From nobody Sun Feb 8 15:05:39 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=gmail.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1582002552201532.4566971686623; Mon, 17 Feb 2020 21:09:12 -0800 (PST) Received: from localhost ([::1]:56650 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j3v89-0004xx-Dn for importer@patchew.org; Tue, 18 Feb 2020 00:09:09 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:41388) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j3v7C-0003MO-PO for qemu-devel@nongnu.org; Tue, 18 Feb 2020 00:08:12 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j3v7A-0004UZ-L4 for qemu-devel@nongnu.org; Tue, 18 Feb 2020 00:08:10 -0500 Received: from mail-pl1-x641.google.com ([2607:f8b0:4864:20::641]:45943) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1j3v7A-0004UH-Ct for qemu-devel@nongnu.org; Tue, 18 Feb 2020 00:08:08 -0500 Received: by mail-pl1-x641.google.com with SMTP id b22so7576303pls.12 for ; Mon, 17 Feb 2020 21:08:08 -0800 (PST) Received: from localhost.localdomain ([2402:9e80:0:1000::1:c192]) by smtp.googlemail.com with ESMTPSA id 3sm1181613pjg.27.2020.02.17.21.08.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 17 Feb 2020 21:08:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=somfXtqn1AIDOM38Cq280CYKrla4QNtFWNSuCjJxyLo=; b=SZewBSgR4506zM/tuykeZ/DQ/JcHaTcyLTfFn/z1fei36lmv9DXOhie/13vn16kcCf WRIJw4U8ytRfCP+2u8mmN9DyRnwIgjVWDsOiJRZ7BiTEif9TnIwG7GfjvAXkFbQofKEE IiNC8rSRbnXBo47EVQum4HLrIJmprlv0rdzamY2mslrSxuLCJX/x0eli0pV1tG9D6GwE bszGlqPXLtyDHoj1tcRRzhj/PNaNStMYeWQ/Ts+mfMh5i+hclo8O91K8oMdbo4msQ9b+ eIYVKgWDfRVY+dfh8YEphZhypTnSJaQCSg4/WULjZl74mggYH97jnB/YKfhABup1YxqQ VRIw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=somfXtqn1AIDOM38Cq280CYKrla4QNtFWNSuCjJxyLo=; b=pfE6hJi/fvN4J/oEdU3tPogozQpxLqPey4yPlNYySHAMUSC7ommtyyZSZSoVinT8P4 NLoWKxIXigmlZa9FpAk6x7yIcxcrZ9eBs5wllD5R7NYxlFUyshVb/i8oGRP8JL5dUZxp MNo3HVRoUwpLL7L0gdbXSpV74mwu0OdZOhPvApvss4A8O+fXwxLh7myk8GXAu6FeZRCo 9XX7KWHXLI9CbrnB/ld6ShLUV09Vl79qqNfR17Y/5fytqEgbH7Xqk3gbrrLDgxwJxtIy bKR7Lq5ZvrrpIFcPYH4HrNMNT1tOecDdH2dqV/ZvzedfDELK77Ob/FXi0GUHlG2kQx5W q8HQ== X-Gm-Message-State: APjAAAUHoKs/3JZwtVzrxrD2FnQYgCS+QgD3PceutFJWZBaUbSbnIN7H XmDRUhrkhlHnUVG2xjZjI53Xk7pYZ6k= X-Google-Smtp-Source: APXvYqw+IpBc7/MgdIwpRrOwWst2EmhFCQ67PJzQLGSReOssT+U04Seq1Q/sINK94YvjIuqazwmDPg== X-Received: by 2002:a17:902:348:: with SMTP id 66mr19131160pld.137.1582002485390; Mon, 17 Feb 2020 21:08:05 -0800 (PST) From: Coiby Xu To: qemu-devel@nongnu.org Subject: [PATCH v4 2/5] generic vhost user server Date: Tue, 18 Feb 2020 13:07:08 +0800 Message-Id: <20200218050711.8133-3-coiby.xu@gmail.com> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200218050711.8133-1-coiby.xu@gmail.com> References: <20200218050711.8133-1-coiby.xu@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2607:f8b0:4864:20::641 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, bharatlkmlkvm@gmail.com, Coiby Xu , stefanha@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" Sharing QEMU devices via vhost-user protocol Signed-off-by: Coiby Xu --- util/Makefile.objs | 3 + util/vhost-user-server.c | 427 +++++++++++++++++++++++++++++++++++++++ util/vhost-user-server.h | 56 +++++ 3 files changed, 486 insertions(+) create mode 100644 util/vhost-user-server.c create mode 100644 util/vhost-user-server.h diff --git a/util/Makefile.objs