Patchwork [RFC,2/2] virtio-net: introduce a new control to set macaddr

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Submitter Amos Kong
Date Jan. 10, 2013, 2:45 p.m.
Message ID <1357829141-25455-3-git-send-email-akong@redhat.com>
Download mbox | patch
Permalink /patch/211028/
State New
Headers show

Comments

Amos Kong - Jan. 10, 2013, 2:45 p.m.
From: Amos Kong <akong@redhat.com>

Currently we write MAC address to pci config space byte by byte,
this means that we have an intermediate step where mac is wrong.
This patch introduced a new control command to set MAC address
in one time.

VIRTIO_NET_F_CTRL_MAC_ADDR is a new feature bit for compatibility.

Signed-off-by: Amos Kong <akong@redhat.com>
---
 drivers/net/virtio_net.c        | 16 +++++++++++++++-
 include/uapi/linux/virtio_net.h |  8 +++++++-
 2 files changed, 22 insertions(+), 2 deletions(-)
Jason Wang - Jan. 10, 2013, 2:57 p.m.
On 01/10/2013 10:45 PM, akong@redhat.com wrote:
> From: Amos Kong <akong@redhat.com>
>
> Currently we write MAC address to pci config space byte by byte,
> this means that we have an intermediate step where mac is wrong.
> This patch introduced a new control command to set MAC address
> in one time.
>
> VIRTIO_NET_F_CTRL_MAC_ADDR is a new feature bit for compatibility.
>
> Signed-off-by: Amos Kong <akong@redhat.com>
> ---
>  drivers/net/virtio_net.c        | 16 +++++++++++++++-
>  include/uapi/linux/virtio_net.h |  8 +++++++-
>  2 files changed, 22 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 395ab4f..ff22bcd 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -803,13 +803,26 @@ static int virtnet_set_mac_address(struct net_device *dev, void *p)
>  	struct virtio_device *vdev = vi->vdev;
>  	int ret;
>  
> +	struct scatterlist sg;
> +
>  	ret = eth_mac_addr(dev, p);
>  	if (ret)
>  		return ret;
>  
> -	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
> +	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
> +		/* Set MAC address by sending vq command */
> +		sg_init_one(&sg, dev->dev_addr, dev->addr_len);
> +		virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
> +				     VIRTIO_NET_CTRL_MAC_ADDR_SET,
> +				     &sg, 1, 0);
> +		return 0;
> +	}
> +

