[Qemu-devel] [PATCH v3 0/3] virtio_net: allow hypervisor to indicate linkspeed and duplex setting

[Qemu-devel] [PATCH v3 0/3] virtio_net: allow hypervisor to indicate linkspeed and duplex setting

[Jason Baron]

We have found it useful to be able to set the linkspeed and duplex
settings from the host-side for virtio_net. This obviates the need
for guest changes and settings for these fields, and does not require
custom ethtool commands for virtio_net.

The ability to set linkspeed and duplex is useful in various cases
as described here:

16032be virtio_net: add ethtool support for set and get of settings                                                                                                                                                           
Using 'ethtool -s' continues to over-write the linkspeed/duplex
settings with this patch.

The 1/3 patch is against net-next, while the 2-3/3 patch are the associated
qemu changes that would go in after as update-linux-headers.sh should
be run first. So the qemu patches are a demonstration of how I intend this
to work.

Thanks,

-Jason  

linux changes:

changes from v2:
* move speed/duplex read into virtnet_config_changed_work() so link up changes
  are detected

Jason Baron (1):
  virtio_net: propagate linkspeed/duplex settings from the hypervisor

 drivers/net/virtio_net.c        | 19 ++++++++++++++++++-
 include/uapi/linux/virtio_net.h | 13 +++++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)

qemu changes:

changes from v2:
* if link up return configured speed/duplex, else return UNKNOWN speed and duplex

Jason Baron (2):
  qemu: virtio-net: use 64-bit values for feature flags
  qemu: add linkspeed and duplex settings to virtio-net

 hw/net/virtio-net.c                         | 89 ++++++++++++++++++++---------
 include/hw/virtio/virtio-net.h              |  5 +-
 include/standard-headers/linux/virtio_net.h | 13 +++++
 3 files changed, 79 insertions(+), 28 deletions(-)


-- 
2.6.1

[Qemu-devel] [PATCH v3 2/3] qemu: virtio-net: use 64-bit values for feature flags

[Jason Baron]

In prepartion for using some of the high order feature bits, make sure that
virtio-net uses 64-bit values everywhere.

Signed-off-by: Jason Baron <jbaron@akamai.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: virtio-dev@lists.oasis-open.org
---
 hw/net/virtio-net.c            | 54 +++++++++++++++++++++---------------------
 include/hw/virtio/virtio-net.h |  2 +-
 2 files changed, 28 insertions(+), 28 deletions(-)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 38674b0..adc20df 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -48,18 +48,18 @@
     (offsetof(container, field) + sizeof(((container *)0)->field))
 
 typedef struct VirtIOFeature {
-    uint32_t flags;
+    uint64_t flags;
     size_t end;
 } VirtIOFeature;
 
 static VirtIOFeature feature_sizes[] = {
-    {.flags = 1 << VIRTIO_NET_F_MAC,
+    {.flags = 1ULL << VIRTIO_NET_F_MAC,
      .end = endof(struct virtio_net_config, mac)},
-    {.flags = 1 << VIRTIO_NET_F_STATUS,
+    {.flags = 1ULL << VIRTIO_NET_F_STATUS,
      .end = endof(struct virtio_net_config, status)},
-    {.flags = 1 << VIRTIO_NET_F_MQ,
+    {.flags = 1ULL << VIRTIO_NET_F_MQ,
      .end = endof(struct virtio_net_config, max_virtqueue_pairs)},
-    {.flags = 1 << VIRTIO_NET_F_MTU,
+    {.flags = 1ULL << VIRTIO_NET_F_MTU,
      .end = endof(struct virtio_net_config, mtu)},
     {}
 };
@@ -1938,7 +1938,7 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
     int i;
 
     if (n->net_conf.mtu) {
-        n->host_features |= (0x1 << VIRTIO_NET_F_MTU);
+        n->host_features |= (1ULL << VIRTIO_NET_F_MTU);
     }
 
     virtio_net_set_config_size(n, n->host_features);
@@ -2109,45 +2109,45 @@ static const VMStateDescription vmstate_virtio_net = {
 };
 
