diff mbox series

[net-next,V2] virtio-net: synchronize operstate with admin state on up/down

Message ID 20240530032055.8036-1-jasowang@redhat.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series [net-next,V2] virtio-net: synchronize operstate with admin state on up/down | expand

Checks

Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 902 this patch: 902
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 9 of 9 maintainers
netdev/build_clang success Errors and warnings before: 906 this patch: 906
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 906 this patch: 906
netdev/checkpatch warning WARNING: Block comments use * on subsequent lines WARNING: Block comments use a trailing */ on a separate line
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-05-30--06-00 (tests: 1042)

Commit Message

Jason Wang May 30, 2024, 3:20 a.m. UTC
This patch synchronize operstate with admin state per RFC2863.

This is done by trying to toggle the carrier upon open/close and
synchronize with the config change work. This allows propagate status
correctly to stacked devices like:

ip link add link enp0s3 macvlan0 type macvlan
ip link set link enp0s3 down
ip link show

Before this patch:

3: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
    link/ether 00:00:05:00:00:09 brd ff:ff:ff:ff:ff:ff
......
5: macvlan0@enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether b2:a9:c5:04:da:53 brd ff:ff:ff:ff:ff:ff

After this patch:

3: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
    link/ether 00:00:05:00:00:09 brd ff:ff:ff:ff:ff:ff
...
5: macvlan0@enp0s3: <NO-CARRIER,BROADCAST,MULTICAST,UP,M-DOWN> mtu 1500 qdisc noqueue state LOWERLAYERDOWN mode DEFAULT group default qlen 1000
    link/ether b2:a9:c5:04:da:53 brd ff:ff:ff:ff:ff:ff

Cc: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
Cc: Gia-Khanh Nguyen <gia-khanh.nguyen@oracle.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
Changes since V1:
- rebase
- add ack/review tags
---
 drivers/net/virtio_net.c | 94 +++++++++++++++++++++++++++-------------
 1 file changed, 63 insertions(+), 31 deletions(-)

Comments

Michael S. Tsirkin May 30, 2024, 6:10 a.m. UTC | #1
On Thu, May 30, 2024 at 11:20:55AM +0800, Jason Wang wrote:
> This patch synchronize operstate with admin state per RFC2863.
> 
> This is done by trying to toggle the carrier upon open/close and
> synchronize with the config change work. This allows propagate status
> correctly to stacked devices like:
> 
> ip link add link enp0s3 macvlan0 type macvlan
> ip link set link enp0s3 down
> ip link show
> 
> Before this patch:
> 
> 3: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
>     link/ether 00:00:05:00:00:09 brd ff:ff:ff:ff:ff:ff
> ......
> 5: macvlan0@enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
>     link/ether b2:a9:c5:04:da:53 brd ff:ff:ff:ff:ff:ff
> 
> After this patch:
> 
> 3: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
>     link/ether 00:00:05:00:00:09 brd ff:ff:ff:ff:ff:ff
> ...
> 5: macvlan0@enp0s3: <NO-CARRIER,BROADCAST,MULTICAST,UP,M-DOWN> mtu 1500 qdisc noqueue state LOWERLAYERDOWN mode DEFAULT group default qlen 1000
>     link/ether b2:a9:c5:04:da:53 brd ff:ff:ff:ff:ff:ff
> 
> Cc: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
> Cc: Gia-Khanh Nguyen <gia-khanh.nguyen@oracle.com>
> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> Acked-by: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
> Changes since V1:
> - rebase
> - add ack/review tags





> ---
>  drivers/net/virtio_net.c | 94 +++++++++++++++++++++++++++-------------
>  1 file changed, 63 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 4a802c0ea2cb..69e4ae353c51 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -433,6 +433,12 @@ struct virtnet_info {
>  	/* The lock to synchronize the access to refill_enabled */
>  	spinlock_t refill_lock;
>  
> +	/* Is config change enabled? */
> +	bool config_change_enabled;
> +
> +	/* The lock to synchronize the access to config_change_enabled */
> +	spinlock_t config_change_lock;
> +
>  	/* Work struct for config space updates */
>  	struct work_struct config_work;
>  


But we already have dev->config_lock and dev->config_enabled.

And it actually works better - instead of discarding config
change events it defers them until enabled.



