Hello All: This series is an update version of multiqueue virtio-net driver based on Krishna Kumar's work to let virtio-net use multiple rx/tx queues to do the packets reception and transmission. Please review and comments. Test Environment: - Intel(R) Xeon(R) CPU E5620 @ 2.40GHz, 8 cores 2 numa nodes - Two directed connected 82599 Test Summary: - Highlights: huge improvements on TCP_RR test - Lowlights: regression on small packet transmission, higher cpu utilization than single queue, need further optimization Analysis of the performance result: - I count the number of packets sending/receiving during the test, and multiqueue show much more ability in terms of packets per second. - For the tx regression, multiqueue send about 1-2 times of more packets compared to single queue, and the packets size were much smaller than single queue does. I suspect tcp does less batching in multiqueue, so I hack the tcp_write_xmit() to forece more batching, multiqueue works as well as singlequeue for both small transmission and throughput - I didn't pack the accelerate RFS with virtio-net in this sereis as it still need further shaping, for the one that interested in this please see: http://www.mail-archive.com/kvm at vger.kernel.org/msg64111.html Detail result: Test results: smp = 2 pin vhosts and vcpus in the same node - 1 sq 2 mq(q=2) - TCP_MAERTS (Guest to external Host): sessions size throughput1 throughput2 norm1 norm2: 1 64 424.91 401.49 94% 13.20 12.35 93% 2 64 1211.06 878.31 72% 24.35 15.80 64% 4 64 1292.46 1081.78 83% 26.46 20.14 76% 8 64 1355.57 826.06 60% 27.88 15.32 54% 1 256 1489.37 1406.51 94% 46.93 43.72 93% 2 256 4936.19 2688.46 54% 100.24 46.39 46% 4 256 5251.10 2900.08 55% 107.98 50.47 46% 8 256 5270.11 3562.10 67% 108.26 66.19 61% 1 512 1877.57 2697.64 143% 57.29 83.02 144% 2 512 9183.49 5056.33 55% 205.26 86.43 42% 4 512 9349.59 8918.77 95% 212.78 176.99 83% 8 512 9318.29 8947.69 96% 216.55 176.34 81% 1 1024 4746.47 4669.10 98% 143.87 140.63 97% 2 1024 7406.49 4738.58 63% 245.16 131.04 53% 4 1024 8955.70 9337.82 104% 254.49 208.66 81% 8 1024 9384.48 9378.41 99% 260.24 197.77 75% 1 2048 8947.29 8955.98 100% 338.39 338.60 100% 2 2048 9259.04 9383.77 101% 326.02 224.92 68% 4 2048 9043.04 9325.38 103% 305.09 214.77 70% 8 2048 9358.04 8413.21 89% 291.07 189.74 65% 1 4096 8882.55 8885.40 100% 329.83 326.42 98% 2 4096 9247.07 9387.49 101% 345.55 240.51 69% 4 4096 9365.30 9341.82 99% 333.40 211.97 63% 8 4096 9397.64 8472.35 90% 312.21 182.51 58% 1 16384 8843.82 8725.50 98% 315.06 312.29 99% 2 16384 7978.70 9176.16 115% 280.34 317.62 113% 4 16384 8906.91 9251.15 103% 312.85 226.13 72% 8 16384 9385.36 9401.39 100% 341.53 207.53 60% - TCP_RR sessions size trans1 trans2 norm1 norm2 50 1 63021.83 93003.57 147% 2360.36 1972.08 83% 100 1 54599.87 93724.43 171% 2042.64 2119.50 103% 250 1 86546.75 119738.71 138% 2414.80 2508.14 103% 50 64 59785.19 97761.24 163% 2264.59 2136.85 94% 100 64 56028.20 103233.18 184% 2063.65 2260.91 109% 250 64 99116.82 113948.86 114% 2452.77 2393.88 97% 50 128 58025.96 84971.26 146% 2284.48 1907.75 83% 100 128 66302.76 83110.60 125% 2579.87 1881.60 72% 250 128 109262.23 137571.13 125% 2603.96 2911.55 111% 50 256 59766.57 77370.93 129% 2393.53 2018.02 84% 100 256 60862.02 80737.50 132% 2426.71 2024.51 83% 250 256 90076.66 141780.44 157% 2453.06 3056.27 124% - TCP_STREAM (External Host to Guest) sessions size throughput1 throughput2 norm1 norm2 1 64 373.53 575.24 154% 15.37 33.44 217% 2 64 1314.17 1087.49 82% 54.21 32.97 60% 4 64 3352.93 2404.70 71% 136.35 53.72 39% 8 64 6866.17 6587.17 95% 252.06 147.03 58% 1 256 677.37 767.65 113% 26.59 29.80 112% 2 256 4386.83 4550.40 103% 164.17 174.81 106% 4 256 8446.27 8814.95 104% 307.02 186.95 60% 8 256 6529.46 9370.44 143% 237.52 207.77 87% 1 512 2542.48 1371.31 53% 102.14 51.68 50% 2 512 9183.10 9354.81 101% 319.85 333.62 104% 4 512 8488.12 9230.58 108% 303.14 258.55 85% 8 512 8115.66 9393.33 115% 293.83 219.82 74% 1 1024 2653.16 2507.78 94% 100.88 96.56 95% 2 1024 6490.12 5033.35 77% 316.74 102.74 32% 4 1024 7582.51 9183.60 121% 298.87 210.48 70% 8 1024 8304.13 9341.48 112% 298.06 242.32 81% 1 2048 2495.06 2508.12 100% 99.60 102.96 103% 2 2048 8968.12 7554.57 84% 324.57 175.56 54% 4 2048 8627.85 9192.90 106% 310.91 205.98 66% 8 2048 7781.72 9422.10 121% 284.31 208.77 73% 1 4096 6067.46 4489.04 73% 233.63 171.01 73% 2 4096 9029.43 8684.09 96% 323.17 191.19 59% 4 4096 8284.30 9253.33 111% 306.93 268.67 87% 8 4096 7789.39 9388.32 120% 283.97 238.28 83% 1 16384 8660.90 9313.87 107% 318.88 315.61 98% 2 16384 8646.37 8871.30 102% 318.81 318.88 100% 4 16384 8386.02 9397.13 112% 306.28 205.44 67% 8 16384 8006.27 9404.98 117% 288.41 224.83 77% Test results: smp = 4 no pinning - 1 sq 2 mq(q=4) - TCP_MAERTS - Guest to External Host sessions size throughput1 throughput2 norm1 norm2 1 64 513.13 331.27 64% 15.86 10.39 65% 2 64 1325.72 543.38 40% 26.54 12.59 47% 4 64 2735.18 1168.01 42% 37.61 12.63 33% 8 64 3084.53 2278.38 73% 41.20 27.01 65% 1 256 1313.25 996.64 75% 41.23 28.59 69% 2 256 3425.64 3337.68 97% 71.57 61.69 86% 4 256 8174.33 4252.54 52% 126.63 49.68 39% 8 256 9365.96 8411.91 89% 145.00 101.64 70% 1 512 2363.07 2370.35 100% 73.00 73.52 100% 2 512 6047.23 3636.29 60% 135.43 61.02 45% 4 512 9330.76 7165.99 76% 184.18 95.50 51% 8 512 8178.20 9221.16 112% 162.52 122.44 75% 1 1024 3196.63 4016.30 125% 98.41 120.75 122% 2 1024 4940.41 9296.51 188% 140.03 191.95 137% 4 1024 5696.43 9018.76 158% 147.30 150.01 101% 8 1024 9355.07 9342.43 99% 216.90 140.48 64% 1 2048 4248.99 5189.24 122% 131.95 157.01 118% 2 2048 9021.22 9262.81 102% 242.37 198.21 81% 4 2048 8357.81 9241.94 110% 225.88 180.61 79% 8 2048 8024.56 9327.27 116% 205.75 145.76 70% 1 4096 9270.51 8199.32 88% 326.88 269.53 82% 2 4096 9151.10 9348.33 102% 257.92 214.46 83% 4 4096 9243.34 9294.30 100% 281.20 164.35 58% 8 4096 9020.35 9339.32 103% 249.87 143.54 57% 1 16384 9357.69 9355.69 99% 319.15 322.94 101% 2 16384 9319.39 9076.63 97% 319.26 215.64 67% 4 16384 9352.99 9183.41 98% 308.98 145.26 47% 8 16384 9384.67 9353.54 99% 322.49 155.78 48% - TCP_RR sessions size throughput1 throughput2 norm1 norm2 50 1 59677.80 71761.59 120% 2020.92 1585.19 78% 100 1 55324.42 81302.10 146% 1889.49 1439.22 76% 250 1 73973.48 155031.82 209% 2495.73 2195.91 87% 50 64 53093.57 67893.59 127% 1879.41 1266.19 67% 100 64 59186.33 60128.69 101% 2044.43 1084.57 53% 250 64 64159.90 137389.38 214% 2186.02 1994.61 91% 50 128 54323.45 51615.38 95% 1924.99 908.08 47% 100 128 57543.49 69999.21 121% 2049.99 1266.95 61% 250 128 71541.81 123915.35 173% 2448.38 1845.62 75% 50 256 57184.12 68314.09 119% 2204.47 1393.02 63% 100 256 51983.40 61931.00 119% 1897.89 1216.24 64% 250 256 66542.32 119435.53 179% 2267.97 1887.71 83% - TCP_STREAM - External Host to Guest sessions size throughput1 throughput2 norm1 norm2 1 64 589.10 634.81 107% 27.01 34.51 127% 2 64 1805.57 1442.49 79% 70.44 39.59 56% 4 64 3066.91 3869.26 126% 121.89 84.96 69% 8 64 6602.37 7626.61 115% 211.07 116.27 55% 1 256 775.25 2092.37 