diff mbox

[net-next,v2,1/3] virtio_net: propagate linkspeed/duplex settings from the hypervisor

Message ID 44da522ecee60792ec918234ee4d61a84e4574f0.1513974243.git.jbaron@akamai.com (mailing list archive)
State New, archived
Headers show

Commit Message

Denis V. Lunev" via Dec. 22, 2017, 9:54 p.m. UTC
The ability to set speed and duplex for virtio_net in useful in various
scenarios as described here:

16032be virtio_net: add ethtool support for set and get of settings

However, it would be nice to be able to set this from the hypervisor,
such that virtio_net doesn't require custom guest ethtool commands.

Introduce a new feature flag, VIRTIO_NET_F_SPEED_DUPLEX, which allows
the hypervisor to export a linkspeed and duplex setting. The user can
subsequently overwrite it later if desired via: 'ethtool -s'.

Signed-off-by: Jason Baron <jbaron@akamai.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
---
 drivers/net/virtio_net.c        | 17 ++++++++++++++++-
 include/uapi/linux/virtio_net.h |  5 +++++
 2 files changed, 21 insertions(+), 1 deletion(-)

Comments

David Miller Dec. 27, 2017, 9:43 p.m. UTC | #1
From: Jason Baron <jbaron@akamai.com>
Date: Fri, 22 Dec 2017 16:54:01 -0500

> The ability to set speed and duplex for virtio_net in useful in various
> scenarios as described here:
> 
> 16032be virtio_net: add ethtool support for set and get of settings
> 
> However, it would be nice to be able to set this from the hypervisor,
> such that virtio_net doesn't require custom guest ethtool commands.
> 
> Introduce a new feature flag, VIRTIO_NET_F_SPEED_DUPLEX, which allows
> the hypervisor to export a linkspeed and duplex setting. The user can
> subsequently overwrite it later if desired via: 'ethtool -s'.
> 
> Signed-off-by: Jason Baron <jbaron@akamai.com>
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>

Looks mostly fine to me but need some virtio_net reviewers on this one.

> @@ -57,6 +57,8 @@
>  					 * Steering */
>  #define VIRTIO_NET_F_CTRL_MAC_ADDR 23	/* Set MAC address */
>  
> +#define VIRTIO_NET_F_SPEED_DUPLEX 63	/* Host set linkspeed and duplex */
> +

Why use a value so far away from the largest existing one?

Just curious.
Denis V. Lunev" via Dec. 28, 2017, 3:53 p.m. UTC | #2
On 12/27/2017 04:43 PM, David Miller wrote:
> From: Jason Baron <jbaron@akamai.com>
> Date: Fri, 22 Dec 2017 16:54:01 -0500
> 
>> The ability to set speed and duplex for virtio_net in useful in various
>> scenarios as described here:
>>
>> 16032be virtio_net: add ethtool support for set and get of settings
>>
>> However, it would be nice to be able to set this from the hypervisor,
>> such that virtio_net doesn't require custom guest ethtool commands.
>>
>> Introduce a new feature flag, VIRTIO_NET_F_SPEED_DUPLEX, which allows
>> the hypervisor to export a linkspeed and duplex setting. The user can
>> subsequently overwrite it later if desired via: 'ethtool -s'.
>>
>> Signed-off-by: Jason Baron <jbaron@akamai.com>
>> Cc: "Michael S. Tsirkin" <mst@redhat.com>
>> Cc: Jason Wang <jasowang@redhat.com>
> 
> Looks mostly fine to me but need some virtio_net reviewers on this one.
> 
>> @@ -57,6 +57,8 @@
>>  					 * Steering */
>>  #define VIRTIO_NET_F_CTRL_MAC_ADDR 23	/* Set MAC address */
>>  
>> +#define VIRTIO_NET_F_SPEED_DUPLEX 63	/* Host set linkspeed and duplex */
>> +
> 
> Why use a value so far away from the largest existing one?
> 
> Just curious.
> 

So that came from a discussion with Michael about which bit to use for
this, and he suggested using 63:

"
Transports started from bit 24 and are growing up.
So I would say devices should start from bit 63 and grow down.
"

https://patchwork.ozlabs.org/patch/848814/#1826669

I will add a comment to explain it.