Better to check the return of virtnet_send_command() and give a warn
like other command. Btw, need we fail back to try the old way then?
> +	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
> +		/* Set MAC address by writing config space */
>  		vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
>  		                  dev->dev_addr, dev->addr_len);
> +	}
>  
>  	return 0;
>  }
> @@ -1627,6 +1640,7 @@ static unsigned int features[] = {
>  	VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
>  	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,
>  };
>  
>  static struct virtio_driver virtio_net_driver = {
> diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
> index 848e358..a5a8c88 100644
> --- a/include/uapi/linux/virtio_net.h
> +++ b/include/uapi/linux/virtio_net.h
> @@ -53,6 +53,7 @@
>  					 * network */
>  #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_S_LINK_UP	1	/* Link is up */
>  #define VIRTIO_NET_S_ANNOUNCE	2	/* Announcement is needed */
> @@ -127,7 +128,7 @@ typedef __u8 virtio_net_ctrl_ack;
>   #define VIRTIO_NET_CTRL_RX_NOBCAST      5
>  
>  /*
> - * Control the MAC filter table.
> + * Control the MAC
>   *
>   * The MAC filter table is managed by the hypervisor, the guest should
>   * assume the size is infinite.  Filtering should be considered
> @@ -140,6 +141,10 @@ typedef __u8 virtio_net_ctrl_ack;
>   * first sg list contains unicast addresses, the second is for multicast.
>   * This functionality is present if the VIRTIO_NET_F_CTRL_RX feature
>   * is available.
> + *
> + * The ADDR_SET command requests one out scatterlist, it contains a
> + * 6 bytes MAC address. This functionality is present if the
> + * VIRTIO_NET_F_CTRL_MAC_ADDR feature is available.
>   */
>  struct virtio_net_ctrl_mac {
>  	__u32 entries;
> @@ -148,6 +153,7 @@ struct virtio_net_ctrl_mac {
>  
>  #define VIRTIO_NET_CTRL_MAC    1
>   #define VIRTIO_NET_CTRL_MAC_TABLE_SET        0
> + #define VIRTIO_NET_CTRL_MAC_ADDR_SET         1
>  
>  /*
>   * Control VLAN filtering
Michael S. Tsirkin - Jan. 10, 2013, 3:26 p.m.
On Thu, Jan 10, 2013 at 10:45:41PM +0800, akong@redhat.com wrote:
> From: Amos Kong <akong@redhat.com>
> 
> Currently we write MAC address to pci config space byte by byte,
> this means that we have an intermediate step where mac is wrong.
> This patch introduced a new control command to set MAC address
> in one time.
> 
> VIRTIO_NET_F_CTRL_MAC_ADDR is a new feature bit for compatibility.
> 
> Signed-off-by: Amos Kong <akong@redhat.com>
> ---
>  drivers/net/virtio_net.c        | 16 +++++++++++++++-
>  include/uapi/linux/virtio_net.h |  8 +++++++-
>  2 files changed, 22 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 395ab4f..ff22bcd 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -803,13 +803,26 @@ static int virtnet_set_mac_address(struct net_device *dev, void *p)
>  	struct virtio_device *vdev = vi->vdev;
>  	int ret;
>  
> +	struct scatterlist sg;
> +
>  	ret = eth_mac_addr(dev, p);
>  	if (ret)
>  		return ret;
>  
> -	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
> +	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
> +		/* Set MAC address by sending vq command */
> +		sg_init_one(&sg, dev->dev_addr, dev->addr_len);
> +		virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
> +				     VIRTIO_NET_CTRL_MAC_ADDR_SET,
> +				     &sg, 1, 0);

I think we should check status and return an error if the command failed.
Also, delay eth_mac_addr until after it passes.

> +		return 0;
> +	}
> +
> +	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
> +		/* Set MAC address by writing config space */
>  		vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
>  		                  dev->dev_addr, dev->addr_len);
> +	}
>  

By the way, why don't we fail the command if VIRTIO_NET_F_MAC is off?
Rusty?

>  	return 0;
>  }
> @@ -1627,6 +1640,7 @@ static unsigned int features[] = {
>  	VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
>  	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,
>  };
>  
>  static struct virtio_driver virtio_net_driver = {
> diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
> index 848e358..a5a8c88 100644
> --- a/include/uapi/linux/virtio_net.h
> +++ b/include/uapi/linux/virtio_net.h
> @@ -53,6 +53,7 @@
>  					 * network */
>  #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_S_LINK_UP	1	/* Link is up */
>  #define VIRTIO_NET_S_ANNOUNCE	2	/* Announcement is needed */
> @@ -127,7 +128,7 @@ typedef __u8 virtio_net_ctrl_ack;
>   #define VIRTIO_NET_CTRL_RX_NOBCAST      5
>  
>  /*
> - * Control the MAC filter table.
> + * Control the MAC
>   *
>   * The MAC filter table is managed by the hypervisor, the guest should
>   * assume the size is infinite.  Filtering should be considered
> @@ -140,6 +141,10 @@ typedef __u8 virtio_net_ctrl_ack;
>   * first sg list contains unicast addresses, the second is for multicast.
>   * This functionality is present if the VIRTIO_NET_F_CTRL_RX feature
>   * is available.
> + *
> + * The ADDR_SET command requests one out scatterlist, it contains a
> + * 6 bytes MAC address. This functionality is present if the
> + * VIRTIO_NET_F_CTRL_MAC_ADDR feature is available.
>   */
>  struct virtio_net_ctrl_mac {
>  	__u32 entries;
> @@ -148,6 +153,7 @@ struct virtio_net_ctrl_mac {
>  
>  #define VIRTIO_NET_CTRL_MAC    1
>   #define VIRTIO_NET_CTRL_MAC_TABLE_SET        0
> + #define VIRTIO_NET_CTRL_MAC_ADDR_SET         1
>  
>  /*
>   * Control VLAN filtering
> -- 
> 1.7.11.7
Rusty Russell - Jan. 11, 2013, 12:43 a.m.
"Michael S. Tsirkin" <mst@redhat.com> writes:
>> +	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
>> +		/* Set MAC address by writing config space */
>>  		vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
>>  		                  dev->dev_addr, dev->addr_len);
>> +	}
>>  
>
> By the way, why don't we fail the command if VIRTIO_NET_F_MAC is off?
> Rusty?

