[PATCH v2] vhost-vsock: SOCK_SEQPACKET feature bit support

[Arseny Krasnov]

This adds processing of VIRTIO_VSOCK_F_SEQPACKET features bit. Guest
negotiates it with vhost, thus both will know that SOCK_SEQPACKET
supported by peer.

Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com>
---
 hw/virtio/vhost-vsock.c                       | 12 ++++++++++--
 include/standard-headers/linux/virtio_vsock.h |  3 +++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/hw/virtio/vhost-vsock.c b/hw/virtio/vhost-vsock.c
index c8f0699b4f..0406a5d3dc 100644
--- a/hw/virtio/vhost-vsock.c
+++ b/hw/virtio/vhost-vsock.c
@@ -103,12 +103,20 @@ static void vhost_vsock_set_status(VirtIODevice *vdev, 
uint8_t status)
     }
 }
 
+const int feature_bits[] = {
+    VIRTIO_VSOCK_F_SEQPACKET,
+    VHOST_INVALID_FEATURE_BIT
+};
+
 static uint64_t vhost_vsock_get_features(VirtIODevice *vdev,
                                          uint64_t requested_features,
                                          Error **errp)
 {
-    /* No feature bits used yet */
-    return requested_features;
+    VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
+
+    virtio_add_feature(&requested_features, VIRTIO_VSOCK_F_SEQPACKET);
+    return vhost_get_features(&vvc->vhost_dev, feature_bits,
+                                requested_features);
 }
 
 static const VMStateDescription vmstate_virtio_vhost_vsock = {
diff --git a/include/standard-headers/linux/virtio_vsock.h 
b/include/standard-headers/linux/virtio_vsock.h
index be443211ce..5eac522ee2 100644
--- a/include/standard-headers/linux/virtio_vsock.h
+++ b/include/standard-headers/linux/virtio_vsock.h
@@ -38,6 +38,9 @@
 #include "standard-headers/linux/virtio_ids.h"
 #include "standard-headers/linux/virtio_config.h"
 
+/* The feature bitmap for virtio vsock */
+#define VIRTIO_VSOCK_F_SEQPACKET       1       /* SOCK_SEQPACKET supported */
+
 struct virtio_vsock_config {
        uint64_t guest_cid;
 } QEMU_PACKED;
-- 
2.25.1