From: Changchun Ouyang <changchun.ouy...@intel.com> This patch is initially based a patch from Nikolay Nikolaev.
This patch adds vhost-user multiple queue support, by creating a nc and vhost_net pair for each queue. Qemu exits if find that the backend can't support the number of requested queues (by providing queues=# option). The max number is queried by a new message, VHOST_USER_GET_QUEUE_NUM, and is sent only when protocol feature VHOST_USER_PROTOCOL_F_MQ is present first. The max queue check is done at vhost-user initiation stage. We initiate one queue first, which, in the meantime, also gets the max_queues the backend supports. In older version, it was reported that some messages are sent more times than necessary. Here we came an agreement with Michael that we could categorize vhost user messages to 2 types: dev specific messages, which should be sent only once, and vring specific messages, which should be sent per queue. Here I introduced a helper function vhost_user_dev_request(), which lists following messages as dev specific messages: VHOST_USER_SET_OWNER VHOST_USER_RESET_DEVICE VHOST_USER_SET_MEM_TABLE VHOST_USER_GET_QUEUE_NUM For above messages, we simply ignore them when they are not sent the first time. Signed-off-by: Nikolay Nikolaev <n.nikol...@virtualopensystems.com> Signed-off-by: Changchun Ouyang <changchun.ouy...@intel.com> Signed-off-by: Yuanhan Liu <yuanhan....@linux.intel.com> Reviewed-by: Jason Wang <jasow...@redhat.com> Tested-by: Marcel Apfelbaum <mar...@redhat.com> --- v12: rename vhost_user_one_time_request() to vhost_user_dev_request(). use vhost_net_set_vq_index() instead direct assignment. v11: inovke qmp_set_link() directly --- docs/specs/vhost-user.txt | 15 +++++ hw/net/vhost_net.c | 20 ++++--- hw/virtio/vhost-user.c | 22 ++++++++ hw/virtio/vhost.c | 5 +- net/vhost-user.c | 141 ++++++++++++++++++++++++++++++---------------- qapi-schema.json | 6 +- qemu-options.hx | 5 +- 7 files changed, 152 insertions(+), 62 deletions(-) diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt index 5346df2..477edd1 100644 --- a/docs/specs/vhost-user.txt +++ b/docs/specs/vhost-user.txt @@ -136,6 +136,21 @@ As older slaves don't support negotiating protocol features, a feature bit was dedicated for this purpose: #define VHOST_USER_F_PROTOCOL_FEATURES 30 +Multiple queue support +---------------------- + +Multiple queue is treated as a protocol extension, hence the slave has to +implement protocol features first. The multiple queues feature is supported +only when the protocol feature VHOST_USER_PROTOCOL_F_MQ (bit 0) is set: +#define VHOST_USER_PROTOCOL_F_MQ 0 + +The max number of queues the slave supports can be queried with message +VHOST_USER_GET_PROTOCOL_FEATURES. Master should stop when the number of +requested queues is bigger than that. + +As all queues share one connection, the master uses a unique index for each +queue in the sent message to identify a specified queue. + Message types ------------- diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c index f663e5a..e2cb40b 100644 --- a/hw/net/vhost_net.c +++ b/hw/net/vhost_net.c @@ -138,6 +138,11 @@ static int vhost_net_get_fd(NetClientState *backend) } } +static void vhost_net_set_vq_index(struct vhost_net *net, int vq_index) +{ + net->dev.vq_index = vq_index; +} + struct vhost_net *vhost_net_init(VhostNetOptions *options) { int r; @@ -148,8 +153,11 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options) fprintf(stderr, "vhost-net requires net backend to be setup\n"); goto fail; } + net->nc = options->net_backend; net->dev.max_queues = 1; + net->dev.nvqs = 2; + net->dev.vqs = net->vqs; if (backend_kernel) { r = vhost_net_get_fd(options->net_backend); @@ -164,11 +172,10 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options) net->dev.backend_features = 0; net->dev.protocol_features = 0; net->backend = -1; - } - net->nc = options->net_backend; - net->dev.nvqs = 2; - net->dev.vqs = net->vqs; + /* vhost-user needs vq_index to initiate a specific queue pair */ + vhost_net_set_vq_index(net, net->nc->queue_index * net->dev.nvqs); + } r = vhost_dev_init(&net->dev, options->opaque, options->backend_type); @@ -196,11 +203,6 @@ fail: return NULL; } -static void vhost_net_set_vq_index(struct vhost_net *net, int vq_index) -{ - net->dev.vq_index = vq_index; -} - static int vhost_net_set_vnet_endian(VirtIODevice *dev, NetClientState *peer, bool set) { diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c index 5018fd6..d6850d5 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -187,6 +187,19 @@ static int vhost_user_write(struct vhost_dev *dev, VhostUserMsg *msg, 0 : -1; } +static bool vhost_user_dev_request(VhostUserRequest request) +{ + switch (request) { + case VHOST_USER_SET_OWNER: + case VHOST_USER_RESET_DEVICE: + case VHOST_USER_SET_MEM_TABLE: + case VHOST_USER_GET_QUEUE_NUM: + return true; + default: + return false; + } +} + static int vhost_user_call(struct vhost_dev *dev, unsigned long int request, void *arg) { @@ -207,6 +220,15 @@ static int vhost_user_call(struct vhost_dev *dev, unsigned long int request, msg_request = request; } + /* + * For dev specific requests, like VHOST_USER_SET_MEM_TABLE, we just + * need send it once in the first time. For later such request, we + * ignore it. + */ + if (vhost_user_dev_request(msg_request) && dev->vq_index != 0) { + return 0; + } + msg.request = msg_request; msg.flags = VHOST_USER_VERSION; msg.size = 0; diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 7a7812d..c0ed5b2 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -874,8 +874,9 @@ static void vhost_eventfd_del(MemoryListener *listener, static int vhost_virtqueue_init(struct vhost_dev *dev, struct vhost_virtqueue *vq, int n) { + int vhost_vq_index = dev->vhost_ops->vhost_backend_get_vq_index(dev, n); struct vhost_vring_file file = { - .index = n, + .index = vhost_vq_index, }; int r = event_notifier_init(&vq->masked_notifier, 0); if (r < 0) { @@ -926,7 +927,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque, } for (i = 0; i < hdev->nvqs; ++i) { - r = vhost_virtqueue_init(hdev, hdev->vqs + i, i); + r = vhost_virtqueue_init(hdev, hdev->vqs + i, hdev->vq_index + i); if (r < 0) { goto fail_vq; } diff --git a/net/vhost-user.c b/net/vhost-user.c index 93dcecd..1abec97 100644 --- a/net/vhost-user.c +++ b/net/vhost-user.c @@ -14,6 +14,7 @@ #include "sysemu/char.h" #include "qemu/config-file.h" #include "qemu/error-report.h" +#include "qmp-commands.h" typedef struct VhostUserState { NetClientState nc; @@ -39,37 +40,77 @@ static int vhost_user_running(VhostUserState *s) return (s->vhost_net) ? 1 : 0; } -static int vhost_user_start(VhostUserState *s) +static void vhost_user_stop(int queues, NetClientState *ncs[]) { - VhostNetOptions options; - - if (vhost_user_running(s)) { - return 0; - } + VhostUserState *s; + int i; - options.backend_type = VHOST_BACKEND_TYPE_USER; - options.net_backend = &s->nc; - options.opaque = s->chr; + for (i = 0; i < queues; i++) { + assert (ncs[i]->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER); - s->vhost_net = vhost_net_init(&options); + s = DO_UPCAST(VhostUserState, nc, ncs[i]); + if (!vhost_user_running(s)) { + continue; + } - return vhost_user_running(s) ? 0 : -1; + if (s->vhost_net) { + vhost_net_cleanup(s->vhost_net); + s->vhost_net = NULL; + } + } } -static void vhost_user_stop(VhostUserState *s) +static int vhost_user_start(int queues, NetClientState *ncs[]) { - if (vhost_user_running(s)) { - vhost_net_cleanup(s->vhost_net); + VhostNetOptions options; + VhostUserState *s; + int max_queues; + int i; + + options.backend_type = VHOST_BACKEND_TYPE_USER; + + for (i = 0; i < queues; i++) { + assert (ncs[i]->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER); + + s = DO_UPCAST(VhostUserState, nc, ncs[i]); + if (vhost_user_running(s)) { + continue; + } + + options.net_backend = ncs[i]; + options.opaque = s->chr; + s->vhost_net = vhost_net_init(&options); + if (!s->vhost_net) { + error_report("failed to init vhost_net for queue %d\n", i); + goto err; + } + + if (i == 0) { + max_queues = vhost_net_get_max_queues(s->vhost_net); + if (queues > max_queues) { + error_report("you are asking more queues than " + "supported: %d\n", max_queues); + goto err; + } + } } - s->vhost_net = 0; + return 0; + +err: + vhost_user_stop(i + 1, ncs); + return -1; } static void vhost_user_cleanup(NetClientState *nc) { VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc); - vhost_user_stop(s); + if (s->vhost_net) { + vhost_net_cleanup(s->vhost_net); + s->vhost_net = NULL; + } + qemu_purge_queued_packets(nc); } @@ -95,59 +136,61 @@ static