From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1BE5CC3A5A8 for ; Mon, 2 Sep 2019 04:15:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D9C4023431 for ; Mon, 2 Sep 2019 04:15:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729441AbfIBEPT (ORCPT ); Mon, 2 Sep 2019 00:15:19 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53028 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729341AbfIBEPT (ORCPT ); Mon, 2 Sep 2019 00:15:19 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1B05481F13; Mon, 2 Sep 2019 04:15:17 +0000 (UTC) Received: from [10.72.12.232] (ovpn-12-232.pek2.redhat.com [10.72.12.232]) by smtp.corp.redhat.com (Postfix) with ESMTP id AA7A35D6B7; Mon, 2 Sep 2019 04:15:05 +0000 (UTC) Subject: Re: [RFC v3] vhost: introduce mdev based hardware vhost backend To: Tiwei Bie , mst@redhat.com, alex.williamson@redhat.com, maxime.coquelin@redhat.com Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, dan.daly@intel.com, cunming.liang@intel.com, zhihong.wang@intel.com, lingshan.zhu@intel.com References: <20190828053712.26106-1-tiwei.bie@intel.com> From: Jason Wang Message-ID: Date: Mon, 2 Sep 2019 12:15:05 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190828053712.26106-1-tiwei.bie@intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Mon, 02 Sep 2019 04:15:17 +0000 (UTC) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2019/8/28 下午1:37, Tiwei Bie wrote: > Details about this can be found here: > > https://lwn.net/Articles/750770/ > > What's new in this version > ========================== > > There are three choices based on the discussion [1] in RFC v2: > >> #1. We expose a VFIO device, so we can reuse the VFIO container/group >> based DMA API and potentially reuse a lot of VFIO code in QEMU. >> >> But in this case, we have two choices for the VFIO device interface >> (i.e. the interface on top of VFIO device fd): >> >> A) we may invent a new vhost protocol (as demonstrated by the code >> in this RFC) on VFIO device fd to make it work in VFIO's way, >> i.e. regions and irqs. >> >> B) Or as you proposed, instead of inventing a new vhost protocol, >> we can reuse most existing vhost ioctls on the VFIO device fd >> directly. There should be no conflicts between the VFIO ioctls >> (type is 0x3B) and VHOST ioctls (type is 0xAF) currently. >> >> #2. Instead of exposing a VFIO device, we may expose a VHOST device. >> And we will introduce a new mdev driver vhost-mdev to do this. >> It would be natural to reuse the existing kernel vhost interface >> (ioctls) on it as much as possible. But we will need to invent >> some APIs for DMA programming (reusing VHOST_SET_MEM_TABLE is a >> choice, but it's too heavy and doesn't support vIOMMU by itself). > This version is more like a quick PoC to try Jason's proposal on > reusing vhost ioctls. And the second way (#1/B) in above three > choices was chosen in this version to demonstrate the idea quickly. > > Now the userspace API looks like this: > > - VFIO's container/group based IOMMU API is used to do the > DMA programming. > > - Vhost's existing ioctls are used to setup the device. > > And the device will report device_api as "vfio-vhost". > > Note that, there are dirty hacks in this