| Message ID | 20220515064330.75604-1-alvaro.karsz@solid-run.com (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [v2] net: virtio_net: support interrupt coalescing | expand |
On Sun, May 15, 2022 at 09:43:30AM +0300, Alvaro Karsz wrote: > Control a Virtio network device interrupt coalescing parameters > using the control virtqueue. > > New VirtIO network feature: VIRTIO_NET_F_INTR_COAL. > > A device that supports this fetature can receive > VIRTIO_NET_CTRL_INTR_COAL control commands. > > - VIRTIO_NET_CTRL_INTR_COAL_USECS_SET: > change the rx-usecs and tx-usecs parameters. > > rx-usecs - Time to delay an RX interrupt after packet arrival in > microseconds. > > tx-usecs - Time to delay a TX interrupt after a sending a packet > in microseconds. > > - VIRTIO_NET_CTRL_INTR_COAL_FRAMES_SET: > change the rx-max-frames and tx-max-frames parameters. > > rx-max-frames: Number of packets to delay an RX interrupt after > packet arrival. > > tx-max-frames: Number of packets to delay a TX interrupt after > sending a packet. > > Signed-off-by: Alvaro Karsz <alvaro.karsz@solid-run.com> > --- > v2: > - usage of __virtio vairables. > - send commands to device only if the values have changed. > --- > drivers/net/virtio_net.c | 116 ++++++++++++++++++++++++++++---- > include/uapi/linux/virtio_net.h | 34 +++++++++- This needs review of the virtio TC, and a vote. Let's wait for this before merging please. Until then pls post RFC patches. For patch itself, I'm going on vacation until May 25, will review afterwards. > 2 files changed, 136 insertions(+), 14 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index cbba9d2e8f3..e40f453edb9 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -261,6 +261,12 @@ struct virtnet_info { > u8 duplex; > u32 speed; > > + /* Interrupt coalescing settings */ > + u32 tx_usecs; > + u32 rx_usecs; > + u32 tx_frames_max; > + u32 rx_frames_max; > + > unsigned long guest_offloads; > unsigned long guest_offloads_capable; > > @@ -2594,19 +2600,83 @@ static int virtnet_set_coalesce(struct net_device *dev, > { > struct virtnet_info *vi = netdev_priv(dev); > int i, napi_weight; > + struct scatterlist sgs_usecs, sgs_frames; > + struct virtio_net_ctrl_coal_frames c_frames; > + struct virtio_net_ctrl_coal_usec c_usecs; > + bool update_napi, > + intr_coal = virtio_has_feature(vi->vdev, VIRTIO_NET_F_INTR_COAL); > + > + /* rx_coalesce_usecs/tx_coalesce_usecs are supported only > + * if VIRTIO_NET_F_INTR_COAL feature is set. > + */ > + if (!intr_coal && (ec->rx_coalesce_usecs || ec->tx_coalesce_usecs)) > + return -EOPNOTSUPP; > > - if (ec->tx_max_coalesced_frames > 1 || > - ec->rx_max_coalesced_frames != 1) > + if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_INTR_COAL)) { > + /* Send usec command only if value has changed */ > + if (ec->tx_coalesce_usecs != vi->tx_usecs || > + ec->rx_coalesce_usecs != vi->rx_usecs) { > + c_usecs.tx_usecs = cpu_to_virtio32(vi->vdev, ec->tx_coalesce_usecs); > + c_usecs.rx_usecs = cpu_to_virtio32(vi->vdev, ec->rx_coalesce_usecs); > + sg_init_one(&sgs_usecs, &c_usecs, sizeof(c_usecs)); > + > + if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_INTR_COAL, > + VIRTIO_NET_CTRL_INTR_COAL_USECS_SET, > + &sgs_usecs)) > + return -EINVAL; > + > + /* Save parameters */ > + vi->tx_usecs = ec->tx_coalesce_usecs; > + vi->rx_usecs = ec->rx_coalesce_usecs; > + } > + > + /* Send frames command only if value has changed */ > + if (ec->tx_max_coalesced_frames != vi->tx_frames_max || > + ec->rx_max_coalesced_frames != vi->rx_frames_max) { > + c_frames.tx_frames_max = cpu_to_virtio32(vi->vdev, > + ec->tx_max_coalesced_frames); > + c_frames.rx_frames_max = cpu_to_virtio32(vi->vdev, > + ec->rx_max_coalesced_frames); > + sg_init_one(&sgs_frames, &c_frames, sizeof(c_frames)); > + > + if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_INTR_COAL, > + VIRTIO_NET_CTRL_INTR_COAL_FRAMES_SET, > + &sgs_frames)) > + return -EINVAL; > + > + /* Save parameters */ > + vi->tx_frames_max = ec->tx_max_coalesced_frames; > + vi->rx_frames_max = ec->rx_max_coalesced_frames; > + } > + } > + > + /* Should we update NAPI? */ > + update_napi = ec->tx_max_coalesced_frames <= 1 && > + ec->rx_max_coalesced_frames == 1; > + > + /* If interrupt coalesing feature is not set, and we can't update NAPI, return an error */ > + if (!intr_coal && !update_napi) > return -EINVAL; > > - napi_weight = ec->tx_max_coalesced_frames ? NAPI_POLL_WEIGHT : 0; > - if (napi_weight ^ vi->sq[0].napi.weight) { > - if (dev->flags & IFF_UP) > - return -EBUSY; > - for (i = 0; i < vi->max_queue_pairs; i++) > - vi->sq[i].napi.weight = napi_weight; > + if (update_napi) { > + napi_weight = ec->tx_max_coalesced_frames ? NAPI_POLL_WEIGHT : 0; > + if (napi_weight ^ vi->sq[0].napi.weight) { > + if (dev->flags & IFF_UP) { > + /* If Interrupt coalescing feature is not set, return an error. > + * Otherwise exit without changing the NAPI paremeters > + */ > + if (!intr_coal) > + return -EBUSY; > + > + goto exit; > + } > + > + for (i = 0; i < vi->max_queue_pairs; i++) > + vi->sq[i].napi.weight = napi_weight; > + } > } > > +exit: > return 0; > } > > @@ -2616,14 +2686,25 @@ static int virtnet_get_coalesce(struct net_device *dev, > struct netlink_ext_ack *extack) > { > struct ethtool_coalesce ec_default = { > - .cmd = ETHTOOL_GCOALESCE, > - .rx_max_coalesced_frames = 1, > + .cmd = ETHTOOL_GCOALESCE > }; > + > struct virtnet_info *vi = netdev_priv(dev); > + bool intr_coal = virtio_has_feature(vi->vdev, VIRTIO_NET_F_INTR_COAL); > + > + /* Add Interrupt coalescing settings */ > + if (intr_coal) { > + ec_default.rx_coalesce_usecs = vi->rx_usecs; > + ec_default.tx_coalesce_usecs = vi->tx_usecs; > + ec_default.tx_max_coalesced_frames = vi->tx_frames_max; > + ec_default.rx_max_coalesced_frames = vi->rx_frames_max; > + } else { > + ec_default.rx_max_coalesced_frames = 1; > + } > > memcpy(ec, &ec_default, sizeof(ec_default)); > > - if (vi->sq[0].napi.weight) > + if (!intr_coal && vi->sq[0].napi.weight) > ec->tx_max_coalesced_frames = 1; > > return 0; > @@ -2743,7 +2824,7 @@ static int virtnet_set_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info) > } > > static const struct ethtool_ops virtnet_ethtool_ops = { > - .supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES, > + .supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES | ETHTOOL_COALESCE_USECS, > .get_drvinfo = virtnet_get_drvinfo, > .get_link = ethtool_op_get_link, > .get_ringparam = virtnet_get_ringparam, > @@ -3423,6 +3504,8 @@ static bool virtnet_validate_features(struct virtio_device *vdev) > VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_RSS, > "VIRTIO_NET_F_CTRL_VQ") || > VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_HASH_REPORT, > + "VIRTIO_NET_F_CTRL_VQ") || > + VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_INTR_COAL, > "VIRTIO_NET_F_CTRL_VQ"))) { > return false; > } > @@ -3558,6 +3641,13 @@ static int virtnet_probe(struct virtio_device *vdev) > if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) > vi->mergeable_rx_bufs = true; > > + if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_INTR_COAL)) { > + vi->rx_usecs = 0; > + vi->tx_usecs = 0; > + vi->tx_frames_max = 