Thanks,

-Jason
Michael S. Tsirkin Jan. 3, 2018, 1:49 p.m. UTC | #3
On Thu, Dec 28, 2017 at 10:53:54AM -0500, Jason Baron wrote:
> 
> 
> On 12/27/2017 04:43 PM, David Miller wrote:
> > From: Jason Baron <jbaron@akamai.com>
> > Date: Fri, 22 Dec 2017 16:54:01 -0500
> > 
> >> The ability to set speed and duplex for virtio_net in useful in various
> >> scenarios as described here:
> >>
> >> 16032be virtio_net: add ethtool support for set and get of settings
> >>
> >> However, it would be nice to be able to set this from the hypervisor,
> >> such that virtio_net doesn't require custom guest ethtool commands.
> >>
> >> Introduce a new feature flag, VIRTIO_NET_F_SPEED_DUPLEX, which allows
> >> the hypervisor to export a linkspeed and duplex setting. The user can
> >> subsequently overwrite it later if desired via: 'ethtool -s'.
> >>
> >> Signed-off-by: Jason Baron <jbaron@akamai.com>
> >> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> >> Cc: Jason Wang <jasowang@redhat.com>
> > 
> > Looks mostly fine to me but need some virtio_net reviewers on this one.
> > 
> >> @@ -57,6 +57,8 @@
> >>  					 * Steering */
> >>  #define VIRTIO_NET_F_CTRL_MAC_ADDR 23	/* Set MAC address */
> >>  
> >> +#define VIRTIO_NET_F_SPEED_DUPLEX 63	/* Host set linkspeed and duplex */
> >> +
> > 
> > Why use a value so far away from the largest existing one?
> > 
> > Just curious.
> > 
> 
> So that came from a discussion with Michael about which bit to use for
> this, and he suggested using 63:
> 
> "
> Transports started from bit 24 and are growing up.
> So I would say devices should start from bit 63 and grow down.
> "
> 
> https://patchwork.ozlabs.org/patch/848814/#1826669
> 
> I will add a comment to explain it.

Maybe in the commit log. I don't think we need it in the header.

> Thanks,
> 
> -Jason
Michael S. Tsirkin Jan. 3, 2018, 2:01 p.m. UTC | #4
On Fri, Dec 22, 2017 at 04:54:01PM -0500, Jason Baron wrote:
> The ability to set speed and duplex for virtio_net in useful in various
> scenarios as described here:
> 
> 16032be virtio_net: add ethtool support for set and get of settings
> 
> However, it would be nice to be able to set this from the hypervisor,
> such that virtio_net doesn't require custom guest ethtool commands.
> 
> Introduce a new feature flag, VIRTIO_NET_F_SPEED_DUPLEX, which allows
> the hypervisor to export a linkspeed and duplex setting. The user can
> subsequently overwrite it later if desired via: 'ethtool -s'.
> 
> Signed-off-by: Jason Baron <jbaron@akamai.com>
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> ---
>  drivers/net/virtio_net.c        | 17 ++++++++++++++++-
>  include/uapi/linux/virtio_net.h |  5 +++++
>  2 files changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 511f833..4168d82 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -2621,6 +2621,20 @@ static int virtnet_probe(struct virtio_device *vdev)
>  	netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
>  
>  	virtnet_init_settings(dev);
> +	if (virtio_has_feature(vdev, VIRTIO_NET_F_SPEED_DUPLEX)) {
> +		u32 speed;
> +		u8 duplex;
> +
> +		speed = virtio_cread32(vdev, offsetof(struct virtio_net_config,
> +				       speed));
> +		if (ethtool_validate_speed(speed))
> +			vi->speed = speed;
> +		duplex = virtio_cread8(vdev,
> +				       offsetof(struct virtio_net_config,
> +				       duplex));
> +		if (ethtool_validate_duplex(duplex))
> +			vi->duplex = duplex;
> +	}
>  
>  	err = register_netdev(dev);
>  	if (err) {

It would seem that speed/duplex can change at link up time.
Update it from virtnet_config_changed_work please.

