| Message ID | 20170520080658.337-1-maxime.coquelin@redhat.com |
|---|---|
| State | New |
| Headers | show |
Maxime Coquelin <maxime.coquelin@redhat.com> writes: > This patch removes MTU from the list of features supported by > the kernel backend, so that vhost kernel backend does not have > to advertise it to be negotiated. > > Cc: Aaron Conole <aconole@redhat.com> > Suggested-by: Michael S. Tsirkin <mst@redhat.com> > Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com> > --- Acked-by: Aaron Conole <aconole@redhat.com>
On Sat, May 20, 2017 at 10:06:58AM +0200, Maxime Coquelin wrote: > This patch removes MTU from the list of features supported by > the kernel backend, so that vhost kernel backend does not have > to advertise it to be negotiated. > > Cc: Aaron Conole <aconole@redhat.com> > Suggested-by: Michael S. Tsirkin <mst@redhat.com> > Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com> This will break cross-version migration when the kernel does not advertise it though. I'm afraid we'll need a compat flag. > --- > hw/net/vhost_net.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c > index 22874a9..bdd8633 100644 > --- a/hw/net/vhost_net.c > +++ b/hw/net/vhost_net.c > @@ -51,7 +51,6 @@ static const int kernel_feature_bits[] = { > VIRTIO_RING_F_EVENT_IDX, > VIRTIO_NET_F_MRG_RXBUF, > VIRTIO_F_VERSION_1, > - VIRTIO_NET_F_MTU, > VIRTIO_F_IOMMU_PLATFORM, > VHOST_INVALID_FEATURE_BIT > }; > -- > 2.9.3
On 05/22/2017 07:24 PM, Michael S. Tsirkin wrote: > On Sat, May 20, 2017 at 10:06:58AM +0200, Maxime Coquelin wrote: >> This patch removes MTU from the list of features supported by >> the kernel backend, so that vhost kernel backend does not have >> to advertise it to be negotiated. >> >> Cc: Aaron Conole <aconole@redhat.com> >> Suggested-by: Michael S. Tsirkin <mst@redhat.com> >> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com> > > This will break cross-version migration when the kernel > does not advertise it though. I'm afraid we'll need > a compat flag. Ok, you are right. The difficulty with a compat flag is that vhost-net is not a driver, so we cannot add it a new property to make it kernel-backend only. For consistency, maybe we can add a new internal property to virtio-net driver, to bypass backend negotiation for this feature for all backends? I will propose a new version shortly. Thanks, Maxime >> --- >> hw/net/vhost_net.c | 1 - >> 1 file changed, 1 deletion(-) >> >> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c >> index 22874a9..bdd8633 100644 >> --- a/hw/net/vhost_net.c >> +++ b/hw/net/vhost_net.c >> @@ -51,7 +51,6 @@ static const int kernel_feature_bits[] = { >> VIRTIO_RING_F_EVENT_IDX, >> VIRTIO_NET_F_MRG_RXBUF, >> VIRTIO_F_VERSION_1, >> - VIRTIO_NET_F_MTU, >> VIRTIO_F_IOMMU_PLATFORM, >> VHOST_INVALID_FEATURE_BIT >> }; >> -- >> 2.9.3
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c index 22874a9..bdd8633 100644 --- a/hw/net/vhost_net.c +++ b/hw/net/vhost_net.c @@ -51,7 +51,6 @@ static const int kernel_feature_bits[] = { VIRTIO_RING_F_EVENT_IDX, VIRTIO_NET_F_MRG_RXBUF, VIRTIO_F_VERSION_1, - VIRTIO_NET_F_MTU, VIRTIO_F_IOMMU_PLATFORM, VHOST_INVALID_FEATURE_BIT };
This patch removes MTU from the list of features supported by the kernel backend, so that vhost kernel backend does not have to advertise it to be negotiated. Cc: Aaron Conole <aconole@redhat.com> Suggested-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com> --- hw/net/vhost_net.c | 1 - 1 file changed, 1 deletion(-)