Looked back through the history for this one.  I think the theory is that
if the guest doesn't set VIRTIO_NET_F_MAC, it means it doesn't care:
it's up to the guest.

Cheers,
Rusty.
Amos Kong - Jan. 16, 2013, 5:23 a.m.
On Thu, Jan 10, 2013 at 10:57:05PM +0800, Jason Wang wrote:
> On 01/10/2013 10:45 PM, akong@redhat.com wrote:
> > From: Amos Kong <akong@redhat.com>
> >
> > Currently we write MAC address to pci config space byte by byte,
> > this means that we have an intermediate step where mac is wrong.
> > This patch introduced a new control command to set MAC address
> > in one time.
> >
> > VIRTIO_NET_F_CTRL_MAC_ADDR is a new feature bit for compatibility.
> >
> > Signed-off-by: Amos Kong <akong@redhat.com>
> > ---
> >  drivers/net/virtio_net.c        | 16 +++++++++++++++-
> >  include/uapi/linux/virtio_net.h |  8 +++++++-
> >  2 files changed, 22 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > index 395ab4f..ff22bcd 100644
> > --- a/drivers/net/virtio_net.c
> > +++ b/drivers/net/virtio_net.c
> > @@ -803,13 +803,26 @@ static int virtnet_set_mac_address(struct net_device *dev, void *p)
> >  	struct virtio_device *vdev = vi->vdev;
> >  	int ret;
> >  
> > +	struct scatterlist sg;
> > +
> >  	ret = eth_mac_addr(dev, p);
> >  	if (ret)
> >  		return ret;
> >  
> > -	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
> > +	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
> > +		/* Set MAC address by sending vq command */
> > +		sg_init_one(&sg, dev->dev_addr, dev->addr_len);
> > +		virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
> > +				     VIRTIO_NET_CTRL_MAC_ADDR_SET,
> > +				     &sg, 1, 0);
> > +		return 0;
> > +	}
> > +
> 
> Better to check the return of virtnet_send_command() and give a warn
> like other command. Btw, need we fail back to try the old way then?

Yes, it's necessary to check the return value of
virtnet_send_command().