> @@ -623,6 +629,20 @@ static void disable_delayed_refill(struct virtnet_info *vi)
>  	spin_unlock_bh(&vi->refill_lock);
>  }
>  
> +static void enable_config_change(struct virtnet_info *vi)
> +{
> +	spin_lock_irq(&vi->config_change_lock);
> +	vi->config_change_enabled = true;
> +	spin_unlock_irq(&vi->config_change_lock);
> +}
> +
> +static void disable_config_change(struct virtnet_info *vi)
> +{
> +	spin_lock_irq(&vi->config_change_lock);
> +	vi->config_change_enabled = false;
> +	spin_unlock_irq(&vi->config_change_lock);
> +}
> +
>  static void enable_rx_mode_work(struct virtnet_info *vi)
>  {
>  	rtnl_lock();
> @@ -2421,6 +2441,25 @@ static int virtnet_enable_queue_pair(struct virtnet_info *vi, int qp_index)
>  	return err;
>  }
>  
> +static void virtnet_update_settings(struct virtnet_info *vi)
> +{
> +	u32 speed;
> +	u8 duplex;
> +
> +	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX))
> +		return;
> +
> +	virtio_cread_le(vi->vdev, struct virtio_net_config, speed, &speed);
> +
> +	if (ethtool_validate_speed(speed))
> +		vi->speed = speed;
> +
> +	virtio_cread_le(vi->vdev, struct virtio_net_config, duplex, &duplex);
> +
> +	if (ethtool_validate_duplex(duplex))
> +		vi->duplex = duplex;
> +}
> +
>  static int virtnet_open(struct net_device *dev)
>  {
>  	struct virtnet_info *vi = netdev_priv(dev);
> @@ -2439,6 +2478,18 @@ static int virtnet_open(struct net_device *dev)
>  			goto err_enable_qp;
>  	}
>  
> +	/* Assume link up if device can't report link status,
> +	   otherwise get link status from config. */
> +	netif_carrier_off(dev);
> +	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
> +		enable_config_change(vi);
> +		schedule_work(&vi->config_work);
> +	} else {
> +		vi->status = VIRTIO_NET_S_LINK_UP;
> +		virtnet_update_settings(vi);
> +		netif_carrier_on(dev);
> +	}
> +
>  	return 0;
>  
>  err_enable_qp:
> @@ -2875,12 +2926,19 @@ static int virtnet_close(struct net_device *dev)
>  	disable_delayed_refill(vi);
>  	/* Make sure refill_work doesn't re-enable napi! */
>  	cancel_delayed_work_sync(&vi->refill);
> +	/* Make sure config notification doesn't schedule config work */
> +	disable_config_change(vi);
> +	/* Make sure status updating is cancelled */
> +	cancel_work_sync(&vi->config_work);
>  
>  	for (i = 0; i < vi->max_queue_pairs; i++) {
>  		virtnet_disable_queue_pair(vi, i);
>  		cancel_work_sync(&vi->rq[i].dim.work);
>  	}
>  
> +	vi->status &= ~VIRTIO_NET_S_LINK_UP;
> +	netif_carrier_off(dev);
> +
>  	return 0;
>  }
>  
> @@ -4583,25 +4641,6 @@ static void virtnet_init_settings(struct net_device *dev)
>  	vi->duplex = DUPLEX_UNKNOWN;
>  }
>  
> -static void virtnet_update_settings(struct virtnet_info *vi)
> -{
> -	u32 speed;
> -	u8 duplex;
> -
> -	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX))
> -		return;
> -
> -	virtio_cread_le(vi->vdev, struct virtio_net_config, speed, &speed);
> -
> -	if (ethtool_validate_speed(speed))
> -		vi->speed = speed;
> -
> -	virtio_cread_le(vi->vdev, struct virtio_net_config, duplex, &duplex);
> -
> -	if (ethtool_validate_duplex(duplex))
> -		vi->duplex = duplex;
> -}
> -
>  static u32 virtnet_get_rxfh_key_size(struct net_device *dev)
>  {
>  	return ((struct virtnet_info *)netdev_priv(dev))->rss_key_size;
> @@ -5163,7 +5202,10 @@ static void virtnet_config_changed(struct virtio_device *vdev)
>  {
>  	struct virtnet_info *vi = vdev->priv;
>  
> -	schedule_work(&vi->config_work);
> +	spin_lock_irq(&vi->config_change_lock);
> +	if (vi->config_change_enabled)
> +		schedule_work(&vi->config_work);
> +	spin_unlock_irq(&vi->config_change_lock);
>  }
>  
>  static void virtnet_free_queues(struct virtnet_info *vi)
> @@ -5706,6 +5748,7 @@ static int virtnet_probe(struct virtio_device *vdev)
>  	INIT_WORK(&vi->config_work, virtnet_config_changed_work);
>  	INIT_WORK(&vi->rx_mode_work, virtnet_rx_mode_work);
>  	spin_lock_init(&vi->refill_lock);
> +	spin_lock_init(&vi->config_change_lock);
>  
>  	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) {
>  		vi->mergeable_rx_bufs = true;
> @@ -5901,17 +5944,6 @@ static int virtnet_probe(struct virtio_device *vdev)
>  		goto free_unregister_netdev;
>  	}
>  
> -	/* Assume link up if device can't report link status,
> -	   otherwise get link status from config. */
> -	netif_carrier_off(dev);
> -	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
> -		schedule_work(&vi->config_work);
> -	} else {
> -		vi->status = VIRTIO_NET_S_LINK_UP;
> -		virtnet_update_settings(vi);
> -		netif_carrier_on(dev);
> -	}
> -
>  	for (i = 0; i < ARRAY_SIZE(guest_offloads); i++)
>  		if (virtio_has_feature(vi->vdev, guest_offloads[i]))
>  			set_bit(guest_offloads[i], &vi->guest_offloads);
> -- 
> 2.42.0
Jason Wang May 30, 2024, 10:29 a.m. UTC | #2
On Thu, May 30, 2024 at 2:10 PM Michael S. Tsirkin <mst@redhat.com> wrote:
>
> On Thu, May 30, 2024 at 11:20:55AM +0800, Jason Wang wrote:
> > This patch synchronize operstate with admin state per RFC2863.
> >
> > This is done by trying to toggle the carrier upon open/close and
> > synchronize with the config change work. This allows propagate status
> > correctly to stacked devices like:
> >
> > ip link add link enp0s3 macvlan0 type macvlan
> > ip link set link enp0s3 down
> > ip link show
> >
> > Before this patch:
> >
> > 3: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
> >     link/ether 00:00:05:00:00:09 brd ff:ff:ff:ff:ff:ff
> > ......
> > 5: macvlan0@enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
> >     link/ether b2:a9:c5:04:da:53 brd ff:ff:ff:ff:ff:ff
> >
> > After this patch:
> >
> > 3: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
> >     link/ether 00:00:05:00:00:09 brd ff:ff:ff:ff:ff:ff
> > ...
> > 5: macvlan0@enp0s3: <NO-CARRIER,BROADCAST,MULTICAST,UP,M-DOWN> mtu 1500 qdisc noqueue state LOWERLAYERDOWN mode DEFAULT group default qlen 1000
> >     link/ether b2:a9:c5:04:da:53 brd ff:ff:ff:ff:ff:ff
> >
> > Cc: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
> > Cc: Gia-Khanh Nguyen <gia-khanh.nguyen@oracle.com>
> > Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> > Acked-by: Michael S. Tsirkin <mst@redhat.com>
> > Signed-off-by: Jason Wang <jasowang@redhat.com>
> > ---
> > Changes since V1:
> > - rebase
> > - add ack/review tags
>
>
>
>
>
> > ---
> >  drivers/net/virtio_net.c | 94 +++++++++++++++++++++++++++-------------
> >  1 file changed, 63 insertions(+), 31 deletions(-)
> >
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > index 4a802c0ea2cb..69e4ae353c51 100644
> > --- a/drivers/net/virtio_net.c
> > +++ b/drivers/net/virtio_net.c
> > @@ -433,6 +433,12 @@ struct virtnet_info {
> >       /* The lock to synchronize the access to refill_enabled */
> >       spinlock_t refill_lock;
> >
> > +     /* Is config change enabled? */
> > +     bool config_change_enabled;
> > +
> > +     /* The lock to synchronize the access to config_change_enabled */
> > +     spinlock_t config_change_lock;
> > +
> >       /* Work struct for config space updates */
> >       struct work_struct config_work;
> >
>
>
> But we already have dev->config_lock and dev->config_enabled.
>
> And it actually works better - instead of discarding config
> change events it defers them until enabled.
>

Yes but then both virtio-net driver and virtio core can ask to enable
and disable and then we need some kind of synchronization which is
non-trivial.