0; > + vi->rx_frames_max = 0; > + } > + > if (virtio_has_feature(vdev, VIRTIO_NET_F_HASH_REPORT)) > vi->has_rss_hash_report = true; > > @@ -3786,7 +3876,7 @@ static struct virtio_device_id id_table[] = { > VIRTIO_NET_F_CTRL_MAC_ADDR, \ > VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \ > VIRTIO_NET_F_SPEED_DUPLEX, VIRTIO_NET_F_STANDBY, \ > - VIRTIO_NET_F_RSS, VIRTIO_NET_F_HASH_REPORT > + VIRTIO_NET_F_RSS, VIRTIO_NET_F_HASH_REPORT, VIRTIO_NET_F_INTR_COAL > > static unsigned int features[] = { > VIRTNET_FEATURES, > diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h > index 3f55a4215f1..05da9eb6ad9 100644 > --- a/include/uapi/linux/virtio_net.h > +++ b/include/uapi/linux/virtio_net.h > @@ -56,7 +56,7 @@ > #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_F_INTR_COAL 24 /* Guest can handle Interrupt coalescing */ > #define VIRTIO_NET_F_HASH_REPORT 57 /* Supports hash report */ > #define VIRTIO_NET_F_RSS 60 /* Supports RSS RX steering */ > #define VIRTIO_NET_F_RSC_EXT 61 /* extended coalescing info */ > @@ -355,4 +355,36 @@ struct virtio_net_hash_config { > #define VIRTIO_NET_CTRL_GUEST_OFFLOADS 5 > #define VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET 0 > > +/* > + * Control interrupt coalescing. > + * > + * Request the device to change the interrupt coalescing parameters. > + * > + * Available with the VIRTIO_NET_F_INTR_COAL feature bit. > + */ > +#define VIRTIO_NET_CTRL_INTR_COAL 6 > +/* > + * Set the rx-usecs/tx-usecs patameters. > + * rx-usecs - Number of microseconds to delay an RX interrupt after packet arrival. > + * tx-usecs - Number of microseconds to delay a TX interrupt after a sending a packet. > + */ > +struct virtio_net_ctrl_coal_usec { > + __virtio32 tx_usecs; > + __virtio32 rx_usecs; > +}; > + > +#define VIRTIO_NET_CTRL_INTR_COAL_USECS_SET 0 > + > +/* > + * Set the rx-max-frames/tx-max-frames patameters. > + * rx-max-frames - Number of packets to delay an RX interrupt after packet arrival. > + * tx-max-frames - Number of packets to delay a TX interrupt after sending a packet. > + */ > +struct virtio_net_ctrl_coal_frames { > + __virtio32 tx_frames_max; > + __virtio32 rx_frames_max; > +}; > + > +#define VIRTIO_NET_CTRL_INTR_COAL_FRAMES_SET 1 > + > #endif /* _UAPI_LINUX_VIRTIO_NET_H */ > -- > 2.32.0
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index cbba9d2e8f3..e40f453edb9 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -261,6 +261,12 @@ struct virtnet_info { u8 duplex; u32 speed; + /* Interrupt coalescing settings */ + u32 tx_usecs; + u32 rx_usecs; + u32 tx_frames_max; + u32 rx_frames_max; + unsigned long guest_offloads; unsigned long guest_offloads_capable; @@ -2594,19 +2600,83 @@ static int virtnet_set_coalesce(struct net_device *dev, { struct virtnet_info *vi = netdev_priv(dev); int i, napi_weight; + struct scatterlist sgs_usecs, sgs_frames; + struct virtio_net_ctrl_coal_frames c_frames; + struct virtio_net_ctrl_coal_usec c_usecs; + bool update_napi, + intr_coal = virtio_has_feature(vi->vdev, VIRTIO_NET_F_INTR_COAL); + + /* rx_coalesce_usecs/tx_coalesce_usecs are supported only + * if VIRTIO_NET_F_INTR_COAL feature is set. + */ + if (!intr_coal && (ec->rx_coalesce_usecs || ec->tx_coalesce_usecs)) + return -EOPNOTSUPP; - if (ec->tx_max_coalesced_frames > 1 || - ec->rx_max_coalesced_frames != 1) + if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_INTR_COAL)) { + /* Send usec command only if value has changed */ + if (ec->tx_coalesce_usecs != vi->tx_usecs || + ec->rx_coalesce_usecs != vi->rx_usecs) { + c_usecs.tx_usecs = cpu_to_virtio32(vi->vdev, ec->tx_coalesce_usecs); + c_usecs.rx_usecs = cpu_to_virtio32(vi->vdev, ec->rx_coalesce_usecs); + sg_init_one(&sgs_usecs, &c_usecs, sizeof(c_usecs)); + + if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_INTR_COAL, + VIRTIO_NET_CTRL_INTR_COAL_USECS_SET, + &sgs_usecs)) + return -EINVAL; + + /* Save parameters */ + vi->tx_usecs = ec->tx_coalesce_usecs; + vi->rx_usecs = ec->rx_coalesce_usecs; + } + + /* Send frames command only if value has changed */ + if (ec->tx_max_coalesced_frames != vi->tx_frames_max || + ec->rx_max_coalesced_frames != vi->rx_frames_max) { + c_frames.tx_frames_max = cpu_to_virtio32(vi->vdev, + ec->tx_max_coalesced_frames); + c_frames.rx_frames_max = cpu_to_virtio32(vi->vdev, + ec->rx_max_coalesced_frames); + sg_init_one(&sgs_frames, &c_frames, sizeof(c_frames)); + + if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_INTR_COAL, + VIRTIO_NET_CTRL_INTR_COAL_FRAMES_SET, + &sgs_frames)) + return -EINVAL; + + /* Save parameters */ + vi->tx_frames_max = ec->tx_max_coalesced_frames; + vi->rx_frames_max = ec->rx_max_coalesced_frames; + } + } + + /* Should we update NAPI? */ + update_napi = ec->tx_max_coalesced_frames <= 1 && + ec->rx_max_coalesced_frames == 1; + + /* If interrupt coalesing feature is not set, and we can't update NAPI, return an error */ + if (!intr_coal && !update_napi) return -EINVAL; - napi_weight = ec->tx_max_coalesced_frames ? NAPI_POLL_WEIGHT : 0; - if (napi_weight ^ vi->sq[0].napi.weight) { - if (dev->flags & IFF_UP) - return -EBUSY; - for (i = 0; i < vi->max_queue_pairs; i++) - vi->sq[i].napi.weight = napi_weight; + if (update_napi) { + napi_weight = ec->tx_max_coalesced_frames ? NAPI_POLL_WEIGHT : 0; + if (napi_weight ^ vi->sq[0].napi.weight) { + if (dev->flags & IFF_UP) { + /* If Interrupt coalescing feature is not set, return an error. + * Otherwise exit without changing the NAPI paremeters + */ + if (!intr_coal) + return -EBUSY; + + goto exit; + } + + for (i = 0; i < vi->max_queue_pairs; i++) + vi->sq[i].napi.weight = napi_weight; + } } +exit: return 0; } @@ -2616,14 +2686,25 @@ static int virtnet_get_coalesce(struct net_device *dev, struct netlink_ext_ack *extack) { struct ethtool_coalesce ec_default = { - .cmd = ETHTOOL_GCOALESCE, - .rx_max_coalesced_frames = 1, + .cmd = ETHTOOL_GCOALESCE }; + struct virtnet_info *vi = netdev_priv(dev); + bool intr_coal = virtio_has_feature(vi->vdev, VIRTIO_NET_F_INTR_COAL); + + /* Add Interrupt coalescing settings */ + if (intr_coal) { + ec_default.rx_coalesce_usecs = vi->rx_usecs; + ec_default.tx_coalesce_usecs = vi->tx_usecs; + ec_default.tx_max_coalesced_frames = vi->tx_frames_max; + ec_default.rx_max_coalesced_frames = vi->rx_frames_max; + } else { + ec_default.rx_max_coalesced_frames = 1; + } memcpy(ec, &ec_default, sizeof(ec_default)); - if (vi->sq[0].napi.weight) + if (!intr_coal && vi->sq[0].napi.weight) ec->tx_max_coalesced_frames = 1; return 0; @@ -2743,7 +2824,7 @@ static int virtnet_set_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info) } static const struct ethtool_ops virtnet_ethtool_ops = { - .supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES, + .supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES | ETHTOOL_COALESCE_USECS, .get_drvinfo = virtnet_get_drvinfo, .get_link = ethtool_op_get_link, .get_ringparam = virtnet_get_ringparam, @@ -3423,6 +3504,8 @@ static bool virtnet_validate_features(struct virtio_device *vdev) VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_RSS, "VIRTIO_NET_F_CTRL_VQ") || VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_HASH_REPORT, + "VIRTIO_NET_F_CTRL_VQ") || + VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_INTR_COAL, "VIRTIO_NET_F_CTRL_VQ"))) { return