 static Property virtio_net_properties[] = {
-    DEFINE_PROP_BIT("csum", VirtIONet, host_features, VIRTIO_NET_F_CSUM, true),
-    DEFINE_PROP_BIT("guest_csum", VirtIONet, host_features,
+    DEFINE_PROP_BIT64("csum", VirtIONet, host_features, VIRTIO_NET_F_CSUM, true),
+    DEFINE_PROP_BIT64("guest_csum", VirtIONet, host_features,
                     VIRTIO_NET_F_GUEST_CSUM, true),
-    DEFINE_PROP_BIT("gso", VirtIONet, host_features, VIRTIO_NET_F_GSO, true),
-    DEFINE_PROP_BIT("guest_tso4", VirtIONet, host_features,
+    DEFINE_PROP_BIT64("gso", VirtIONet, host_features, VIRTIO_NET_F_GSO, true),
+    DEFINE_PROP_BIT64("guest_tso4", VirtIONet, host_features,
                     VIRTIO_NET_F_GUEST_TSO4, true),
-    DEFINE_PROP_BIT("guest_tso6", VirtIONet, host_features,
+    DEFINE_PROP_BIT64("guest_tso6", VirtIONet, host_features,
                     VIRTIO_NET_F_GUEST_TSO6, true),
-    DEFINE_PROP_BIT("guest_ecn", VirtIONet, host_features,
+    DEFINE_PROP_BIT64("guest_ecn", VirtIONet, host_features,
                     VIRTIO_NET_F_GUEST_ECN, true),
-    DEFINE_PROP_BIT("guest_ufo", VirtIONet, host_features,
+    DEFINE_PROP_BIT64("guest_ufo", VirtIONet, host_features,
                     VIRTIO_NET_F_GUEST_UFO, true),
-    DEFINE_PROP_BIT("guest_announce", VirtIONet, host_features,
+    DEFINE_PROP_BIT64("guest_announce", VirtIONet, host_features,
                     VIRTIO_NET_F_GUEST_ANNOUNCE, true),
-    DEFINE_PROP_BIT("host_tso4", VirtIONet, host_features,
+    DEFINE_PROP_BIT64("host_tso4", VirtIONet, host_features,
                     VIRTIO_NET_F_HOST_TSO4, true),
-    DEFINE_PROP_BIT("host_tso6", VirtIONet, host_features,
+    DEFINE_PROP_BIT64("host_tso6", VirtIONet, host_features,
                     VIRTIO_NET_F_HOST_TSO6, true),
-    DEFINE_PROP_BIT("host_ecn", VirtIONet, host_features,
+    DEFINE_PROP_BIT64("host_ecn", VirtIONet, host_features,
                     VIRTIO_NET_F_HOST_ECN, true),
-    DEFINE_PROP_BIT("host_ufo", VirtIONet, host_features,
+    DEFINE_PROP_BIT64("host_ufo", VirtIONet, host_features,
                     VIRTIO_NET_F_HOST_UFO, true),
-    DEFINE_PROP_BIT("mrg_rxbuf", VirtIONet, host_features,
+    DEFINE_PROP_BIT64("mrg_rxbuf", VirtIONet, host_features,
                     VIRTIO_NET_F_MRG_RXBUF, true),
-    DEFINE_PROP_BIT("status", VirtIONet, host_features,
+    DEFINE_PROP_BIT64("status", VirtIONet, host_features,
                     VIRTIO_NET_F_STATUS, true),
-    DEFINE_PROP_BIT("ctrl_vq", VirtIONet, host_features,
+    DEFINE_PROP_BIT64("ctrl_vq", VirtIONet, host_features,
                     VIRTIO_NET_F_CTRL_VQ, true),
-    DEFINE_PROP_BIT("ctrl_rx", VirtIONet, host_features,
+    DEFINE_PROP_BIT64("ctrl_rx", VirtIONet, host_features,
                     VIRTIO_NET_F_CTRL_RX, true),
-    DEFINE_PROP_BIT("ctrl_vlan", VirtIONet, host_features,
+    DEFINE_PROP_BIT64("ctrl_vlan", VirtIONet, host_features,
                     VIRTIO_NET_F_CTRL_VLAN, true),
-    DEFINE_PROP_BIT("ctrl_rx_extra", VirtIONet, host_features,
+    DEFINE_PROP_BIT64("ctrl_rx_extra", VirtIONet, host_features,
                     VIRTIO_NET_F_CTRL_RX_EXTRA, true),
-    DEFINE_PROP_BIT("ctrl_mac_addr", VirtIONet, host_features,
+    DEFINE_PROP_BIT64("ctrl_mac_addr", VirtIONet, host_features,
                     VIRTIO_NET_F_CTRL_MAC_ADDR, true),
-    DEFINE_PROP_BIT("ctrl_guest_offloads", VirtIONet, host_features,
+    DEFINE_PROP_BIT64("ctrl_guest_offloads", VirtIONet, host_features,
                     VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, true),
-    DEFINE_PROP_BIT("mq", VirtIONet, host_features, VIRTIO_NET_F_MQ, false),
+    DEFINE_PROP_BIT64("mq", VirtIONet, host_features, VIRTIO_NET_F_MQ, false),
     DEFINE_NIC_PROPERTIES(VirtIONet, nic_conf),
     DEFINE_PROP_UINT32("x-txtimer", VirtIONet, net_conf.txtimer,
                        TX_TIMER_INTERVAL),
diff --git a/include/hw/virtio/virtio-net.h b/include/hw/virtio/virtio-net.h
index b81b6a4..e7634c9 100644
--- a/include/hw/virtio/virtio-net.h
+++ b/include/hw/virtio/virtio-net.h
@@ -67,7 +67,7 @@ typedef struct VirtIONet {
     uint32_t has_vnet_hdr;
     size_t host_hdr_len;
     size_t guest_hdr_len;
-    uint32_t host_features;
+    uint64_t host_features;
     uint8_t has_ufo;
     uint32_t mergeable_rx_bufs;
     uint8_t promisc;
-- 
2.6.1

[Qemu-devel] [PATCH net-next v3 1/3] virtio_net: propagate linkspeed/duplex settings from the hypervisor

[Jason Baron]

The ability to set speed and duplex for virtio_net is 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'.

Note that VIRTIO_NET_F_SPEED_DUPLEX is defined as bit 63, the intention
is that device feature bits are to grow down from bit 63, since the
transports are starting from bit 24 and growing up.

Signed-off-by: Jason Baron <jbaron@akamai.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: virtio-dev@lists.oasis-open.org
---
 drivers/net/virtio_net.c        | 19 ++++++++++++++++++-
 include/uapi/linux/virtio_net.h | 13 +++++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 6fb7b65..0b2d314 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2146,6 +2146,22 @@ static void virtnet_config_changed_work(struct work_struct *work)
 
 	vi->status = v;
 
+	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX)) {
+		u32 speed;
+		u8 duplex;
+
+		speed = virtio_cread32(vi->vdev,
+				       offsetof(struct virtio_net_config,
+						speed));
+		if (ethtool_validate_speed(speed))
+			vi->speed = speed;
+		duplex = virtio_cread8(vi->vdev,
+				       offsetof(struct virtio_net_config,
+						duplex));
+		if (ethtool_validate_duplex(duplex))
+			vi->duplex = duplex;
+	}
+
 	if (vi->status & VIRTIO_NET_S_LINK_UP) {
 		netif_carrier_on(vi->dev);
 		netif_tx_wake_all_queues(vi->dev);
@@ -2796,7 +2812,8 @@ 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..5de6ed3 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	/* Device 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 +78,17 @@ struct virtio_net_config {
 	__u16 max_virtqueue_pairs;
 	/* Default maximum transmit unit advice */
 	__u16 mtu;
+	/*
+	 * 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