> @@ -2746,7 +2760,8 @@ static struct virtio_device_id id_table[] = {
>  	VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
>  	VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
>  	VIRTIO_NET_F_CTRL_MAC_ADDR, \
> -	VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS
> +	VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \
> +	VIRTIO_NET_F_SPEED_DUPLEX
>  
>  static unsigned int features[] = {
>  	VIRTNET_FEATURES,
> diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
> index fc353b5..0f1548e 100644
> --- a/include/uapi/linux/virtio_net.h
> +++ b/include/uapi/linux/virtio_net.h
> @@ -57,6 +57,8 @@
>  					 * Steering */
>  #define VIRTIO_NET_F_CTRL_MAC_ADDR 23	/* Set MAC address */
>  
> +#define VIRTIO_NET_F_SPEED_DUPLEX 63	/* Host set linkspeed and duplex */
> +

Host -> device, to match virtio spec terminology.

>  #ifndef VIRTIO_NET_NO_LEGACY
>  #define VIRTIO_NET_F_GSO	6	/* Host handles pkts w/ any GSO type */
>  #endif /* VIRTIO_NET_NO_LEGACY */
> @@ -76,6 +78,9 @@ struct virtio_net_config {
>  	__u16 max_virtqueue_pairs;
>  	/* Default maximum transmit unit advice */
>  	__u16 mtu;
> +	/* Host exported linkspeed and duplex */

I would rather drop this and document each field.

/*
speed, in units of 1Mb. All values 0 to INT_MAX are legal.
Any other value stands for unknown.
*/

> +	__u32 speed;

/*
0x00 - half duplex
0x01 - full duplex
Any other value stands for unknown.
*/

> +	__u8 duplex;


>  } __attribute__((packed));
>  
>  /*
> -- 
> 2.6.1
Michael S. Tsirkin Jan. 3, 2018, 2:03 p.m. UTC | #5
On Fri, Dec 22, 2017 at 04:54:01PM -0500, Jason Baron wrote:
> The ability to set speed and duplex for virtio_net in useful in various
> scenarios as described here:
> 
> 16032be virtio_net: add ethtool support for set and get of settings
> 
> However, it would be nice to be able to set this from the hypervisor,
> such that virtio_net doesn't require custom guest ethtool commands.
> 
> Introduce a new feature flag, VIRTIO_NET_F_SPEED_DUPLEX, which allows
> the hypervisor to export a linkspeed and duplex setting. The user can
> subsequently overwrite it later if desired via: 'ethtool -s'.
> 
> Signed-off-by: Jason Baron <jbaron@akamai.com>
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>

Same as any host/guest API change, please send a copy to the virtio TC
to make sure we avoid conflicts.

