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[209.132.180.67]) by mx.google.com with ESMTP id w58si978483edc.312.2019.09.17.02.45.38; Tue, 17 Sep 2019 02:46:02 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392597AbfIQH0u (ORCPT + 99 others); Tue, 17 Sep 2019 03:26:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34014 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392510AbfIQH0u (ORCPT ); Tue, 17 Sep 2019 03:26:50 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 312FF18CB90B; Tue, 17 Sep 2019 07:26:49 +0000 (UTC) Received: from [10.72.12.121] (ovpn-12-121.pek2.redhat.com [10.72.12.121]) by smtp.corp.redhat.com (Postfix) with ESMTP id DACBF60126; Tue, 17 Sep 2019 07:26:34 +0000 (UTC) Subject: Re: [RFC v4 3/3] vhost: introduce mdev based hardware 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: <20190917010204.30376-1-tiwei.bie@intel.com> <20190917010204.30376-4-tiwei.bie@intel.com> From: Jason Wang Message-ID: <0b0f74ba-8958-dd7d-3e98-f7a58b1ec5f7@redhat.com> Date: Tue, 17 Sep 2019 15:26:30 +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: <20190917010204.30376-4-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 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.63]); Tue, 17 Sep 2019 07:26:49 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/9/17 上午9:02, Tiwei Bie wrote: > More details about this patch can be found from the cover > letter for now. Only compile test has been done for now. > > Signed-off-by: Tiwei Bie > --- > drivers/vhost/Kconfig | 9 + > drivers/vhost/Makefile | 3 + > drivers/vhost/mdev.c | 462 +++++++++++++++++++++++++++++++ > drivers/vhost/vhost.c | 39 ++- > drivers/vhost/vhost.h | 6 + > include/uapi/linux/vhost.h | 10 + > include/uapi/linux/vhost_types.h | 5 + > 7 files changed, 528 insertions(+), 6 deletions(-) > create mode 100644 drivers/vhost/mdev.c > > diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig > index 3d03ccbd1adc..ef9783156d2e 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 "Mediated device based hardware vhost accelerator" > + 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..8c6597aff45e > --- /dev/null > +++ b/drivers/vhost/mdev.c > @@ -0,0 +1,462 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) 2018-2019 Intel Corporation. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "vhost.h" > + > +struct vhost_mdev { > + struct mutex mutex; > + struct vhost_dev dev; > + struct vhost_virtqueue *vqs; > + int nvqs; > + u64 state; > + u64 features; > + u64 acked_features; > + struct vfio_group *vfio_group; > + struct vfio_device *vfio_device; > + struct mdev_device *mdev; > +}; > + > +/* > + * XXX > + * We assume virtio_mdev.ko exposes below symbols for now, as we > + * don't have a proper way to access parent ops directly yet. > + * > + * virtio_mdev_readl() > + * virtio_mdev_writel() > + */ > +extern u32 virtio_mdev_readl(struct mdev_device *mdev, loff_t off); > +extern void virtio_mdev_writel(struct mdev_device *mdev, loff_t off, u32 val); Need to consider a better approach, I feel we should do it through some kind of mdev driver instead of talk to mdev device directly. > + > +static u8 mdev_get_status(struct mdev_device *mdev) > +{ > + return virtio_mdev_readl(mdev, VIRTIO_MDEV_STATUS); > +} > + > +static void mdev_set_status(struct mdev_device *mdev, u8 status) > +{ > + virtio_mdev_writel(mdev, VIRTIO_MDEV_STATUS, status); > +} > + > +static void mdev_add_status(struct mdev_device *mdev, u8 status) > +{ > + status |= mdev_get_status(mdev); > + mdev_set_status(mdev, status); > +} > + > +static void mdev_reset(struct mdev_device *mdev) > +{ > + mdev_set_status(mdev, 0); > +} > + > +static void handle_vq_kick(struct vhost_work *work) > +{ > + struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, > + poll.work); > + struct vhost_mdev *m = container_of(vq->dev, struct vhost_mdev, dev); > + > + virtio_mdev_writel(m->mdev, VIRTIO_MDEV_QUEUE_NOTIFY, vq - m->vqs); > +} > + > +static long vhost_mdev_start_backend(struct vhost_mdev *m) > +{ > + struct mdev_device *mdev = m->mdev; > + u64 features = m->acked_features; > + u64 addr; > + struct vhost_virtqueue *vq; > + int queue_id; > + > + features |= 1ULL << VIRTIO_F_IOMMU_PLATFORM; Is it better to get this feature from backend? > + > + virtio_mdev_writel(mdev, VIRTIO_MDEV_DRIVER_FEATURES_SEL, 1); > + virtio_mdev_writel(mdev, VIRTIO_MDEV_DRIVER_FEATURES, > + (u32)(features >> 32)); > + > + virtio_mdev_writel(mdev, VIRTIO_MDEV_DRIVER_FEATURES_SEL, 0); > + virtio_mdev_writel(mdev, VIRTIO_MDEV_DRIVER_FEATURES, > + (u32)features); > + > + mdev_add_status(mdev, VIRTIO_CONFIG_S_FEATURES_OK); > + if (!(mdev_get_status(mdev) & VIRTIO_CONFIG_S_FEATURES_OK)) > + return -ENODEV; > + > + for (queue_id = 0; queue_id < m->nvqs; queue_id++) { > + vq = &m->vqs[queue_id]; > + > + if (!vq->desc || !vq->avail || !vq->used) > + break; > + > + virtio_mdev_writel(mdev, VIRTIO_MDEV_QUEUE_NUM, vq->num); > + > + if (!vhost_translate_ring_addr(vq, (u64)vq->desc, > + vhost_get_desc_size(vq, vq->num), > + &addr)) > + return -EINVAL; Interesting, any reason for doing such kinds of translation to HVA? I believe the add should already an IOVA that has been map by VFIO. > + > + virtio_mdev_writel(mdev, VIRTIO_MDEV_QUEUE_DESC_LOW, addr); > + virtio_mdev_writel(mdev, VIRTIO_MDEV_QUEUE_DESC_HIGH, > + (addr >> 32)); > + > + if (!vhost_translate_ring_addr(vq, (u64)vq->avail, > + vhost_get_avail_size(vq, vq->num), > + &addr)) > + return -EINVAL; > + > + virtio_mdev_writel(mdev, VIRTIO_MDEV_QUEUE_AVAIL_LOW, addr); > + virtio_mdev_writel(mdev, VIRTIO_MDEV_QUEUE_AVAIL_HIGH, > + (addr >> 32)); > + > + if (!vhost_translate_ring_addr(vq, (u64)vq->used, > + vhost_get_used_size(vq, vq->num), > + &addr)) > + return -EINVAL; > + > + virtio_mdev_writel(mdev, VIRTIO_MDEV_QUEUE_USED_LOW, addr); > + virtio_mdev_writel(mdev, VIRTIO_MDEV_QUEUE_USED_HIGH, > + (addr >> 32)); > + > + // XXX: we need to support set_vring_base I'm working on V2 that support this API. > + > + virtio_mdev_writel(mdev, VIRTIO_MDEV_QUEUE_READY, 1); > + } > + > + // XXX: we need to setup interrupt as well V2 will have a better interrupt API like some kind of callback. It could be as simple as a wrapper of eventfd_signal(). > + > + mdev_add_status(mdev, VIRTIO_CONFIG_S_DRIVER_OK); > + return 0; > +} > + > +static long vhost_mdev_stop_backend(struct vhost_mdev *m) > +{ > + struct mdev_device *mdev = m->mdev; > + > + mdev_reset(mdev); > + mdev_add_status(mdev, VIRTIO_CONFIG_S_ACKNOWLEDGE); > + mdev_add_status(mdev, VIRTIO_CONFIG_S_DRIVER); > + return 0; > +} > + > +static long vhost_set_state(struct vhost_mdev *m, u64 __user *statep) > +{ > + u64 state; > + long r; > + > + if (copy_from_user(&state, statep, sizeof(state))) > + return -EFAULT; > + > + if (state >= VHOST_MDEV_S_MAX) > + return -EINVAL; > + > + if (m->state == state) > + return 0; > + > + m->state = state; > + > + switch (m->state) { > + case VHOST_MDEV_S_RUNNING: > + r = vhost_mdev_start_backend(m); > + break; > + case VHOST_MDEV_S_STOPPED: > + r = vhost_mdev_stop_backend(m); > + break; > + default: > + r = -EINVAL; > + break; > + } > + > + return r; > +} > + > +static long vhost_get_features(struct vhost_mdev *m, u64 __user *featurep) > +{ > + if (copy_to_user(featurep, &m->features, sizeof(m->features))) > + return -EFAULT; > + return 0; > +} > + > +static long vhost_set_features(struct vhost_mdev *m, u64 __user *featurep) > +{ > + u64 features; > + > + if (copy_from_user(&features, featurep, sizeof(features))) > + return -EFAULT; > + > + if (features & ~m->features) > + return -EINVAL; > + > + m->acked_features = features; > + > + return 0; > +} > + > +static long vhost_get_vring_base(struct vhost_mdev *m, void __user *argp) > +{ > + struct vhost_virtqueue *vq; > + u32 idx; > + long r; > + > + r = get_user(idx, (u32 __user *)argp); > + if (r < 0) > + return r; > + if (idx >= m->nvqs) > + return -ENOBUFS; > + > + vq = &m->vqs[idx]; > + > + // XXX: we need to support get_vring_base > + //vq->last_avail_idx = virtio_mdev_readl(b->mdev, ...); > + > + return vhost_vring_ioctl(&m->dev, VHOST_GET_VRING_BASE, argp); > +} > + > +static void vhost_mdev_release_backend(struct vhost_mdev *m) > +{ > + if (!m->mdev) > + return; > + > + if (m->state != VHOST_MDEV_S_STOPPED) { > + m->state = VHOST_MDEV_S_STOPPED; > + vhost_mdev_stop_backend(m); > + } > + > + vhost_dev_stop(&m->dev); > + vhost_dev_cleanup(&m->dev); > + > + kfree(m->dev.vqs); > + kfree(m->vqs); > + > + vfio_device_put(m->vfio_device); > + vfio_group_put_external_user(m->vfio_group); > + > + m->mdev = NULL; > +} > + > +static long vhost_mdev_set_backend(struct vhost_mdev *m, > + struct vhost_mdev_backend __user *argp) > +{ > + struct vhost_mdev_backend backend; > + struct mdev_device *mdev; > + struct vhost_dev *dev; > + struct vhost_virtqueue **vqs; > + struct file *file; > + struct vfio_device *device; > + struct vfio_group *group; > + unsigned long magic; > + u64 features; > + int i, nvqs; > + long r; > + > + vhost_mdev_release_backend(m); > + > + if (copy_from_user(&backend, argp, sizeof(backend))) { > + r = -EFAULT; > + goto err; > + } > + > + file = fget(backend.group_fd); > + if (!file) { > + r = -EBADF; > + goto err; > + } > + > + group = vfio_group_get_external_user(file); > + fput(file); > + if (IS_ERR(group)) { > + r = PTR_ERR(group); > + goto err; > + } > + > + device = vfio_device_get_from_fd(group, backend.device_fd); > + if (!IS_ERR(device)) { > + r = PTR_ERR(device); > + goto err_put_group; > + } > + > + if (!vfio_device_ops_match(device, &vfio_mdev_dev_ops)) { > + r = -EINVAL; > + goto err_put_device; > + } It looks to me that we can avoid to expose vfio_mdev_dev_ops here. > + > + mdev = vfio_device_data(m->vfio_device); > + > + magic = virtio_mdev_readl(mdev, VIRTIO_MDEV_MAGIC_VALUE); > + if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) { > + r = -ENODEV; > + goto err_put_device; > + } > + > + mdev_reset(mdev); > + mdev_add_status(mdev, VIRTIO_CONFIG_S_ACKNOWLEDGE); > + mdev_add_status(mdev, VIRTIO_CONFIG_S_DRIVER); > + > + virtio_mdev_writel(mdev, VIRTIO_MDEV_DEVICE_FEATURES_SEL, 1); > + features = virtio_mdev_readl(mdev, VIRTIO_MDEV_DEVICE_FEATURES); > + features <<= 32; > + > + virtio_mdev_writel(mdev, VIRTIO_MDEV_DEVICE_FEATURES_SEL, 0); > + features |= virtio_mdev_readl(mdev, VIRTIO_MDEV_DEVICE_FEATURES); > + > + if (!