| Message ID | 1464901859-25906-1-git-send-email-aconole@redhat.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
On Thu, Jun 02, 2016 at 05:10:59PM -0400, Aaron Conole wrote: > This commit adds the feature bit and associated mtu device entry for the > virtio network device. When a virtio device comes up, it checks the > feature bit for the VIRTIO_NET_F_MTU feature. If such feature bit is > enabled, the driver will read the advised MTU and use it as the initial > value. > > Signed-off-by: Aaron Conole <aconole@redhat.com> > --- > v1->v2: > * Fixed omitted hunk from virtio_net.h > * Squashed to a single commit > * Fixed commit message. > > drivers/net/virtio_net.c | 7 +++++++ > include/uapi/linux/virtio_net.h | 3 +++ > 2 files changed, 10 insertions(+) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index e0638e5..ef5ee01 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -1896,6 +1896,12 @@ static int virtnet_probe(struct virtio_device *vdev) > if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) > vi->has_cvq = true; > > + if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) { > + dev->mtu = virtio_cread16(vdev, > + offsetof(struct virtio_net_config, > + mtu)); > + } > + > if (vi->any_header_sg) > dev->needed_headroom = vi->hdr_len; > One comment though: I think we should validate the mtu. If it's invalid, clear VIRTIO_NET_F_MTU and ignore. > @@ -2067,6 +2073,7 @@ static unsigned int features[] = { > VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, > VIRTIO_NET_F_CTRL_MAC_ADDR, > VIRTIO_F_ANY_LAYOUT, > + VIRTIO_NET_F_MTU, > }; > > static struct virtio_driver virtio_net_driver = { > diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h > index ec32293..1ab4ea6 100644 > --- a/include/uapi/linux/virtio_net.h > +++ b/include/uapi/linux/virtio_net.h > @@ -55,6 +55,7 @@ > #define VIRTIO_NET_F_MQ 22 /* Device supports Receive Flow > * Steering */ > #define VIRTIO_NET_F_CTRL_MAC_ADDR 23 /* Set MAC address */ > +#define VIRTIO_NET_F_MTU 25 /* Initial MTU advice */ > > #ifndef VIRTIO_NET_NO_LEGACY > #define VIRTIO_NET_F_GSO 6 /* Host handles pkts w/ any GSO type */ > @@ -73,6 +74,8 @@ struct virtio_net_config { > * Legal values are between 1 and 0x8000 > */ > __u16 max_virtqueue_pairs; > + /* Default maximum transmit unit advice */ > + __u16 mtu; > } __attribute__((packed)); > > /* > -- > 2.5.5
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index e0638e5..ef5ee01 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1896,6 +1896,12 @@ static int virtnet_probe(struct virtio_device *vdev) if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) vi->has_cvq = true; + if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) { + dev->mtu = virtio_cread16(vdev, + offsetof(struct virtio_net_config, + mtu)); + } + if (vi->any_header_sg) dev->needed_headroom = vi->hdr_len; @@ -2067,6 +2073,7 @@ static unsigned int features[] = { VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, VIRTIO_NET_F_CTRL_MAC_ADDR, VIRTIO_F_ANY_LAYOUT, + VIRTIO_NET_F_MTU, }; static struct virtio_driver virtio_net_driver = { diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h index ec32293..1ab4ea6 100644 --- a/include/uapi/linux/virtio_net.h +++ b/include/uapi/linux/virtio_net.h @@ -55,6 +55,7 @@ #define VIRTIO_NET_F_MQ 22 /* Device supports Receive Flow * Steering */ #define VIRTIO_NET_F_CTRL_MAC_ADDR 23 /* Set MAC address */ +#define VIRTIO_NET_F_MTU 25 /* Initial MTU advice */ #ifndef VIRTIO_NET_NO_LEGACY #define VIRTIO_NET_F_GSO 6 /* Host handles pkts w/ any GSO type */ @@ -73,6 +74,8 @@ struct virtio_net_config { * Legal values are between 1 and 0x8000 */ __u16 max_virtqueue_pairs; + /* Default maximum transmit unit advice */ + __u16 mtu; } __attribute__((packed)); /*
This commit adds the feature bit and associated mtu device entry for the virtio network device. When a virtio device comes up, it checks the feature bit for the VIRTIO_NET_F_MTU feature. If such feature bit is enabled, the driver will read the advised MTU and use it as the initial value. Signed-off-by: Aaron Conole <aconole@redhat.com> --- v1->v2: * Fixed omitted hunk from virtio_net.h * Squashed to a single commit * Fixed commit message. drivers/net/virtio_net.c | 7 +++++++ include/uapi/linux/virtio_net.h | 3 +++ 2 files changed, 10 insertions(+)