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=-19.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 8DD78C433DB for ; Thu, 24 Dec 2020 02:13:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 46AB422571 for ; Thu, 24 Dec 2020 02:13:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728305AbgLXCN0 (ORCPT ); Wed, 23 Dec 2020 21:13:26 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:42824 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726288AbgLXCN0 (ORCPT ); Wed, 23 Dec 2020 21:13:26 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1608775919; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=swnlJja9vV9IaQUf+Cmbgo9v/rpw1W8NO8amK8k/76w=; b=OoUngNy+XMzo+U9wGATfFjmKjlPA4LDx124qGaR3jDmjVRG6VbXIsRe0z/b7QQSPkok8uX jmkPLgVA0ET679OA0gRk9PvWyhI7hG1/zTLfH7dOrNkVtgoQnF+bQP9z5I0gAh2z6gtSzM xE+zsecSw5NgZpDlpko7karOiRIYf5E= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-595-kM5oObpROuyJDzDHe6-P1A-1; Wed, 23 Dec 2020 21:11:55 -0500 X-MC-Unique: kM5oObpROuyJDzDHe6-P1A-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6C510107ACE6; Thu, 24 Dec 2020 02:11:54 +0000 (UTC) Received: from [10.72.13.109] (ovpn-13-109.pek2.redhat.com [10.72.13.109]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7C11B5D9C6; Thu, 24 Dec 2020 02:11:42 +0000 (UTC) Subject: Re: [PATCH v2] vhost/vsock: add IOTLB API support To: Stefano Garzarella , virtualization@lists.linux-foundation.org Cc: netdev@vger.kernel.org, "Michael S. Tsirkin" , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Stefan Hajnoczi References: <20201223143638.123417-1-sgarzare@redhat.com> From: Jason Wang Message-ID: <28e8b1cf-513a-5bc6-096d-432dfa6620cb@redhat.com> Date: Thu, 24 Dec 2020 10:11:40 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201223143638.123417-1-sgarzare@redhat.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 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 2020/12/23 下午10:36, Stefano Garzarella wrote: > This patch enables the IOTLB API support for vhost-vsock devices, > allowing the userspace to emulate an IOMMU for the guest. > > These changes were made following vhost-net, in details this patch: > - exposes VIRTIO_F_ACCESS_PLATFORM feature and inits the iotlb > device if the feature is acked > - implements VHOST_GET_BACKEND_FEATURES and > VHOST_SET_BACKEND_FEATURES ioctls > - calls vq_meta_prefetch() before vq processing to prefetch vq > metadata address in IOTLB > - provides .read_iter, .write_iter, and .poll callbacks for the > chardev; they are used by the userspace to exchange IOTLB messages > > This patch was tested specifying "intel_iommu=strict" in the guest > kernel command line. I used QEMU with a patch applied [1] to fix a > simple issue (that patch was merged in QEMU v5.2.0): > $ qemu -M q35,accel=kvm,kernel-irqchip=split \ > -drive file=fedora.qcow2,format=qcow2,if=virtio \ > -device intel-iommu,intremap=on,device-iotlb=on \ > -device vhost-vsock-pci,guest-cid=3,iommu_platform=on,ats=on > > [1] https://lists.gnu.org/archive/html/qemu-devel/2020-10/msg09077.html > > Reviewed-by: Stefan Hajnoczi > Signed-off-by: Stefano Garzarella Acked-by: Jason Wang > --- > > The patch is the same of v1, but I re-tested it with: > - QEMU v5.2.0-551-ga05f8ecd88 > - Linux 5.9.15 (host) > - Linux 5.9.15 and 5.10.0 (guest) > Now, enabling 'ats' it works well, there are just a few simple changes. > > v1: https://www.spinics.net/lists/kernel/msg3716022.html > v2: > - updated commit message about QEMU version and string used to test > - rebased on mst/vhost branch > > Thanks, > Stefano > --- > drivers/vhost/vsock.c | 68 +++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 65 insertions(+), 3 deletions(-) > > diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c > index a483cec31d5c..5e78fb719602 100644 > --- a/drivers/vhost/vsock.c > +++ b/drivers/vhost/vsock.c > @@ -30,7 +30,12 @@ > #define VHOST_VSOCK_PKT_WEIGHT 256 > > enum { > - VHOST_VSOCK_FEATURES = VHOST_FEATURES, > + VHOST_VSOCK_FEATURES = VHOST_FEATURES | > + (1ULL << VIRTIO_F_ACCESS_PLATFORM) > +}; > + > +enum { > + VHOST_VSOCK_BACKEND_FEATURES = (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2) > }; > > /* Used to track all the vhost_vsock instances on the system. */ > @@ -94,6 +99,9 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock, > if (!vhost_vq_get_backend(vq)) > goto out; > > + if (!vq_meta_prefetch(vq)) > + goto out; > + > /* Avoid further vmexits, we're already processing the virtqueue */ > vhost_disable_notify(&vsock->dev, vq); > > @@ -449,6 +457,9 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work) > if (!vhost_vq_get_backend(vq)) > goto out; > > + if (!vq_meta_prefetch(vq)) > + goto out; > + > vhost_disable_notify(&vsock->dev, vq); > do { > u32 len; > @@ -766,8 +777,12 @@ static int vhost_vsock_set_features(struct vhost_vsock *vsock, u64 features) > mutex_lock(&vsock->dev.mutex); > if ((features & (1 << VHOST_F_LOG_ALL)) && > !vhost_log_access_ok(&vsock->dev)) { > - mutex_unlock(&vsock->dev.mutex); > - return -EFAULT; > + goto err; > + } > + > + if ((features & (1ULL << VIRTIO_F_ACCESS_PLATFORM))) { > + if (vhost_init_device_iotlb(&vsock->dev, true)) > + goto err; > } > > for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) { > @@ -778,6 +793,10 @@ static int vhost_vsock_set_features(struct vhost_vsock *vsock, u64 features) > } > mutex_unlock(&vsock->dev.mutex); > return 0; > + > +err: > + mutex_unlock(&vsock->dev.mutex); > + return -EFAULT; > } > > static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl, > @@ -811,6 +830,18 @@ static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl, > if (copy_from_user(&features, argp, sizeof(features))) > return -EFAULT; > return vhost_vsock_set_features(vsock, features); > + case VHOST_GET_BACKEND_FEATURES: > + features = VHOST_VSOCK_BACKEND_FEATURES; > + if (copy_to_user(argp, &features, sizeof(features))) > + return -EFAULT; > + return 0; > + case VHOST_SET_BACKEND_FEATURES: > + if (copy_from_user(&features, argp, sizeof(features))) > + return -EFAULT; > + if (features & ~VHOST_VSOCK_BACKEND_FEATURES) > + return -EOPNOTSUPP; > + vhost_set_backend_features(&vsock->dev, features); > + return 0; > default: > mutex_lock(&vsock->dev.mutex); > r = vhost_dev_ioctl(&vsock->dev, ioctl, argp); > @@ -823,6 +854,34 @@ static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl, > } > } > > +static ssize_t vhost_vsock_chr_read_iter(struct kiocb *iocb, struct iov_iter *to) > +{ > + struct file *file = iocb->ki_filp; > + struct vhost_vsock *vsock = file->private_data; > + struct vhost_dev *dev = &vsock->dev; > + int noblock = file->f_flags & O_NONBLOCK; > + > + return vhost_chr_read_iter(dev, to, noblock); > +} > + > +static ssize_t vhost_vsock_chr_write_iter(struct kiocb *iocb, > + struct iov_iter *from) > +{ > + struct file *file = iocb->ki_filp; > + struct vhost_vsock *vsock = file->private_data; > + struct vhost_dev *dev = &vsock->dev; > + > + return vhost_chr_write_iter(dev, from); > +} > + > +static __poll_t vhost_vsock_chr_poll(struct file *file, poll_table *wait) > +{ > + struct vhost_vsock *vsock = file->private_data; > + struct vhost_dev *dev = &vsock->dev; > + > + return vhost_chr_poll(file, dev, wait); > +} > + > static const struct file_operations vhost_vsock_fops = { > .owner = THIS_MODULE, > .open = vhost_vsock_dev_open, > @@ -830,6 +889,9 @@ static const struct file_operations vhost_vsock_fops = { > .llseek = noop_llseek, > .unlocked_ioctl = vhost_vsock_dev_ioctl, > .compat_ioctl = compat_ptr_ioctl, > + .read_iter = vhost_vsock_chr_read_iter, > + .write_iter = vhost_vsock_chr_write_iter, > + .poll = vhost_vsock_chr_poll, > }; > > static struct miscdevice vhost_vsock_misc = {