Re: [Qemu-devel] [PATCH net-next v3 1/3] virtio_net: propagate linkspeed/duplex settings from the hypervisor

[Michael S. Tsirkin]

On Thu, Jan 04, 2018 at 12:16:44AM -0500, Jason Baron wrote:
> The ability to set speed and duplex for virtio_net is 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'.
> 
> Note that VIRTIO_NET_F_SPEED_DUPLEX is defined as bit 63, the intention
> is that device feature bits are to grow down from bit 63, since the
> transports are starting from bit 24 and growing up.
> 
> Signed-off-by: Jason Baron <jbaron@akamai.com>
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> Cc: virtio-dev@lists.oasis-open.org
> ---
>  drivers/net/virtio_net.c        | 19 ++++++++++++++++++-
>  include/uapi/linux/virtio_net.h | 13 +++++++++++++
>  2 files changed, 31 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 6fb7b65..0b2d314 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -2146,6 +2146,22 @@ static void virtnet_config_changed_work(struct work_struct *work)
>  
>  	vi->status = v;
>  
> +	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX)) {
> +		u32 speed;
> +		u8 duplex;
> +
> +		speed = virtio_cread32(vi->vdev,
> +				       offsetof(struct virtio_net_config,
> +						speed));
> +		if (ethtool_validate_speed(speed))
> +			vi->speed = speed;
> +		duplex = virtio_cread8(vi->vdev,
> +				       offsetof(struct virtio_net_config,
> +						duplex));
> +		if (ethtool_validate_duplex(duplex))
> +			vi->duplex = duplex;
> +	}
> +
>  	if (vi->status & VIRTIO_NET_S_LINK_UP) {
>  		netif_carrier_on(vi->dev);
>  		netif_tx_wake_all_queues(vi->dev);
> @@ -2796,7 +2812,8 @@ 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,

Still missing the update from virtnet_config_changed_work, and I think
it's important to reflex host changes within guest when the
feature bit has been acked.

> diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
> index fc353b5..5de6ed3 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	/* Device 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 +78,17 @@ struct virtio_net_config {
>  	__u16 max_virtqueue_pairs;
>  	/* Default maximum transmit unit advice */
>  	__u16 mtu;
> +	/*
> +	 * 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

Re: [Qemu-devel] [PATCH net-next v3 1/3] virtio_net: propagate linkspeed/duplex settings from the hypervisor

[Jason Baron]

On 01/04/2018 11:27 AM, Michael S. Tsirkin wrote:
> On Thu, Jan 04, 2018 at 12:16:44AM -0500, Jason Baron wrote:
>> The ability to set speed and duplex for virtio_net is 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'.
>>
>> Note that VIRTIO_NET_F_SPEED_DUPLEX is defined as bit 63, the intention
>> is that device feature bits are to grow down from bit 63, since the
>> transports are starting from bit 24 and growing up.
>>
>> Signed-off-by: Jason Baron <jbaron@akamai.com>
>> Cc: "Michael S. Tsirkin" <mst@redhat.com>
>> Cc: Jason Wang <jasowang@redhat.com>
>> Cc: virtio-dev@lists.oasis-open.org
>> ---
>>  drivers/net/virtio_net.c        | 19 ++++++++++++++++++-
>>  include/uapi/linux/virtio_net.h | 13 +++++++++++++
>>  2 files changed, 31 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
>> index 6fb7b65..0b2d314 100644
>> --- a/drivers/net/virtio_net.c
>> +++ b/drivers/net/virtio_net.c
>> @@ -2146,6 +2146,22 @@ static void virtnet_config_changed_work(struct work_struct *work)
>>  
>>  	vi->status = v;
>>  
>> +	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX)) {
>> +		u32 speed;
>> +		u8 duplex;
>> +
>> +		speed = virtio_cread32(vi->vdev,
>> +				       offsetof(struct virtio_net_config,
>> +						speed));
>> +		if (ethtool_validate_speed(speed))
>> +			vi->speed = speed;
>> +		duplex = virtio_cread8(vi->vdev,
>> +				       offsetof(struct virtio_net_config,
>> +						duplex));
>> +		if (ethtool_validate_duplex(duplex))
>> +			vi->duplex = duplex;
>> +	}
>> +
>>  	if (vi->status & VIRTIO_NET_S_LINK_UP) {
>>  		netif_carrier_on(vi->dev);
>>  		netif_tx_wake_all_queues(vi->dev);
>> @@ -2796,7 +2812,8 @@ 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,
> 
> Still missing the update from virtnet_config_changed_work, and I think
> it's important to reflex host changes within guest when the
> feature bit has been acked.
> 

I update vi->speed and vi->duplex in virtnet_config_changed_work(). And
I tested using the 'set_link' on/off from the qemu monitor.
Specifically, an 'off' sets the speed and link to 'unknown', and an 'on'
returns the speed and link to the configured speed and duplex. So they
are being updated dynamically now. What host changes are you referring
to that are not reflected?

