On 1/19/2016 3:44 PM, Xie, Huawei wrote:

On 1/19/2016 1:53 PM, Yuanhan Liu wrote:

quoted

On Mon, Jan 18, 2016 at 04:50:16PM +0000, Xie, Huawei wrote:

quoted

On 1/15/2016 12:34 PM, Yuanhan Liu wrote:

quoted

-static void
+static int
 virtio_negotiate_features(struct virtio_hw *hw)
 {
 	uint64_t host_features;

@@ -949,6 +949,22 @@ virtio_negotiate_features(struct virtio_hw *hw)
 	hw->guest_features = vtpci_negotiate_features(hw, host_features);

Here if we are not modern device, we should remove VIRTIO_F_VERSION_1 in
guest features.

VIRTIO_F_VERSION_1 should not be set for legacy virtio device at all.

Yes, but here this patch sets this VIRTIO_F_VERSION_1 feature even for
legacy virtio device.
It doesn't cause issues, but better remove it for legacy virtio device.

OK, I see the legacy_get_features return a 32bit value which masks the
higher bits which contains the host VIRTIO_F_VERSION_1 feature. This is
very implict.

quoted

	--yliu