similar to: [V5 PATCH] virtio-net: send gratuitous packets when needed

As hypervior does not have the knowledge of guest network configuration, it's better to ask guest to send gratuitous packet when needed. Guest test VIRTIO_NET_S_ANNOUNCE bit during config change interrupt and when it is set, a workqueue is scheduled to send gratuitous packet through NETDEV_NOTIFY_PEERS. This feature is negotiated through bit VIRTIO_NET_F_GUEST_ANNOUNCE. Changes from v3: -

As hypervior does not have the knowledge of guest network configuration, it's better to ask guest to send gratuitous packet when needed. Guest test VIRTIO_NET_S_ANNOUNCE bit during config change interrupt and when it is set, a workqueue is scheduled to send gratuitous packet through NETDEV_NOTIFY_PEERS. This feature is negotiated through bit VIRTIO_NET_F_GUEST_ANNOUNCE. Changes from v3: -

As hypervior does not have the knowledge of guest network configuration, it's better to ask guest to send gratuitous packets when needed. Guest tests VIRTIO_NET_S_ANNOUNCE bit during config change interrupt and when it is set, a workqueue is scheduled to send gratuitous packet through NETDEV_NOTIFY_PEERS. This feature is negotiated through bit VIRTIO_NET_F_GUEST_ANNOUNCE. Changes from v5: -

As hypervior does not have the knowledge of guest network configuration, it's better to ask guest to send gratuitous packets when needed. Guest tests VIRTIO_NET_S_ANNOUNCE bit during config change interrupt and when it is set, a workqueue is scheduled to send gratuitous packet through NETDEV_NOTIFY_PEERS. This feature is negotiated through bit VIRTIO_NET_F_GUEST_ANNOUNCE. Changes from v5: -

As hypervior does not have the knowledge of guest network configuration, it's better to ask guest to send gratuitous packets when needed. This patch implements VIRTIO_NET_F_GUEST_ANNOUNCE feature: hypervisor would notice the guest when it thinks it's time for guest to announce the link presnece. Guest tests VIRTIO_NET_S_ANNOUNCE bit during config change interrupt and woule send gratuitous

As hypervior does not have the knowledge of guest network configuration, it's better to ask guest to send gratuitous packets when needed. This patch implements VIRTIO_NET_F_GUEST_ANNOUNCE feature: hypervisor would notice the guest when it thinks it's time for guest to announce the link presnece. Guest tests VIRTIO_NET_S_ANNOUNCE bit during config change interrupt and woule send gratuitous

Fix theoretical races related to refill work: 1. After napi is disabled by ndo_stop, refill work can run and re-enable it. 2. Refill can get scheduled on many cpus in parallel. if this happens it will corrupt the vq linked list as there's no locking 3. refill work is cancelled after unregister netdev For small bufs this means it can alloc an skb for a device which is

Fix theoretical races related to refill work: 1. After napi is disabled by ndo_stop, refill work can run and re-enable it. 2. Refill can get scheduled on many cpus in parallel. if this happens it will corrupt the vq linked list as there's no locking 3. refill work is cancelled after unregister netdev For small bufs this means it can alloc an skb for a device which is

Fix theoretical races related to refill work: 1. After napi is disabled by ndo_stop, refill work can run and re-enable it. 2. Refill can reschedule itself, if this happens it can run after cancel_delayed_work_sync, and will access device after it is destroyed. As a solution, add flags to track napi state and to disable refill, and toggle them on start, stop and remove; check these flags

Fix theoretical races related to refill work: 1. After napi is disabled by ndo_stop, refill work can run and re-enable it. 2. Refill can reschedule itself, if this happens it can run after cancel_delayed_work_sync, and will access device after it is destroyed. As a solution, add flags to track napi state and to disable refill, and toggle them on start, stop and remove; check these flags

Use per-cpu variables to maintain 64 bit statistics. Compile tested only. Signed-off-by: Stephen Hemminger <shemminger at vyatta.com> --- a/drivers/net/virtio_net.c 2011-06-14 15:18:46.448596355 -0400 +++ b/drivers/net/virtio_net.c 2011-06-15 09:54:22.914426067 -0400 @@ -40,6 +40,15 @@ module_param(gso, bool, 0444); #define VIRTNET_SEND_COMMAND_SG_MAX 2 +struct virtnet_stats { +

Use per-cpu variables to maintain 64 bit statistics. Compile tested only. Signed-off-by: Stephen Hemminger <shemminger at vyatta.com> --- a/drivers/net/virtio_net.c 2011-06-14 15:18:46.448596355 -0400 +++ b/drivers/net/virtio_net.c 2011-06-15 09:54:22.914426067 -0400 @@ -40,6 +40,15 @@ module_param(gso, bool, 0444); #define VIRTNET_SEND_COMMAND_SG_MAX 2 +struct virtnet_stats { +

During link announcement, driver needs a method to notify device that it has received the notification and let it clear the VIRITO_NET_S_ANNOUNCE bit in the status field. Doing this through a dedicated command looks suitable for all platforms (especially for the ones who don't trap the status read or write) with a ctrl vq and can solve the race between host and guest. So this patch makes

During link announcement, driver needs a method to notify device that it has received the notification and let it clear the VIRITO_NET_S_ANNOUNCE bit in the status field. Doing this through a dedicated command looks suitable for all platforms (especially for the ones who don't trap the status read or write) with a ctrl vq and can solve the race between host and guest. So this patch makes

During link announcement, driver needs a method to notify device that it has received the notification and let it clear the VIRITO_NET_S_ANNOUNCE bit in the status field. Doing this through a dedicated command looks suitable for all platforms (especially for the ones who don't trap the status read or write) with a ctrl vq and can solve the race between host and guest. So this patch makes

During link announcement, driver needs a method to notify device that it has received the notification and let it clear the VIRITO_NET_S_ANNOUNCE bit in the status field. Doing this through a dedicated command looks suitable for all platforms (especially for the ones who don't trap the status read or write) with a ctrl vq and can solve the race between host and guest. So this patch makes

This patch splits the device status field of virtio-net into ro and rw byte. This would simplify the implementation of both host and guest and make the layout more clean. As VIRTIO_NET_S_ANNOUNCE is a rw bit, it was moved to bit 8 (0x100). btw. looks like there's no implementation that depends on VIRTIO_NET_S_ANNOUNCE, so the move is safe. Signed-off-by: Jason Wang <jasowang at

This patch splits the device status field of virtio-net into ro and rw byte. This would simplify the implementation of both host and guest and make the layout more clean. As VIRTIO_NET_S_ANNOUNCE is a rw bit, it was moved to bit 8 (0x100). btw. looks like there's no implementation that depends on VIRTIO_NET_S_ANNOUNCE, so the move is safe. Signed-off-by: Jason Wang <jasowang at

Remove wrapper functions. This makes the allocation type explicit in all callers; I used GPF_KERNEL where it seemed obvious, left it at GFP_ATOMIC otherwise. Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -171,7 +171,7 @@ static bool

Remove wrapper functions. This makes the allocation type explicit in all callers; I used GPF_KERNEL where it seemed obvious, left it at GFP_ATOMIC otherwise. Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -171,7 +171,7 @@ static bool