(features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))) { > + r = -EINVAL; > + goto err_put_device; > + } > + > + m->features = features; > + > + nvqs = virtio_mdev_readl(mdev, VIRTIO_MDEV_QUEUE_NUM_MAX); > + m->nvqs = nvqs; > + > + m->vqs = kmalloc_array(nvqs, sizeof(struct vhost_virtqueue), > + GFP_KERNEL); > + if (!m->vqs) { > + r = -ENOMEM; > + goto err_put_device; > + } > + > + vqs = kmalloc_array(nvqs, sizeof(*vqs), GFP_KERNEL); > + if (!vqs) { > + r = -ENOMEM; > + goto err_free_vqs; > + } > + > + dev = &m->dev; > + for (i = 0; i < nvqs; i++) { > + vqs[i] = &m->vqs[i]; > + vqs[i]->handle_kick = handle_vq_kick; > + } > + vhost_dev_init(dev, vqs, nvqs, 0, 0, 0); > + > + m->vfio_group = group; > + m->vfio_device = device; > + m->mdev = mdev; > + > + return 0; > + > +err_free_vqs: > + kfree(m->vqs); > +err_put_device: > + vfio_device_put(device); > +err_put_group: > + vfio_group_put_external_user(group); > +err: > + return r; > +} > + > +static int vhost_mdev_open(struct inode *inode, struct file *f) > +{ > + struct vhost_mdev *m; > + > + m = kzalloc(sizeof(*m), GFP_KERNEL | __GFP_RETRY_MAYFAIL); > + if (!m) > + return -ENOMEM; > + > + mutex_init(&m->mutex); > + f->private_data = m; > + > + return 0; > +} > + > +static int vhost_mdev_release(struct inode *inode, struct file *f) > +{ > + struct vhost_mdev *m = f->private_data; > + > + vhost_mdev_release_backend(m); > + mutex_destroy(&m->mutex); > + kfree(m); > + > + return 0; > +} > + > +static long vhost_mdev_ioctl(struct file *f, unsigned int cmd, > + unsigned long arg) > +{ > + void __user *argp = (void __user *)arg; > + struct vhost_mdev *m = f->private_data; > + long r; > + > + mutex_lock(&m->mutex); > + > + if (cmd == VHOST_MDEV_SET_BACKEND) { > + r = vhost_mdev_set_backend(m, argp); > + goto done; > + } > + > + if (!m->mdev) { > + r = -EINVAL; > + goto done; > + } > + > + switch (cmd) { > + case VHOST_MDEV_SET_STATE: > + r = vhost_set_state(m, argp); > + break; > + case VHOST_GET_FEATURES: > + r = vhost_get_features(m, argp); > + break; > + case VHOST_SET_FEATURES: > + r = vhost_set_features(m, argp); > + break; > + case VHOST_GET_VRING_BASE: > + r = vhost_get_vring_base(m, argp); > + break; > + default: > + r = vhost_dev_ioctl(&m->dev, cmd, argp); > + if (r == -ENOIOCTLCMD) > + r = vhost_vring_ioctl(&m->dev, cmd, argp); > + } > + > +done: > + mutex_lock(&m->mutex); > + return r; > +} > + > +#ifdef CONFIG_COMPAT > +static long vhost_mdev_compat_ioctl(struct file *f, unsigned int ioctl, > + unsigned long arg) > +{ > + return vhost_mdev_ioctl(f, ioctl, (unsigned long)compat_ptr(arg)); > +} > +#endif > + > +static const struct file_operations vhost_mdev_fops = { > + .owner = THIS_MODULE, > + .release = vhost_mdev_release, > + .unlocked_ioctl = vhost_mdev_ioctl, > +#ifdef CONFIG_COMPAT > + .compat_ioctl = vhost_mdev_compat_ioctl, > +#endif > + .open = vhost_mdev_open, > + .llseek = noop_llseek, > +}; > + > +static struct miscdevice vhost_mdev_misc = { > + .minor = MISC_DYNAMIC_MINOR, > + .name = "vhost-mdev", > + .fops = &vhost_mdev_fops, > +}; > + > +static int __init vhost_mdev_init(void) > +{ > + return misc_register(&vhost_mdev_misc); > +} > +module_init(vhost_mdev_init); > + > +static void __exit vhost_mdev_exit(void) > +{ > + misc_deregister(&vhost_mdev_misc); > +} > +module_exit(vhost_mdev_exit); > + > +MODULE_VERSION("0.0.0"); > +MODULE_LICENSE("GPL v2"); > +MODULE_DESCRIPTION("Hardware vhost accelerator abstraction"); > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > index 5dc174ac8cac..0f7236a17a56 100644 > --- a/drivers/vhost/vhost.c > +++ b/drivers/vhost/vhost.c > @@ -426,8 +426,7 @@ bool vhost_exceeds_weight(struct vhost_virtqueue *vq, > } > EXPORT_SYMBOL_GPL(vhost_exceeds_weight); > > -static size_t vhost_get_avail_size(struct vhost_virtqueue *vq, > - unsigned int num) > +size_t vhost_get_avail_size(struct vhost_virtqueue *vq, unsigned int num) > { > size_t event __maybe_unused = > vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; > @@ -435,9 +434,9 @@ static size_t vhost_get_avail_size(struct vhost_virtqueue *vq, > return sizeof(*vq->avail) + > sizeof(*vq->avail->ring) * num + event; > } > +EXPORT_SYMBOL_GPL(vhost_get_avail_size); > > -static size_t vhost_get_used_size(struct vhost_virtqueue *vq, > - unsigned int num) > +size_t vhost_get_used_size(struct vhost_virtqueue *vq, unsigned int num) > { > size_t event __maybe_unused = > vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; > @@ -445,12 +444,13 @@ static size_t vhost_get_used_size(struct vhost_virtqueue *vq, > return sizeof(*vq->used) + > sizeof(*vq->used->ring) * num + event; > } > +EXPORT_SYMBOL_GPL(vhost_get_used_size); > > -static size_t vhost_get_desc_size(struct vhost_virtqueue *vq, > - unsigned int num) > +size_t vhost_get_desc_size(struct vhost_virtqueue *vq, unsigned int num) > { > return sizeof(*vq->desc) * num; > } > +EXPORT_SYMBOL_GPL(vhost_get_desc_size); > > void vhost_dev_init(struct vhost_dev *dev, > struct vhost_virtqueue **vqs, int nvqs, > @@ -2617,6 +2617,33 @@ struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev, > } > EXPORT_SYMBOL_GPL(vhost_dequeue_msg); > > +bool vhost_translate_ring_addr(struct vhost_virtqueue *vq, u64 ring_addr, > + u64 len, u64 *addr) > +{ > + struct vhost_umem *umem = vq->umem; > + struct vhost_umem_node *u; > + > + if (vhost_overflow(ring_addr, len)) > + return false; > + > + if (vq->iotlb) { > + /* Ring address is already IOVA */ > + *addr = ring_addr; > + return true; > + } > + > + /* Ring address is host virtual address. */ > + list_for_each_entry(u, &umem->umem_list, link) { > + if (u->userspace_addr <= ring_addr && > + u->userspace_addr + u->size >= ring_addr + len) { > + *addr = ring_addr - u->userspace_addr + u->start; > + return true; > + } > + } > + > + return false; > +} > +EXPORT_SYMBOL_GPL(vhost_translate_ring_addr); As we've discussed, this is necessary. Thanks > > static int __init vhost_init(void) > { > diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h > index e9ed2722b633..294a6bcb6adf 100644 > --- a/drivers/vhost/vhost.h > +++ b/drivers/vhost/vhost.h > @@ -189,6 +189,12 @@ long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp); > long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp); > bool vhost_vq_access_ok(struct vhost_virtqueue *vq); > bool vhost_log_access_ok(struct vhost_dev *); > +bool vhost_translate_ring_addr(struct vhost_virtqueue *vq, u64 ring_addr, > + u64 len, u64 *addr); > + > +size_t vhost_get_avail_size(struct vhost_virtqueue *vq, unsigned int num); > +size_t vhost_get_used_size(struct vhost_virtqueue *vq, unsigned int num); > +size_t vhost_get_desc_size(struct vhost_virtqueue *vq, unsigned int num); > > int vhost_get_vq_desc(struct vhost_virtqueue *, > struct iovec iov[], unsigned int iov_count, > diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h > index 40d028eed645..7213aedc8506 100644 > --- a/include/uapi/linux/vhost.h > +++ b/include/uapi/linux/vhost.h > @@ -116,4 +116,14 @@ > #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_BACKEND _IOW(VHOST_VIRTIO, 0x70, \ > + struct vhost_mdev_backend) > +#define VHOST_MDEV_SET_STATE _IOW(VHOST_VIRTIO, 0x71, __u64) > + > +#define VHOST_MDEV_S_STOPPED 0 > +#define VHOST_MDEV_S_RUNNING 1 > +#define VHOST_MDEV_S_MAX 2 > + > #endif > diff --git a/include/uapi/linux/vhost_types.h b/include/uapi/linux/vhost_types.h > index c907290ff065..f06f0dbb7e51 100644 > --- a/include/uapi/linux/vhost_types.h > +++ b/include/uapi/linux/vhost_types.h > @@ -119,6 +119,11 @@ struct vhost_scsi_target { > unsigned short reserved; > }; > > +struct vhost_mdev_backend { > + int group_fd; > + int device_fd; > +}; > + > /* Feature bits */ > /* Log all write descriptors. Can be changed while device is active. */ > #define VHOST_F_LOG_ALL 26