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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 29870C433F5 for ; Tue, 8 Feb 2022 09:09:41 +0000 (UTC) Received: from localhost ([::1]:47148 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nHMVH-00055m-3o for qemu-devel@archiver.kernel.org; Tue, 08 Feb 2022 04:09:39 -0500 Received: from eggs.gnu.org ([209.51.188.92]:37870) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nHLqz-0002Dt-V4 for qemu-devel@nongnu.org; Tue, 08 Feb 2022 03:28:02 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:29537) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nHLqw-0002yB-Rg for qemu-devel@nongnu.org; Tue, 08 Feb 2022 03:28:01 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1644308878; 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=i1ub9xr/QwA4MhJV+FioBawD7/GrfPqiQxLzRBzhsSs=; b=CJJUmgY7vek4jvzqB2haBYcJbugc65c4JRXFTILmtzZPIIufzsDCLMly154FbuBSCz1U0U WGX+bqrST78dXbuYAODMf80okTPQH2taVQBQk3Z9A4AzlusbXUoi5vG4h3LjPsu/yBWAg4 pLdUGaMa9QsNbntoF2WzyGeYv/fBfn8= Received: from mail-pf1-f199.google.com (mail-pf1-f199.google.com [209.85.210.199]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-478-JfhL699OPiGmI7cWL7IriQ-1; Tue, 08 Feb 2022 03:27:54 -0500 X-MC-Unique: JfhL699OPiGmI7cWL7IriQ-1 Received: by mail-pf1-f199.google.com with SMTP id b11-20020aa7950b000000b004df185959c4so6987876pfp.8 for ; Tue, 08 Feb 2022 00:27:53 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=i1ub9xr/QwA4MhJV+FioBawD7/GrfPqiQxLzRBzhsSs=; b=L+rBjKCO1e/jdLWt9FDMtH899U1sCg8ljp38GPP1Yq+x7OXwxOKLDZqRvh/7usP6T0 w/tzcfGeTvWnsmgUis/PcmMl7yrsxXA07gkVn3/ujGDTCnc9tqdow1nty8+Y+snt7beW KdkmMUA7pCA24DdKB8j57AGKNhrJ4g2l/xuslkJViroXL02MGMR+8DsmWXYVokeoIJHc ZLZIfkJ6ECj0SfPWoAmE77m1IDP66xETHi34xZVUrDjqyQ7RiXy0TqM8XK4EkJZrYvTw FHlJbyLPNGNTntxFILZrf9OG89uDcAePtSPdJdLsI+XXAlorYx5K0MvlAxu8Iy4xGk2l HKgw== X-Gm-Message-State: AOAM530UZHeNoFfesCEoX93aynXFEWMNDd9ZGjiKmx7mCsPo1SszPsEm FHJWvulLj0v06IVJM5WQoQfzKnK/q5JDdIPEpRgf4LbV45XLXPuDKjohLZ9i/5dbgDfslylUdIA 7R8astpSA2DgJ6kw= X-Received: by 2002:a17:902:f68a:: with SMTP id l10mr3489645plg.146.1644308872669; Tue, 08 Feb 2022 00:27:52 -0800 (PST) X-Google-Smtp-Source: ABdhPJxpy3xwX9tx9I3wRAwY9kln8W9qHfGjeT7shrOFQnY9sFs9u6bR7EvCTCIWyfnHFjWUf3u30w== X-Received: by 2002:a17:902:f68a:: with SMTP id l10mr3489603plg.146.1644308872240; Tue, 08 Feb 2022 00:27:52 -0800 (PST) Received: from [10.72.13.12] ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id md9sm1840360pjb.6.2022.02.08.00.27.45 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 08 Feb 2022 00:27:51 -0800 (PST) Message-ID: Date: Tue, 8 Feb 2022 16:27:43 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.5.1 Subject: Re: [PATCH 00/31] vDPA shadow virtqueue To: Eugenio Perez Martin References: <20220121202733.404989-1-eperezma@redhat.com> <7d86c715-6d71-8a27-91f5-8d47b71e3201@redhat.com> From: Jason Wang In-Reply-To: Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jasowang@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=jasowang@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Laurent Vivier , Parav Pandit , Cindy Lu , "Michael S. Tsirkin" , Juan Quintela , Richard Henderson , qemu-level , Gautam Dawar , Markus Armbruster , Eduardo Habkost , Harpreet Singh Anand , Xiao W Wang , Peter Xu , Stefan Hajnoczi , Eli Cohen , Paolo Bonzini , Zhu Lingshan , virtualization , Eric Blake , Stefano Garzarella Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" 在 2022/1/31 下午5:15, Eugenio Perez Martin 写道: > On Fri, Jan 28, 2022 at 7:02 AM Jason Wang wrote: >> >> 在 2022/1/22 上午4:27, Eugenio Pérez 写道: >>> This series enables shadow virtqueue (SVQ) for vhost-vdpa devices. This >>> is intended as a new method of tracking the memory the devices touch >>> during a migration process: Instead of relay on vhost device's dirty >>> logging capability, SVQ intercepts the VQ dataplane forwarding the >>> descriptors between VM and device. This way qemu is the effective >>> writer of guests memory, like in qemu's emulated virtio device >>> operation. >>> >>> When SVQ is enabled qemu offers a new virtual address space to the >>> device to read and write into, and it maps new vrings and the guest >>> memory in it. SVQ also intercepts kicks and