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=-5.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS 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 88533C76195 for ; Mon, 22 Jul 2019 08:40:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6AE5E21E6B for ; Mon, 22 Jul 2019 08:40:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728582AbfGVIkI (ORCPT ); Mon, 22 Jul 2019 04:40:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48780 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728177AbfGVIjx (ORCPT ); Mon, 22 Jul 2019 04:39:53 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 749F93E2D3; Mon, 22 Jul 2019 08:39:52 +0000 (UTC) Received: from redhat.com (ovpn-120-233.rdu2.redhat.com [10.10.120.233]) by smtp.corp.redhat.com (Postfix) with ESMTP id B365B1001B09; Mon, 22 Jul 2019 08:39:49 +0000 (UTC) Date: Mon, 22 Jul 2019 04:39:47 -0400 From: "Michael S. Tsirkin" To: =?utf-8?B?5p2O6I+y?= Cc: virtio-dev@lists.oasis-open.org, linux-kernel@vger.kernel.org, Jason Wang , Pawel Moll , Suzuki K Poulose , Fam Zheng Subject: Re: [External Email] Re: [PATCH v1 0/2] virtio-mmio: support multiple interrupt vectors Message-ID: <20190722043707-mutt-send-email-mst@kernel.org> References: <20190719133135.32418-1-lifei.shirley@bytedance.com> <20190719110852-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Mon, 22 Jul 2019 08:39:52 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 22, 2019 at 11:22:02AM +0800, 李菲 wrote: > On Fri, Jul 19, 2019 at 11:14 PM Michael S. Tsirkin wrote: > > > > On Fri, Jul 19, 2019 at 09:31:33PM +0800, Fei Li wrote: > > > Hi, > > > > > > This patch series implements multiple interrupt vectors support for > > > virtio-mmio device. This is especially useful for multiqueue vhost-net > > > device when using firecracker micro-vms as the guest. > > > > > > Test result: > > > With 8 vcpus & 8 net queues set, one vhost-net device with 8 irqs can > > > receive 9 times more pps comparing with only one irq: > > > - 564830.38 rxpck/s for 8 irqs on > > > - 67665.06 rxpck/s for 1 irq on > > > > > > Please help to review, thanks! > > > > > > Have a nice day > > > Fei > > > > > > Interesting. The spec says though: > > > > 4.2.3.4 > > Notifications From The Device > > The memory mapped virtio device is using a single, dedicated interrupt signal, which is asserted when at > > least one of the bits described in the description of InterruptStatus is set. This is how the device sends a > > used buffer notification or a configuration change notification to the device. > > > Yes, the spec needs to be updated if we want to use mult-irqs. > > > > So I'm guessing we need to change the host/guest interface? > Just to confirm, does the "the host/guest interface" you mentioned mean how to > pass the irq information from the user space tool to guest kernel? > In this patch, we do this by passing the [irq_start, irq_end] > interface via setting guest > kernel command line, that is done in vm_cmdline_set(). > Also there is another way to do this: add two new registers describing irq info > (irq_start & irq_end OR irq_start & irq_numbers) to the virtio config space. > > Which one do you prefer? I'm not sure - so far irq was passed on the command line, right? The first step in implementing any spec change would be to update qemu code to virtio 1. Which is not a huge project but so far no one bothered. > > If true pls cc virtio-dev. > Sure. > > > > Also, do we need to update dt bindings documentation? > You mean the following doc? Sure. :) > https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/virtio/mmio.txt > > Thanks for the review! > > Have a nice day > Fei > > > > > > > > > > Fam Zheng (1): > > > virtio-mmio: Process vrings more proactively > > > > > > Fei Li (1): > > > virtio-mmio: support multiple interrupt vectors > > > > > > drivers/virtio/virtio_mmio.c | 238 +++++++++++++++++++++++++++++++++++-------- > > > 1 file changed, 196 insertions(+), 42 deletions(-) > > > > > > -- > > > 2.11.0