From f24bb7287ddbdfd9b75fe782c366abc7939a4190 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= Date: Fri, 3 May 2019 15:00:31 +0200 Subject: [PATCH] Add vhost-user-backend MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Create a vhost-user-backend object that holds a connection to a vhost-user backend (or "slave" process) and can be referenced from virtio devices that support it. See later patches for input & gpu usage. Note: a previous iteration of this object made it user-creatable, and allowed managed sub-process spawning, but that has been dropped for now. Signed-off-by: Marc-André Lureau Message-id: 20190503130034.24916-4-marcandre.lureau@redhat.com Signed-off-by: Gerd Hoffmann --- MAINTAINERS | 2 + backends/Makefile.objs | 2 + backends/vhost-user.c | 209 ++++++++++++++++++++++++++++ include/sysemu/vhost-user-backend.h | 57 ++++++++ 4 files changed, 270 insertions(+) create mode 100644 backends/vhost-user.c create mode 100644 include/sysemu/vhost-user-backend.h diff --git a/MAINTAINERS b/MAINTAINERS index 66ddbda9c9..2e40390ebc 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1478,6 +1478,8 @@ F: hw/*/*vhost* F: docs/interop/vhost-user.json F: docs/interop/vhost-user.txt F: contrib/vhost-user-*/ +F: backends/vhost-user.c +F: include/sysemu/vhost-user-backend.h virtio M: Michael S. Tsirkin diff --git a/backends/Makefile.objs b/backends/Makefile.objs index ff619d31b4..981e8e122f 100644 --- a/backends/Makefile.objs +++ b/backends/Makefile.objs @@ -14,4 +14,6 @@ common-obj-y += cryptodev-vhost.o common-obj-$(CONFIG_VHOST_CRYPTO) += cryptodev-vhost-user.o endif +common-obj-$(call land,$(CONFIG_VHOST_USER),$(CONFIG_VIRTIO)) += vhost-user.o + common-obj-$(CONFIG_LINUX) += hostmem-memfd.o diff --git a/backends/vhost-user.c b/backends/vhost-user.c new file mode 100644 index 0000000000..2b055544a7 --- /dev/null +++ b/backends/vhost-user.c @@ -0,0 +1,209 @@ +/* + * QEMU vhost-user backend + * + * Copyright (C) 2018 Red Hat Inc + * + * Authors: + * Marc-André Lureau + * + * 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 "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; + } + + if (!vhost_user_init(&b->vhost_user, &b->chr, errp)) { + return -1; + } + + b->vdev = vdev; + b->dev.nvqs = nvqs; + b->dev.vqs = g_new(struct vhost_virtqueue, nvqs); + + ret = vhost_dev_init(&b->dev, &b->vhost_user, 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 = BUS(qdev_get_parent_bus(DEVICE(b->vdev))); + VirtioBusClass *k = 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 = vhost_dev_enable_notifiers(&b->dev, b->vdev); + if (ret < 0) { + return; + } + + ret = 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 = b->vdev->guest_features; + ret = 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 = 0; i < b->dev.nvqs; i++) { + vhost_virtqueue_mask(&b->dev, b->vdev, + b->dev.vq_index + i, false); + } + + b->started = 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 = BUS(qdev_get_parent_bus(DEVICE(b->vdev))); + VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); + int ret = 0; + + if (!b->started) { + return; + } + + vhost_dev_stop(&b->dev, b->vdev); + + if (k->set_guest_notifiers) { + ret = k->set_guest_notifiers(qbus->parent, + b->dev.nvqs, false); + if (ret < 0) { + error_report("vhost guest notifier cleanup failed: %d", ret); + } + } + assert(ret >= 0); + + vhost_dev_disable_notifiers(&b->dev, b->vdev); + b->started = false; +} + +static void set_chardev(Object *obj, const char *value, Error **errp) +{ + VhostUserBackend *b = VHOST_USER_BACKEND(obj); + Chardev *chr; + + if (b->completed) { + error_setg(errp, QERR_PERMISSION_DENIED); + return; + } + + g_free(b->chr_name); + b->chr_name = g_strdup(value); + + chr = qemu_chr_find(b->chr_name); + if (chr == 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; + } + + b->completed = true; + /* could call vhost_dev_init() so early message can be exchanged */ +} + +static char *get_chardev(Object *obj, Error **errp) +{ + VhostUserBackend *b = VHOST_USER_BACKEND(obj); + Chardev *chr = 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, "chardev", get_chardev, set_chardev, NULL); +} + +static void vhost_user_backend_finalize(Object *obj) +{ + VhostUserBackend *b = VHOST_USER_BACKEND(obj); + + g_free(b->dev.vqs); + g_free(b->chr_name); + + vhost_user_cleanup(&b->vhost_user); + qemu_chr_fe_deinit(&b->chr, true); +} + +static const TypeInfo vhost_user_backend_info = { + .name = TYPE_VHOST_USER_BACKEND, + .parent = TYPE_OBJECT, + .instance_size = sizeof(VhostUserBackend), + .instance_init = vhost_user_backend_init, + .instance_finalize = vhost_user_backend_finalize, + .class_size = sizeof(VhostUserBackendClass), +}; + +static void register_types(void) +{ + type_register_static(&vhost_user_backend_info); +} + +type_init(register_types); diff --git a/include/sysemu/vhost-user-backend.h b/include/sysemu/vhost-user-backend.h new file mode 100644 index 0000000000..9abf8f06a1 --- /dev/null +++ b/include/sysemu/vhost-user-backend.h @@ -0,0 +1,57 @@ +/* + * QEMU vhost-user backend + * + * Copyright (C) 2018 Red Hat Inc + * + * Authors: + * Marc-André Lureau + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * 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 "hw/virtio/vhost-user.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_BACKEND) + +typedef struct VhostUserBackend VhostUserBackend; +typedef struct VhostUserBackendClass VhostUserBackendClass; + +struct VhostUserBackendClass { + ObjectClass parent_class; +}; + +struct VhostUserBackend { + /* private */ + Object parent; + + char *chr_name; + CharBackend chr; + VhostUserState vhost_user; + struct vhost_dev dev; + 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