And device enabling on the core is different from bringing the device
up in the networking subsystem. Here we just delay to deal with the
config change interrupt on ndo_open(). (E.g try to ack announce is
meaningless when the device is down).

Thanks
Jason Wang May 30, 2024, 12:12 p.m. UTC | #3
On Thu, May 30, 2024 at 6:29 PM Jason Wang <jasowang@redhat.com> wrote:
>
> On Thu, May 30, 2024 at 2:10 PM Michael S. Tsirkin <mst@redhat.com> wrote:
> >
> > On Thu, May 30, 2024 at 11:20:55AM +0800, Jason Wang wrote:
> > > This patch synchronize operstate with admin state per RFC2863.
> > >
> > > This is done by trying to toggle the carrier upon open/close and
> > > synchronize with the config change work. This allows propagate status
> > > correctly to stacked devices like:
> > >
> > > ip link add link enp0s3 macvlan0 type macvlan
> > > ip link set link enp0s3 down
> > > ip link show
> > >
> > > Before this patch:
> > >
> > > 3: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
> > >     link/ether 00:00:05:00:00:09 brd ff:ff:ff:ff:ff:ff
> > > ......
> > > 5: macvlan0@enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
> > >     link/ether b2:a9:c5:04:da:53 brd ff:ff:ff:ff:ff:ff
> > >
> > > After this patch:
> > >
> > > 3: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
> > >     link/ether 00:00:05:00:00:09 brd ff:ff:ff:ff:ff:ff
> > > ...
> > > 5: macvlan0@enp0s3: <NO-CARRIER,BROADCAST,MULTICAST,UP,M-DOWN> mtu 1500 qdisc noqueue state LOWERLAYERDOWN mode DEFAULT group default qlen 1000
> > >     link/ether b2:a9:c5:04:da:53 brd ff:ff:ff:ff:ff:ff
> > >
> > > Cc: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
> > > Cc: Gia-Khanh Nguyen <gia-khanh.nguyen@oracle.com>
> > > Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> > > Acked-by: Michael S. Tsirkin <mst@redhat.com>
> > > Signed-off-by: Jason Wang <jasowang@redhat.com>
> > > ---
> > > Changes since V1:
> > > - rebase
> > > - add ack/review tags
> >
> >
> >
> >
> >
> > > ---
> > >  drivers/net/virtio_net.c | 94 +++++++++++++++++++++++++++-------------
> > >  1 file changed, 63 insertions(+), 31 deletions(-)
> > >
> > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > index 4a802c0ea2cb..69e4ae353c51 100644
> > > --- a/drivers/net/virtio_net.c
> > > +++ b/drivers/net/virtio_net.c
> > > @@ -433,6 +433,12 @@ struct virtnet_info {
> > >       /* The lock to synchronize the access to refill_enabled */
> > >       spinlock_t refill_lock;
> > >
> > > +     /* Is config change enabled? */
> > > +     bool config_change_enabled;
> > > +
> > > +     /* The lock to synchronize the access to config_change_enabled */
> > > +     spinlock_t config_change_lock;
> > > +
> > >       /* Work struct for config space updates */
> > >       struct work_struct config_work;
> > >
> >
> >
> > But we already have dev->config_lock and dev->config_enabled.
> >
> > And it actually works better - instead of discarding config
> > change events it defers them until enabled.
> >
>
> Yes but then both virtio-net driver and virtio core can ask to enable
> and disable and then we need some kind of synchronization which is
> non-trivial.
>
> And device enabling on the core is different from bringing the device
> up in the networking subsystem. Here we just delay to deal with the
> config change interrupt on ndo_open(). (E.g try to ack announce is
> meaningless when the device is down).

Or maybe you meant to make config_enabled a nest counter?

Thanks

>
> Thanks
Michael S. Tsirkin May 30, 2024, 1:09 p.m. UTC | #4
On Thu, May 30, 2024 at 06:29:51PM +0800, Jason Wang wrote:
> On Thu, May 30, 2024 at 2:10 PM Michael S. Tsirkin <mst@redhat.com> wrote:
> >
> > On Thu, May 30, 2024 at 11:20:55AM +0800, Jason Wang wrote:
> > > This patch synchronize operstate with admin state per RFC2863.
> > >
> > > This is done by trying to toggle the carrier upon open/close and
> > > synchronize with the config change work. This allows propagate status
> > > correctly to stacked devices like:
> > >
> > > ip link add link enp0s3 macvlan0 type macvlan
> > > ip link set link enp0s3 down
> > > ip link show
> > >
> > > Before this patch:
> > >
> > > 3: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
> > >     link/ether 00:00:05:00:00:09 brd ff:ff:ff:ff:ff:ff
> > > ......
> > > 5: macvlan0@enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
> > >     link/ether b2:a9:c5:04:da:53 brd ff:ff:ff:ff:ff:ff
> > >
> > > After this patch:
> > >
> > > 3: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
> > >     link/ether 00:00:05:00:00:09 brd ff:ff:ff:ff:ff:ff
> > > ...
> > > 5: macvlan0@enp0s3: <NO-CARRIER,BROADCAST,MULTICAST,UP,M-DOWN> mtu 1500 qdisc noqueue state LOWERLAYERDOWN mode DEFAULT group default qlen 1000
> > >     link/ether b2:a9:c5:04:da:53 brd ff:ff:ff:ff:ff:ff
> > >
> > > Cc: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
> > > Cc: Gia-Khanh Nguyen <gia-khanh.nguyen@oracle.com>
> > > Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> > > Acked-by: Michael S. Tsirkin <mst@redhat.com>
> > > Signed-off-by: Jason Wang <jasowang@redhat.com>
> > > ---
> > > Changes since V1:
> > > - rebase
> > > - add ack/review tags
> >
> >
> >
> >
> >
> > > ---
> > >  drivers/net/virtio_net.c | 94 +++++++++++++++++++++++++++-------------
> > >  1 file changed, 63 insertions(+), 31 deletions(-)
> > >
> > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > index 4a802c0ea2cb..69e4ae353c51 100644
> > > --- a/drivers/net/virtio_net.c
> > > +++ b/drivers/net/virtio_net.c
> > > @@ -433,6 +433,12 @@ struct virtnet_info {
> > >       /* The lock to synchronize the access to refill_enabled */
> > >       spinlock_t refill_lock;
> > >
> > > +     /* Is config change enabled? */
> > > +     bool config_change_enabled;
> > > +
> > > +     /* The lock to synchronize the access to config_change_enabled */
> > > +     spinlock_t config_change_lock;
> > > +
> > >       /* Work struct for config space updates */
> > >       struct work_struct config_work;
> > >
> >
> >
> > But we already have dev->config_lock and dev->config_enabled.
> >
> > And it actually works better - instead of discarding config
> > change events it defers them until enabled.
> >
> 
> Yes but then both virtio-net driver and virtio core can ask to enable
> and disable and then we need some kind of synchronization which is
> non-trivial.