Thanks,

-Jason


>> diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
>> index fc353b5..5de6ed3 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	/* Device 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 +78,17 @@ struct virtio_net_config {
>>  	__u16 max_virtqueue_pairs;
>>  	/* Default maximum transmit unit advice */
>>  	__u16 mtu;
>> +	/*
>> +	 * 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

Re: [Qemu-devel] [PATCH net-next v3 1/3] virtio_net: propagate linkspeed/duplex settings from the hypervisor

[Michael S. Tsirkin]

On Thu, Jan 04, 2018 at 11:57:44AM -0500, Jason Baron wrote:
> 
> 
> On 01/04/2018 11:27 AM, Michael S. Tsirkin wrote:
> > On Thu, Jan 04, 2018 at 12:16:44AM -0500, Jason Baron wrote:
> >> The ability to set speed and duplex for virtio_net is 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'.
> >>
> >> Note that VIRTIO_NET_F_SPEED_DUPLEX is defined as bit 63, the intention
> >> is that device feature bits are to grow down from bit 63, since the
> >> transports are starting from bit 24 and growing up.
> >>
> >> Signed-off-by: Jason Baron <jbaron@akamai.com>
> >> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> >> Cc: Jason Wang <jasowang@redhat.com>
> >> Cc: virtio-dev@lists.oasis-open.org
> >> ---
> >>  drivers/net/virtio_net.c        | 19 ++++++++++++++++++-
> >>  include/uapi/linux/virtio_net.h | 13 +++++++++++++
> >>  2 files changed, 31 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> >> index 6fb7b65..0b2d314 100644
> >> --- a/drivers/net/virtio_net.c
> >> +++ b/drivers/net/virtio_net.c
> >> @@ -2146,6 +2146,22 @@ static void virtnet_config_changed_work(struct work_struct *work)
> >>  
> >>  	vi->status = v;
> >>  
> >> +	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX)) {
> >> +		u32 speed;
> >> +		u8 duplex;
> >> +
> >> +		speed = virtio_cread32(vi->vdev,
> >> +				       offsetof(struct virtio_net_config,
> >> +						speed));
> >> +		if (ethtool_validate_speed(speed))
> >> +			vi->speed = speed;
> >> +		duplex = virtio_cread8(vi->vdev,
> >> +				       offsetof(struct virtio_net_config,
> >> +						duplex));
> >> +		if (ethtool_validate_duplex(duplex))
> >> +			vi->duplex = duplex;
> >> +	}
> >> +
> >>  	if (vi->status & VIRTIO_NET_S_LINK_UP) {
> >>  		netif_carrier_on(vi->dev);
> >>  		netif_tx_wake_all_queues(vi->dev);
> >> @@ -2796,7 +2812,8 @@ 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,
> > 
> > Still missing the update from virtnet_config_changed_work, and I think
> > it's important to reflex host changes within guest when the
> > feature bit has been acked.
> > 
> 
> I update vi->speed and vi->duplex in virtnet_config_changed_work(). And
> I tested using the 'set_link' on/off from the qemu monitor.
> Specifically, an 'off' sets the speed and link to 'unknown', and an 'on'
> returns the speed and link to the configured speed and duplex. So they
> are being updated dynamically now. What host changes are you referring
> to that are not reflected?
> 
> Thanks,
> 
> -Jason

Ouch, I was reviewing an old version and replied to this one.
Sorry, will re-read now.

> 
> >> diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
> >> index fc353b5..5de6ed3 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	/* Device 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 +78,17 @@ struct virtio_net_config {
> >>  	__u16 max_virtqueue_pairs;
> >>  	/* Default maximum transmit unit advice */
> >>  	__u16 mtu;
> >> +	/*
> >> +	 * 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

Re: [Qemu-devel] [PATCH net-next v3 1/3] virtio_net: propagate linkspeed/duplex settings from the hypervisor

[Michael S. Tsirkin]

On Thu, Jan 04, 2018 at 12:16:44AM -0500, Jason Baron wrote:
> The ability to set speed and duplex for virtio_net is 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'.
> 
> Note that VIRTIO_NET_F_SPEED_DUPLEX is defined as bit 63, the intention
> is that device feature bits are to grow down from bit 63, since the
> transports are starting from bit 24 and growing up.
> 
> Signed-off-by: Jason Baron <jbaron@akamai.com>
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> Cc: virtio-dev@lists.oasis-open.org
> ---
>  drivers/net/virtio_net.c        | 19 ++++++++++++++++++-
>  include/uapi/linux/virtio_net.h | 13 +++++++++++++
>  2 files changed, 31 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 6fb7b65..0b2d314 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -2146,6 +2146,22 @@ static void virtnet_config_changed_work(struct work_struct *work)
>  
>  	vi->status = v;
>  
> +	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX)) {

BTW we can avoid this read for when link goes down.
Not a big deal but still.

> +		u32 speed;
> +		u8 duplex;
> +
> +		speed = virtio_cread32(vi->vdev,
> +				       offsetof(struct virtio_net_config,
> +						speed));
> +		if (ethtool_validate_speed(speed))
> +			vi->speed = speed;
> +		duplex = virtio_cread8(vi->vdev,
> +				       offsetof(struct virtio_net_config,
> +						duplex));
> +		if (ethtool_validate_duplex(duplex))
> +			vi->duplex = duplex;
> +	}
> +
>  	if (vi->status & VIRTIO_NET_S_LINK_UP) {
>  		netif_carrier_on(vi->dev);
>  		netif_tx_wake_all_queues(vi->dev);

OK so this handles the case when VIRTIO_NET_F_STATUS is set,
but when it's clear we need to call this from virtnet_probe.

I propose moving this chunk to a function and calling from two places.