version. If we decide to > go this way, some refactoring in vhost.c/vhost.h may be needed. > > PS. The direct mapping of the notify registers isn't implemented > in this version. > > [1] https://lkml.org/lkml/2019/7/9/101 Thanks for the patch, see comments inline. > > Signed-off-by: Tiwei Bie > --- > drivers/vhost/Kconfig | 9 + > drivers/vhost/Makefile | 3 + > drivers/vhost/mdev.c | 382 +++++++++++++++++++++++++++++++++++++ > include/linux/vhost_mdev.h | 58 ++++++ > include/uapi/linux/vfio.h | 2 + > include/uapi/linux/vhost.h | 8 + > 6 files changed, 462 insertions(+) > create mode 100644 drivers/vhost/mdev.c > create mode 100644 include/linux/vhost_mdev.h > > diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig > index 3d03ccbd1adc..2ba54fcf43b7 100644 > --- a/drivers/vhost/Kconfig > +++ b/drivers/vhost/Kconfig > @@ -34,6 +34,15 @@ config VHOST_VSOCK > To compile this driver as a module, choose M here: the module will be called > vhost_vsock. > > +config VHOST_MDEV > + tristate "Hardware vhost accelerator abstraction" > + depends on EVENTFD && VFIO && VFIO_MDEV > + select VHOST > + default n > + ---help--- > + Say Y here to enable the vhost_mdev module > + for use with hardware vhost accelerators > + > config VHOST > tristate > ---help--- > diff --git a/drivers/vhost/Makefile b/drivers/vhost/Makefile > index 6c6df24f770c..ad9c0f8c6d8c 100644 > --- a/drivers/vhost/Makefile > +++ b/drivers/vhost/Makefile > @@ -10,4 +10,7 @@ vhost_vsock-y := vsock.o > > obj-$(CONFIG_VHOST_RING) += vringh.o > > +obj-$(CONFIG_VHOST_MDEV) += vhost_mdev.o > +vhost_mdev-y := mdev.o > + > obj-$(CONFIG_VHOST) += vhost.o > diff --git a/drivers/vhost/mdev.c b/drivers/vhost/mdev.c > new file mode 100644 > index 000000000000..6bef1d9ae2e6 > --- /dev/null > +++ b/drivers/vhost/mdev.c > @@ -0,0 +1,382 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) 2018-2019 Intel Corporation. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "vhost.h" > + > +struct vhost_mdev { > + struct vhost_dev dev; > + bool opened; > + int nvqs; > + u64 state; > + u64 acked_features; > + u64 features; > + const struct vhost_mdev_device_ops *ops; > + struct mdev_device *mdev; > + void *private; > + struct vhost_virtqueue vqs[]; > +}; > + > +static void handle_vq_kick(struct vhost_work *work) > +{ > + struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, > + poll.work); > + struct vhost_mdev *vdpa = container_of(vq->dev, struct vhost_mdev, dev); > + > + vdpa->ops->notify(vdpa, vq - vdpa->vqs); > +} > + > +static int vhost_set_state(struct vhost_mdev *vdpa, u64 __user *statep) > +{ > + u64 state; > + > + if (copy_from_user(&state, statep, sizeof(state))) > + return -EFAULT; > + > + if (state >= VHOST_MDEV_S_MAX) > + return -EINVAL; > + > + if (vdpa->state == state) > + return 0; > + > + mutex_lock(&vdpa->dev.mutex); > + > + vdpa->state = state; > + > + switch (vdpa->state) { > + case VHOST_MDEV_S_RUNNING: > + vdpa->ops->start(vdpa); > + break; > + case VHOST_MDEV_S_STOPPED: > + vdpa->ops->stop(vdpa); > + break; > + } > + > + mutex_unlock(&vdpa->dev.mutex); > + > + return 0; > +} > + > +static int vhost_set_features(struct vhost_mdev *vdpa, u64 __user *featurep) > +{ > + u64 features; > + > + if (copy_from_user(&features, featurep, sizeof(features))) > + return -EFAULT; > + > + if (features & ~vdpa->features) > + return -EINVAL; > + > + vdpa->acked_features = features; > + vdpa->ops->features_changed(vdpa); > + return 0; > +} > + > +static int vhost_get_features(struct vhost_mdev *vdpa, u64 __user *featurep) > +{ > + if (copy_to_user(featurep, &vdpa->features, sizeof(vdpa->features))) > + return -EFAULT; > + return 0; > +} > + > +static int vhost_get_vring_base(struct vhost_mdev *vdpa, void __user *argp) > +{ > + struct vhost_virtqueue *vq; > + u32 idx; > + int r; > + > + r = get_user(idx, (u32 __user *)argp); > + if (r < 0) > + return r; > + > + vq = &vdpa->vqs[idx]; > + vq->last_avail_idx = vdpa->ops->get_vring_base(vdpa, idx); > + > + return vhost_vring_ioctl(&vdpa->dev, VHOST_GET_VRING_BASE, argp); > +} > + > +/* > + * Helpers for backend to register mdev. > + */ > + > +struct vhost_mdev *vhost_mdev_alloc(struct mdev_device *mdev, void *private, > + int nvqs) > +{ > + struct vhost_mdev *vdpa; > + struct vhost_dev *dev; > + struct vhost_virtqueue **vqs; > + size_t size; > + int i; > + > + size = sizeof(struct vhost_mdev) + nvqs * sizeof(struct vhost_virtqueue); > + > + vdpa = kzalloc(size, GFP_KERNEL); > + if (!vdpa) > + return NULL; > + > + vdpa->nvqs = nvqs; > + > + vqs = kmalloc_array(nvqs, sizeof(*vqs), GFP_KERNEL); > + if (!vqs) { > + kfree(vdpa); > + return NULL; > + } > + > + dev = &vdpa->dev; > + for (i = 0; i < nvqs; i++) { > + vqs[i] = &vdpa->vqs[i]; > + vqs[i]->handle_kick = handle_vq_kick; > + } > + vhost_dev_init(dev, vqs, nvqs, 0, 0, 0); > + > + vdpa->private = private; > + vdpa->mdev = mdev; > + > + mdev_set_drvdata(mdev, vdpa); > + > + return vdpa; > +} > +EXPORT_SYMBOL(vhost_mdev_alloc); > + > +void vhost_mdev_free(struct vhost_mdev *vdpa) > +{ > + struct mdev_device *mdev; > + > + mdev = vdpa->mdev; > + mdev_set_drvdata(mdev, NULL); > + > + vhost_dev_stop(&vdpa->dev); > + vhost_dev_cleanup(&vdpa->dev); > + kfree(vdpa->dev.vqs); > + kfree(vdpa); > +} > +EXPORT_SYMBOL(vhost_mdev_free); > + > +ssize_t vhost_mdev_read(struct mdev_device *mdev, char __user *buf, > + size_t count, loff_t *ppos) > +{ > + return -EINVAL; > +} > +EXPORT_SYMBOL(vhost_mdev_read); > + > + > +ssize_t vhost_mdev_write(struct mdev_device *mdev, const char __user *buf, > + size_t count, loff_t *ppos) > +{ > + return -EINVAL; > +} > +EXPORT_SYMBOL(vhost_mdev_write); > + > +int vhost_mdev_mmap(struct mdev_device *mdev, struct vm_area_struct *vma) > +{ > + // TODO > + return -EINVAL; > +} > +EXPORT_SYMBOL(vhost_mdev_mmap); > + > +long vhost_mdev_ioctl(struct mdev_device *mdev, unsigned int cmd, > + unsigned long arg) > +{ > + void __user *argp = (void __user *)arg; > + struct vhost_mdev *vdpa; > + unsigned long minsz; > + int ret = 0; > + > + if (!mdev) > + return -EINVAL; > + > + vdpa = mdev_get_drvdata(mdev); > + if (!vdpa) > + return -ENODEV; > + > + switch (cmd) { > + case VFIO_DEVICE_GET_INFO: > + { > + struct vfio_device_info info; > + > + minsz = offsetofend(struct vfio_device_info, num_irqs); > + > + if (copy_from_user(&info, (void __user *)arg, minsz)) { > + ret = -EFAULT; > + break; > + } > + > + if (info.argsz < minsz) { > + ret = -EINVAL; > + break; > + } > + > + info.flags = VFIO_DEVICE_FLAGS_VHOST; > + info.num_regions = 0; > + info.num_irqs = 0; > + > + if (copy_to_user((void __user *)arg, &info, minsz)) { > + ret = -EFAULT; > + break; > + } > + > + break; > + } > + case VFIO_DEVICE_GET_REGION_INFO: > + case VFIO_DEVICE_GET_IRQ_INFO: > + case VFIO_DEVICE_SET_IRQS: > + case VFIO_DEVICE_RESET: > + ret = -EINVAL; > + break; > + > + case VHOST_MDEV_SET_STATE: > + ret = vhost_set_state(vdpa, argp); > + break; So this is used to start or stop the device. This means if userspace want to drive a network device, the API is not 100% compatible. Any blocker for this? E.g for SET_BACKEND, we can pass a fd and then identify the type of backend. Another question is, how can user know the type of a device? > + case VHOST_GET_FEATURES: > + ret = vhost_get_features(vdpa, argp); > + break; > + case VHOST_SET_FEATURES: > + ret = vhost_set_features(vdpa, argp); > + break; > + case VHOST_GET_VRING_BASE: > + ret = vhost_get_vring_base(vdpa, argp); > + break; > + default: > + ret = vhost_dev_ioctl(&vdpa->dev, cmd, argp); > + if (ret == -ENOIOCTLCMD) > + ret = vhost_vring_ioctl(&vdpa->dev, cmd, argp); > + } > + > + return ret; > +} > +EXPORT_SYMBOL(vhost_mdev_ioctl); > + > +int vhost_mdev_open(struct mdev_device *mdev) > +{ > + struct vhost_mdev *vdpa; > + int ret = 0; > + > + vdpa = mdev_get_drvdata(mdev); > + if (!vdpa) > + return -ENODEV; > + > + mutex_lock(&vdpa->dev.mutex); > + > + if (vdpa->opened) > + ret = -EBUSY; > + else > + vdpa->opened = true; > + > + mutex_unlock(&vdpa->dev.mutex); > + > + return ret; > +} > +EXPORT_SYMBOL(vhost_mdev_open); > + > +void vhost_mdev_close(struct mdev_device *mdev) > +{ > + struct vhost_mdev *vdpa; > + > + vdpa = mdev_get_drvdata(mdev); > + > + mutex_lock(&vdpa->dev.mutex); > + > + vhost_dev_stop(&vdpa->dev); > + vhost_dev_cleanup(&vdpa->dev); > + > + vdpa->opened = false; > + mutex_unlock(&vdpa->dev.mutex); > +} > +EXPORT_SYMBOL(vhost_mdev_close); > + > +/* > + * Helpers for backend to set/get information. > + */ > + > +int vhost_mdev_set_device_ops(struct vhost_mdev *vdpa, > + const struct vhost_mdev_device_ops *ops) > +{ > + vdpa->ops = ops; > + return 0; > +} > +EXPORT_SYMBOL(vhost_mdev_set_device_ops); > + > +int vhost_mdev_set_features(struct vhost_mdev *vdpa, u64 features) > +{ > + vdpa->features = features; > + return 0; > +} > +EXPORT_SYMBOL(vhost_mdev_set_features); > + > +struct eventfd_ctx * > +vhost_mdev_get_call_ctx(struct vhost_mdev *vdpa, int queue_id) > +{ > + return vdpa->vqs[queue_id].call_ctx; > +} > +EXPORT_SYMBOL(vhost_mdev_get_call_ctx); > + > +int vhost_mdev_get_acked_features(struct vhost_mdev *vdpa, u64 *features) > +{ > + *features = vdpa->acked_features; > + return 0; > +} > +EXPORT_SYMBOL(vhost_mdev_get_acked_features); > + > +int vhost_mdev_get_vring_num(struct vhost_mdev *vdpa, int queue_id, u16 *num) > +{ > + *num = vdpa->vqs[queue_id].num; > + return 0; > +} > +EXPORT_SYMBOL(vhost_mdev_get_vring_num); > + > +int vhost_mdev_get_vring_base(struct vhost_mdev *vdpa, int queue_id, u16 *base) > +{ > + *base = vdpa->vqs[queue_id].last_avail_idx; > + return 0; > +} > +EXPORT_SYMBOL(vhost_mdev_get_vring_base); > + > +int vhost_mdev_get_vring_addr(struct vhost_mdev *vdpa, int queue_id, > + struct vhost_vring_addr *addr) > +{ > + struct vhost_virtqueue *vq = &vdpa->vqs[queue_id]; > + > + /* > + * XXX: we need userspace to pass guest physical address or > + * IOVA directly. > + */ > + addr->flags = vq->log_used ? (0x1 << VHOST_VRING_F_LOG) : 0; > + addr->desc_user_addr = (__u64)vq->desc; > + addr->avail_user_addr = (__u64)vq->avail; > + addr->used_user_addr = (__u64)vq->used; > + addr->log_guest_addr = (__u64)vq->log_addr; > + return 0; > +} > +EXPORT_SYMBOL(vhost_mdev_get_vring_addr); > + > +int vhost_mdev_get_log_base(struct vhost_mdev *vdpa, int queue_id, > + void **log_base, u64 *log_size) > +{ > + // TODO > + return 0; > +} > +EXPORT_SYMBOL(vhost_mdev_get_log_base); > + > +struct mdev_device *vhost_mdev_get_mdev(struct vhost_mdev *vdpa) > +{ > + return vdpa->mdev; > +} > +EXPORT_SYMBOL(vhost_mdev_get_mdev); > + > +void *vhost_mdev_get_private(struct vhost_mdev *vdpa) > +{ > + return vdpa->private; > +} > +EXPORT_SYMBOL(vhost_mdev_get_private); > + > +MODULE_VERSION("0.0.0"); > +MODULE_LICENSE("GPL v2"); > +MODULE_DESCRIPTION("Hardware vhost accelerator abstraction"); > diff --git a/include/linux/vhost_mdev.h b/include/linux/vhost_mdev.h > new file mode 100644 > index 000000000000..070787ce6b36 > --- /dev/null > +++ b/include/linux/vhost_mdev.h > @@ -0,0 +1,58 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) 2018-2019 Intel Corporation. > + */ > + > +#ifndef _VHOST_MDEV_H > +#define _VHOST_MDEV_H > + > +struct mdev_device; > +struct vhost_mdev; > + > +typedef int (*vhost_mdev_start_device_t)(struct vhost_mdev *vdpa); > +typedef int (*vhost_mdev_stop_device_t)(struct vhost_mdev *vdpa); > +typedef int (*vhost_mdev_set_features_t)(struct vhost_mdev *vdpa); > +typedef void (*vhost_mdev_notify_device_t)(struct vhost_mdev *vdpa, int queue_id); > +typedef u64 (*vhost_mdev_get_notify_addr_t)(struct vhost_mdev *vdpa, int queue_id); > +typedef u16 (*vhost_mdev_get_vring_base_t)(struct vhost_mdev *vdpa, int queue_id); > +typedef void (*vhost_mdev_features_changed_t)(struct vhost_mdev *vdpa); > + > +struct vhost_mdev_device_ops { > + vhost_mdev_start_device_t start; > + vhost_mdev_stop_device_t stop; > + vhost_mdev_notify_device_t notify; > + vhost_mdev_get_notify_addr_t get_notify_addr; > + vhost_mdev_get_vring_base_t get_vring_base; > + vhost_mdev_features_changed_t features_changed; > +}; Consider we want to implement a network device, who is going to implement the device configuration space? I believe it's not good to invent another set of API for doing this. So I believe we want something like read_config/write_config here. Then I came up an idea: 1) introduce a new mdev bus transport, and a new mdev driver virtio_mdev 2) vDPA (either software or hardware) can register as a device of virtio mdev device 3) then we can use kernel virtio driver to drive vDPA device and utilize kernel networking/storage stack 4) for userspace driver like vhost-mdev, it could be built of top of mdev transport Having a full new transport for virtio, the advantages are obvious: 1) A generic solution for both kernel and userspace driver and support configuration space access 2) For kernel driver, exist kernel networking/storage stack could be reused, and so did fast path implementation (e.g XDP, io_uring etc). 