b/util/Makefile.objs index 11262aafaf..5e450e501c 100644 --- a/util/Makefile.objs +++ b/util/Makefile.objs @@ -36,6 +36,9 @@ util-obj-y +=3D readline.o util-obj-y +=3D rcu.o util-obj-$(CONFIG_MEMBARRIER) +=3D sys_membarrier.o util-obj-y +=3D qemu-coroutine.o qemu-coroutine-lock.o qemu-coroutine-io.o +ifdef CONFIG_LINUX +util-obj-y +=3D vhost-user-server.o +endif util-obj-y +=3D qemu-coroutine-sleep.o util-obj-y +=3D qemu-co-shared-resource.o util-obj-y +=3D coroutine-$(CONFIG_COROUTINE_BACKEND).o diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c new file mode 100644 index 0000000000..70ff6d6701 --- /dev/null +++ b/util/vhost-user-server.c @@ -0,0 +1,427 @@ +/* + * Sharing QEMU devices via vhost-user protocol + * + * Author: Coiby Xu + * + * This work is licensed under the terms of the GNU GPL, version 2 or + * later. See the COPYING file in the top-level directory. + */ +#include "qemu/osdep.h" +#include +#include "qemu/main-loop.h" +#include "vhost-user-server.h" + +static void vmsg_close_fds(VhostUserMsg *vmsg) +{ + int i; + for (i =3D 0; i < vmsg->fd_num; i++) { + close(vmsg->fds[i]); + } +} + +static void vmsg_unblock_fds(VhostUserMsg *vmsg) +{ + int i; + for (i =3D 0; i < vmsg->fd_num; i++) { + qemu_set_nonblock(vmsg->fds[i]); + } +} + + +static void close_client(VuClient *client) +{ + vu_deinit(&client->parent); + client->sioc =3D NULL; + object_unref(OBJECT(client->ioc)); + client->closed =3D true; + +} + +static void panic_cb(VuDev *vu_dev, const char *buf) +{ + if (buf) { + error_report("vu_panic: %s", buf); + } + + VuClient *client =3D container_of(vu_dev, VuClient, parent); + VuServer *server =3D client->server; + if (!client->closed) { + close_client(client); + QTAILQ_REMOVE(&server->clients, client, next); + } + + if (server->device_panic_notifier) { + server->device_panic_notifier(client); + } +} + + + +static bool coroutine_fn +vu_message_read(VuDev *vu_dev, int conn_fd, VhostUserMsg *vmsg) +{ + struct iovec iov =3D { + .iov_base =3D (char *)vmsg, + .iov_len =3D VHOST_USER_HDR_SIZE, + }; + int rc, read_bytes =3D 0; + /* + * VhostUserMsg is a packed structure, gcc will complain about passing + * pointer to a packed structure member if we pass &VhostUserMsg.fd_num + * and &VhostUserMsg.fds directly when calling qio_channel_readv_full, + * thus two temporary variables nfds and fds are used here. + */ + size_t nfds =3D 0, nfds_t =3D 0; + int *fds =3D NULL, *fds_t =3D NULL; + VuClient *client =3D container_of(vu_dev, VuClient, parent); + QIOChannel *ioc =3D client->ioc; + + Error *erp; + assert(qemu_in_coroutine()); + do { + /* + * qio_channel_readv_full may have short reads, keeping calling it + * until getting VHOST_USER_HDR_SIZE or 0 bytes in total + */ + rc =3D qio_channel_readv_full(ioc, &iov, 1, &fds_t, &nfds_t, &erp); + if (rc < 0) { + if (rc =3D=3D QIO_CHANNEL_ERR_BLOCK) { + qio_channel_yield(ioc, G_IO_IN); + continue; + } else { + error_report("Error while recvmsg: %s", strerror(errno)); + return false; + } + } + read_bytes +=3D rc; + fds =3D g_renew(int, fds_t, nfds + nfds_t); + memcpy(fds + nfds, fds_t, nfds_t); + nfds +=3D nfds_t; + if (read_bytes =3D=3D VHOST_USER_HDR_SIZE || rc =3D=3D 0) { + break; + } + } while (true); + + vmsg->fd_num =3D nfds; + memcpy(vmsg->fds, fds, nfds * sizeof(int)); + g_free(fds); + /* qio_channel_readv_full will make socket fds blocking, unblock