269% 26.38 115.47 437% 2 256 6213.63 3527.24 56% 191.89 84.18 43% 4 256 7333.13 9190.87 125% 230.74 218.05 94% 8 256 6776.23 9396.71 138% 216.14 153.14 70% 1 512 4308.25 3536.38 82% 160.93 140.38 87% 2 512 7159.09 9212.97 128% 240.80 201.42 83% 4 512 7095.49 9241.70 130% 229.77 193.26 84% 8 512 6935.59 9398.09 135% 221.37 152.36 68% 1 1024 5566.68 6155.74 110% 250.52 245.05 97% 2 1024 7303.83 9212.72 126% 299.33 229.91 76% 4 1024 7179.31 9334.93 130% 233.62 192.51 82% 8 1024 7080.91 9396.46 132% 226.37 173.81 76% 1 2048 7477.66 2671.34 35% 250.25 96.85 38% 2 2048 6743.70 8986.82 133% 295.51 230.07 77% 4 2048 7186.19 9239.56 128% 228.13 219.78 96% 8 2048 6883.19 9375.34 136% 221.11 164.59 74% 1 4096 7582.83 5040.55 66% 291.98 178.36 61% 2 4096 7617.98 9345.37 122% 245.74 197.78 80% 4 4096 7157.87 9383.81 131% 226.80 188.65 83% 8 4096 5916.83 9401.45 158% 189.64 147.61 77% 1 16384 8417.28 5351.11 63% 309.57 301.47 97% 2 16384 8426.42 9303.45 110% 302.13 197.14 65% 4 16384 5695.26 8678.73 152% 180.68 192.30 106% 8 16384 6761.33 9374.67 138% 214.50 160.25 74% Changes from V3: - Rebase to the net-next - Let queue 2 to be the control virtqueue to obey the spec - Prodives irq affinity - Choose txq based on processor id References: - V3: http://lwn.net/Articles/467283/ --- Jason Wang (3): virtio_ring: move queue_index to vring_virtqueue virtio: introduce a method to get the irq of a specific virtqueue virtio_net: multiqueue support Krishna Kumar (1): virtio_net: Introduce VIRTIO_NET_F_MULTIQUEUE drivers/lguest/lguest_device.c | 8 drivers/net/virtio_net.c | 695 +++++++++++++++++++++++++++++----------- drivers/s390/kvm/kvm_virtio.c | 6 drivers/virtio/virtio_mmio.c | 13 + drivers/virtio/virtio_pci.c | 24 + drivers/virtio/virtio_ring.c | 17 + include/linux/virtio.h | 4 include/linux/virtio_config.h | 4 include/linux/virtio_net.h | 3 9 files changed, 572 insertions(+), 202 deletions(-) -- Jason Wang
Jason Wang
2012-Jun-25 09:17 UTC
[net-next RFC V4 PATCH 1/4] virtio_net: Introduce VIRTIO_NET_F_MULTIQUEUE
From: Krishna Kumar <krkumar2 at in.ibm.com> Introduce VIRTIO_NET_F_MULTIQUEUE. Signed-off-by: Krishna Kumar <krkumar2 at in.ibm.com> Signed-off-by: Jason Wang <jasowang at redhat.com> --- include/linux/virtio_net.h | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index 2470f54..1bc7e30 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -51,6 +51,7 @@ #define VIRTIO_NET_F_CTRL_RX_EXTRA 20 /* Extra RX mode control support */ #define VIRTIO_NET_F_GUEST_ANNOUNCE 21 /* Guest can announce device on the * network */ +#define VIRTIO_NET_F_MULTIQUEUE 22 /* Device supports multiple TXQ/RXQ */ #define VIRTIO_NET_S_LINK_UP 1 /* Link is up */ #define VIRTIO_NET_S_ANNOUNCE 2 /* Announcement is needed */
Jason Wang
2012-Jun-25 09:17 UTC
[net-next RFC V4 PATCH 2/4] virtio_ring: move queue_index to vring_virtqueue
Instead of storing the queue index in virtio infos, this patch moves them to vring_virtqueue and introduces helpers to set and get the value. This would simplify the management and tracing. Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/virtio/virtio_mmio.c | 5 +---- drivers/virtio/virtio_pci.c | 12 +++++------- drivers/virtio/virtio_ring.c | 17 +++++++++++++++++ include/linux/virtio.h | 4 ++++ 4 files changed, 27 insertions(+), 11 deletions(-) diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index 453db0c..f5432b6 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -131,9 +131,6 @@ struct virtio_mmio_vq_info { /* the number of entries in the queue */ unsigned int num; - /* the index of the queue */ - int queue_index; - /* the virtual address of the ring queue */ void *queue; @@ -324,7 +321,6 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index, err = -ENOMEM; goto error_kmalloc; } - info->queue_index = index; /* Allocate pages for the queue - start with a queue as big as * possible (limited by maximum size allowed by device), drop down @@ -363,6 +359,7 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index, goto error_new_virtqueue; } + virtqueue_set_queue_index(vq, index); vq->priv = info; info->vq = vq; diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index 2e03d41..adb24f2 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -79,9 +79,6 @@ struct virtio_pci_vq_info /* the number of entries in the queue */ int num; - /* the index of the queue */ - int queue_index; - /* the virtual address of the ring queue */ void *queue; @@ -202,11 +199,11 @@ static void vp_reset(struct virtio_device *vdev) static void vp_notify(struct virtqueue *vq) { struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev); - struct virtio_pci_vq_info *info = vq->priv; /* we write the queue's selector into the notification register to * signal the other end */ - iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY); + iowrite16(virtqueue_get_queue_index(vq), + vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY); } /* Handle a configuration change: Tell driver if it wants to know. */ @@ -402,7 +399,6 @@ static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index, if (!info) return ERR_PTR(-ENOMEM); - info->queue_index = index; info->num = num; info->msix_vector = msix_vec; @@ -425,6 +421,7 @@ static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index, goto out_activate_queue; } + virtqueue_set_queue_index(vq, index); vq->priv = info; info->vq = vq; @@ -467,7 +464,8 @@ static void vp_del_vq(struct virtqueue *vq) list_del(&info->node); spin_unlock_irqrestore(&vp_dev->lock, flags); - iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL); + iowrite16(virtqueue_get_queue_index(vq), + vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL); if (vp_dev->msix_enabled) { iowrite16(VIRTIO_MSI_NO_VECTOR, diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 5aa43c3..9c5aeea 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -106,6 +106,9 @@ struct vring_virtqueue /* How to notify other side. FIXME: commonalize hcalls! */ void (*notify)(struct virtqueue *vq); + /* Index of the queue */ + int queue_index; + #ifdef DEBUG /* They're supposed to lock for us. */ unsigned int in_use; @@ -171,6 +174,20 @@ static int vring_add_indirect(struct vring_virtqueue *vq, return head; } +void virtqueue_set_queue_index(struct virtqueue *_vq, int queue_index) +{ + struct vring_virtqueue *vq = to_vvq(_vq); + vq->queue_index = queue_index; +} +EXPORT_SYMBOL_GPL(virtqueue_set_queue_index); + +int virtqueue_get_queue_index(struct virtqueue *_vq) +{ + struct vring_virtqueue *vq = to_vvq(_vq); + return vq->queue_index; +} +EXPORT_SYMBOL_GPL(virtqueue_get_queue_index); + /** * virtqueue_add_buf - expose buffer to other end * @vq: the struct virtqueue we're talking about. diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 8efd28a..0d8ed46 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -50,6 +50,10 @@ void *virtqueue_detach_unused_buf(struct virtqueue *vq); unsigned int virtqueue_get_vring_size(struct virtqueue *vq); +void virtqueue_set_queue_index(struct virtqueue *vq, int queue_index); + +int virtqueue_get_queue_index(struct virtqueue *vq); + /** * virtio_device - representation of a device using virtio * @index: unique position on the virtio bus
