From nobody Tue Feb 10 13:17:54 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1527873038146993.4762168510584; Fri, 1 Jun 2018 10:10:38 -0700 (PDT) Received: from localhost ([::1]:56840 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fOnZV-0002KT-Au for importer@patchew.org; Fri, 01 Jun 2018 13:10:37 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39203) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fOmuP-0003CY-Cr for qemu-devel@nongnu.org; Fri, 01 Jun 2018 12:28:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fOmuN-0007pc-Jb for qemu-devel@nongnu.org; Fri, 01 Jun 2018 12:28:09 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:47000 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fOmuN-0007pU-EC for qemu-devel@nongnu.org; Fri, 01 Jun 2018 12:28:07 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0BFD4C12AD for ; Fri, 1 Jun 2018 16:28:07 +0000 (UTC) Received: from localhost (ovpn-112-61.ams2.redhat.com [10.36.112.61]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6BC3663F72; Fri, 1 Jun 2018 16:28:01 +0000 (UTC) From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= To: qemu-devel@nongnu.org Date: Fri, 1 Jun 2018 18:27:41 +0200 Message-Id: <20180601162749.27406-5-marcandre.lureau@redhat.com> In-Reply-To: <20180601162749.27406-1-marcandre.lureau@redhat.com> References: <20180601162749.27406-1-marcandre.lureau@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Fri, 01 Jun 2018 16:28:07 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Fri, 01 Jun 2018 16:28:07 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'marcandre.lureau@redhat.com' RCPT:'' Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [RFC v2 04/12] Add vhost-user-backend X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Gerd Hoffmann Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Type: text/plain; charset="utf-8" Create a vhost-user-backend object that holds a connection to a vhost-user backend and can be referenced from virtio devices that support it. See later patches for input & gpu usage. A chardev can be specified to communicate with the vhost-user backend, ex: -chardev socket,id=3Dchar0,path=3D/tmp/foo.sock -object vhost-user-backend,id=3Dvuid,chardev=3Dchar0. Alternatively, an executable with its arguments may be given as 'cmd' property, ex: -object vhost-user-backend,id=3Dvui,cmd=3D"./vhost-user-input /dev/input..". The executable is then spawn and, by convention, the vhost-user socket is passed as fd=3D3. It may be considered a security breach to allow creating processes that may execute arbitrary executables, so this may be restricted to some known executables (via signature etc) or directory. Signed-off-by: Marc-Andr=C3=A9 Lureau --- include/sysemu/vhost-user-backend.h | 58 +++++ backends/vhost-user.c | 330 ++++++++++++++++++++++++++++ vl.c | 3 +- backends/Makefile.objs | 4 + 4 files changed, 394 insertions(+), 1 deletion(-) create mode 100644 include/sysemu/vhost-user-backend.h create mode 100644 backends/vhost-user.c diff --git a/include/sysemu/vhost-user-backend.h b/include/sysemu/vhost-use= r-backend.h new file mode 100644 index 0000000000..890db176fd --- /dev/null +++ b/include/sysemu/vhost-user-backend.h @@ -0,0 +1,58 @@ +/* + * QEMU vhost-user backend + * + * Copyright (C) 2018 Red Hat Inc + * + * Authors: + * Marc-Andr=C3=A9 Lureau + * + * This work is licensed under the terms of the GNU GPL, version 2 or late= r. + * See the COPYING file in the top-level directory. + */ +#ifndef QEMU_VHOST_USER_BACKEND_H +#define QEMU_VHOST_USER_BACKEND_H + +#include "qom/object.h" +#include "exec/memory.h" +#include "qemu/option.h" +#include "qemu/bitmap.h" +#include "hw/virtio/vhost.h" +#include "chardev/char-fe.h" +#include "io/channel.h" + +#define TYPE_VHOST_USER_BACKEND "vhost-user-backend" +#define VHOST_USER_BACKEND(obj) \ + OBJECT_CHECK(VhostUserBackend, (obj), TYPE_VHOST_USER_BACKEND) +#define VHOST_USER_BACKEND_GET_CLASS(obj) \ + OBJECT_GET_CLASS(VhostUserBackendClass, (obj), TYPE_VHOST_USER_BACKEND) +#define VHOST_USER_BACKEND_CLASS(klass) \ + OBJECT_CLASS_CHECK(VhostUserBackendClass, (klass), TYPE_VHOST_USER_BAC= KEND) + +typedef struct VhostUserBackend VhostUserBackend; +typedef struct VhostUserBackendClass VhostUserBackendClass; + +struct VhostUserBackendClass { + ObjectClass parent_class; +}; + +struct VhostUserBackend { + /* private */ + Object parent; + + char *cmd; + char *chr_name; + + CharBackend chr; + struct vhost_dev dev; + QIOChannel *child; + VirtIODevice *vdev; + bool started; + bool completed; +}; + +int vhost_user_backend_dev_init(VhostUserBackend *b, VirtIODevice *vdev, + unsigned nvqs, Error **errp); +void vhost_user_backend_start(VhostUserBackend *b); +void vhost_user_backend_stop(VhostUserBackend *b); + +#endif diff --git a/backends/vhost-user.c b/backends/vhost-user.c new file mode 100644 index 0000000000..ae40dee373 --- /dev/null +++ b/backends/vhost-user.c @@ -0,0 +1,330 @@ +/* + * QEMU vhost-user backend + * + * Copyright (C) 2018 Red Hat Inc + * + * Authors: + * Marc-Andr=C3=A9 Lureau + * + * This work is licensed under the terms of the GNU GPL, version 2 or late= r. + * See the COPYING file in the top-level directory. + */ + + +#include "qemu/osdep.h" +#include "hw/qdev.h" +#include "qapi/error.h" +#include "qapi/qmp/qerror.h" +#include "qemu/error-report.h" +#include "qom/object_interfaces.h" +#include "sysemu/vhost-user-backend.h" +#include "sysemu/kvm.h" +#include "io/channel-command.h" +#include "hw/virtio/virtio-bus.h" + +static bool +ioeventfd_enabled(void) +{ + return kvm_enabled() && kvm_eventfds_enabled(); +} + +int +vhost_user_backend_dev_init(VhostUserBackend *b, VirtIODevice *vdev, + unsigned nvqs, Error **errp) +{ + int ret; + + assert(!b->vdev && vdev); + + if (!ioeventfd_enabled()) { + error_setg(errp, "vhost initialization failed: requires kvm"); + return -1; + } + + b->vdev =3D vdev; + b->dev.nvqs =3D nvqs; + b->dev.vqs =3D g_new(struct vhost_virtqueue, nvqs); + + ret =3D vhost_dev_init(&b->dev, &b->chr, VHOST_BACKEND_TYPE_USER, 0); + if (ret < 0) { + error_setg_errno(errp, -ret, "vhost initialization failed"); + return -1; + } + + return 0; +} + +void +vhost_user_backend_start(VhostUserBackend *b) +{ + BusState *qbus =3D BUS(qdev_get_parent_bus(DEVICE(b->vdev))); + VirtioBusClass *k =3D VIRTIO_BUS_GET_CLASS(qbus); + int ret, i ; + + if (b->started) { + return; + } + + if (!k->set_guest_notifiers) { + error_report("binding does not support guest notifiers"); + return; + } + + ret =3D vhost_dev_enable_notifiers(&b->dev, b->vdev); + if (ret < 0) { + return; + } + + ret =3D k->set_guest_notifiers(qbus->parent, b->dev.nvqs, true); + if (ret < 0) { + error_report("Error binding guest notifier"); + goto err_host_notifiers; + } + + b->dev.acked_features =3D b->vdev->guest_features; + ret =3D vhost_dev_start(&b->dev, b->vdev); + if (ret < 0) { + error_report("Error start vhost dev"); + goto err_guest_notifiers; + } + + /* guest_notifier_mask/pending not used yet, so just unmask + * everything here. virtio-pci will do the right thing by + * enabling/disabling irqfd. + */ + for (i =3D 0; i < b->dev.nvqs; i++) { + vhost_virtqueue_mask(&b->dev, b->vdev, + b->dev.vq_index + i, false); + } + + b->started =3D true; + return; + +err_guest_notifiers: + k->set_guest_notifiers(qbus->parent, b->dev.nvqs, false); +err_host_notifiers: + vhost_dev_disable_notifiers(&b->dev, b->vdev); +} + +void +vhost_user_backend_stop(VhostUserBackend *b) +{ + BusState *qbus =3D BUS(qdev_get_parent_bus(DEVICE(b->vdev))); + VirtioBusClass *k =3D VIRTIO_BUS_GET_CLASS(qbus); + int ret =3D 0; + + if (!b->started) { + return; + } + + vhost_dev_stop(&b->dev, b->vdev); + + if (k->set_guest_notifiers) { + ret =3D k->set_guest_notifiers(qbus->parent, + b->dev.nvqs, false); + if (ret < 0) { + error_report("vhost guest notifier cleanup failed: %d", ret); + } + } + assert(ret >=3D 0); + + vhost_dev_disable_notifiers(&b->dev, b->vdev); + b->started =3D false; +} + +static int +vhost_user_backend_spawn_cmd(VhostUserBackend *b, int vhostfd, Error **err= p) +{ + int devnull =3D open("/dev/null", O_RDWR); + pid_t pid; + + assert(!b->child); + + if (!b->cmd) { + error_setg_errno(errp, errno, "Missing cmd property"); + return -1; + } + if (devnull < 0) { + error_setg_errno(errp, errno, "Unable to open /dev/null"); + return -1; + } + + pid =3D qemu_fork(errp); + if (pid < 0) { + close(devnull); + return -1; + } + + if (pid =3D=3D 0) { /* child */ + int fd, maxfd =3D sysconf(_SC_OPEN_MAX); + + dup2(devnull, STDIN_FILENO); + dup2(devnull, STDOUT_FILENO); + dup2(vhostfd, 3); + + signal(SIGINT, SIG_IGN); + + for (fd =3D 4; fd < maxfd; fd++) { + close(fd); + } + + execlp("/bin/sh", "sh", "-c", b->cmd, NULL); + _exit(1); + } + + b->child =3D QIO_CHANNEL(qio_channel_command_new_pid(devnull, devnull,= pid)); + + return 0; +} + +static void +vhost_user_backend_complete(UserCreatable *uc, Error **errp) +{ + VhostUserBackend *b =3D VHOST_USER_BACKEND(uc); + Chardev *chr; + + if (!!b->chr_name + !!b->cmd !=3D 1) { + error_setg(errp, "You may specificy only one of 'chardev' or 'cmd'= ."); + return; + } + + if (b->chr_name) { + chr =3D qemu_chr_find(b->chr_name); + if (chr =3D=3D NULL) { + error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND, + "Chardev '%s' not found", b->chr_name); + return; + } + + if (!qemu_chr_fe_init(&b->chr, chr, errp)) { + return; + } + } else { + int sv[2]; + + if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) =3D=3D -1) { + error_setg_errno(errp, errno, "socketpair() failed"); + return; + } + + chr =3D CHARDEV(object_new(TYPE_CHARDEV_SOCKET)); + if (!chr || qemu_chr_add_client(chr, sv[0]) =3D=3D -1) { + error_setg(errp, "Failed to make socket chardev"); + object_unref(OBJECT(chr)); + return; + } + + if (!qemu_chr_fe_init(&b->chr, chr, errp)) { + return; + } + + vhost_user_backend_spawn_cmd(b, sv[1], errp); + + close(sv[1]); + } + + b->completed =3D true; + /* could vhost_dev_init() happen here, so early vhost-user message + * can be exchanged */ +} + +static char *get_cmd(Object *obj, Error **errp) +{ + VhostUserBackend *b =3D VHOST_USER_BACKEND(obj); + + return g_strdup(b->cmd); +} + +static void set_cmd(Object *obj, const char *str, Error **errp) +{ + VhostUserBackend *b =3D VHOST_USER_BACKEND(obj); + + if (b->child) { + error_setg(errp, "cannot change property value"); + return; + } + + g_free(b->cmd); + b->cmd =3D g_strdup(str); +} + +static void set_chardev(Object *obj, const char *value, Error **errp) +{ + VhostUserBackend *b =3D VHOST_USER_BACKEND(obj); + + if (b->completed) { + error_setg(errp, QERR_PERMISSION_DENIED); + } else { + g_free(b->chr_name); + b->chr_name =3D g_strdup(value); + } +} + +static char *get_chardev(Object *obj, Error **errp) +{ + VhostUserBackend *b =3D VHOST_USER_BACKEND(obj); + Chardev *chr =3D qemu_chr_fe_get_driver(&b->chr); + + if (chr && chr->label) { + return g_strdup(chr->label); + } + + return NULL; +} + +static void vhost_user_backend_init(Object *obj) +{ + object_property_add_str(obj, "cmd", get_cmd, set_cmd, NULL); + object_property_add_str(obj, "chardev", get_chardev, set_chardev, NULL= ); +} + +static void vhost_user_backend_finalize(Object *obj) +{ + VhostUserBackend *b =3D VHOST_USER_BACKEND(obj); + + g_free(b->dev.vqs); + g_free(b->cmd); + g_free(b->chr_name); + + qemu_chr_fe_deinit(&b->chr, true); + + if (b->child) { + object_unref(OBJECT(b->child)); + } +} + +static bool +vhost_user_backend_can_be_deleted(UserCreatable *uc) +{ + return true; +} + +static void +vhost_user_backend_class_init(ObjectClass *oc, void *data) +{ + UserCreatableClass *ucc =3D USER_CREATABLE_CLASS(oc); + + ucc->complete =3D vhost_user_backend_complete; + ucc->can_be_deleted =3D vhost_user_backend_can_be_deleted; +} + +static const TypeInfo vhost_user_backend_info =3D { + .name =3D TYPE_VHOST_USER_BACKEND, + .parent =3D TYPE_OBJECT, + .instance_size =3D sizeof(VhostUserBackend), + .instance_init =3D vhost_user_backend_init, + .instance_finalize =3D vhost_user_backend_finalize, + .class_size =3D sizeof(VhostUserBackendClass), + .class_init =3D vhost_user_backend_class_init, + .interfaces =3D (InterfaceInfo[]) { + { TYPE_USER_CREATABLE }, + { } + } +}; + +static void register_types(void) +{ + type_register_static(&vhost_user_backend_info); +} + +type_init(register_types); diff --git a/vl.c b/vl.c index c4fe25560c..4ed094dd71 100644 --- a/vl.c +++ b/vl.c @@ -2833,7 +2833,8 @@ static bool object_create_initial(const char *type) } =20 #if defined(CONFIG_VHOST_USER) && defined(CONFIG_LINUX) - if (g_str_equal(type, "cryptodev-vhost-user")) { + if (g_str_equal(type, "cryptodev-vhost-user") || + g_str_equal(type, "vhost-user-backend")) { return false; } #endif diff --git a/backends/Makefile.objs b/backends/Makefile.objs index ad7c0325ed..bac27de11b 100644 --- a/backends/Makefile.objs +++ b/backends/Makefile.objs @@ -16,3 +16,7 @@ common-obj-$(call land,$(CONFIG_VHOST_USER),$(CONFIG_LINU= X)) +=3D \ endif =20 common-obj-$(CONFIG_LINUX) +=3D hostmem-memfd.o + +ifdef CONFIG_LINUX +common-obj-$(CONFIG_VIRTIO) +=3D vhost-user.o +endif --=20 2.17.1.906.g10fd178552