them = */ + vmsg_unblock_fds(vmsg); + if (vmsg->size > sizeof(vmsg->payload)) { + error_report("Error: too big message request: %d, " + "size: vmsg->size: %u, " + "while sizeof(vmsg->payload) =3D %zu", + vmsg->request, vmsg->size, sizeof(vmsg->payload)); + goto fail; + } + + struct iovec iov_payload =3D { + .iov_base =3D (char *)&vmsg->payload, + .iov_len =3D vmsg->size, + }; + if (vmsg->size) { + rc =3D qio_channel_readv_all_eof(ioc, &iov_payload, 1, &erp); + if (rc =3D=3D -1) { + error_report("Error while reading: %s", strerror(errno)); + goto fail; + } + } + + return true; + +fail: + vmsg_close_fds(vmsg); + + return false; +} + + +static coroutine_fn void vu_client_next_trip(VuClient *client); + +static coroutine_fn void vu_client_trip(void *opaque) +{ + VuClient *client =3D opaque; + + vu_dispatch(&client->parent); + client->co_trip =3D NULL; + if (!client->closed) { + vu_client_next_trip(client); + } +} + +static coroutine_fn void vu_client_next_trip(VuClient *client) +{ + if (!client->co_trip) { + client->co_trip =3D qemu_coroutine_create(vu_client_trip, client); + aio_co_schedule(client->ioc->ctx, client->co_trip); + } +} + +static void vu_client_start(VuClient *client) +{ + client->co_trip =3D qemu_coroutine_create(vu_client_trip, client); + aio_co_enter(client->ioc->ctx, client->co_trip); +} + +static void coroutine_fn vu_kick_cb_next(VuClient *client, + kick_info *data); + +static void coroutine_fn vu_kick_cb(void *opaque) +{ + kick_info *data =3D (kick_info *) opaque; + int index =3D data->index; + VuDev *dev =3D data->vu_dev; + VuClient *client; + client =3D container_of(dev, VuClient, parent); + VuVirtq *vq =3D &dev->vq[index]; + int sock =3D vq->kick_fd; + if (sock =3D=3D -1) { + return; + } + assert(sock =3D=3D data->fd); + eventfd_t kick_data; + ssize_t rc; + /* + * When eventfd is closed, the revent is POLLNVAL (=3DG_IO_NVAL) and + * reading eventfd will return errno=3DEBADF (Bad file number). + * Calling qio_channel_yield(ioc, G_IO_IN) will set reading handler + * for QIOChannel, but aio_dispatch_handlers will only dispatch + * G_IO_IN | G_IO_HUP | G_IO_ERR revents while ignoring + * G_IO_NVAL (POLLNVAL) revents. + * + * Thus when eventfd is closed by vhost-user client, QEMU will ignore + * G_IO_NVAL and keeping polling by repeatedly calling qemu_poll_ns wh= ich + * will lead to 100% CPU usage. + * + * To aovid this issue, make sure set_watch and remove_watch use the s= ame + * AIOContext for QIOChannel. Thus remove_watch will eventually succef= ully + * remove eventfd from the set of file descriptors polled for + * corresponding GSource. + */ + rc =3D read(sock, &kick_data, sizeof(eventfd_t)); + if (rc !=3D sizeof(eventfd_t)) { + if (errno =3D=3D EAGAIN) { + qio_channel_yield(data->ioc, G_IO_IN); + } else if (errno !=3D EINTR) { + data->co =3D NULL; + return; + } + } else { + vq->handler(dev, index); + } + data->co =3D NULL; + vu_kick_cb_next(client, data); + +} + +static void coroutine_fn vu_kick_cb_next(VuClient *client, + kick_info *cb_data) +{ + if (!cb_data->co) { + cb_data->co =3D qemu_coroutine_create(vu_kick_cb, cb_data); + aio_co_schedule(client->ioc->ctx, cb_data->co); + } +} +static const CoIface co_iface =3D { + .read_msg =3D vu_message_read, + .kick_callback =3D vu_kick_cb, +}; + + +static void +set_watch(VuDev *vu_dev, int fd, int vu_evt, + vu_watch_cb_packed_data