Jason Wang
2012-Jun-25 09:41 UTC
[net-next RFC V4 PATCH 3/4] virtio: introduce a method to get the irq of a specific virtqueue
Device specific irq optimizations such as irq affinity may be used by virtio drivers. So this patch introduce a new method to get the irq of a specific virtqueue. After this patch, virtio device drivers could query the irq and do device specific optimizations. First user would be virtio-net. Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/lguest/lguest_device.c | 8 ++++++++ drivers/s390/kvm/kvm_virtio.c | 6 ++++++ drivers/virtio/virtio_mmio.c | 8 ++++++++ drivers/virtio/virtio_pci.c | 12 ++++++++++++ include/linux/virtio_config.h | 4 ++++ 5 files changed, 38 insertions(+), 0 deletions(-) diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c index 9e8388e..bcd080f 100644 --- a/drivers/lguest/lguest_device.c +++ b/drivers/lguest/lguest_device.c @@ -392,6 +392,13 @@ static const char *lg_bus_name(struct virtio_device *vdev) return ""; } +static int lg_get_vq_irq(struct virtio_device *vdev, struct virtqueue *vq) +{ + struct lguest_vq_info *lvq = vq->priv; + + return lvq->config.irq; +} + /* The ops structure which hooks everything together. */ static struct virtio_config_ops lguest_config_ops = { .get_features = lg_get_features, @@ -404,6 +411,7 @@ static struct virtio_config_ops lguest_config_ops = { .find_vqs = lg_find_vqs, .del_vqs = lg_del_vqs, .bus_name = lg_bus_name, + .get_vq_irq = lg_get_vq_irq, }; /* diff --git a/drivers/s390/kvm/kvm_virtio.c b/drivers/s390/kvm/kvm_virtio.c index d74e9ae..a897de2 100644 --- a/drivers/s390/kvm/kvm_virtio.c +++ b/drivers/s390/kvm/kvm_virtio.c @@ -268,6 +268,11 @@ static const char *kvm_bus_name(struct virtio_device *vdev) return ""; } +static int kvm_get_vq_irq(struct virtio_device *vdev, struct virtqueue *vq) +{ + return 0x2603; +} + /* * The config ops structure as defined by virtio config */ @@ -282,6 +287,7 @@ static struct virtio_config_ops kvm_vq_configspace_ops = { .find_vqs = kvm_find_vqs, .del_vqs = kvm_del_vqs, .bus_name = kvm_bus_name, + .get_vq_irq = kvm_get_vq_irq, }; /* diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index f5432b6..2ba37ed 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -411,6 +411,13 @@ static const char *vm_bus_name(struct virtio_device *vdev) return vm_dev->pdev->name; } +static int vm_get_vq_irq(struct virtio_device *vdev, struct virtqueue *vq) +{ + struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); + + return platform_get_irq(vm_dev->pdev, 0); +} + static struct virtio_config_ops virtio_mmio_config_ops = { .get = vm_get, .set = vm_set, @@ -422,6 +429,7 @@ static struct virtio_config_ops virtio_mmio_config_ops = { .get_features = vm_get_features, .finalize_features = vm_finalize_features, .bus_name = vm_bus_name, + .get_vq_irq = vm_get_vq_irq, }; diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index adb24f2..c062227 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -607,6 +607,17 @@ static const char *vp_bus_name(struct virtio_device *vdev) return pci_name(vp_dev->pci_dev); } +static int vp_get_vq_irq(struct virtio_device *vdev, struct virtqueue *vq) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + struct virtio_pci_vq_info *info = vq->priv; + + if (vp_dev->intx_enabled) + return vp_dev->pci_dev->irq; + else + return vp_dev->msix_entries[info->msix_vector].vector; +} + static struct virtio_config_ops virtio_pci_config_ops = { .get = vp_get, .set = vp_set, @@ -618,6 +629,7 @@ static struct virtio_config_ops virtio_pci_config_ops = { .get_features = vp_get_features, .finalize_features = vp_finalize_features, .bus_name = vp_bus_name, + .get_vq_irq = vp_get_vq_irq, }; static void virtio_pci_release_dev(struct device *_d) diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index fc457f4..acd6930 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -98,6 +98,9 @@ * vdev: the virtio_device * This returns a pointer to the bus name a la pci_name from which * the caller can then copy. + * @get_vq_irq: get the irq numer of the specific virt queue. + * vdev: the virtio_device + * vq: the virtqueue */ typedef void vq_callback_t(struct virtqueue *); struct virtio_config_ops { @@ -116,6 +119,7 @@ struct virtio_config_ops { u32 (*get_features)(struct virtio_device *vdev); void (*finalize_features)(struct virtio_device *vdev); const char *(*bus_name)(struct virtio_device *vdev); + int (*get_vq_irq)(struct virtio_device *vdev, struct virtqueue *vq); }; /* If driver didn't advertise the feature, it will never appear. */ -- 1.7.1
Jason Wang
2012-Jun-25 09:41 UTC
[net-next RFC V4 PATCH 4/4] virtio_net: multiqueue support
This addes multiqueue support to virtio_net driver. This feature is negotiated through VIRTIO_NET_F_MULTIQUEUE. The driver expects the number of rx/tx queue paris is equal to the number of vcpus. To maximize the performance under this per-cpu rx/tx queue pairs, some optimization were introduced: - Txq selection is based on the processor id in order to avoid contending a lock whose owner may exits to host. - Since the txq/txq were per-cpu, affinity hint were set to the cpu that owns the queue pairs. Signed-off-by: Krishna Kumar <krkumar2 at in.ibm.com> Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/net/virtio_net.c | 695 ++++++++++++++++++++++++++++++++------------ include/linux/virtio_net.h | 2 + 2 files changed, 506 insertions(+), 191 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index f18149a..5c719de 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -26,6 +26,7 @@ #include <linux/scatterlist.h> #include <linux/if_vlan.h> #include <linux/slab.h> +#include <linux/interrupt.h> static int napi_weight = 128; module_param(napi_weight, int, 0444); @@ -51,43 +52,73 @@ struct virtnet_stats { u64 rx_packets; }; -struct virtnet_info { - struct virtio_device *vdev; - struct virtqueue *rvq, *svq, *cvq; - struct net_device *dev; +/* Internal representation of a send virtqueue */ +struct send_queue { + /* Virtqueue associated with this send _queue */ + struct virtqueue *vq; + + /* TX: fragments + linear part + virtio header */ + struct scatterlist sg[MAX_SKB_FRAGS + 2]; + + cpumask_var_t affinity_mask; +}; + +/* Internal representation of a receive virtqueue */ +struct receive_queue { + /* Virtqueue associated with this receive_queue */ + struct virtqueue *vq; + + /* Back pointer to the virtnet_info */ + struct virtnet_info *vi; + struct napi_struct napi; - unsigned int status; /* Number of input buffers, and max we've ever had. */ unsigned int num, max; + /* Work struct for refilling if we run low on memory. */ + struct delayed_work refill; + + /* Chain pages by the private ptr. */ + struct page *pages; + + /* RX: fragments + linear part + virtio header */ + struct scatterlist sg[MAX_SKB_FRAGS + 2]; + + cpumask_var_t affinity_mask; +}; + +struct virtnet_info { + int num_queue_pairs; /* # of RX/TX vq pairs */ + + struct send_queue **sq; + struct receive_queue **rq; + struct virtqueue *cvq; + + struct virtio_device *vdev; + struct net_device *dev; + unsigned int status; + /* I like... big packets and I cannot lie! */ bool big_packets; /* Host will merge rx buffers for big packets (shake it! shake it!) */ bool mergeable_rx_bufs; + /* Has control virtqueue */ + bool has_cvq; + /* enable config space updates */ bool config_enable; /* Active statistics */ struct virtnet_stats __percpu *stats; - /* Work struct for refilling if we run low on memory. */ - struct delayed_work refill; - /* Work struct for config space updates */ struct work_struct config_work; /* Lock for config space updates */ struct mutex config_lock; - - /* Chain pages by the private ptr. */ - struct page *pages; - - /* fragments + linear part + virtio header */ - struct scatterlist rx_sg[MAX_SKB_FRAGS + 2]; - struct scatterlist tx_sg[MAX_SKB_FRAGS + 2]; }; struct skb_vnet_hdr { @@ -108,6 +139,22 @@ struct padded_vnet_hdr { char padding[6]; }; +static inline int txq_get_qnum(struct virtnet_info *vi, struct virtqueue *vq) +{ + int ret = virtqueue_get_queue_index(vq); + + /* skip ctrl vq */ + if (vi->has_cvq) + return (ret - 1) / 2; + else + return ret / 2; +} + +static inline int rxq_get_qnum(struct virtnet_info *vi, struct virtqueue *vq) +{ + return virtqueue_get_queue_index(vq) / 2; +} + static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb) { return (struct skb_vnet_hdr *)skb->cb; @@ -117,22 +164,22 @@ static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb) * private is used to chain pages for big packets, put the whole * most recent used list in the beginning for reuse */ -static void give_pages(struct virtnet_info *vi, struct page *page) +static void give_pages(struct receive_queue *rq, struct page *page) { struct page *end; /* Find end of list, sew whole thing into vi->pages. */ for (end = page; end->private; end = (struct page *)end->private); - end->private = (unsigned long)vi->pages; - vi->pages = page; + end->private = (unsigned long)rq->pages; + rq->pages = page; } -static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask) +static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask) { - struct page *p = vi->pages; + struct page *p = rq->pages; if (p) { - vi->pages = (struct page *)p->private; + rq->pages = (struct page *)p->private; /* clear private here, it is used to chain pages */ p->private = 0; } else @@ -140,15 +187,15 @@ static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask) return p; } -static void skb_xmit_done(struct virtqueue *svq) +static void skb_xmit_done(struct virtqueue *vq) { - struct virtnet_info *vi = svq->vdev->priv; + struct virtnet_info *vi = vq->vdev->priv; /* Suppress further interrupts. */ - virtqueue_disable_cb(svq); + virtqueue_disable_cb(vq); /* We were probably waiting for more output buffers. */ - netif_wake_queue(vi->dev); + netif_wake_subqueue(vi->dev, txq_get_qnum(vi, vq)); } static void set_skb_frag(struct sk_buff *skb, struct page *page, @@ -167,9 +214,10 @@ static void set_skb_frag(struct sk_buff *skb, struct page *page, } /* Called from bottom half context */ -static struct sk_buff *page_to_skb(struct virtnet_info *vi, +static struct sk_buff *page_to_skb(struct receive_queue *rq, struct page *page, unsigned int len) { + struct virtnet_info *vi = rq->vi; struct sk_buff *skb; struct skb_vnet_hdr *hdr; unsigned int copy, hdr_len, offset; @@ -225,12 +273,12 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, } if (page) - give_pages(vi, page); + give_pages(rq, page); return skb; } -static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb) +static int receive_mergeable(struct receive_queue *rq, struct sk_buff *skb) { struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); struct page *page; @@ -244,7 +292,7 @@ static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb) skb->dev->stats.rx_length_errors++; return -EINVAL; } - page = virtqueue_get_buf(vi->rvq, &len); + page = virtqueue_get_buf(rq->vq, &len); if (!page) { pr_debug("%s: rx error: %d buffers missing\n", skb->dev->name, hdr->mhdr.num_buffers); @@ -257,13 +305,14 @@ static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb) set_skb_frag(skb, page, 0, &len); - --vi->num; + --rq->num; } return 0; } -static void receive_buf(struct net_device *dev, void *buf, unsigned int len) +static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len) { + struct net_device *dev = rq->vi->dev; struct virtnet_info *vi = netdev_priv(dev); struct virtnet_stats *stats = this_cpu_ptr(vi->stats); struct sk_buff *skb; @@ -274,7 +323,7 @@ static void receive_buf(struct net_device *dev, void *buf, unsigned int len) pr_debug("%s: short packet %i\n", dev->name, len); dev->stats.rx_length_errors++; if (vi->mergeable_rx_bufs || vi->big_packets) - give_pages(vi, buf); + give_pages(rq, buf); else dev_kfree_skb(buf); return; @@ -286,14 +335,14 @@ static void receive_buf(struct net_device *dev, void *buf, unsigned int len) skb_trim(skb, len); } else { page = buf; - skb = page_to_skb(vi, page, len); + skb = page_to_skb(rq, page, len); if (unlikely(!skb)) { dev->stats.rx_dropped++; - give_pages(vi, page); + give_pages(rq, page); return; } if (vi->mergeable_rx_bufs) - if (receive_mergeable(vi, skb)) { + if (receive_mergeable(rq, skb)) { dev_kfree_skb(skb); return; } @@ -363,90 +412,91 @@ frame_err: dev_kfree_skb(skb); } -static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp) +static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp) { struct sk_buff *skb; struct skb_vnet_hdr *hdr; int err; - skb = __netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN, gfp); + skb = __netdev_alloc_skb_ip_align(rq->vi->dev, MAX_PACKET_LEN, gfp); if (unlikely(!skb)) return -ENOMEM; skb_put(skb, MAX_PACKET_LEN); hdr = skb_vnet_hdr(skb); - sg_set_buf(vi->rx_sg, &hdr->hdr, sizeof hdr->hdr); + sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr); - skb_to_sgvec(skb, vi->rx_sg + 1, 0, skb->len); + skb_to_sgvec(skb, rq->sg + 1, 0, skb->len); + + err = virtqueue_add_buf(rq->vq, rq->sg, 0, 2, skb, gfp); - err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, 2, skb, gfp); if (err < 0) dev_kfree_skb(skb); return err; } -static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp) +static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp) { struct page *first, *list = NULL; char *p; int i, err, offset; - /* page in vi->rx_sg[MAX_SKB_FRAGS + 1] is list tail */ + /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */ for (i = MAX_SKB_FRAGS + 1; i > 1; --i) { - first = get_a_page(vi, gfp); + first = get_a_page(rq, gfp); if (!first) { if (list) - give_pages(vi, list); + give_pages(rq, list); return -ENOMEM; } - sg_set_buf(&vi->rx_sg[i], page_address(first), PAGE_SIZE); + sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE); /* chain new page in list head to match sg */ first->private = (unsigned long)list; list = first; } - first = get_a_page(vi, gfp); + first = get_a_page(rq, gfp); if (!first) { - give_pages(vi, list); + give_pages(rq, list); return -ENOMEM; } p = page_address(first); - /* vi->rx_sg[0], vi->rx_sg[1] share the same page */ - /* a separated vi->rx_sg[0] for virtio_net_hdr only due to QEMU bug */ - sg_set_buf(&vi->rx_sg[0], p, sizeof(struct virtio_net_hdr)); + /* rq->sg[0], rq->sg[1] share the same page */ + /* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */ + sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr)); - /* vi->rx_sg[1] for data packet, from offset */ + /* rq->sg[1] for data packet, from offset */ offset = sizeof(struct padded_vnet_hdr); - sg_set_buf(&vi->rx_sg[1], p + offset, PAGE_SIZE - offset); + sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset); /* chain first in list head */ first->private = (unsigned long)list; - err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, MAX_SKB_FRAGS + 2, + err = virtqueue_add_buf(rq->vq, rq->sg, 0, MAX_SKB_FRAGS + 2, first, gfp); if (err < 0) - give_pages(vi, first); + give_pages(rq, first); return err; } -static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp) +static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp) { struct page *page; int err; - page = get_a_page(vi, gfp); + page = get_a_page(rq, gfp); if (!page) return -ENOMEM; - sg_init_one(vi->rx_sg, page_address(page), PAGE_SIZE); + sg_init_one(rq->sg, page_address(page), PAGE_SIZE); - err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, 1, page, gfp); + err = virtqueue_add_buf(rq->vq, rq->sg, 0, 1, page, gfp); if (err < 0) - give_pages(vi, page); + give_pages(rq, page); return err; } @@ -458,97 +508,104 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp) * before we're receiving packets, or from refill_work which is * careful to disable receiving (using napi_disable). */ -static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp) +static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp) { + struct virtnet_info *vi = rq->vi; int err; bool oom; do { if (vi->mergeable_rx_bufs) - err = add_recvbuf_mergeable(vi, gfp); + err = add_recvbuf_mergeable(rq, gfp); else if (vi->big_packets) - err = add_recvbuf_big(vi, gfp); + err = add_recvbuf_big(rq, gfp); else - err = add_recvbuf_small(vi, gfp); + err = add_recvbuf_small(rq, gfp); oom = err == -ENOMEM; if (err < 0) break; - ++vi->num; + ++rq->num; } while (err > 0); - if (unlikely(vi->num > vi->max)) - vi->max = vi->num; - virtqueue_kick(vi->rvq); + if (unlikely(rq->num > rq->max)) + rq->max = rq->num; + virtqueue_kick(rq->vq); return !oom; } -static void skb_recv_done(struct virtqueue *rvq) +static void skb_recv_done(struct virtqueue *vq) { - struct virtnet_info *vi = rvq->vdev->priv; + struct virtnet_info *vi = vq->vdev->priv; + struct napi_struct *napi = &vi->rq[rxq_get_qnum(vi, vq)]->napi; + /* Schedule NAPI, Suppress further interrupts if successful. */ - if (napi_schedule_prep(&vi->napi)) { - virtqueue_disable_cb(rvq); - __napi_schedule(&vi->napi); + if (napi_schedule_prep(napi)) { + virtqueue_disable_cb(vq); + __napi_schedule(napi); } } -static void virtnet_napi_enable(struct virtnet_info *vi) +static void virtnet_napi_enable(struct receive_queue *rq) { - napi_enable(&vi->napi); + napi_enable(&rq->napi); /* If all buffers were filled by other side before we napi_enabled, we * won't get another interrupt, so process any outstanding packets * now. virtnet_poll wants re-enable the queue, so we disable here. * We synchronize against interrupts via NAPI_STATE_SCHED */ - if (napi_schedule_prep(&vi->napi)) { - virtqueue_disable_cb(vi->rvq); + if (napi_schedule_prep(&rq->napi)) { + virtqueue_disable_cb(rq->vq); local_bh_disable(); - __napi_schedule(&vi->napi); + __napi_schedule(&rq->napi); local_bh_enable(); } } static void refill_work(struct work_struct *work) { - struct virtnet_info *vi; + struct napi_struct *napi; + struct receive_queue *rq; bool still_empty; - vi = container_of(work, struct virtnet_info, refill.work); - napi_disable(&vi->napi); - still_empty = !try_fill_recv(vi, GFP_KERNEL); - virtnet_napi_enable(vi); + rq = container_of(work, struct receive_queue, refill.work); + napi = &rq->napi; + + napi_disable(napi); + still_empty = !try_fill_recv(rq, GFP_KERNEL); + virtnet_napi_enable(rq); /* In theory, this can happen: if we don't get any buffers in * we will *never* try to fill again. */ if (still_empty) - queue_delayed_work(system_nrt_wq, &vi->refill, HZ/2); + queue_delayed_work(system_nrt_wq, &rq->refill, HZ/2); } static int virtnet_poll(struct napi_struct *napi, int budget) { - struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi); + struct receive_queue *rq = container_of(napi, struct receive_queue, + napi); void *buf; unsigned int len, received = 0; again: while (received < budget && - (buf = virtqueue_get_buf(vi->rvq, &len)) != NULL) { - receive_buf(vi->dev, buf, len); - --vi->num; + (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) { + receive_buf(rq, buf, len); + --rq->num; received++; } - if (vi->num < vi->max / 2) { - if (!try_fill_recv(vi, GFP_ATOMIC)) - queue_delayed_work(system_nrt_wq, &vi->refill, 0); + if (rq->num < rq->max / 2) { + if (!try_fill_recv(rq, GFP_ATOMIC)) + queue_delayed_work(system_nrt_wq, &rq->refill, 0); } /* Out of packets? */ if (received < budget) { napi_complete(napi); - if (unlikely(!virtqueue_enable_cb(vi->rvq)) && + if (unlikely(!virtqueue_enable_cb(rq->vq)) && napi_schedule_prep(napi)) { - virtqueue_disable_cb(vi->rvq); + virtqueue_disable_cb(rq->vq); __napi_schedule(napi); goto again; } @@ -557,13 +614,14 @@ again: return received; } -static unsigned int free_old_xmit_skbs(struct virtnet_info *vi) +static unsigned int free_old_xmit_skbs(struct virtnet_info *vi, + struct virtqueue *vq) { struct sk_buff *skb; unsigned int len, tot_sgs = 0; struct virtnet_stats *stats = this_cpu_ptr(vi->stats); - while ((skb = virtqueue_get_buf(vi->svq, &len)) != NULL) { + while ((skb = virtqueue_get_buf(vq, &len)) != NULL) { pr_debug("Sent skb %p\n", skb); u64_stats_update_begin(&stats->tx_syncp); @@ -577,7 +635,8 @@ static unsigned int free_old_xmit_skbs(struct virtnet_info *vi) return tot_sgs; } -static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb) +static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb, + struct virtqueue *vq, struct scatterlist *sg) { struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; @@ -615,44 +674,47 @@ static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb) /* Encode metadata header at front. */ if (vi->mergeable_rx_bufs) - sg_set_buf(vi->tx_sg, &hdr->mhdr, sizeof hdr->mhdr); + sg_set_buf(sg, &hdr->mhdr, sizeof hdr->mhdr); else - sg_set_buf(vi->tx_sg, &hdr->hdr, sizeof hdr->hdr); + sg_set_buf(sg, &hdr->hdr, sizeof hdr->hdr); - hdr->num_sg = skb_to_sgvec(skb, vi->tx_sg + 1, 0, skb->len) + 1; - return virtqueue_add_buf(vi->svq, vi->tx_sg, hdr->num_sg, + hdr->num_sg = skb_to_sgvec(skb, sg + 1, 0, skb->len) + 1; + return virtqueue_add_buf(vq, sg, hdr->num_sg, 0, skb, GFP_ATOMIC); } static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) { struct