false; } @@ -3558,6 +3641,13 @@ static int virtnet_probe(struct virtio_device *vdev) if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) vi->mergeable_rx_bufs = true; + if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_INTR_COAL)) { + vi->rx_usecs = 0; + vi->tx_usecs = 0; + vi->tx_frames_max = 0; + vi->rx_frames_max = 0; + } + if (virtio_has_feature(vdev, VIRTIO_NET_F_HASH_REPORT)) vi->has_rss_hash_report = true; @@ -3786,7 +3876,7 @@ static struct virtio_device_id id_table[] = { VIRTIO_NET_F_CTRL_MAC_ADDR, \ VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \ VIRTIO_NET_F_SPEED_DUPLEX, VIRTIO_NET_F_STANDBY, \ - VIRTIO_NET_F_RSS, VIRTIO_NET_F_HASH_REPORT + VIRTIO_NET_F_RSS, VIRTIO_NET_F_HASH_REPORT, VIRTIO_NET_F_INTR_COAL static unsigned int features[] = { VIRTNET_FEATURES, diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h index 3f55a4215f1..05da9eb6ad9 100644 --- a/include/uapi/linux/virtio_net.h +++ b/include/uapi/linux/virtio_net.h @@ -56,7 +56,7 @@ #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_F_INTR_COAL 24 /* Guest can handle Interrupt coalescing */ #define VIRTIO_NET_F_HASH_REPORT 57 /* Supports hash report */ #define VIRTIO_NET_F_RSS 60 /* Supports RSS RX steering */ #define VIRTIO_NET_F_RSC_EXT 61 /* extended coalescing info */ @@ -355,4 +355,36 @@ struct virtio_net_hash_config { #define VIRTIO_NET_CTRL_GUEST_OFFLOADS 5 #define VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET 0 +/* + * Control interrupt coalescing. + * + * Request the device to change the interrupt coalescing parameters. + * + * Available with the VIRTIO_NET_F_INTR_COAL feature bit. + */ +#define VIRTIO_NET_CTRL_INTR_COAL 6 +/* + * Set the rx-usecs/tx-usecs patameters. + * rx-usecs - Number of microseconds to delay an RX interrupt after packet arrival. + * tx-usecs - Number of microseconds to delay a TX interrupt after a sending a packet. + */ +struct virtio_net_ctrl_coal_usec { + __virtio32 tx_usecs; + __virtio32 rx_usecs; +}; + +#define VIRTIO_NET_CTRL_INTR_COAL_USECS_SET 0 + +/* + * Set the rx-max-frames/tx-max-frames patameters. + * rx-max-frames - Number of packets to delay an RX interrupt after packet arrival. + * tx-max-frames - Number of packets to delay a TX interrupt after sending a packet. + */ +struct virtio_net_ctrl_coal_frames { + __virtio32 tx_frames_max; + __virtio32 rx_frames_max; +}; + +#define VIRTIO_NET_CTRL_INTR_COAL_FRAMES_SET 1 + #endif /* _UAPI_LINUX_VIRTIO_NET_H */
Control a Virtio network device interrupt coalescing parameters using the control virtqueue. New VirtIO network feature: VIRTIO_NET_F_INTR_COAL. A device that supports this fetature can receive VIRTIO_NET_CTRL_INTR_COAL control commands. - VIRTIO_NET_CTRL_INTR_COAL_USECS_SET: change the rx-usecs and tx-usecs parameters. rx-usecs - Time to delay an RX interrupt after packet arrival in microseconds. tx-usecs - Time to delay a TX interrupt after a sending a packet in microseconds. - VIRTIO_NET_CTRL_INTR_COAL_FRAMES_SET: change the rx-max-frames and tx-max-frames parameters. rx-max-frames: Number of packets to delay an RX interrupt after packet arrival. tx-max-frames: Number of packets to delay a TX interrupt after sending a packet. Signed-off-by: Alvaro Karsz <alvaro.karsz@solid-run.com> --- v2: - usage of __virtio vairables. - send commands to device only if the values have changed. --- drivers/net/virtio_net.c | 116 ++++++++++++++++++++++++++++---- include/uapi/linux/virtio_net.h | 34 +++++++++- 2 files changed, 136 insertions(+), 14 deletions(-)