Well for core it happens on bring up path before driver works
and later on tear down after it is gone.
So I do not think they ever do it at the same time.


> And device enabling on the core is different from bringing the device
> up in the networking subsystem. Here we just delay to deal with the
> config change interrupt on ndo_open(). (E.g try to ack announce is
> meaningless when the device is down).
> 
> Thanks

another thing is that it is better not to re-read all config
on link up if there was no config interrupt - less vm exits.
Jason Wang May 31, 2024, 12:18 a.m. UTC | #5
On Thu, May 30, 2024 at 9:09 PM Michael S. Tsirkin <mst@redhat.com> wrote:
>
> On Thu, May 30, 2024 at 06:29:51PM +0800, Jason Wang wrote:
> > On Thu, May 30, 2024 at 2:10 PM Michael S. Tsirkin <mst@redhat.com> wrote:
> > >
> > > On Thu, May 30, 2024 at 11:20:55AM +0800, Jason Wang wrote:
> > > > This patch synchronize operstate with admin state per RFC2863.
> > > >
> > > > This is done by trying to toggle the carrier upon open/close and
> > > > synchronize with the config change work. This allows propagate status
> > > > correctly to stacked devices like:
> > > >
> > > > ip link add link enp0s3 macvlan0 type macvlan
> > > > ip link set link enp0s3 down
> > > > ip link show
> > > >
> > > > Before this patch:
> > > >
> > > > 3: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
> > > >     link/ether 00:00:05:00:00:09 brd ff:ff:ff:ff:ff:ff
> > > > ......
> > > > 5: macvlan0@enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
> > > >     link/ether b2:a9:c5:04:da:53 brd ff:ff:ff:ff:ff:ff
> > > >
> > > > After this patch:
> > > >
> > > > 3: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
> > > >     link/ether 00:00:05:00:00:09 brd ff:ff:ff:ff:ff:ff
> > > > ...
> > > > 5: macvlan0@enp0s3: <NO-CARRIER,BROADCAST,MULTICAST,UP,M-DOWN> mtu 1500 qdisc noqueue state LOWERLAYERDOWN mode DEFAULT group default qlen 1000
> > > >     link/ether b2:a9:c5:04:da:53 brd ff:ff:ff:ff:ff:ff
> > > >
> > > > Cc: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
> > > > Cc: Gia-Khanh Nguyen <gia-khanh.nguyen@oracle.com>
> > > > Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> > > > Acked-by: Michael S. Tsirkin <mst@redhat.com>
> > > > Signed-off-by: Jason Wang <jasowang@redhat.com>
> > > > ---
> > > > Changes since V1:
> > > > - rebase
> > > > - add ack/review tags
> > >
> > >
> > >
> > >
> > >
> > > > ---
> > > >  drivers/net/virtio_net.c | 94 +++++++++++++++++++++++++++-------------
> > > >  1 file changed, 63 insertions(+), 31 deletions(-)
> > > >
> > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > > index 4a802c0ea2cb..69e4ae353c51 100644
> > > > --- a/drivers/net/virtio_net.c
> > > > +++ b/drivers/net/virtio_net.c
> > > > @@ -433,6 +433,12 @@ struct virtnet_info {
> > > >       /* The lock to synchronize the access to refill_enabled */
> > > >       spinlock_t refill_lock;
> > > >
> > > > +     /* Is config change enabled? */
> > > > +     bool config_change_enabled;
> > > > +
> > > > +     /* The lock to synchronize the access to config_change_enabled */
> > > > +     spinlock_t config_change_lock;
> > > > +
> > > >       /* Work struct for config space updates */
> > > >       struct work_struct config_work;
> > > >
> > >
> > >
> > > But we already have dev->config_lock and dev->config_enabled.
> > >
> > > And it actually works better - instead of discarding config
> > > change events it defers them until enabled.
> > >
> >
> > Yes but then both virtio-net driver and virtio core can ask to enable
> > and disable and then we need some kind of synchronization which is
> > non-trivial.
>
> Well for core it happens on bring up path before driver works
> and later on tear down after it is gone.
> So I do not think they ever do it at the same time.

For example, there could be a suspend/resume when the admin state is down.

>
>
> > And device enabling on the core is different from bringing the device
> > up in the networking subsystem. Here we just delay to deal with the
> > config change interrupt on ndo_open(). (E.g try to ack announce is
> > meaningless when the device is down).
> >
> > Thanks
>
> another thing is that it is better not to re-read all config
> on link up if there was no config interrupt - less vm exits.

Yes, but it should not matter much as it's done in the ndo_open().