virtnet_info *vi = netdev_priv(dev); + int qnum = skb_get_queue_mapping(skb); + struct virtqueue *vq = vi->sq[qnum]->vq; int capacity; /* Free up any pending old buffers before queueing new ones. */ - free_old_xmit_skbs(vi); + free_old_xmit_skbs(vi, vq); /* Try to transmit */ - capacity = xmit_skb(vi, skb); + capacity = xmit_skb(vi, skb, vq, vi->sq[qnum]->sg); /* This can happen with OOM and indirect buffers. */ if (unlikely(capacity < 0)) { if (likely(capacity == -ENOMEM)) { if (net_ratelimit()) dev_warn(&dev->dev, - "TX queue failure: out of memory\n"); + "TXQ (%d) failure: out of memory\n", + qnum); } else { dev->stats.tx_fifo_errors++; if (net_ratelimit()) dev_warn(&dev->dev, - "Unexpected TX queue failure: %d\n", - capacity); + "Unexpected TXQ (%d) failure: %d\n", + qnum, capacity); } dev->stats.tx_dropped++; kfree_skb(skb); return NETDEV_TX_OK; } - virtqueue_kick(vi->svq); + virtqueue_kick(vq); /* Don't wait up for transmitted skbs to be freed. */ skb_orphan(skb); @@ -661,13 +723,13 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) /* Apparently nice girls don't return TX_BUSY; stop the queue * before it gets out of hand. Naturally, this wastes entries. */ if (capacity < 2+MAX_SKB_FRAGS) { - netif_stop_queue(dev); - if (unlikely(!virtqueue_enable_cb_delayed(vi->svq))) { + netif_stop_subqueue(dev, qnum); + if (unlikely(!virtqueue_enable_cb_delayed(vq))) { /* More just got used, free them then recheck. */ - capacity += free_old_xmit_skbs(vi); + capacity += free_old_xmit_skbs(vi, vq); if (capacity >= 2+MAX_SKB_FRAGS) { - netif_start_queue(dev); - virtqueue_disable_cb(vi->svq); + netif_start_subqueue(dev, qnum); + virtqueue_disable_cb(vq); } } } @@ -700,7 +762,8 @@ static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev, unsigned int start; for_each_possible_cpu(cpu) { - struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu); + struct virtnet_stats __percpu *stats + = per_cpu_ptr(vi->stats, cpu); u64 tpackets, tbytes, rpackets, rbytes; do { @@ -734,20 +797,31 @@ static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev, static void virtnet_netpoll(struct net_device *dev) { struct virtnet_info *vi = netdev_priv(dev); + int i; - napi_schedule(&vi->napi); + for (i = 0; i < vi->num_queue_pairs; i++) + napi_schedule(&vi->rq[i]->napi); } #endif +static void free_stats(struct virtnet_info *vi) +{ + free_percpu(vi->stats); +} + static int virtnet_open(struct net_device *dev) { struct virtnet_info *vi = netdev_priv(dev); + int i; - /* Make sure we have some buffers: if oom use wq. */ - if (!try_fill_recv(vi, GFP_KERNEL)) - queue_delayed_work(system_nrt_wq, &vi->refill, 0); + for (i = 0; i < vi->num_queue_pairs; i++) { + /* Make sure we have some buffers: if oom use wq. */ + if (!try_fill_recv(vi->rq[i], GFP_KERNEL)) + queue_delayed_work(system_nrt_wq, + &vi->rq[i]->refill, 0); + virtnet_napi_enable(vi->rq[i]); + } - virtnet_napi_enable(vi); return 0; } @@ -809,10 +883,13 @@ static void virtnet_ack_link_announce(struct virtnet_info *vi) static int virtnet_close(struct net_device *dev) { struct virtnet_info *vi = netdev_priv(dev); + int i; /* Make sure refill_work doesn't re-enable napi! */ - cancel_delayed_work_sync(&vi->refill); - napi_disable(&vi->napi); + for (i = 0; i < vi->num_queue_pairs; i++) { + cancel_delayed_work_sync(&vi->rq[i]->refill); + napi_disable(&vi->rq[i]->napi); + } return 0; } @@ -924,11 +1001,10 @@ static void virtnet_get_ringparam(struct net_device *dev, { struct virtnet_info *vi = netdev_priv(dev); - ring->rx_max_pending = virtqueue_get_vring_size(vi->rvq); - ring->tx_max_pending = virtqueue_get_vring_size(vi->svq); + ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0]->vq); + ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0]->vq); ring->rx_pending = ring->rx_max_pending; ring->tx_pending = ring->tx_max_pending; - } @@ -961,6 +1037,19 @@ static int virtnet_change_mtu(struct net_device *dev, int new_mtu) return 0; } +/* To avoid contending a lock hold by a vcpu who would exit to host, select the + * txq based on the processor id. + */ +static u16 virtnet_select_queue(struct net_device *dev, struct sk_buff *skb) +{ + int txq = skb_rx_queue_recorded(skb) ? skb_get_rx_queue(skb) : + smp_processor_id(); + + while (unlikely(txq >= dev->real_num_tx_queues)) + txq -= dev->real_num_tx_queues; + return txq; +} + static const struct net_device_ops virtnet_netdev = { .ndo_open = virtnet_open, .ndo_stop = virtnet_close, @@ -972,6 +1061,7 @@ static const struct net_device_ops virtnet_netdev = { .ndo_get_stats64 = virtnet_stats, .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid, .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, + .ndo_select_queue = virtnet_select_queue, #ifdef CONFIG_NET_POLL_CONTROLLER .ndo_poll_controller = virtnet_netpoll, #endif @@ -1007,10 +1097,10 @@ static void virtnet_config_changed_work(struct work_struct *work) if (vi->status & VIRTIO_NET_S_LINK_UP) { netif_carrier_on(vi->dev); - netif_wake_queue(vi->dev); + netif_tx_wake_all_queues(vi->dev); } else { netif_carrier_off(vi->dev); - netif_stop_queue(vi->dev); + netif_tx_stop_all_queues(vi->dev); } done: mutex_unlock(&vi->config_lock); @@ -1023,41 +1113,252 @@ static void virtnet_config_changed(struct virtio_device *vdev) queue_work(system_nrt_wq, &vi->config_work); } -static int init_vqs(struct virtnet_info *vi) +static void free_receive_bufs(struct virtnet_info *vi) +{ + int i; + + for (i = 0; i < vi->num_queue_pairs; i++) { + while (vi->rq[i]->pages) + __free_pages(get_a_page(vi->rq[i], GFP_KERNEL), 0); + } +} + +/* Free memory allocated for send and receive queues */ +static void free_rq_sq(struct virtnet_info *vi) { - struct virtqueue *vqs[3]; - vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL}; - const char *names[] = { "input", "output", "control" }; - int nvqs, err; + int i; - /* We expect two virtqueues, receive then send, - * and optionally control. */ - nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2; + free_stats(vi); - err = vi->vdev->config->find_vqs(vi->vdev, nvqs, vqs, callbacks, names); - if (err) - return err; + if (vi->rq) { + for (i = 0; i < vi->num_queue_pairs; i++) + kfree(vi->rq[i]); + kfree(vi->rq); + } + + if (vi->sq) { + for (i = 0; i < vi->num_queue_pairs; i++) + kfree(vi->sq[i]); + kfree(vi->sq); + } +} + +static void free_unused_bufs(struct virtnet_info *vi) +{ + void *buf; + int i; + + for (i = 0; i < vi->num_queue_pairs; i++) { + struct virtqueue *vq = vi->sq[i]->vq; + + while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) + dev_kfree_skb(buf); + } + + for (i = 0; i < vi->num_queue_pairs; i++) { + struct virtqueue *vq = vi->rq[i]->vq; - vi->rvq = vqs[0]; - vi->svq = vqs[1]; + while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) { + if (vi->mergeable_rx_bufs || vi->big_packets) + give_pages(vi->rq[i], buf); + else + dev_kfree_skb(buf); + --vi->rq[i]->num; + } + BUG_ON(vi->rq[i]->num != 0); + } +} + +static int virtnet_find_vqs(struct virtnet_info *vi) +{ + vq_callback_t **callbacks; + struct virtqueue **vqs; + int ret = -ENOMEM; + int i, total_vqs; + char **names; + + /* + * We expect 1 RX virtqueue followed by 1 TX virtqueue, followd by + * possible control virtqueue and followed by the same + * 'vi->num_queue_pairs-1' more times + */ + total_vqs = vi->num_queue_pairs * 2 + + virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ); + + /* Allocate space for find_vqs parameters */ + vqs = kmalloc(total_vqs * sizeof(*vqs), GFP_KERNEL); + callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL); + names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL); + if (!vqs || !callbacks || !names) + goto err; + + /* Parameters for control virtqueue, if any */ + if (vi->has_cvq) { + callbacks[2] = NULL; + names[2] = "control"; + } + + /* Allocate/initialize parameters for send/receive virtqueues */ + for (i = 0; i < vi->num_queue_pairs * 2; i += 2) { + int j = (i == 0 ? i : i + vi->has_cvq); + callbacks[j] = skb_recv_done; + callbacks[j + 1] = skb_xmit_done; + names[j] = kasprintf(GFP_KERNEL, "input.%d", i / 2); + names[j + 1] = kasprintf(GFP_KERNEL, "output.%d", i / 2); + } - if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) { + ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks, + (const char **)names); + if (ret) + goto err; + + if (vi->has_cvq) vi->cvq = vqs[2]; - if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) - vi->dev->features |= NETIF_F_HW_VLAN_FILTER; + for (i = 0; i < vi->num_queue_pairs * 2; i += 2) { + int j = i == 0 ? i : i + vi->has_cvq; + vi->rq[i / 2]->vq = vqs[j]; + vi->sq[i / 2]->vq = vqs[j + 1]; } + +err: + if (ret && names) + for (i = 0; i < vi->num_queue_pairs * 2; i++) + kfree(names[i]); + + kfree(names); + kfree(callbacks); + kfree(vqs); + + return ret; +} + +static int allocate_queues(struct virtnet_info *vi) +{ + int ret = -ENOMEM; + int i; + + vi->rq = kcalloc(vi->num_queue_pairs, sizeof(*vi->rq), GFP_KERNEL); + vi->sq = kcalloc(vi->num_queue_pairs, sizeof(*vi->sq), GFP_KERNEL); + if (!vi->sq || !vi->rq) + goto err; + + for (i = 0; i < vi->num_queue_pairs; i++) { + vi->rq[i] = kzalloc(sizeof(*vi->rq[i]), GFP_KERNEL); + vi->sq[i] = kzalloc(sizeof(*vi->sq[i]), GFP_KERNEL); + if (!vi->rq[i] || !vi->sq[i]) + goto err; + } + + ret = 0; + + /* setup initial receive and send queue parameters */ + for (i = 0; i < vi->num_queue_pairs; i++) { + vi->rq[i]->vi = vi; + vi->rq[i]->pages = NULL; + INIT_DELAYED_WORK(&vi->rq[i]->refill, refill_work); + netif_napi_add(vi->dev, &vi->rq[i]->napi, virtnet_poll, + napi_weight); + + sg_init_table(vi->rq[i]->sg, ARRAY_SIZE(vi->rq[i]->sg)); + sg_init_table(vi->sq[i]->sg, ARRAY_SIZE(vi->sq[i]->sg)); + } + +err: + if (ret) + free_rq_sq(vi); + + return ret; +} + +static int virtnet_setup_vqs(struct virtnet_info *vi) +{ + int ret; + + /* Allocate send & receive queues */ + ret = allocate_queues(vi); + if (!ret) { + ret = virtnet_find_vqs(vi); + if (ret) + free_rq_sq(vi); + } + + return ret; +} + +static void _virtnet_free_affinity(struct virtnet_info *vi, int i) +{ + struct virtio_device *vdev = vi->vdev; + int irq; + + while (i) { + i--; + irq = vdev->config->get_vq_irq(vdev, vi->rq[i]->vq); + irq_set_affinity_hint(irq, NULL); + free_cpumask_var(vi->rq[i]->affinity_mask); + irq = vdev->config->get_vq_irq(vdev, vi->sq[i]->vq); + irq_set_affinity_hint(irq, NULL); + free_cpumask_var(vi->sq[i]->affinity_mask); + } +} + +static int virtnet_init_affinity(struct virtnet_info *vi) +{ + struct virtio_device *vdev = vi->vdev; + int i, irq; + + for (i = 0; i < vi->num_queue_pairs; i++) { + if (!alloc_cpumask_var(&vi->rq[i]->affinity_mask, GFP_KERNEL)) + goto err_out; + if (!alloc_cpumask_var(&vi->sq[i]->affinity_mask, GFP_KERNEL)) { + free_cpumask_var(vi->rq[i]->affinity_mask); + goto err_out; + } + cpumask_set_cpu(i, vi->rq[i]->affinity_mask); + cpumask_set_cpu(i, vi->sq[i]->affinity_mask); + + irq = vdev->config->get_vq_irq(vdev, vi->rq[i]->vq); + if (irq_set_affinity_hint(irq, vi->rq[i]->affinity_mask)) + goto err_out; + irq = vdev->config->get_vq_irq(vdev, vi->sq[i]->vq); + if (irq_set_affinity_hint(irq, vi->sq[i]->affinity_mask)) { + irq = vdev->config->get_vq_irq(vdev, vi->rq[i]->vq); + irq_set_affinity_hint(irq, NULL); + goto err_out; + } + } + return 0; +err_out: + _virtnet_free_affinity(vi, i); + return -ENOMEM; +} + +static void virtnet_free_affinity(struct virtnet_info *vi) +{ + _virtnet_free_affinity(vi, vi->num_queue_pairs); } static int virtnet_probe(struct virtio_device *vdev) { - int err; + int i, err; struct net_device *dev; struct virtnet_info *vi; + u16 num_queues, num_queue_pairs; + + /* Find if host supports multiqueue virtio_net device */ + err = virtio_config_val(vdev, VIRTIO_NET_F_MULTIQUEUE, + offsetof(struct virtio_net_config, + num_queues), &num_queues); + + /* We need atleast 2 queue's */ + if (err || num_queues < 2) + num_queues = 2; + + num_queue_pairs = num_queues / 2; /* Allocate ourselves a network device with room for our info */ - dev = alloc_etherdev(sizeof(struct virtnet_info)); + dev = alloc_etherdev_mq(sizeof(struct virtnet_info), num_queue_pairs); if (!dev) return -ENOMEM; @@ -1103,22 +1404,18 @@ static int virtnet_probe(struct virtio_device *vdev) /* Set up our device-specific information */ vi = netdev_priv(dev); - netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight); vi->dev = dev; vi->vdev = vdev; vdev->priv = vi; - vi->pages = NULL; vi->stats = alloc_percpu(struct virtnet_stats); err = -ENOMEM; if (vi->stats == NULL) - goto free; + goto free_netdev; - INIT_DELAYED_WORK(&vi->refill, refill_work); mutex_init(&vi->config_lock); vi->config_enable = true; INIT_WORK(&vi->config_work, virtnet_config_changed_work); - sg_init_table(vi->rx_sg, ARRAY_SIZE(vi->rx_sg)); - sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg)); + vi->num_queue_pairs = num_queue_pairs; /* If we can receive ANY GSO packets, we must allocate large ones. */ if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || @@ -1129,9 +1426,17 @@ static int virtnet_probe(struct virtio_device *vdev) if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) vi->mergeable_rx_bufs = true; - err = init_vqs(vi); + if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) + vi->has_cvq = true; + + /* Allocate/initialize the rx/tx queues, and invoke find_vqs */ + err = virtnet_setup_vqs(vi); if (err) - goto free_stats; + goto free_netdev; + + if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) && + virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) + dev->features |= NETIF_F_HW_VLAN_FILTER; err = register_netdev(dev); if (err) { @@ -1140,12 +1445,21 @@ static int virtnet_probe(struct virtio_device *vdev) } /* Last of all, set up some receive buffers. */ - try_fill_recv(vi, GFP_KERNEL); + for (i = 0; i < num_queue_pairs; i++) { + try_fill_recv(vi->rq[i], GFP_KERNEL); + + /* If we didn't even get one input buffer, we're useless. */ + if (vi->rq[i]->num == 0) { + free_unused_bufs(vi); + err = -ENOMEM; + goto free_recv_bufs; + } + } - /* If we didn't