calls between the device >>> and the guest. Used buffers relay would cause dirty memory being >>> tracked, but at this RFC SVQ is not enabled on migration automatically. >>> >>> Thanks of being a buffers relay system, SVQ can be used also to >>> communicate devices and drivers with different capabilities, like >>> devices that only support packed vring and not split and old guests with >>> no driver packed support. >>> >>> It is based on the ideas of DPDK SW assisted LM, in the series of >>> DPDK's https://patchwork.dpdk.org/cover/48370/ . However, these does >>> not map the shadow vq in guest's VA, but in qemu's. >>> >>> This version of SVQ is limited in the amount of features it can use with >>> guest and device, because this series is already very big otherwise. >>> Features like indirect or event_idx will be addressed in future series. >>> >>> SVQ needs to be enabled with cmdline parameter x-svq, like: >>> >>> -netdev type=vhost-vdpa,vhostdev=/dev/vhost-vdpa-0,id=vhost-vdpa0,x-svq=true >>> >>> In this version it cannot be enabled or disabled in runtime. Further >>> series will remove this limitation and will enable it only for migration >>> time. >>> >>> Some patches are intentionally very small to ease review, but they can >>> be squashed if preferred. >>> >>> Patches 1-10 prepares the SVQ and QEMU to support both guest to device >>> and device to guest notifications forwarding, with the extra qemu hop. >>> That part can be tested in isolation if cmdline change is reproduced. >>> >>> Patches from 11 to 18 implement the actual buffer forwarding, but with >>> no IOMMU support. It requires a vdpa device capable of addressing all >>> qemu vaddr. >>> >>> Patches 19 to 23 adds the iommu support, so the device with address >>> range limitations can access SVQ through this new virtual address space >>> created. >>> >>> The rest of the series add the last pieces needed for migration. >>> >>> Comments are welcome. >> >> I wonder the performance impact. So performance numbers are more than >> welcomed. >> > Sure, I'll do it for the next revision. Since this one brings a decent > amount of changes, I chose to collect the feedback first. A simple single TCP_STREAM netperf test should be sufficient to give some basic understanding about the performance impact. Thanks > > Thanks! > >> Thanks >> >> >>> TODO: >>> * Event, indirect, packed, and other features of virtio. >>> * To separate buffers forwarding in its own AIO context, so we can >>> throw more threads to that task and we don't need to stop the main >>> event loop. >>> * Support virtio-net control vq. >>> * Proper documentation. >>> >>> Changes from v5 RFC: >>> * Remove dynamic enablement of SVQ, making less dependent of the device. >>> * Enable live migration if SVQ is enabled. >>> * Fix SVQ when driver reset. >>> * Comments addressed, specially in the iova area. >>> * Rebase on latest master, adding multiqueue support (but no networking >>> control vq processing). >>> v5 link: >>> https://lists.gnu.org/archive/html/qemu-devel/2021-10/msg07250.html >>> >>> Changes from v4 RFC: >>> * Support of allocating / freeing iova ranges in IOVA tree. Extending >>> already present iova-tree for that. >>> * Proper validation of guest features. Now SVQ can negotiate a >>> different set of features with the device when enabled. >>> * Support of host notifiers memory regions >>> * Handling of SVQ full queue in case guest's descriptors span to >>> different memory regions (qemu's VA chunks). >>> * Flush pending used buffers at end of SVQ operation. >>> * QMP command now looks by NetClientState name. Other devices will need >>> to implement it's way to enable vdpa. >>> * Rename QMP command to set, so it looks more like a way of working >>> * Better use of qemu error system >>> * Make a few assertions proper error-handling paths. >>> * Add more documentation >>> * Less coupling of virtio / vhost, that could cause friction on changes >>> * Addressed many other small comments and small fixes. >>> >>> Changes from v3 RFC: >>> * Move everything to vhost-vdpa backend. A big change, this allowed >>> some cleanup but more code has been added in other places. >>> * More use of glib utilities, especially to manage memory. >>> v3 link: >>> https://lists.nongnu.org/archive/html/qemu-devel/2021-05/msg06032.html >>> >>> Changes from v2 RFC: >>> * Adding vhost-vdpa devices support >>> * Fixed some memory leaks pointed by different comments >>> v2 link: >>> https://lists.nongnu.org/archive/html/qemu-devel/2021-03/msg05600.html >>> >>> Changes from v1 RFC: >>> * Use QMP instead of migration to start SVQ mode. >>> * Only accepting IOMMU devices, closer behavior with target devices >>> (vDPA) >>> * Fix invalid masking/unmasking of vhost call fd. >>> * Use of proper methods for synchronization. >>> * No need to modify VirtIO device code, all of the changes are >>> contained in vhost code. >>> * Delete superfluous code. >>> * An intermediate RFC was sent with only the notifications forwarding >>> changes. It can be seen in >>> https://patchew.org/QEMU/20210129205415.876290-1-eperezma@redhat.com/ >>> v1 link: >>> https://lists.gnu.org/archive/html/qemu-devel/2020-11/msg05372.html >>> >>> Eugenio Pérez (20): >>> virtio: Add VIRTIO_F_QUEUE_STATE >>> virtio-net: Honor VIRTIO_CONFIG_S_DEVICE_STOPPED >>> virtio: Add virtio_queue_is_host_notifier_enabled >>> vhost: Make vhost_virtqueue_{start,stop} public >>> vhost: Add x-vhost-enable-shadow-vq qmp >>> vhost: Add VhostShadowVirtqueue >>> vdpa: Register vdpa devices in a list >>> vhost: Route guest->host notification through shadow virtqueue >>> Add vhost_svq_get_svq_call_notifier >>> Add vhost_svq_set_guest_call_notifier >>> vdpa: Save call_fd in vhost-vdpa >>> vhost-vdpa: Take into account SVQ in vhost_vdpa_set_vring_call >>> vhost: Route host->guest notification through shadow virtqueue >>> virtio: Add vhost_shadow_vq_get_vring_addr >>> vdpa: Save host and guest features >>> vhost: Add vhost_svq_valid_device_features to shadow vq >>> vhost: Shadow virtqueue buffers forwarding >>> vhost: Add VhostIOVATree >>> vhost: Use a tree to store memory mappings >>> vdpa: Add custom IOTLB translations to SVQ >>> >>> Eugenio Pérez (31): >>> vdpa: Reorder virtio/vhost-vdpa.c functions >>> vhost: Add VhostShadowVirtqueue >>> vdpa: Add vhost_svq_get_dev_kick_notifier >>> vdpa: Add vhost_svq_set_svq_kick_fd >>> vhost: Add Shadow VirtQueue kick forwarding capabilities >>> vhost: Route guest->host notification through shadow virtqueue >>> vhost: dd vhost_svq_get_svq_call_notifier >>> vhost: Add vhost_svq_set_guest_call_notifier >>> vhost-vdpa: Take into account SVQ in vhost_vdpa_set_vring_call >>> vhost: Route host->guest notification through shadow virtqueue >>> vhost: Add vhost_svq_valid_device_features to shadow vq >>> vhost: Add vhost_svq_valid_guest_features to shadow vq >>> vhost: Add vhost_svq_ack_guest_features to shadow vq >>> virtio: Add vhost_shadow_vq_get_vring_addr >>> vdpa: Add vhost_svq_get_num >>> vhost: pass queue index to vhost_vq_get_addr >>> vdpa: adapt vhost_ops callbacks to svq >>> vhost: Shadow virtqueue buffers forwarding >>> utils: Add internal DMAMap to iova-tree >>> util: Store DMA entries in a list >>> util: Add iova_tree_alloc >>> vhost: Add VhostIOVATree >>> vdpa: Add custom IOTLB translations to SVQ >>> vhost: Add vhost_svq_get_last_used_idx >>> vdpa: Adapt vhost_vdpa_get_vring_base to SVQ >>> vdpa: Clear VHOST_VRING_F_LOG at vhost_vdpa_set_vring_addr in SVQ >>> vdpa: Never set log_base addr if SVQ is enabled >>> vdpa: Expose VHOST_F_LOG_ALL on SVQ >>> vdpa: Make ncs autofree >>> vdpa: Move vhost_vdpa_get_iova_range to net/vhost-vdpa.c >>> vdpa: Add x-svq to NetdevVhostVDPAOptions >>> >>> qapi/net.json | 5 +- >>> hw/virtio/vhost-iova-tree.h | 27 + >>> hw/virtio/vhost-shadow-virtqueue.h | 46 ++ >>> include/hw/virtio/vhost-vdpa.h | 7 + >>> include/qemu/iova-tree.h | 17 + >>> hw/virtio/vhost-iova-tree.c | 157 ++++++ >>> hw/virtio/vhost-shadow-virtqueue.c | 761 +++++++++++++++++++++++++++++ >>> hw/virtio/vhost-vdpa.c | 740 ++++++++++++++++++++++++---- >>> hw/virtio/vhost.c | 6 +- >>> net/vhost-vdpa.c | 58 ++- >>> util/iova-tree.c | 161 +++++- >>> hw/virtio/meson.build | 2 +- >>> 12 files changed, 1852 insertions(+), 135 deletions(-) >>> create mode 100644 hw/virtio/vhost-iova-tree.h >>> create mode 100644 hw/virtio/vhost-shadow-virtqueue.h >>> create mode 100644 hw/virtio/vhost-iova-tree.c >>> create mode 100644 hw/virtio/vhost-shadow-virtqueue.c >>>