Thanks

>
> --
> MST
>
Jason Wang June 6, 2024, 12:22 a.m. UTC | #6
On Fri, May 31, 2024 at 8:18 AM Jason Wang <jasowang@redhat.com> wrote:
>
> On Thu, May 30, 2024 at 9:09 PM Michael S. Tsirkin <mst@redhat.com> wrote:
> >
> > On Thu, May 30, 2024 at 06:29:51PM +0800, Jason Wang wrote:
> > > On Thu, May 30, 2024 at 2:10 PM Michael S. Tsirkin <mst@redhat.com> wrote:
> > > >
> > > > On Thu, May 30, 2024 at 11:20:55AM +0800, Jason Wang wrote:
> > > > > This patch synchronize operstate with admin state per RFC2863.
> > > > >
> > > > > This is done by trying to toggle the carrier upon open/close and
> > > > > synchronize with the config change work. This allows propagate status
> > > > > correctly to stacked devices like:
> > > > >
> > > > > ip link add link enp0s3 macvlan0 type macvlan
> > > > > ip link set link enp0s3 down
> > > > > ip link show
> > > > >
> > > > > Before this patch:
> > > > >
> > > > > 3: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
> > > > >     link/ether 00:00:05:00:00:09 brd ff:ff:ff:ff:ff:ff
> > > > > ......
> > > > > 5: macvlan0@enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
> > > > >     link/ether b2:a9:c5:04:da:53 brd ff:ff:ff:ff:ff:ff
> > > > >
> > > > > After this patch:
> > > > >
> > > > > 3: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
> > > > >     link/ether 00:00:05:00:00:09 brd ff:ff:ff:ff:ff:ff
> > > > > ...
> > > > > 5: macvlan0@enp0s3: <NO-CARRIER,BROADCAST,MULTICAST,UP,M-DOWN> mtu 1500 qdisc noqueue state LOWERLAYERDOWN mode DEFAULT group default qlen 1000
> > > > >     link/ether b2:a9:c5:04:da:53 brd ff:ff:ff:ff:ff:ff
> > > > >
> > > > > Cc: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
> > > > > Cc: Gia-Khanh Nguyen <gia-khanh.nguyen@oracle.com>
> > > > > Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> > > > > Acked-by: Michael S. Tsirkin <mst@redhat.com>
> > > > > Signed-off-by: Jason Wang <jasowang@redhat.com>
> > > > > ---
> > > > > Changes since V1:
> > > > > - rebase
> > > > > - add ack/review tags
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > > ---
> > > > >  drivers/net/virtio_net.c | 94 +++++++++++++++++++++++++++-------------
> > > > >  1 file changed, 63 insertions(+), 31 deletions(-)
> > > > >
> > > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > > > index 4a802c0ea2cb..69e4ae353c51 100644
> > > > > --- a/drivers/net/virtio_net.c
> > > > > +++ b/drivers/net/virtio_net.c
> > > > > @@ -433,6 +433,12 @@ struct virtnet_info {
> > > > >       /* The lock to synchronize the access to refill_enabled */
> > > > >       spinlock_t refill_lock;
> > > > >
> > > > > +     /* Is config change enabled? */
> > > > > +     bool config_change_enabled;
> > > > > +
> > > > > +     /* The lock to synchronize the access to config_change_enabled */
> > > > > +     spinlock_t config_change_lock;
> > > > > +
> > > > >       /* Work struct for config space updates */
> > > > >       struct work_struct config_work;
> > > > >
> > > >
> > > >
> > > > But we already have dev->config_lock and dev->config_enabled.
> > > >
> > > > And it actually works better - instead of discarding config
> > > > change events it defers them until enabled.
> > > >
> > >
> > > Yes but then both virtio-net driver and virtio core can ask to enable
> > > and disable and then we need some kind of synchronization which is
> > > non-trivial.
> >
> > Well for core it happens on bring up path before driver works
> > and later on tear down after it is gone.
> > So I do not think they ever do it at the same time.
>
> For example, there could be a suspend/resume when the admin state is down.
>
> >
> >
> > > And device enabling on the core is different from bringing the device
> > > up in the networking subsystem. Here we just delay to deal with the
> > > config change interrupt on ndo_open(). (E.g try to ack announce is
> > > meaningless when the device is down).
> > >
> > > Thanks
> >
> > another thing is that it is better not to re-read all config
> > on link up if there was no config interrupt - less vm exits.
>
> Yes, but it should not matter much as it's done in the ndo_open().

Michael, any more comments on this?

Please confirm if this patch is ok or not. If you prefer to reuse the
config_disable() I can change it from a boolean to a counter that
allows to be nested.

Thanks

>
> Thanks
>
> >
> > --
> > MST
> >
Jason Wang June 17, 2024, 1:50 a.m. UTC | #7
On Thu, Jun 6, 2024 at 8:22 AM Jason Wang <jasowang@redhat.com> wrote:
>
> On Fri, May 31, 2024 at 8:18 AM Jason Wang <jasowang@redhat.com> wrote:
> >
> > On Thu, May 30, 2024 at 9:09 PM Michael S. Tsirkin <mst@redhat.com> wrote:
> > >
> > > On Thu, May 30, 2024 at 06:29:51PM +0800, Jason Wang wrote:
> > > > On Thu, May 30, 2024 at 2:10 PM Michael S. Tsirkin <mst@redhat.com> wrote:
> > > > >
> > > > > On Thu, May 30, 2024 at 11:20:55AM +0800, Jason Wang wrote:
> > > > > > This patch synchronize operstate with admin state per RFC2863.
> > > > > >
> > > > > > This is done by trying to toggle the carrier upon open/close and
> > > > > > synchronize with the config change work. This allows propagate status
> > > > > > correctly to stacked devices like:
> > > > > >
> > > > > > ip link add link enp0s3 macvlan0 type macvlan
> > > > > > ip link set link enp0s3 down
> > > > > > ip link show
> > > > > >
> > > > > > Before this patch:
> > > > > >
> > > > > > 3: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
> > > > > >     link/ether 00:00:05:00:00:09 brd ff:ff:ff:ff:ff:ff
> > > > > > ......
> > > > > > 5: macvlan0@enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
> > > > > >     link/ether b2:a9:c5:04:da:53 brd ff:ff:ff:ff:ff:ff
> > > > > >
> > > > > > After this patch:
> > > > > >
> > > > > > 3: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
> > > > > >     link/ether 00:00:05:00:00:09 brd ff:ff:ff:ff:ff:ff
> > > > > > ...
> > > > > > 5: macvlan0@enp0s3: <NO-CARRIER,BROADCAST,MULTICAST,UP,M-DOWN> mtu 1500 qdisc noqueue state LOWERLAYERDOWN mode DEFAULT group default qlen 1000
> > > > > >     link/ether b2:a9:c5:04:da:53 brd ff:ff:ff:ff:ff:ff
> > > > > >
> > > > > > Cc: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
> > > > > > Cc: Gia-Khanh Nguyen <gia-khanh.nguyen@oracle.com>
> > > > > > Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> > > > > > Acked-by: Michael S. Tsirkin <mst@redhat.com>
> > > > > > Signed-off-by: Jason Wang <jasowang@redhat.com>
> > > > > > ---
> > > > > > Changes since V1:
> > > > > > - rebase
> > > > > > - add ack/review tags
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > > ---
> > > > > >  drivers/net/virtio_net.c | 94 +++++++++++++++++++++++++++-------------
> > > > > >  1 file changed, 63 insertions(+), 31 deletions(-)
> > > > > >
> > > > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > > > > index 4a802c0ea2cb..69e4ae353c51 100644
> > > > > > --- a/drivers/net/virtio_net.c
> > > > > > +++ b/drivers/net/virtio_net.c
> > > > > > @@ -433,6 +433,12 @@ struct virtnet_info {
> > > > > >       /* The lock to synchronize the access to refill_enabled */
> > > > > >       spinlock_t refill_lock;
> > > > > >
> > > > > > +     /* Is config change enabled? */
> > > > > > +     bool config_change_enabled;
> > > > > > +
> > > > > > +     /* The lock to synchronize the access to config_change_enabled */
> > > > > > +     spinlock_t config_change_lock;
> > > > > > +
> > > > > >       /* Work struct for config space updates */
> > > > > >       struct work_struct config_work;
> > > > > >
> > > > >
> > > > >
> > > > > But we already have dev->config_lock and dev->config_enabled.
> > > > >
> > > > > And it actually works better - instead of discarding config
> > > > > change events it defers them until enabled.
> > > > >
> > > >
> > > > Yes but then both virtio-net driver and virtio core can ask to enable
> > > > and disable and then we need some kind of synchronization which is
> > > > non-trivial.
> > >
> > > Well for core it happens on bring up path before driver works
> > > and later on tear down after it is gone.
> > > So I do not think they ever do it at the same time.
> >
> > For example, there could be a suspend/resume when the admin state is down.
> >
> > >
> > >
> > > > And device enabling on the core is different from bringing the device
> > > > up in the networking subsystem. Here we just delay to deal with the
> > > > config change interrupt on ndo_open(). (E.g try to ack announce is
> > > > meaningless when the device is down).
> > > >
> > > > Thanks
> > >
> > > another thing is that it is better not to re-read all config
> > > on link up if there was no config interrupt - less vm exits.
> >
> > Yes, but it should not matter much as it's done in the ndo_open().
>
> Michael, any more comments on this?