even get one input buffer, we're useless. */ - if (vi->num == 0) { - err = -ENOMEM; - goto unregister; + err = virtnet_init_affinity(vi); + if (err) { + pr_debug("virtio_net: fail to initialize irq affinity\n"); + goto free_recv_bufs; } /* Assume link up if device can't report link status, @@ -1158,42 +1472,26 @@ static int virtnet_probe(struct virtio_device *vdev) netif_carrier_on(dev); } - pr_debug("virtnet: registered device %s\n", dev->name); + pr_debug("virtnet: registered device %s with %d RX and TX vq's\n", + dev->name, num_queue_pairs); + return 0; -unregister: +free_recv_bufs: + free_receive_bufs(vi); unregister_netdev(dev); free_vqs: + for (i = 0; i < num_queue_pairs; i++) + cancel_delayed_work_sync(&vi->rq[i]->refill); vdev->config->del_vqs(vdev); -free_stats: - free_percpu(vi->stats); -free: + +free_netdev: + free_rq_sq(vi); + free_netdev(dev); return err; } -static void free_unused_bufs(struct virtnet_info *vi) -{ - void *buf; - while (1) { - buf = virtqueue_detach_unused_buf(vi->svq); - if (!buf) - break; - dev_kfree_skb(buf); - } - while (1) { - buf = virtqueue_detach_unused_buf(vi->rvq); - if (!buf) - break; - if (vi->mergeable_rx_bufs || vi->big_packets) - give_pages(vi, buf); - else - dev_kfree_skb(buf); - --vi->num; - } - BUG_ON(vi->num != 0); -} - static void remove_vq_common(struct virtnet_info *vi) { vi->vdev->config->reset(vi->vdev); @@ -1203,14 +1501,17 @@ static void remove_vq_common(struct virtnet_info *vi) vi->vdev->config->del_vqs(vi->vdev); - while (vi->pages) - __free_pages(get_a_page(vi, GFP_KERNEL), 0); + free_receive_bufs(vi); } static void __devexit virtnet_remove(struct virtio_device *vdev) { struct virtnet_info *vi = vdev->priv; + /* Stop all the virtqueues. */ + vdev->config->reset(vdev); + + /* Prevent config work handler from accessing the device. */ mutex_lock(&vi->config_lock); vi->config_enable = false; @@ -1220,6 +1521,11 @@ static void __devexit virtnet_remove(struct virtio_device *vdev) remove_vq_common(vi); + virtnet_free_affinity(vi); + + /* Free memory for send and receive queues */ + free_rq_sq(vi); + flush_work(&vi->config_work); free_percpu(vi->stats); @@ -1230,6 +1536,7 @@ static void __devexit virtnet_remove(struct virtio_device *vdev) static int virtnet_freeze(struct virtio_device *vdev) { struct virtnet_info *vi = vdev->priv; + int i; /* Prevent config work handler from accessing the device */ mutex_lock(&vi->config_lock); @@ -1237,10 +1544,13 @@ static int virtnet_freeze(struct virtio_device *vdev) mutex_unlock(&vi->config_lock); netif_device_detach(vi->dev); - cancel_delayed_work_sync(&vi->refill); + for (i = 0; i < vi->num_queue_pairs; i++) + cancel_delayed_work_sync(&vi->rq[i]->refill); if (netif_running(vi->dev)) - napi_disable(&vi->napi); + for (i = 0; i < vi->num_queue_pairs; i++) + napi_disable(&vi->rq[i]->napi); + remove_vq_common(vi); @@ -1252,19 +1562,22 @@ static int virtnet_freeze(struct virtio_device *vdev) static int virtnet_restore(struct virtio_device *vdev) { struct virtnet_info *vi = vdev->priv; - int err; + int err, i; - err = init_vqs(vi); + err = virtnet_setup_vqs(vi); if (err) return err; if (netif_running(vi->dev)) - virtnet_napi_enable(vi); + for (i = 0; i < vi->num_queue_pairs; i++) + virtnet_napi_enable(vi->rq[i]); netif_device_attach(vi->dev); - if (!try_fill_recv(vi, GFP_KERNEL)) - queue_delayed_work(system_nrt_wq, &vi->refill, 0); + for (i = 0; i < vi->num_queue_pairs; i++) + if (!try_fill_recv(vi->rq[i], GFP_KERNEL)) + queue_delayed_work(system_nrt_wq, + &vi->rq[i]->refill, 0); mutex_lock(&vi->config_lock); vi->config_enable = true; @@ -1287,7 +1600,7 @@ static unsigned int features[] = { VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, 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_GUEST_ANNOUNCE, VIRTIO_NET_F_MULTIQUEUE, }; static struct virtio_driver virtio_net_driver = { diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index 1bc7e30..60f09ff 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -61,6 +61,8 @@ struct virtio_net_config { __u8 mac[6]; /* See VIRTIO_NET_F_STATUS and VIRTIO_NET_S_* above */ __u16 status; + /* Total number of RX/TX queues */ + __u16 num_queues; } __attribute__((packed)); /* This is the first element of the scatter-gather list. If you don't -- 1.7.1
Michael S. Tsirkin
2012-Jun-25 10:07 UTC
[net-next RFC V4 PATCH 0/4] Multiqueue virtio-net
On Mon, Jun 25, 2012 at 05:16:48PM +0800, Jason Wang wrote:> Hello All: > > This series is an update version of multiqueue virtio-net driver based on > Krishna Kumar's work to let virtio-net use multiple rx/tx queues to do the > packets reception and transmission. Please review and comments. > > Test Environment: > - Intel(R) Xeon(R) CPU E5620 @ 2.40GHz, 8 cores 2 numa nodes > - Two directed connected 82599 > > Test Summary: > > - Highlights: huge improvements on TCP_RR test > - Lowlights: regression on small packet transmission, higher cpu utilization > than single queue, need further optimizationDidn't review yet, reacting this this paragraph: To avoid regressions, it seems reasonable to make the device use a single queue by default for now. Add a way to switch multiqueue on/off using ethtool. This way guest admin can tune the device for the workload manually until we manage to imlement some self-tuning heuristics. -- MST
On 6/25/2012 2:16 AM, Jason Wang wrote:> Hello All: > > This series is an update version of multiqueue virtio-net driver based on > Krishna Kumar's work to let virtio-net use multiple rx/tx queues to do the > packets reception and transmission. Please review and comments. > > Test Environment: > - Intel(R) Xeon(R) CPU E5620 @ 2.40GHz, 8 cores 2 numa nodes > - Two directed connected 82599 > > Test Summary: > > - Highlights: huge improvements on TCP_RR test > - Lowlights: regression on small packet transmission, higher cpu utilization > than single queue, need further optimizationDoes this also scale with increased number of VMs? Thanks Sridhar> > Analysis of the performance result: > > - I count the number of packets sending/receiving during the test, and > multiqueue show much more ability in terms of packets per second. > > - For the tx regression, multiqueue send about 1-2 times of more packets > compared to single queue, and the packets size were much smaller than single > queue does. I suspect tcp does less batching in multiqueue, so I hack the > tcp_write_xmit() to forece more batching, multiqueue works as well as > singlequeue for both small transmission and throughput > > - I didn't pack the accelerate RFS with virtio-net in this sereis as it still > need further shaping, for the one that interested in this please see: > http://www.mail-archive.com/kvm at vger.kernel.org/msg64111.html > >
Hello Jason, Good work. Do you have local guest to guest results? Thanks Shirley
On 06/26/2012 02:01 AM, Shirley Ma wrote:> Hello Jason, > > Good work. Do you have local guest to guest results? > > Thanks > ShirleyHi Shirley: I would run tests to measure the performance and post here. Thanks