> ---
>  drivers/net/virtio_net.c        | 17 ++++++++++++++++-
>  include/uapi/linux/virtio_net.h |  5 +++++
>  2 files changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 511f833..4168d82 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -2621,6 +2621,20 @@ static int virtnet_probe(struct virtio_device *vdev)
>  	netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
>  
>  	virtnet_init_settings(dev);
> +	if (virtio_has_feature(vdev, VIRTIO_NET_F_SPEED_DUPLEX)) {
> +		u32 speed;
> +		u8 duplex;
> +
> +		speed = virtio_cread32(vdev, offsetof(struct virtio_net_config,
> +				       speed));
> +		if (ethtool_validate_speed(speed))
> +			vi->speed = speed;
> +		duplex = virtio_cread8(vdev,
> +				       offsetof(struct virtio_net_config,
> +				       duplex));
> +		if (ethtool_validate_duplex(duplex))
> +			vi->duplex = duplex;
> +	}
>  
>  	err = register_netdev(dev);
>  	if (err) {
> @@ -2746,7 +2760,8 @@ static struct virtio_device_id id_table[] = {
>  	VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
>  	VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
>  	VIRTIO_NET_F_CTRL_MAC_ADDR, \
> -	VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS
> +	VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \
> +	VIRTIO_NET_F_SPEED_DUPLEX
>  
>  static unsigned int features[] = {
>  	VIRTNET_FEATURES,
> diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
> index fc353b5..0f1548e 100644
> --- a/include/uapi/linux/virtio_net.h
> +++ b/include/uapi/linux/virtio_net.h
> @@ -57,6 +57,8 @@
>  					 * Steering */
>  #define VIRTIO_NET_F_CTRL_MAC_ADDR 23	/* Set MAC address */
>  
> +#define VIRTIO_NET_F_SPEED_DUPLEX 63	/* Host set linkspeed and duplex */
> +
>  #ifndef VIRTIO_NET_NO_LEGACY
>  #define VIRTIO_NET_F_GSO	6	/* Host handles pkts w/ any GSO type */
>  #endif /* VIRTIO_NET_NO_LEGACY */
> @@ -76,6 +78,9 @@ struct virtio_net_config {
>  	__u16 max_virtqueue_pairs;
>  	/* Default maximum transmit unit advice */
>  	__u16 mtu;
> +	/* Host exported linkspeed and duplex */
> +	__u32 speed;
> +	__u8 duplex;
>  } __attribute__((packed));
>  
>  /*
> -- 
> 2.6.1
diff mbox

Patch

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 511f833..4168d82 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2621,6 +2621,20 @@  static int virtnet_probe(struct virtio_device *vdev)
 	netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
 
 	virtnet_init_settings(dev);
+	if (virtio_has_feature(vdev, VIRTIO_NET_F_SPEED_DUPLEX)) {
+		u32 speed;
+		u8 duplex;
+
+		speed = virtio_cread32(vdev, offsetof(struct virtio_net_config,
+				       speed));
+		if (ethtool_validate_speed(speed))
+			vi->speed = speed;
+		duplex = virtio_cread8(vdev,
+				       offsetof(struct virtio_net_config,
+				       duplex));
+		if (ethtool_validate_duplex(duplex))
+			vi->duplex = duplex;
+	}
 
 	err = register_netdev(dev);
 	if (err) {
@@ -2746,7 +2760,8 @@  static struct virtio_device_id id_table[] = {
 	VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
 	VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
 	VIRTIO_NET_F_CTRL_MAC_ADDR, \
-	VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS
+	VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \
+	VIRTIO_NET_F_SPEED_DUPLEX
 
 static unsigned int features[] = {
 	VIRTNET_FEATURES,
diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
index fc353b5..0f1548e 100644
--- a/include/uapi/linux/virtio_net.h
+++ b/include/uapi/linux/virtio_net.h
@@ -57,6 +57,8 @@ 
 					 * Steering */
 #define VIRTIO_NET_F_CTRL_MAC_ADDR 23	/* Set MAC address */
 
+#define VIRTIO_NET_F_SPEED_DUPLEX 63	/* Host set linkspeed and duplex */
+
 #ifndef VIRTIO_NET_NO_LEGACY
 #define VIRTIO_NET_F_GSO	6	/* Host handles pkts w/ any GSO type */
 #endif /* VIRTIO_NET_NO_LEGACY */
@@ -76,6 +78,9 @@  struct virtio_net_config {
 	__u16 max_virtqueue_pairs;
 	/* Default maximum transmit unit advice */
 	__u16 mtu;
+	/* Host exported linkspeed and duplex */
+	__u32 speed;
+	__u8 duplex;
 } __attribute__((packed));
 
 /*