> @@ -2796,7 +2812,8 @@ 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..5de6ed3 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	/* Device 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 +78,17 @@ struct virtio_net_config {
>  	__u16 max_virtqueue_pairs;
>  	/* Default maximum transmit unit advice */
>  	__u16 mtu;
> +	/*
> +	 * 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

Re: [Qemu-devel] [PATCH net-next v3 1/3] virtio_net: propagate linkspeed/duplex settings from the hypervisor

[Jason Baron]

On 01/04/2018 12:05 PM, Michael S. Tsirkin wrote:
> On Thu, Jan 04, 2018 at 12:16:44AM -0500, Jason Baron wrote:
>> The ability to set speed and duplex for virtio_net is 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'.
>>
>> Note that VIRTIO_NET_F_SPEED_DUPLEX is defined as bit 63, the intention
>> is that device feature bits are to grow down from bit 63, since the
>> transports are starting from bit 24 and growing up.
>>
>> Signed-off-by: Jason Baron <jbaron@akamai.com>
>> Cc: "Michael S. Tsirkin" <mst@redhat.com>
>> Cc: Jason Wang <jasowang@redhat.com>
>> Cc: virtio-dev@lists.oasis-open.org
>> ---
>>  drivers/net/virtio_net.c        | 19 ++++++++++++++++++-
>>  include/uapi/linux/virtio_net.h | 13 +++++++++++++
>>  2 files changed, 31 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
>> index 6fb7b65..0b2d314 100644
>> --- a/drivers/net/virtio_net.c
>> +++ b/drivers/net/virtio_net.c
>> @@ -2146,6 +2146,22 @@ static void virtnet_config_changed_work(struct work_struct *work)
>>  
>>  	vi->status = v;
>>  
>> +	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX)) {
> 
> BTW we can avoid this read for when link goes down.
> Not a big deal but still.

So you are saying that we can just set vi->speed and vi->duplex to
'unknown' when the link goes down and not check for the presence of
VIRTIO_NET_F_SPEED_DUPLEX?

If so, that could over-write what the user may have configured in the
guest via 'ethtool -s' when the link goes down, so that would be a
change in behavior, but perhaps that is ok?

I think I would prefer to have the link down event still check for
VIRTIO_NET_F_SPEED_DUPLEX before changing speed/duplex. That way we
still have 2 modes for updating the fields:

1) completely guest controlled. Same as we have now and host does not
change any values and does not set VIRTIO_NET_F_SPEED_DUPLEX flag (hence
don't remove above check).

2) if speed or duplex or speed is set in the qemu command line, then set
the VIRTIO_NET_F_SPEED_DUPLEX and have host control the settings of
speed/duplex (with ability of guest to over-write if it wanted to).


> 
>> +		u32 speed;
>> +		u8 duplex;
>> +
>> +		speed = virtio_cread32(vi->vdev,
>> +				       offsetof(struct virtio_net_config,
>> +						speed));
>> +		if (ethtool_validate_speed(speed))
>> +			vi->speed = speed;
>> +		duplex = virtio_cread8(vi->vdev,
>> +				       offsetof(struct virtio_net_config,
>> +						duplex));
>> +		if (ethtool_validate_duplex(duplex))
>> +			vi->duplex = duplex;
>> +	}
>> +
>>  	if (vi->status & VIRTIO_NET_S_LINK_UP) {
>>  		netif_carrier_on(vi->dev);
>>  		netif_tx_wake_all_queues(vi->dev);
> 
> OK so this handles the case when VIRTIO_NET_F_STATUS is set,
> but when it's clear we need to call this from virtnet_probe.
> 
> I propose moving this chunk to a function and calling from two places.
> 

good point. will update.

Thanks,

-Jason

> 
>> @@ -2796,7 +2812,8 @@ 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..5de6ed3 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	/* Device 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 +78,17 @@ struct virtio_net_config {
>>  	__u16 max_virtqueue_pairs;
>>  	/* Default maximum transmit unit advice */
>>  	__u16 mtu;
>> +	/*
>> +	 * 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

Re: [Qemu-devel] [PATCH net-next v3 1/3] virtio_net: propagate linkspeed/duplex settings from the hypervisor

[Michael S. Tsirkin]

On Thu, Jan 04, 2018 at 01:12:30PM -0500, Jason Baron wrote:
> 
> 
> On 01/04/2018 12:05 PM, Michael S. Tsirkin wrote:
> > On Thu, Jan 04, 2018 at 12:16:44AM -0500, Jason Baron wrote:
> >> The ability to set speed and duplex for virtio_net is 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'.
> >>
> >> Note that VIRTIO_NET_F_SPEED_DUPLEX is defined as bit 63, the intention
> >> is that device feature bits are to grow down from bit 63, since the
> >> transports are starting from bit 24 and growing up.
> >>
> >> Signed-off-by: Jason Baron <jbaron@akamai.com>
> >> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> >> Cc: Jason Wang <jasowang@redhat.com>
> >> Cc: virtio-dev@lists.oasis-open.org
> >> ---
> >>  drivers/net/virtio_net.c        | 19 ++++++++++++++++++-
> >>  include/uapi/linux/virtio_net.h | 13 +++++++++++++
> >>  2 files changed, 31 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> >> index 6fb7b65..0b2d314 100644
> >> --- a/drivers/net/virtio_net.c
> >> +++ b/drivers/net/virtio_net.c
> >> @@ -2146,6 +2146,22 @@ static void virtnet_config_changed_work(struct work_struct *work)
> >>  
> >>  	vi->status = v;
> >>  
> >> +	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX)) {
> > 
> > BTW we can avoid this read for when link goes down.
> > Not a big deal but still.
> 
> So you are saying that we can just set vi->speed and vi->duplex to
> 'unknown' when the link goes down and not check for the presence of
> VIRTIO_NET_F_SPEED_DUPLEX?
> 
> If so, that could over-write what the user may have configured in the
> guest via 'ethtool -s' when the link goes down, so that would be a
> change in behavior, but perhaps that is ok?

No - what I am saying is that your patch overwrites the values
set by user when link goes down.

I suggest limiting this call to when

if (vi->status & VIRTIO_NET_S_LINK_UP)

and then the values are overwritten when link goes up
which seems closer to what a user might expect.