Gentle ping.

Thanks

>
> Please confirm if this patch is ok or not. If you prefer to reuse the
> config_disable() I can change it from a boolean to a counter that
> allows to be nested.
>
> Thanks
>
> >
> > Thanks
> >
> > >
> > > --
> > > MST
> > >
Michael S. Tsirkin June 20, 2024, 5:58 a.m. UTC | #8
On Thu, Jun 06, 2024 at 08:22:13AM +0800, Jason Wang wrote:
> On Fri, May 31, 2024 at 8:18 AM Jason Wang <jasowang@redhat.com> wrote:
> >
> > On Thu, May 30, 2024 at 9:09 PM Michael S. Tsirkin <mst@redhat.com> wrote:
> > >
> > > On Thu, May 30, 2024 at 06:29:51PM +0800, Jason Wang wrote:
> > > > On Thu, May 30, 2024 at 2:10 PM Michael S. Tsirkin <mst@redhat.com> wrote:
> > > > >
> > > > > On Thu, May 30, 2024 at 11:20:55AM +0800, Jason Wang wrote:
> > > > > > This patch synchronize operstate with admin state per RFC2863.
> > > > > >
> > > > > > This is done by trying to toggle the carrier upon open/close and
> > > > > > synchronize with the config change work. This allows propagate status
> > > > > > correctly to stacked devices like:
> > > > > >
> > > > > > ip link add link enp0s3 macvlan0 type macvlan
> > > > > > ip link set link enp0s3 down
> > > > > > ip link show
> > > > > >
> > > > > > Before this patch:
> > > > > >
> > > > > > 3: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
> > > > > >     link/ether 00:00:05:00:00:09 brd ff:ff:ff:ff:ff:ff
> > > > > > ......
> > > > > > 5: macvlan0@enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
> > > > > >     link/ether b2:a9:c5:04:da:53 brd ff:ff:ff:ff:ff:ff
> > > > > >
> > > > > > After this patch:
> > > > > >
> > > > > > 3: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
> > > > > >     link/ether 00:00:05:00:00:09 brd ff:ff:ff:ff:ff:ff
> > > > > > ...
> > > > > > 5: macvlan0@enp0s3: <NO-CARRIER,BROADCAST,MULTICAST,UP,M-DOWN> mtu 1500 qdisc noqueue state LOWERLAYERDOWN mode DEFAULT group default qlen 1000
> > > > > >     link/ether b2:a9:c5:04:da:53 brd ff:ff:ff:ff:ff:ff
> > > > > >
> > > > > > Cc: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
> > > > > > Cc: Gia-Khanh Nguyen <gia-khanh.nguyen@oracle.com>
> > > > > > Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> > > > > > Acked-by: Michael S. Tsirkin <mst@redhat.com>
> > > > > > Signed-off-by: Jason Wang <jasowang@redhat.com>
> > > > > > ---
> > > > > > Changes since V1:
> > > > > > - rebase
> > > > > > - add ack/review tags
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > > ---
> > > > > >  drivers/net/virtio_net.c | 94 +++++++++++++++++++++++++++-------------
> > > > > >  1 file changed, 63 insertions(+), 31 deletions(-)
> > > > > >
> > > > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > > > > index 4a802c0ea2cb..69e4ae353c51 100644
> > > > > > --- a/drivers/net/virtio_net.c
> > > > > > +++ b/drivers/net/virtio_net.c
> > > > > > @@ -433,6 +433,12 @@ struct virtnet_info {
> > > > > >       /* The lock to synchronize the access to refill_enabled */
> > > > > >       spinlock_t refill_lock;
> > > > > >
> > > > > > +     /* Is config change enabled? */
> > > > > > +     bool config_change_enabled;
> > > > > > +
> > > > > > +     /* The lock to synchronize the access to config_change_enabled */
> > > > > > +     spinlock_t config_change_lock;
> > > > > > +
> > > > > >       /* Work struct for config space updates */
> > > > > >       struct work_struct config_work;
> > > > > >
> > > > >
> > > > >
> > > > > But we already have dev->config_lock and dev->config_enabled.
> > > > >
> > > > > And it actually works better - instead of discarding config
> > > > > change events it defers them until enabled.
> > > > >
> > > >
> > > > Yes but then both virtio-net driver and virtio core can ask to enable
> > > > and disable and then we need some kind of synchronization which is
> > > > non-trivial.
> > >
> > > Well for core it happens on bring up path before driver works
> > > and later on tear down after it is gone.
> > > So I do not think they ever do it at the same time.
> >
> > For example, there could be a suspend/resume when the admin state is down.
> >
> > >
> > >
> > > > And device enabling on the core is different from bringing the device
> > > > up in the networking subsystem. Here we just delay to deal with the
> > > > config change interrupt on ndo_open(). (E.g try to ack announce is
> > > > meaningless when the device is down).
> > > >
> > > > Thanks
> > >
> > > another thing is that it is better not to re-read all config
> > > on link up if there was no config interrupt - less vm exits.
> >
> > Yes, but it should not matter much as it's done in the ndo_open().
> 
> Michael, any more comments on this?
> 
> Please confirm if this patch is ok or not. If you prefer to reuse the
> config_disable() I can change it from a boolean to a counter that
> allows to be nested.
> 
> Thanks

I think doing this in core and re-using config_lock is a cleaner approach for sure, yes.

