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=-5.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=no 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 1A2A2C388F9 for ; Fri, 30 Oct 2020 11:45:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AFBA2207DE for ; Fri, 30 Oct 2020 11:45:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="NEecZhC7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726531AbgJ3LpI (ORCPT ); Fri, 30 Oct 2020 07:45:08 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:42874 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726600AbgJ3LpA (ORCPT ); Fri, 30 Oct 2020 07:45:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1604058298; 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=rMzfcfElqXmYjTtD+miGi6l1YpfMLIM07gwUkJW1Ka4=; b=NEecZhC7KZ2JR9DGrtaHbi8GthTPa6bKjljhcAjBJrXk+zDPYS4rU5XHPt+B0h5r35II/6 LFGIjj+AZz5rY2+RIn/0QBANSwTre7PbGZP+186BxdxgPuFi3UjDPgH2eAI0RXNwfN3cR+ /hADoIr6WLVLzPpssK7cn0eHr+IK8aw= 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-584-3sQS_sVaMLePpUqD5ntZlw-1; Fri, 30 Oct 2020 07:44:55 -0400 X-MC-Unique: 3sQS_sVaMLePpUqD5ntZlw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6B6F01017DD0; Fri, 30 Oct 2020 11:44:54 +0000 (UTC) Received: from [10.72.12.248] (ovpn-12-248.pek2.redhat.com [10.72.12.248]) by smtp.corp.redhat.com (Postfix) with ESMTP id 820275CC26; Fri, 30 Oct 2020 11:44:45 +0000 (UTC) Subject: Re: [PATCH] vhost/vsock: add IOTLB API support To: Stefano Garzarella Cc: mst@redhat.com, netdev@vger.kernel.org, Stefan Hajnoczi , kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org References: <20201029174351.134173-1-sgarzare@redhat.com> <751cc074-ae68-72c8-71de-a42458058761@redhat.com> <20201030105422.ju2aj2bmwsckdufh@steredhat> From: Jason Wang Message-ID: <278f4732-e561-2b4f-03ee-b26455760b01@redhat.com> Date: Fri, 30 Oct 2020 19:44:43 +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: <20201030105422.ju2aj2bmwsckdufh@steredhat> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2020/10/30 下午6:54, Stefano Garzarella wrote: > On Fri, Oct 30, 2020 at 06:02:18PM +0800, Jason Wang wrote: >> >> On 2020/10/30 上午1:43, 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 with QEMU and a patch applied [1] to fix a >>> simple issue: >>>     $ qemu -M q35,accel=kvm,kernel-irqchip=split \ >>>            -drive file=fedora.qcow2,format=qcow2,if=virtio \ >>>            -device intel-iommu,intremap=on \ >>>            -device vhost-vsock-pci,guest-cid=3,iommu_platform=on >> >> >> Patch looks good, but a question: >> >> It looks to me you don't enable ATS which means vhost won't get any >> invalidation request or did I miss anything? >> > > You're right, I didn't see invalidation requests, only miss and updates. > Now I have tried to enable 'ats' and 'device-iotlb' but I still don't > see any invalidation. > > How can I test it? (Sorry but I don't have much experience yet with > vIOMMU) I guess it's because the batched unmap. Maybe you can try to use "intel_iommu=strict" in guest kernel command line to see if it works. Btw, make sure the qemu contains the patch [1]. Otherwise ATS won't be enabled for recent Linux Kernel in the guest. Thanks [1] https://patchew.org/QEMU/20200909081731.24688-1-jasowang@redhat.com/ > > Thanks, > Stefano >