> 
> I think I would prefer to have the link down event still check for
> VIRTIO_NET_F_SPEED_DUPLEX before changing speed/duplex. That way we
> still have 2 modes for updating the fields:
> 
> 1) completely guest controlled. Same as we have now and host does not
> change any values and does not set VIRTIO_NET_F_SPEED_DUPLEX flag (hence
> don't remove above check).
> 
> 2) if speed or duplex or speed is set in the qemu command line, then set
> the VIRTIO_NET_F_SPEED_DUPLEX and have host control the settings of
> speed/duplex (with ability of guest to over-write if it wanted to).
> 
> 
> > 
> >> +		u32 speed;
> >> +		u8 duplex;
> >> +
> >> +		speed = virtio_cread32(vi->vdev,
> >> +				       offsetof(struct virtio_net_config,
> >> +						speed));
> >> +		if (ethtool_validate_speed(speed))
> >> +			vi->speed = speed;
> >> +		duplex = virtio_cread8(vi->vdev,
> >> +				       offsetof(struct virtio_net_config,
> >> +						duplex));
> >> +		if (ethtool_validate_duplex(duplex))
> >> +			vi->duplex = duplex;
> >> +	}
> >> +
> >>  	if (vi->status & VIRTIO_NET_S_LINK_UP) {
> >>  		netif_carrier_on(vi->dev);
> >>  		netif_tx_wake_all_queues(vi->dev);
> > 
> > OK so this handles the case when VIRTIO_NET_F_STATUS is set,
> > but when it's clear we need to call this from virtnet_probe.
> > 
> > I propose moving this chunk to a function and calling from two places.
> > 
> 
> good point. will update.
> 
> Thanks,
> 
> -Jason
> 
> > 
> >> @@ -2796,7 +2812,8 @@ 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..5de6ed3 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	/* Device 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 +78,17 @@ struct virtio_net_config {
> >>  	__u16 max_virtqueue_pairs;
> >>  	/* Default maximum transmit unit advice */
> >>  	__u16 mtu;
> >> +	/*
> >> +	 * 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

Re: [Qemu-devel] [PATCH net-next v3 1/3] virtio_net: propagate linkspeed/duplex settings from the hypervisor

[Michael S. Tsirkin]

On Thu, Jan 04, 2018 at 08:22:08PM +0200, Michael S. Tsirkin wrote:
> On Thu, Jan 04, 2018 at 01:12:30PM -0500, Jason Baron wrote:
> > 
> > 
> > On 01/04/2018 12:05 PM, Michael S. Tsirkin wrote:
> > > On Thu, Jan 04, 2018 at 12:16:44AM -0500, Jason Baron wrote:
> > >> The ability to set speed and duplex for virtio_net is 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'.
> > >>
> > >> Note that VIRTIO_NET_F_SPEED_DUPLEX is defined as bit 63, the intention
> > >> is that device feature bits are to grow down from bit 63, since the
> > >> transports are starting from bit 24 and growing up.
> > >>
> > >> Signed-off-by: Jason Baron <jbaron@akamai.com>
> > >> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> > >> Cc: Jason Wang <jasowang@redhat.com>
> > >> Cc: virtio-dev@lists.oasis-open.org
> > >> ---
> > >>  drivers/net/virtio_net.c        | 19 ++++++++++++++++++-
> > >>  include/uapi/linux/virtio_net.h | 13 +++++++++++++
> > >>  2 files changed, 31 insertions(+), 1 deletion(-)
> > >>
> > >> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > >> index 6fb7b65..0b2d314 100644
> > >> --- a/drivers/net/virtio_net.c
> > >> +++ b/drivers/net/virtio_net.c
> > >> @@ -2146,6 +2146,22 @@ static void virtnet_config_changed_work(struct work_struct *work)
> > >>  
> > >>  	vi->status = v;
> > >>  
> > >> +	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX)) {
> > > 
> > > BTW we can avoid this read for when link goes down.
> > > Not a big deal but still.
> > 
> > So you are saying that we can just set vi->speed and vi->duplex to
> > 'unknown' when the link goes down and not check for the presence of
> > VIRTIO_NET_F_SPEED_DUPLEX?
> > 
> > If so, that could over-write what the user may have configured in the
> > guest via 'ethtool -s' when the link goes down, so that would be a
> > change in behavior, but perhaps that is ok?
> 
> No - what I am saying is that your patch overwrites the values
> set by user when link goes down.
> 
> I suggest limiting this call to when
> 
> if (vi->status & VIRTIO_NET_S_LINK_UP)
> 
> and then the values are overwritten when link goes up
> which seems closer to what a user might expect.
> 
> > 
> > I think I would prefer to have the link down event still check for
> > VIRTIO_NET_F_SPEED_DUPLEX before changing speed/duplex. That way we
> > still have 2 modes for updating the fields:
> > 
> > 1) completely guest controlled. Same as we have now and host does not
> > change any values and does not set VIRTIO_NET_F_SPEED_DUPLEX flag (hence
> > don't remove above check).
> > 
> > 2) if speed or duplex or speed is set in the qemu command line, then set
> > the VIRTIO_NET_F_SPEED_DUPLEX and have host control the settings of
> > speed/duplex (with ability of guest to over-write if it wanted to).


I agree - I don't see a reason to touch the speed/duplex values when
VIRTIO_NET_F_SPEED_DUPLEX has not been negotiated.