For remove we do not need stacking. But yes we need it for freeze.

I am not sure how will a counter work. Let's see the patch.


It might be easier, besides config_enabled, to add config_disabled,
document that  config_enabled is controlled by core,
config_disabled by driver.
And we'd have 2 APIs virtio_config_disable_core and
virtio_config_disable_driver.


But I leave that decision in your capable hands.



> >
> > Thanks
> >
> > >
> > > --
> > > MST
> > >
Jason Wang June 20, 2024, 8:27 a.m. UTC | #9
On Thu, Jun 20, 2024 at 1:58 PM Michael S. Tsirkin <mst@redhat.com> wrote:
>
> On Thu, Jun 06, 2024 at 08:22:13AM +0800, Jason Wang wrote:
> > On Fri, May 31, 2024 at 8:18 AM Jason Wang <jasowang@redhat.com> wrote:
> > >
> > > On Thu, May 30, 2024 at 9:09 PM Michael S. Tsirkin <mst@redhat.com> wrote:
> > > >
> > > > On Thu, May 30, 2024 at 06:29:51PM +0800, Jason Wang wrote:
> > > > > On Thu, May 30, 2024 at 2:10 PM Michael S. Tsirkin <mst@redhat.com> wrote:
> > > > > >
> > > > > > On Thu, May 30, 2024 at 11:20:55AM +0800, Jason Wang wrote:
> > > > > > > This patch synchronize operstate with admin state per RFC2863.
> > > > > > >
> > > > > > > This is done by trying to toggle the carrier upon open/close and
> > > > > > > synchronize with the config change work. This allows propagate status
> > > > > > > correctly to stacked devices like:
> > > > > > >
> > > > > > > ip link add link enp0s3 macvlan0 type macvlan
> > > > > > > ip link set link enp0s3 down
> > > > > > > ip link show
> > > > > > >
> > > > > > > Before this patch:
> > > > > > >
> > > > > > > 3: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
> > > > > > >     link/ether 00:00:05:00:00:09 brd ff:ff:ff:ff:ff:ff
> > > > > > > ......
> > > > > > > 5: macvlan0@enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
> > > > > > >     link/ether b2:a9:c5:04:da:53 brd ff:ff:ff:ff:ff:ff
> > > > > > >
> > > > > > > After this patch:
> > > > > > >
> > > > > > > 3: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
> > > > > > >     link/ether 00:00:05:00:00:09 brd ff:ff:ff:ff:ff:ff
> > > > > > > ...
> > > > > > > 5: macvlan0@enp0s3: <NO-CARRIER,BROADCAST,MULTICAST,UP,M-DOWN> mtu 1500 qdisc noqueue state LOWERLAYERDOWN mode DEFAULT group default qlen 1000
> > > > > > >     link/ether b2:a9:c5:04:da:53 brd ff:ff:ff:ff:ff:ff
> > > > > > >
> > > > > > > Cc: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
> > > > > > > Cc: Gia-Khanh Nguyen <gia-khanh.nguyen@oracle.com>
> > > > > > > Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> > > > > > > Acked-by: Michael S. Tsirkin <mst@redhat.com>
> > > > > > > Signed-off-by: Jason Wang <jasowang@redhat.com>
> > > > > > > ---
> > > > > > > Changes since V1:
> > > > > > > - rebase
> > > > > > > - add ack/review tags
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > > ---
> > > > > > >  drivers/net/virtio_net.c | 94 +++++++++++++++++++++++++++-------------
> > > > > > >  1 file changed, 63 insertions(+), 31 deletions(-)
> > > > > > >
> > > > > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > > > > > index 4a802c0ea2cb..69e4ae353c51 100644
> > > > > > > --- a/drivers/net/virtio_net.c
> > > > > > > +++ b/drivers/net/virtio_net.c
> > > > > > > @@ -433,6 +433,12 @@ struct virtnet_info {
> > > > > > >       /* The lock to synchronize the access to refill_enabled */
> > > > > > >       spinlock_t refill_lock;
> > > > > > >
> > > > > > > +     /* Is config change enabled? */
> > > > > > > +     bool config_change_enabled;
> > > > > > > +
> > > > > > > +     /* The lock to synchronize the access to config_change_enabled */
> > > > > > > +     spinlock_t config_change_lock;
> > > > > > > +
> > > > > > >       /* Work struct for config space updates */
> > > > > > >       struct work_struct config_work;
> > > > > > >
> > > > > >
> > > > > >
> > > > > > But we already have dev->config_lock and dev->config_enabled.
> > > > > >
> > > > > > And it actually works better - instead of discarding config
> > > > > > change events it defers them until enabled.
> > > > > >
> > > > >
> > > > > Yes but then both virtio-net driver and virtio core can ask to enable
> > > > > and disable and then we need some kind of synchronization which is
> > > > > non-trivial.
> > > >
> > > > Well for core it happens on bring up path before driver works
> > > > and later on tear down after it is gone.
> > > > So I do not think they ever do it at the same time.
> > >
> > > For example, there could be a suspend/resume when the admin state is down.
> > >
> > > >
> > > >
> > > > > And device enabling on the core is different from bringing the device
> > > > > up in the networking subsystem. Here we just delay to deal with the
> > > > > config change interrupt on ndo_open(). (E.g try to ack announce is
> > > > > meaningless when the device is down).
> > > > >
> > > > > Thanks
> > > >
> > > > another thing is that it is better not to re-read all config
> > > > on link up if there was no config interrupt - less vm exits.
> > >
> > > Yes, but it should not matter much as it's done in the ndo_open().
> >
> > Michael, any more comments on this?
> >
> > Please confirm if this patch is ok or not. If you prefer to reuse the
> > config_disable() I can change it from a boolean to a counter that
> > allows to be nested.
> >
> > Thanks
>
> I think doing this in core and re-using config_lock is a cleaner approach for sure, yes.
>
> For remove we do not need stacking. But yes we need it for freeze.
>
> I am not sure how will a counter work. Let's see the patch.
>
>
> It might be easier, besides config_enabled, to add config_disabled,
> document that  config_enabled is controlled by core,
> config_disabled by driver.
> And we'd have 2 APIs virtio_config_disable_core and
> virtio_config_disable_driver.
>
>
> But I leave that decision in your capable hands.