In fail case, I like to return -EINVAL to userspace, because we don't
only want to set mac successfully, we also want to resolve the
addr inconsistent issue by this feature (vq cmd).
Michael S. Tsirkin - Jan. 16, 2013, 9:17 a.m.
On Wed, Jan 16, 2013 at 01:23:26PM +0800, Amos Kong wrote:
> On Thu, Jan 10, 2013 at 10:57:05PM +0800, Jason Wang wrote:
> > On 01/10/2013 10:45 PM, akong@redhat.com wrote:
> > > From: Amos Kong <akong@redhat.com>
> > >
> > > Currently we write MAC address to pci config space byte by byte,
> > > this means that we have an intermediate step where mac is wrong.
> > > This patch introduced a new control command to set MAC address
> > > in one time.
> > >
> > > VIRTIO_NET_F_CTRL_MAC_ADDR is a new feature bit for compatibility.
> > >
> > > Signed-off-by: Amos Kong <akong@redhat.com>
> > > ---
> > >  drivers/net/virtio_net.c        | 16 +++++++++++++++-
> > >  include/uapi/linux/virtio_net.h |  8 +++++++-
> > >  2 files changed, 22 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > index 395ab4f..ff22bcd 100644
> > > --- a/drivers/net/virtio_net.c
> > > +++ b/drivers/net/virtio_net.c
> > > @@ -803,13 +803,26 @@ static int virtnet_set_mac_address(struct net_device *dev, void *p)
> > >  	struct virtio_device *vdev = vi->vdev;
> > >  	int ret;
> > >  
> > > +	struct scatterlist sg;
> > > +
> > >  	ret = eth_mac_addr(dev, p);
> > >  	if (ret)
> > >  		return ret;
> > >  
> > > -	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
> > > +	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
> > > +		/* Set MAC address by sending vq command */
> > > +		sg_init_one(&sg, dev->dev_addr, dev->addr_len);
> > > +		virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
> > > +				     VIRTIO_NET_CTRL_MAC_ADDR_SET,
> > > +				     &sg, 1, 0);
> > > +		return 0;
> > > +	}
> > > +
> > 
> > Better to check the return of virtnet_send_command() and give a warn
> > like other command. Btw, need we fail back to try the old way then?
> 
> Yes, it's necessary to check the return value of
> virtnet_send_command().
> 
> In fail case, I like to return -EINVAL to userspace, because we don't
> only want to set mac successfully, we also want to resolve the
> addr inconsistent issue by this feature (vq cmd).

It's really a device error but I guess we can.
We probably should print a warning too.

Patch

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 395ab4f..ff22bcd 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -803,13 +803,26 @@  static int virtnet_set_mac_address(struct net_device *dev, void *p)
 	struct virtio_device *vdev = vi->vdev;
 	int ret;
 
+	struct scatterlist sg;
+
 	ret = eth_mac_addr(dev, p);
 	if (ret)
 		return ret;
 
-	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
+	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
+		/* Set MAC address by sending vq command */
+		sg_init_one(&sg, dev->dev_addr, dev->addr_len);
+		virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
+				     VIRTIO_NET_CTRL_MAC_ADDR_SET,
+				     &sg, 1, 0);
+		return 0;
+	}
+
+	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
+		/* Set MAC address by writing config space */
 		vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
 		                  dev->dev_addr, dev->addr_len);
+	}
 
 	return 0;
 }
@@ -1627,6 +1640,7 @@  static unsigned int features[] = {
 	VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
 	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,
 };
 
 static struct virtio_driver virtio_net_driver = {
diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
index 848e358..a5a8c88 100644
--- a/include/uapi/linux/virtio_net.h
+++ b/include/uapi/linux/virtio_net.h
@@ -53,6 +53,7 @@ 
 					 * network */
 #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_S_LINK_UP	1	/* Link is up */
 #define VIRTIO_NET_S_ANNOUNCE	2	/* Announcement is needed */
@@ -127,7 +128,7 @@  typedef __u8 virtio_net_ctrl_ack;
  #define VIRTIO_NET_CTRL_RX_NOBCAST      5
 
 /*
- * Control the MAC filter table.
+ * Control the MAC
  *
  * The MAC filter table is managed by the hypervisor, the guest should
  * assume the size is infinite.  Filtering should be considered
@@ -140,6 +141,10 @@  typedef __u8 virtio_net_ctrl_ack;
  * first sg list contains unicast addresses, the second is for multicast.
  * This functionality is present if the VIRTIO_NET_F_CTRL_RX feature
  * is available.
+ *
+ * The ADDR_SET command requests one out scatterlist, it contains a
+ * 6 bytes MAC address. This functionality is present if the
+ * VIRTIO_NET_F_CTRL_MAC_ADDR feature is available.
  */
 struct virtio_net_ctrl_mac {
 	__u32 entries;
@@ -148,6 +153,7 @@  struct virtio_net_ctrl_mac {
 
 #define VIRTIO_NET_CTRL_MAC    1
  #define VIRTIO_NET_CTRL_MAC_TABLE_SET        0
+ #define VIRTIO_NET_CTRL_MAC_ADDR_SET         1
 
 /*
  * Control VLAN filtering