From cb0ddda2b2b6a7e929a7de43efa2c3e3bab8ab75 Mon Sep 17 00:00:00 2001 From: Xiao Wang Date: Fri, 8 Jul 2016 09:34:11 +0200 Subject: [PATCH 09/16] tap: vhost busy polling support RH-Author: Xiao Wang Message-id: <1467970451-27245-1-git-send-email-jasowang@redhat.com> Patchwork-id: 71074 O-Subject: [RHEL7.3 qemu-kvm-rhev PATCH] tap: vhost busy polling support Bugzilla: 1345715 RH-Acked-by: Thomas Huth RH-Acked-by: Laszlo Ersek RH-Acked-by: Laurent Vivier Bugzilla: 1353791 Test status: Tested by myself Brew Build: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=11323602 This patch add the capability of basic vhost net busy polling which is supported by recent kernel. User could configure the maximum number of us that could be spent on busy polling through a new property of tap "poll-us". Cc: Greg Kurz Reviewed-by: Michael S. Tsirkin Signed-off-by: Jason Wang (cherry picked from commit 69e87b32680a41d9761191443587c595b6f5fc3f) Signed-off-by: Miroslav Rezanina --- hw/net/vhost_net.c | 2 +- hw/scsi/vhost-scsi.c | 2 +- hw/virtio/vhost-backend.c | 8 ++++++++ hw/virtio/vhost.c | 40 ++++++++++++++++++++++++++++++++++++++- include/hw/virtio/vhost-backend.h | 3 +++ include/hw/virtio/vhost.h | 3 ++- include/net/vhost_net.h | 1 + net/tap.c | 7 ++++++- net/vhost-user.c | 1 + qapi-schema.json | 6 +++++- qemu-options.hx | 3 +++ 11 files changed, 70 insertions(+), 6 deletions(-) diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c index 50f4dcd..11fabc0 100644 --- a/hw/net/vhost_net.c +++ b/hw/net/vhost_net.c @@ -172,7 +172,7 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options) } r = vhost_dev_init(&net->dev, options->opaque, - options->backend_type); + options->backend_type, options->busyloop_timeout); if (r < 0) { goto fail; } diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c index 9261d51..2a00f2f 100644 --- a/hw/scsi/vhost-scsi.c +++ b/hw/scsi/vhost-scsi.c @@ -248,7 +248,7 @@ static void vhost_scsi_realize(DeviceState *dev, Error **errp) s->dev.backend_features = 0; ret = vhost_dev_init(&s->dev, (void *)(uintptr_t)vhostfd, - VHOST_BACKEND_TYPE_KERNEL); + VHOST_BACKEND_TYPE_KERNEL, 0); if (ret < 0) { error_setg(errp, "vhost-scsi: vhost initialization failed: %s", strerror(-ret)); diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c index b358902..d62372e 100644 --- a/hw/virtio/vhost-backend.c +++ b/hw/virtio/vhost-backend.c @@ -138,6 +138,12 @@ static int vhost_kernel_set_vring_call(struct vhost_dev *dev, return vhost_kernel_call(dev, VHOST_SET_VRING_CALL, file); } +static int vhost_kernel_set_vring_busyloop_timeout(struct vhost_dev *dev, + struct vhost_vring_state *s) +{ + return vhost_kernel_call(dev, VHOST_SET_VRING_BUSYLOOP_TIMEOUT, s); +} + static int vhost_kernel_set_features(struct vhost_dev *dev, uint64_t features) { @@ -185,6 +191,8 @@ static const VhostOps kernel_ops = { .vhost_get_vring_base = vhost_kernel_get_vring_base, .vhost_set_vring_kick = vhost_kernel_set_vring_kick, .vhost_set_vring_call = vhost_kernel_set_vring_call, + .vhost_set_vring_busyloop_timeout = + vhost_kernel_set_vring_busyloop_timeout, .vhost_set_features = vhost_kernel_set_features, .vhost_get_features = vhost_kernel_get_features, .vhost_set_owner = vhost_kernel_set_owner, diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 4400718..ebf8b08 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -964,6 +964,28 @@ static void vhost_eventfd_del(MemoryListener *listener, { } +static int vhost_virtqueue_set_busyloop_timeout(struct vhost_dev *dev, + int n, uint32_t timeout) +{ + int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); + struct vhost_vring_state state = { + .index = vhost_vq_index, + .num = timeout, + }; + int r; + + if (!dev->vhost_ops->vhost_set_vring_busyloop_timeout) { + return -EINVAL; + } + + r = dev->vhost_ops->vhost_set_vring_busyloop_timeout(dev, &state); + if (r) { + return r; + } + + return 0; +} + static int vhost_virtqueue_init(struct vhost_dev *dev, struct vhost_virtqueue *vq, int n) { @@ -994,7 +1016,7 @@ static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq) } int vhost_dev_init(struct vhost_dev *hdev, void *opaque, - VhostBackendType backend_type) + VhostBackendType backend_type, uint32_t busyloop_timeout) { uint64_t features; int i, r; @@ -1035,6 +1057,17 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque, goto fail_vq; } } + + if (busyloop_timeout) { + for (i = 0; i < hdev->nvqs; ++i) { + r = vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, + busyloop_timeout); + if (r < 0) { + goto fail_busyloop; + } + } + } + hdev->features = features; hdev->memory_listener = (MemoryListener) { @@ -1077,6 +1110,11 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque, hdev->memory_changed = false; memory_listener_register(&hdev->memory_listener, &address_space_memory); return 0; +fail_busyloop: + while (--i >= 0) { + vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 0); + } + i = hdev->nvqs; fail_vq: while (--i >= 0) { vhost_virtqueue_cleanup(hdev->vqs + i); diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h index 95fcc96..84e1cb7 100644 --- a/include/hw/virtio/vhost-backend.h +++ b/include/hw/virtio/vhost-backend.h @@ -57,6 +57,8 @@ typedef int (*vhost_set_vring_kick_op)(struct vhost_dev *dev, struct vhost_vring_file *file); typedef int (*vhost_set_vring_call_op)(struct vhost_dev *dev, struct vhost_vring_file *file); +typedef int (*vhost_set_vring_busyloop_timeout_op)(struct vhost_dev *dev, + struct vhost_vring_state *r); typedef int (*vhost_set_features_op)(struct vhost_dev *dev, uint64_t features); typedef int (*vhost_get_features_op)(struct vhost_dev *dev, @@ -91,6 +93,7 @@ typedef struct VhostOps { vhost_get_vring_base_op vhost_get_vring_base; vhost_set_vring_kick_op vhost_set_vring_kick; vhost_set_vring_call_op vhost_set_vring_call; + vhost_set_vring_busyloop_timeout_op vhost_set_vring_busyloop_timeout; vhost_set_features_op vhost_set_features; vhost_get_features_op vhost_get_features; vhost_set_owner_op vhost_set_owner; diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h index b60d758..2106ed8 100644 --- a/include/hw/virtio/vhost.h +++ b/include/hw/virtio/vhost.h @@ -64,7 +64,8 @@ struct vhost_dev { }; int vhost_dev_init(struct vhost_dev *hdev, void *opaque, - VhostBackendType backend_type); + VhostBackendType backend_type, + uint32_t busyloop_timeout); void vhost_dev_cleanup(struct vhost_dev *hdev); int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev); void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev); diff --git a/include/net/vhost_net.h b/include/net/vhost_net.h index 0bd4877..5a08eff 100644 --- a/include/net/vhost_net.h +++ b/include/net/vhost_net.h @@ -10,6 +10,7 @@ typedef struct vhost_net VHostNetState; typedef struct VhostNetOptions { VhostBackendType backend_type; NetClientState *net_backend; + uint32_t busyloop_timeout; void *opaque; } VhostNetOptions; diff --git a/net/tap.c b/net/tap.c index 6d3969f..b3957d8 100644 --- a/net/tap.c +++ b/net/tap.c @@ -676,6 +676,11 @@ static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer, options.backend_type = VHOST_BACKEND_TYPE_KERNEL; options.net_backend = &s->nc; + if (tap->has_poll_us) { + options.busyloop_timeout = tap->poll_us; + } else { + options.busyloop_timeout = 0; + } if (vhostfdname) { vhostfd = monitor_fd_param(cur_mon, vhostfdname, &err); @@ -700,7 +705,7 @@ static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer, return; } } else if (vhostfdname) { - error_setg(errp, "vhostfd= is not valid without vhost"); + error_setg(errp, "vhostfd(s)= is not valid without vhost"); } } diff --git a/net/vhost-user.c b/net/vhost-user.c index 9402b9c..eb9cbc9 100644 --- a/net/vhost-user.c +++ b/net/vhost-user.c @@ -91,6 +91,7 @@ static int vhost_user_start(int queues, NetClientState *ncs[]) options.net_backend = ncs[i]; options.opaque = s->chr; + options.busyloop_timeout = 0; s->vhost_net = vhost_net_init(&options); if (!s->vhost_net) { error_report("failed to init vhost_net for queue %d", i); diff --git a/qapi-schema.json b/qapi-schema.json index e42d19e..da6b050 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -2535,6 +2535,9 @@ # # @queues: #optional number of queues to be created for multiqueue capable tap # +# @poll-us: #optional maximum number of microseconds that could +# be spent on busy polling for tap (since 2.7) +# # Since 1.2 ## { 'struct': 'NetdevTapOptions', @@ -2551,7 +2554,8 @@ '*vhostfd': 'str', '*vhostfds': 'str', '*vhostforce': 'bool', - '*queues': 'uint32'} } + '*queues': 'uint32', + '*poll-us': 'uint32'} } ## # @NetdevSocketOptions diff --git a/qemu-options.hx b/qemu-options.hx index 0f90bd8..4f8a3cf 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -1564,6 +1564,7 @@ DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" " [,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" + " [,poll-us=n]\n" " configure a host TAP network backend with ID 'str'\n" " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" @@ -1583,6 +1584,8 @@ DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, " use 'vhostfd=h' to connect to an already opened vhost net device\n" " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" + " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n" + " spent on busy polling for vhost net\n" "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" " configure a host TAP network backend with ID 'str' that is\n" " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" -- 1.8.3.1