At this moment this code path is not reached, but vdpa devices can offer
VIRTIO_NET_F_STATUS unconditionally. While the guest must assume that
link is always up by the standard, qemu will set the status bit to 1
always in this case.
This makes little use by itself, but VIRTIO_NET_F_STATUS is needed for
the guest to read status bit VIRTIO_NET_F_GUEST_ANNOUNCE, used by feature
VIRTIO_NET_F_GUEST_ANNOUNCE. So qemu must emulate status feature in case
it needs to emulate the guest announce feature.
Signed-off-by: Eugenio Pérez <epere...@redhat.com>
---
hw/net/vhost_net.c | 27 ++++++++++++++++++++++++++-
1 file changed, 26 insertions(+), 1 deletion(-)
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index d28f8b974b..5660606c1d 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -117,7 +117,32 @@ uint64_t vhost_net_get_features(struct vhost_net *net,
uint64_t features)
int vhost_net_get_config(struct vhost_net *net, uint8_t *config,
uint32_t config_len)
{
- return vhost_dev_get_config(&net->dev, config, config_len, NULL);
+ VirtIODevice *vdev;
+ int r = vhost_dev_get_config(&net->dev, config, config_len, NULL);
+
+ if (unlikely(r != 0)) {
+ return r;
+ }
+
+ if (config_len < endof(struct virtio_net_config, status)) {
+ return 0;
+ }
+
+ /*
+ * TODO: Perform this only if vhost_vdpa.
+ */
+ vdev = net->dev.vdev;
+ if (!vdev) {
+ /* Device is starting */
+ return 0;
+ }
+
+ if ((net->dev.acked_features & BIT_ULL(VIRTIO_NET_F_STATUS)) &&
+ !(net->dev.features & BIT_ULL(VIRTIO_NET_F_STATUS))) {
+ ((struct virtio_net_config *)config)->status |= VIRTIO_NET_S_LINK_UP;
+ }
+
+ return 0;
}
int vhost_net_set_config(struct vhost_net *net, const uint8_t *data,
uint32_t offset, uint32_t size, uint32_t flags)
--
2.31.1