cb, void *pvt) +{ + /* + * since aio_dispatch can only pass one user data pointer to the + * callback function, pack VuDev, pvt into a struct + */ + + VuClient *client; + + client =3D container_of(vu_dev, VuClient, parent); + g_assert(vu_dev); + g_assert(fd >=3D 0); + long index =3D (intptr_t) pvt; + g_assert(cb); + kick_info *kick_info =3D &client->kick_info[index]; + if (!kick_info->co) { + kick_info->fd =3D fd; + QIOChannelFile *fioc =3D qio_channel_file_new_fd(fd); + QIOChannel *ioc =3D QIO_CHANNEL(fioc); + ioc->ctx =3D client->ioc->ctx; + qio_channel_set_blocking(QIO_CHANNEL(ioc), false, NULL); + kick_info->fioc =3D fioc; + kick_info->ioc =3D ioc; + kick_info->vu_dev =3D vu_dev; + kick_info->co =3D qemu_coroutine_create(cb, kick_info); + aio_co_enter(client->ioc->ctx, kick_info->co); + } +} + + +static void remove_watch(VuDev *vu_dev, int fd) +{ + VuClient *client; + int i; + int index =3D -1; + g_assert(vu_dev); + g_assert(fd >=3D 0); + + client =3D container_of(vu_dev, VuClient, parent); + for (i =3D 0; i < vu_dev->max_queues; i++) { + if (client->kick_info[i].fd =3D=3D fd) { + index =3D i; + break; + } + } + + if (index =3D=3D -1) { + return; + } + + kick_info *kick_info =3D &client->kick_info[index]; + if (kick_info->ioc) { + aio_set_fd_handler(client->ioc->ctx, fd, false, NULL, + NULL, NULL, NULL); + kick_info->ioc =3D NULL; + g_free(kick_info->fioc); + kick_info->co =3D NULL; + kick_info->fioc =3D NULL; + } +} + + +static void vu_accept(QIONetListener *listener, QIOChannelSocket *sioc, + gpointer opaque) +{ + VuClient *client; + VuServer *server =3D opaque; + client =3D g_new0(VuClient, 1); + + if (!vu_init_packed_data(&client->parent, server->max_queues, + sioc->fd, panic_cb, + set_watch, remove_watch, + server->vu_iface, &co_iface)) { + error_report("Failed to initialized libvhost-user"); + g_free(client); + return; + } + + client->server =3D server; + client->sioc =3D sioc; + client->kick_info =3D g_new0(struct kick_info, server->max_queues); + /* + * increase the object reference, so cioc will not freed by + * qio_net_listener_channel_func which will call object_unref(OBJECT(s= ioc)) + */ + object_ref(OBJECT(client->sioc)); + qio_channel_set_name(QIO_CHANNEL(sioc), "vhost-user client"); + client->ioc =3D QIO_CHANNEL(sioc); + object_ref(OBJECT(client->ioc)); + object_ref(OBJECT(sioc)); + qio_channel_attach_aio_context(client->ioc, server->ctx); + qio_channel_set_blocking(QIO_CHANNEL(client->sioc), false, NULL); + client->closed =3D false; + QTAILQ_INSERT_TAIL(&server->clients, client, next); + vu_client_start(client); +} + + +void vhost_user_server_stop(VuServer *server) +{ + if (!server) { + return; + } + + VuClient *client, *next; + QTAILQ_FOREACH_SAFE(client, &server->clients, next, next) { + if (!client->closed) { + close_client(client); + QTAILQ_REMOVE(&server->clients, client, next); + } + } + + if (server->listener) { + qio_net_listener_disconnect(server->listener); + object_unref(OBJECT(server->listener)); + } +} + +static void detach_context(VuServer *server) +{ + VuClient *client; + int i; + QTAILQ_FOREACH(client, &server->clients, next) { + qio_channel_detach_aio_context(client->ioc); + for (i =3D 0; i < client->parent.max_queues; i++) { + if (client->kick_info[i].ioc) { + qio_channel_detach_aio_context(client->kick_info[i].ioc); + } + } + } +} + +static void