Let me try to switch to using a counter for config_enabled first.

Thanks

>
>
>
> > >
> > > Thanks
> > >
> > > >
> > > > --
> > > > MST
> > > >
>
diff mbox series

Patch

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 4a802c0ea2cb..69e4ae353c51 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -433,6 +433,12 @@  struct virtnet_info {
 	/* The lock to synchronize the access to refill_enabled */
 	spinlock_t refill_lock;
 
+	/* Is config change enabled? */
+	bool config_change_enabled;
+
+	/* The lock to synchronize the access to config_change_enabled */
+	spinlock_t config_change_lock;
+
 	/* Work struct for config space updates */
 	struct work_struct config_work;
 
@@ -623,6 +629,20 @@  static void disable_delayed_refill(struct virtnet_info *vi)
 	spin_unlock_bh(&vi->refill_lock);
 }
 
+static void enable_config_change(struct virtnet_info *vi)
+{
+	spin_lock_irq(&vi->config_change_lock);
+	vi->config_change_enabled = true;
+	spin_unlock_irq(&vi->config_change_lock);
+}
+
+static void disable_config_change(struct virtnet_info *vi)
+{
+	spin_lock_irq(&vi->config_change_lock);
+	vi->config_change_enabled = false;
+	spin_unlock_irq(&vi->config_change_lock);
+}
+
 static void enable_rx_mode_work(struct virtnet_info *vi)
 {
 	rtnl_lock();
@@ -2421,6 +2441,25 @@  static int virtnet_enable_queue_pair(struct virtnet_info *vi, int qp_index)
 	return err;
 }
 
+static void virtnet_update_settings(struct virtnet_info *vi)
+{
+	u32 speed;
+	u8 duplex;
+
+	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX))
+		return;
+
+	virtio_cread_le(vi->vdev, struct virtio_net_config, speed, &speed);
+
+	if (ethtool_validate_speed(speed))
+		vi->speed = speed;
+
+	virtio_cread_le(vi->vdev, struct virtio_net_config, duplex, &duplex);
+
+	if (ethtool_validate_duplex(duplex))
+		vi->duplex = duplex;
+}
+
 static int virtnet_open(struct net_device *dev)
 {
 	struct virtnet_info *vi = netdev_priv(dev);
@@ -2439,6 +2478,18 @@  static int virtnet_open(struct net_device *dev)
 			goto err_enable_qp;
 	}
 
+	/* Assume link up if device can't report link status,
+	   otherwise get link status from config. */
+	netif_carrier_off(dev);
+	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
+		enable_config_change(vi);
+		schedule_work(&vi->config_work);
+	} else {
+		vi->status = VIRTIO_NET_S_LINK_UP;
+		virtnet_update_settings(vi);
+		netif_carrier_on(dev);
+	}
+
 	return 0;
 
 err_enable_qp:
@@ -2875,12 +2926,19 @@  static int virtnet_close(struct net_device *dev)
 	disable_delayed_refill(vi);
 	/* Make sure refill_work doesn't re-enable napi! */
 	cancel_delayed_work_sync(&vi->refill);
+	/* Make sure config notification doesn't schedule config work */
+	disable_config_change(vi);
+	/* Make sure status updating is cancelled */
+	cancel_work_sync(&vi->config_work);
 
 	for (i = 0; i < vi->max_queue_pairs; i++) {
 		virtnet_disable_queue_pair(vi, i);
 		cancel_work_sync(&vi->rq[i].dim.work);
 	}
 
+	vi->status &= ~VIRTIO_NET_S_LINK_UP;
+	netif_carrier_off(dev);
+
 	return 0;
 }
 
@@ -4583,25 +4641,6 @@  static void virtnet_init_settings(struct net_device *dev)
 	vi->duplex = DUPLEX_UNKNOWN;
 }
 
-static void virtnet_update_settings(struct virtnet_info *vi)
-{
-	u32 speed;
-	u8 duplex;
-
-	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX))
-		return;
-
-	virtio_cread_le(vi->vdev, struct virtio_net_config, speed, &speed);
-
-	if (ethtool_validate_speed(speed))
-		vi->speed = speed;
-
-	virtio_cread_le(vi->vdev, struct virtio_net_config, duplex, &duplex);
-
-	if (ethtool_validate_duplex(duplex))
-		vi->duplex = duplex;
-}
-
 static u32 virtnet_get_rxfh_key_size(struct net_device *dev)
 {
 	return ((struct virtnet_info *)netdev_priv(dev))->rss_key_size;
@@ -5163,7 +5202,10 @@  static void virtnet_config_changed(struct virtio_device *vdev)
 {
 	struct virtnet_info *vi = vdev->priv;
 
-	schedule_work(&vi->config_work);
+	spin_lock_irq(&vi->config_change_lock);
+	if (vi->config_change_enabled)
+		schedule_work(&vi->config_work);
+	spin_unlock_irq(&vi->config_change_lock);
 }
 
 static void virtnet_free_queues(struct virtnet_info *vi)
@@ -5706,6 +5748,7 @@  static int virtnet_probe(struct virtio_device *vdev)
 	INIT_WORK(&vi->config_work, virtnet_config_changed_work);
 	INIT_WORK(&vi->rx_mode_work, virtnet_rx_mode_work);
 	spin_lock_init(&vi->refill_lock);
+	spin_lock_init(&vi->config_change_lock);
 
 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) {
 		vi->mergeable_rx_bufs = true;
@@ -5901,17 +5944,6 @@  static int virtnet_probe(struct virtio_device *vdev)
 		goto free_unregister_netdev;
 	}
 
-	/* Assume link up if device can't report link status,
-	   otherwise get link status from config. */
-	netif_carrier_off(dev);
-	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
-		schedule_work(&vi->config_work);
-	} else {
-		vi->status = VIRTIO_NET_S_LINK_UP;
-		virtnet_update_settings(vi);
-		netif_carrier_on(dev);
-	}
-
 	for (i = 0; i < ARRAY_SIZE(guest_offloads); i++)
 		if (virtio_has_feature(vi->vdev, guest_offloads[i]))
 			set_bit(guest_offloads[i], &vi->guest_offloads);