> > 
> > 
> > > 
> > >> +		u32 speed;
> > >> +		u8 duplex;
> > >> +
> > >> +		speed = virtio_cread32(vi->vdev,
> > >> +				       offsetof(struct virtio_net_config,
> > >> +						speed));
> > >> +		if (ethtool_validate_speed(speed))
> > >> +			vi->speed = speed;
> > >> +		duplex = virtio_cread8(vi->vdev,
> > >> +				       offsetof(struct virtio_net_config,
> > >> +						duplex));
> > >> +		if (ethtool_validate_duplex(duplex))
> > >> +			vi->duplex = duplex;
> > >> +	}
> > >> +
> > >>  	if (vi->status & VIRTIO_NET_S_LINK_UP) {
> > >>  		netif_carrier_on(vi->dev);
> > >>  		netif_tx_wake_all_queues(vi->dev);
> > > 
> > > OK so this handles the case when VIRTIO_NET_F_STATUS is set,
> > > but when it's clear we need to call this from virtnet_probe.
> > > 
> > > I propose moving this chunk to a function and calling from two places.
> > > 
> > 
> > good point. will update.
> > 
> > Thanks,
> > 
> > -Jason
> > 
> > > 
> > >> @@ -2796,7 +2812,8 @@ 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..5de6ed3 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	/* Device 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 +78,17 @@ struct virtio_net_config {
> > >>  	__u16 max_virtqueue_pairs;
> > >>  	/* Default maximum transmit unit advice */
> > >>  	__u16 mtu;
> > >> +	/*
> > >> +	 * 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

Re: [Qemu-devel] [PATCH net-next v3 1/3] virtio_net: propagate linkspeed/duplex settings from the hypervisor

[Jason Baron]

On 01/04/2018 01:22 PM, Michael S. Tsirkin wrote:
> On Thu, Jan 04, 2018 at 01:12:30PM -0500, Jason Baron wrote:
>>
>>
>> On 01/04/2018 12:05 PM, Michael S. Tsirkin wrote:
>>> On Thu, Jan 04, 2018 at 12:16:44AM -0500, Jason Baron wrote:
>>>> The ability to set speed and duplex for virtio_net is 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'.
>>>>
>>>> Note that VIRTIO_NET_F_SPEED_DUPLEX is defined as bit 63, the intention
>>>> is that device feature bits are to grow down from bit 63, since the
>>>> transports are starting from bit 24 and growing up.
>>>>
>>>> Signed-off-by: Jason Baron <jbaron@akamai.com>
>>>> Cc: "Michael S. Tsirkin" <mst@redhat.com>
>>>> Cc: Jason Wang <jasowang@redhat.com>
>>>> Cc: virtio-dev@lists.oasis-open.org
>>>> ---
>>>>  drivers/net/virtio_net.c        | 19 ++++++++++++++++++-
>>>>  include/uapi/linux/virtio_net.h | 13 +++++++++++++
>>>>  2 files changed, 31 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
>>>> index 6fb7b65..0b2d314 100644
>>>> --- a/drivers/net/virtio_net.c
>>>> +++ b/drivers/net/virtio_net.c
>>>> @@ -2146,6 +2146,22 @@ static void virtnet_config_changed_work(struct work_struct *work)
>>>>  
>>>>  	vi->status = v;
>>>>  
>>>> +	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX)) {
>>>
>>> BTW we can avoid this read for when link goes down.
>>> Not a big deal but still.
>>
>> So you are saying that we can just set vi->speed and vi->duplex to
>> 'unknown' when the link goes down and not check for the presence of
>> VIRTIO_NET_F_SPEED_DUPLEX?
>>
>> If so, that could over-write what the user may have configured in the
>> guest via 'ethtool -s' when the link goes down, so that would be a
>> change in behavior, but perhaps that is ok?
> 
> No - what I am saying is that your patch overwrites the values
> set by user when link goes down.
> 
> I suggest limiting this call to when
> 
> if (vi->status & VIRTIO_NET_S_LINK_UP)
> 
> and then the values are overwritten when link goes up
> which seems closer to what a user might expect.
ok, will update this for v4.

Thanks,

-Jason

> 
>>
>> I think I would prefer to have the link down event still check for
>> VIRTIO_NET_F_SPEED_DUPLEX before changing speed/duplex. That way we
>> still have 2 modes for updating the fields:
>>
>> 1) completely guest controlled. Same as we have now and host does not
>> change any values and does not set VIRTIO_NET_F_SPEED_DUPLEX flag (hence
>> don't remove above check).
>>
>> 2) if speed or duplex or speed is set in the qemu command line, then set
>> the VIRTIO_NET_F_SPEED_DUPLEX and have host control the settings of
>> speed/duplex (with ability of guest to over-write if it wanted to).
>>
>>
>>>
>>>> +		u32 speed;
>>>> +		u8 duplex;
>>>> +
>>>> +		speed = virtio_cread32(vi->vdev,
>>>> +				       offsetof(struct virtio_net_config,
>>>> +						speed));
>>>> +		if (ethtool_validate_speed(speed))
>>>> +			vi->speed = speed;
>>>> +		duplex = virtio_cread8(vi->vdev,
>>>> +				       offsetof(struct virtio_net_config,
>>>> +						duplex));
>>>> +		if (ethtool_validate_duplex(duplex))
>>>> +			vi->duplex = duplex;
>>>> +	}
>>>> +
>>>>  	if (vi->status & VIRTIO_NET_S_LINK_UP) {
>>>>  		netif_carrier_on(vi->dev);
>>>>  		netif_tx_wake_all_queues(vi->dev);
>>>
>>> OK so this handles the case when VIRTIO_NET_F_STATUS is set,
>>> but when it's clear we need to call this from virtnet_probe.
>>>
>>> I propose moving this chunk to a function and calling from two places.
>>>
>>
>> good point. will update.
>>
>> Thanks,
>>
>> -Jason
>>
>>>
>>>> @@ -2796,7 +2812,8 @@ 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..5de6ed3 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	/* Device 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 +78,17 @@ struct virtio_net_config {
>>>>  	__u16 max_virtqueue_pairs;
>>>>  	/* Default maximum transmit unit advice */
>>>>  	__u16 mtu;
>>>> +	/*
>>>> +	 * 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

[Qemu-devel] [PATCH v3 3/3] qemu: add linkspeed and duplex settings to virtio-net

[Jason Baron]

Although linkspeed and duplex can be set in a linux guest via 'ethtool -s',
this requires custom ethtool commands for virtio-net by default.