attach_context(VuServer *server, AioContext *ctx) +{ + VuClient *client; + int i; + QTAILQ_FOREACH(client, &server->clients, next) { + qio_channel_attach_aio_context(client->ioc, ctx); + if (client->co_trip) { + aio_co_schedule(ctx, client->co_trip); + } + for (i =3D 0; i < client->parent.max_queues; i++) { + if (client->kick_info[i].co) { + qio_channel_attach_aio_context(client->kick_info[i].ioc, c= tx); + aio_co_schedule(ctx, client->kick_info[i].co); + } + } + } +} +void change_vu_context(AioContext *ctx, VuServer *server) +{ + AioContext *acquire_ctx =3D ctx ? ctx : server->ctx; + aio_context_acquire(acquire_ctx); + server->ctx =3D ctx ? ctx : qemu_get_aio_context(); + if (ctx) { + attach_context(server, ctx); + } else { + detach_context(server); + } + aio_context_release(acquire_ctx); +} + + +VuServer *vhost_user_server_start(uint16_t max_queues, + SocketAddress *socket_addr, + AioContext *ctx, + void *server_ptr, + void *device_panic_notifier, + const VuDevIface *vu_iface, + Error **errp) +{ + VuServer *server =3D g_new0(VuServer, 1); + server->ptr_in_device =3D server_ptr; + server->listener =3D qio_net_listener_new(); + if (qio_net_listener_open_sync(server->listener, socket_addr, 1, errp)= < 0) { + goto error; + } + + qio_net_listener_set_name(server->listener, "vhost-user-backend-listen= er"); + + server->vu_iface =3D vu_iface; + server->max_queues =3D max_queues; + server->ctx =3D ctx; + server->device_panic_notifier =3D device_panic_notifier; + qio_net_listener_set_client_func(server->listener, + vu_accept, + server, + NULL); + + QTAILQ_INIT(&server->clients); + return server; +error: + g_free(server); + return NULL; +} diff --git a/util/vhost-user-server.h b/util/vhost-user-server.h new file mode 100644 index 0000000000..ff6d3145cd --- /dev/null +++ b/util/vhost-user-server.h @@ -0,0 +1,56 @@ +#include "io/channel-socket.h" +#include "io/channel-file.h" +#include "io/net-listener.h" +#include "contrib/libvhost-user/libvhost-user.h" +#include "standard-headers/linux/virtio_blk.h" +#include "qemu/error-report.h" + +typedef struct VuClient VuClient; + +typedef struct VuServer { + QIONetListener *listener; + AioContext *ctx; + QTAILQ_HEAD(, VuClient) clients; + void (*device_panic_notifier)(struct VuClient *client) ; + int max_queues; + const VuDevIface *vu_iface; + /* + * @ptr_in_device: VuServer pointer memory location in vhost-user devi= ce + * struct, so later container_of can be used to get device destruct + */ + void *ptr_in_device; + bool close; +} VuServer; + +typedef struct kick_info { + VuDev *vu_dev; + int fd; /*kick fd*/ + long index; /*queue index*/ + QIOChannel *ioc; /*I/O channel for kick fd*/ + QIOChannelFile *fioc; /*underlying data channel for kick fd*/ + Coroutine *co; +} kick_info; + +struct VuClient { + VuDev parent; + VuServer *server; + QIOChannel *ioc; /* The current I/O channel */ + QIOChannelSocket *sioc; /* The underlying data channel */ + Coroutine *co_trip; + struct kick_info *kick_info; + QTAILQ_ENTRY(VuClient) next; + bool closed; +}; + + +VuServer *vhost_user_server_start(uint16_t max_queues, + SocketAddress *unix_socket, + AioContext *ctx, + void *server_ptr, + void *device_panic_notifier, + const VuDevIface *vu_iface, + Error **errp); + +void vhost_user_server_stop(VuServer *server); + +void change_vu_context(AioContext *ctx, VuServer *server); --=20 2.25.0