = false;
+            }
+            continue;
+
+        default:
+            if (svq_features & BIT_ULL(b)) {
+                svq_features &= ~BIT_ULL(b);
+                ok = false;
+            }
+        }
+    }
+
+    if (!ok) {
+        error_setg(errp, "SVQ Invalid device feature flags, offer: 0x%"PRIx64
+                         ", ok: 0x%"PRIx64, features, svq_features);
+    }
+    return ok;
+}
+
+/**
  * Forward guest notifications.
  *
  * @n: guest kick event notifier, the one that guest set to notify svq.
diff --git a/hw/virtio/vhost-shadow-virtqueue.h b/hw/virtio/vhost-shadow-virtqueue.h
index cbc5213579..9e12f77201 100644
--- a/hw/virtio/vhost-shadow-virtqueue.h
+++ b/hw/virtio/vhost-shadow-virtqueue.h
@@ -33,6 +33,8 @@ typedef struct VhostShadowVirtqueue {
     EventNotifier svq_call;
 } VhostShadowVirtqueue;
 
+bool vhost_svq_valid_features(uint64_t features, Error **errp);
+
 void vhost_svq_set_svq_kick_fd(VhostShadowVirtqueue *svq, int svq_kick_fd);
 void vhost_svq_set_svq_call_fd(VhostShadowVirtqueue *svq, int call_fd);
 
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 9f4333cff5..4e1deb3d04 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -348,11 +348,26 @@ static int vhost_vdpa_init_svq(struct vhost_dev *hdev, struct vhost_vdpa *v,
                                Error **errp)
 {
     g_autoptr(GPtrArray) shadow_vqs = NULL;
+    uint64_t dev_features, svq_features;
+    int r;
+    bool ok;
 
     if (!v->shadow_vqs_enabled) {
         return 0;
     }
 
+    r = hdev->vhost_ops->vhost_get_features(hdev, &dev_features);
+    if (r != 0) {
+        error_setg_errno(errp, -r, "Can't get vdpa device features");
+        return r;
+    }
+
+    svq_features = dev_features;
+    ok = vhost_svq_valid_features(svq_features, errp);
+    if (unlikely(!ok)) {
+        return -1;
+    }
+
     shadow_vqs = g_ptr_array_new_full(hdev->nvqs, vhost_svq_free);
     for (unsigned n = 0; n < hdev->nvqs; ++n) {
         g_autoptr(VhostShadowVirtqueue) svq = vhost_svq_new();