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'.

Linkspeed and duplex settings can be set as:
'-device virtio-net,speed=10000,duplex=full'

where speed is [-1...INT_MAX], and duplex is ["half"|"full"].

Signed-off-by: Jason Baron <jbaron@akamai.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: virtio-dev@lists.oasis-open.org
---
 hw/net/virtio-net.c                         | 35 +++++++++++++++++++++++++++++
 include/hw/virtio/virtio-net.h              |  3 +++
 include/standard-headers/linux/virtio_net.h | 13 +++++++++++
 3 files changed, 51 insertions(+)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index adc20df..eec8422 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -40,6 +40,12 @@
 #define VIRTIO_NET_RX_QUEUE_MIN_SIZE VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE
 #define VIRTIO_NET_TX_QUEUE_MIN_SIZE VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE
 
+/* duplex and speed */
+#define DUPLEX_UNKNOWN          0xff
+#define DUPLEX_HALF             0x00
+#define DUPLEX_FULL             0x01
+#define SPEED_UNKNOWN           -1
+
 /*
  * Calculate the number of bytes up to and including the given 'field' of
  * 'container'.
@@ -61,6 +67,8 @@ static VirtIOFeature feature_sizes[] = {
      .end = endof(struct virtio_net_config, max_virtqueue_pairs)},
     {.flags = 1ULL << VIRTIO_NET_F_MTU,
      .end = endof(struct virtio_net_config, mtu)},
+    {.flags = 1ULL << VIRTIO_NET_F_SPEED_DUPLEX,
+     .end = endof(struct virtio_net_config, duplex)},
     {}
 };
 
@@ -89,6 +97,14 @@ static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
     virtio_stw_p(vdev, &netcfg.max_virtqueue_pairs, n->max_queues);
     virtio_stw_p(vdev, &netcfg.mtu, n->net_conf.mtu);
     memcpy(netcfg.mac, n->mac, ETH_ALEN);
+    if (n->status & VIRTIO_NET_S_LINK_UP) {
+        virtio_stl_p(vdev, &netcfg.speed, n->net_conf.speed);
+        netcfg.duplex = n->net_conf.duplex;
+    } else {
+        virtio_stl_p(vdev, &netcfg.speed, SPEED_UNKNOWN);
+        netcfg.duplex = DUPLEX_UNKNOWN;
+    }
+
     memcpy(config, &netcfg, n->config_size);
 }
 
@@ -1941,6 +1957,23 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
         n->host_features |= (1ULL << VIRTIO_NET_F_MTU);
     }
 
+    n->host_features |= (1ULL << VIRTIO_NET_F_SPEED_DUPLEX);
+    if (n->net_conf.duplex_str) {
+        if (strncmp(n->net_conf.duplex_str, "half", 5) == 0) {
+            n->net_conf.duplex = DUPLEX_HALF;
+        } else if (strncmp(n->net_conf.duplex_str, "full", 5) == 0) {
+            n->net_conf.duplex = DUPLEX_FULL;
+        } else {
+            error_setg(errp, "'duplex' must be 'half' or 'full'");
+        }
+    } else {
+        n->net_conf.duplex = DUPLEX_UNKNOWN;
+    }
+    if (n->net_conf.speed < SPEED_UNKNOWN) {
+            error_setg(errp, "'speed' must be between -1 (SPEED_UNKOWN) and "
+                       "INT_MAX");
+    }
+
     virtio_net_set_config_size(n, n->host_features);
     virtio_init(vdev, "virtio-net", VIRTIO_ID_NET, n->config_size);
 
@@ -2160,6 +2193,8 @@ static Property virtio_net_properties[] = {
     DEFINE_PROP_UINT16("host_mtu", VirtIONet, net_conf.mtu, 0),
     DEFINE_PROP_BOOL("x-mtu-bypass-backend", VirtIONet, mtu_bypass_backend,
                      true),
+    DEFINE_PROP_INT32("speed", VirtIONet, net_conf.speed, SPEED_UNKNOWN),
+    DEFINE_PROP_STRING("duplex", VirtIONet, net_conf.duplex_str),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/include/hw/virtio/virtio-net.h b/include/hw/virtio/virtio-net.h
index e7634c9..02484dc 100644
--- a/include/hw/virtio/virtio-net.h
+++ b/include/hw/virtio/virtio-net.h
@@ -38,6 +38,9 @@ typedef struct virtio_net_conf
     uint16_t rx_queue_size;
     uint16_t tx_queue_size;
     uint16_t mtu;
+    int32_t speed;
+    char *duplex_str;
+    uint8_t duplex;
 } virtio_net_conf;
 
 /* Maximum packet size we can receive from tap device: header + 64k */
diff --git a/include/standard-headers/linux/virtio_net.h b/include/standard-headers/linux/virtio_net.h
index 30ff249..17c8531 100644
--- a/include/standard-headers/linux/virtio_net.h
+++ b/include/standard-headers/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   /* Device 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 +78,17 @@ struct virtio_net_config {
 	uint16_t max_virtqueue_pairs;
 	/* Default maximum transmit unit advice */
 	uint16_t mtu;
+	/*
+	 * speed, in units of 1Mb. All values 0 to INT_MAX are legal.
+	 * Any other value stands for unknown.
+	 */
+	uint32_t speed;
+	/*
+	 * 0x00 - half duplex
+	 * 0x01 - full duplex
+	 * Any other value stands for unknown.
+	 */
+	uint8_t duplex;
 } QEMU_PACKED;
 
 /*