2) For userspace driver, the function of virtio transport is a superset of vhost, any API could be built on top easily (e.g vhost ioctl). What's your thought? Thanks > + > +struct vhost_mdev *vhost_mdev_alloc(struct mdev_device *mdev, > + void *private, int nvqs); > +void vhost_mdev_free(struct vhost_mdev *vdpa); > + > +ssize_t vhost_mdev_read(struct mdev_device *mdev, char __user *buf, > + size_t count, loff_t *ppos); > +ssize_t vhost_mdev_write(struct mdev_device *mdev, const char __user *buf, > + size_t count, loff_t *ppos); > +long vhost_mdev_ioctl(struct mdev_device *mdev, unsigned int cmd, > + unsigned long arg); > +int vhost_mdev_mmap(struct mdev_device *mdev, struct vm_area_struct *vma); > +int vhost_mdev_open(struct mdev_device *mdev); > +void vhost_mdev_close(struct mdev_device *mdev); > + > +int vhost_mdev_set_device_ops(struct vhost_mdev *vdpa, > + const struct vhost_mdev_device_ops *ops); > +int vhost_mdev_set_features(struct vhost_mdev *vdpa, u64 features); > +struct eventfd_ctx *vhost_mdev_get_call_ctx(struct vhost_mdev *vdpa, > + int queue_id); > +int vhost_mdev_get_acked_features(struct vhost_mdev *vdpa, u64 *features); > +int vhost_mdev_get_vring_num(struct vhost_mdev *vdpa, int queue_id, u16 *num); > +int vhost_mdev_get_vring_base(struct vhost_mdev *vdpa, int queue_id, u16 *base); > +int vhost_mdev_get_vring_addr(struct vhost_mdev *vdpa, int queue_id, > + struct vhost_vring_addr *addr); > +int vhost_mdev_get_log_base(struct vhost_mdev *vdpa, int queue_id, > + void **log_base, u64 *log_size); > +struct mdev_device *vhost_mdev_get_mdev(struct vhost_mdev *vdpa); > +void *vhost_mdev_get_private(struct vhost_mdev *vdpa); > + > +#endif /* _VHOST_MDEV_H */ > diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h > index 8f10748dac79..0300d6831cc5 100644 > --- a/include/uapi/linux/vfio.h > +++ b/include/uapi/linux/vfio.h > @@ -201,6 +201,7 @@ struct vfio_device_info { > #define VFIO_DEVICE_FLAGS_AMBA (1 << 3) /* vfio-amba device */ > #define VFIO_DEVICE_FLAGS_CCW (1 << 4) /* vfio-ccw device */ > #define VFIO_DEVICE_FLAGS_AP (1 << 5) /* vfio-ap device */ > +#define VFIO_DEVICE_FLAGS_VHOST (1 << 6) /* vfio-vhost device */ > __u32 num_regions; /* Max region index + 1 */ > __u32 num_irqs; /* Max IRQ index + 1 */ > }; > @@ -217,6 +218,7 @@ struct vfio_device_info { > #define VFIO_DEVICE_API_AMBA_STRING "vfio-amba" > #define VFIO_DEVICE_API_CCW_STRING "vfio-ccw" > #define VFIO_DEVICE_API_AP_STRING "vfio-ap" > +#define VFIO_DEVICE_API_VHOST_STRING "vfio-vhost" > > /** > * VFIO_DEVICE_GET_REGION_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 8, > diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h > index 40d028eed645..5afbc2f08fa3 100644 > --- a/include/uapi/linux/vhost.h > +++ b/include/uapi/linux/vhost.h > @@ -116,4 +116,12 @@ > #define VHOST_VSOCK_SET_GUEST_CID _IOW(VHOST_VIRTIO, 0x60, __u64) > #define VHOST_VSOCK_SET_RUNNING _IOW(VHOST_VIRTIO, 0x61, int) > > +/* VHOST_MDEV specific defines */ > + > +#define VHOST_MDEV_SET_STATE _IOW(VHOST_VIRTIO, 0x70, __u64) > + > +#define VHOST_MDEV_S_STOPPED 0 > +#define VHOST_MDEV_S_RUNNING 1 > +#define VHOST_MDEV_S_MAX 2 > + > #endif