NetClientInfo net_vhost_user_info = { .has_ufo = vhost_user_has_ufo, }; -static void net_vhost_link_down(VhostUserState *s, bool link_down) -{ - s->nc.link_down = link_down; - - if (s->nc.peer) { - s->nc.peer->link_down = link_down; - } - - if (s->nc.info->link_status_changed) { - s->nc.info->link_status_changed(&s->nc); - } - - if (s->nc.peer && s->nc.peer->info->link_status_changed) { - s->nc.peer->info->link_status_changed(s->nc.peer); - } -} - static void net_vhost_user_event(void *opaque, int event) { - VhostUserState *s = opaque; + const char *name = opaque; + NetClientState *ncs[MAX_QUEUE_NUM]; + VhostUserState *s; + Error *err = NULL; + int queues; + queues = qemu_find_net_clients_except(name, ncs, + NET_CLIENT_OPTIONS_KIND_NIC, + MAX_QUEUE_NUM); + s = DO_UPCAST(VhostUserState, nc, ncs[0]); switch (event) { case CHR_EVENT_OPENED: - vhost_user_start(s); - net_vhost_link_down(s, false); + if (vhost_user_start(queues, ncs) < 0) { + exit(1); + } + qmp_set_link(name, true, &err); error_report("chardev \"%s\" went up", s->chr->label); break; case CHR_EVENT_CLOSED: - net_vhost_link_down(s, true); - vhost_user_stop(s); + qmp_set_link(name, false, &err); + vhost_user_stop(queues, ncs); error_report("chardev \"%s\" went down", s->chr->label); break; } + + if (err) { + error_report_err(err); + } } static int net_vhost_user_init(NetClientState *peer, const char *device, - const char *name, CharDriverState *chr) + const char *name, CharDriverState *chr, + int queues) { NetClientState *nc; VhostUserState *s; + int i; - nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name); + for (i = 0; i < queues; i++) { + nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name); - snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user to %s", - chr->label); + snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user%d to %s", + i, chr->label); - s = DO_UPCAST(VhostUserState, nc, nc); + /* We don't provide a receive callback */ + nc->receive_disabled = 1; + nc->queue_index = i; - /* We don't provide a receive callback */ - s->nc.receive_disabled = 1; - s->chr = chr; + s = DO_UPCAST(VhostUserState, nc, nc); + s->chr = chr; + } - qemu_chr_add_handlers(s->chr, NULL, NULL, net_vhost_user_event, s); + qemu_chr_add_handlers(chr, NULL, NULL, net_vhost_user_event, (void*)name); return 0; } @@ -226,6 +269,7 @@ static int net_vhost_check_net(void *opaque, QemuOpts *opts, Error **errp) int net_init_vhost_user(const NetClientOptions *opts, const char *name, NetClientState *peer, Error **errp) { + int queues; const NetdevVhostUserOptions *vhost_user_opts; CharDriverState *chr; @@ -243,6 +287,7 @@ int net_init_vhost_user(const NetClientOptions *opts, const char *name, return -1; } + queues = vhost_user_opts->has_queues ? vhost_user_opts->queues : 1; - return net_vhost_user_init(peer, "vhost_user", name, chr); + return net_vhost_user_init(peer, "vhost_user", name, chr, queues); } diff --git a/qapi-schema.json b/qapi-schema.json index 527690d..582a817 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -2481,12 +2481,16 @@ # # @vhostforce: #optional vhost on for non-MSIX virtio guests (default: false). # +# @queues: #optional number of queues to be created for multiqueue vhost-user +# (default: 1) (Since 2.5) +# # Since 2.1 ## { 'struct': 'NetdevVhostUserOptions', 'data': { 'chardev': 'str', - '*vhostforce': 'bool' } } + '*vhostforce': 'bool', + '*queues': 'int' } } ## # @NetClientOptions diff --git a/qemu-options.hx b/qemu-options.hx index 7e147b8..328404c 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -1990,13 +1990,14 @@ The hubport netdev lets you connect a NIC to a QEMU "vlan" instead of a single netdev. @code{-net} and @code{-device} with parameter @option{vlan} create the required hub automatically. -@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off] +@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n] Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should be a unix domain socket backed one. The vhost-user uses a specifically defined protocol to pass vhost ioctl replacement messages to an application on the other end of the socket. On non-MSIX guests, the feature can be forced with -@var{vhostforce}. +@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to +be created for multiqueue vhost-user. Example: @example -- 1.9.0