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=-22.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 2A260C432BE for ; Thu, 26 Aug 2021 08:42:25 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 6EFF560F45 for ; Thu, 26 Aug 2021 08:42:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 6EFF560F45 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:34660 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mJAxr-0008RB-Gu for qemu-devel@archiver.kernel.org; Thu, 26 Aug 2021 04:42:23 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:46778) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mJAwY-000733-Nq for qemu-devel@nongnu.org; Thu, 26 Aug 2021 04:41:03 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:57823) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mJAwU-0007Fl-Pv for qemu-devel@nongnu.org; Thu, 26 Aug 2021 04:41:01 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1629967256; 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=R24vFnkGkeb3UrlS06slb+CN5ohRSpiRo6WqQGLlR/A=; b=S72Y4gG/epTx3/VVDhdiuBeN8spr3aomW2qlv5aKxc+tYH4oXF6VYAdEdvCVrZLVpAtGXI wcy5AISttcGXY5pHVrf/aPUFJevV3B47kiGowaCvJ7ha0CC7jHAPxhI8li0dQzhXS1GkSs NCfh7LNVdH2cRDG2YacT1E0Gy4vZh6M= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-297-5XO50trSOZ6HaXdAV4CZcA-1; Thu, 26 Aug 2021 04:40:52 -0400 X-MC-Unique: 5XO50trSOZ6HaXdAV4CZcA-1 Received: by mail-wm1-f72.google.com with SMTP id a201-20020a1c7fd2000000b002e748bf0544so4034486wmd.2 for ; Thu, 26 Aug 2021 01:40:52 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=R24vFnkGkeb3UrlS06slb+CN5ohRSpiRo6WqQGLlR/A=; b=GeemJdnGfVXKurPc6JH30K+mVllKiVekJy+fF1ftA+nVOPYxWcXhDzW89AjUMQUxDo EUmi8bPW0IXe3MdiMAFgfU8UTL284ggKqfDl8x6XYBqROR0hzJuE1JFci9NtiLekEMv5 9DKK40dM6fA1oSd64jmzH3PwEIs7aC5m8N/MYep832XIvgCcBxn1BVx6Btc1lxFipElv NBkMgqqHL+Z5YsK5A/2SwobijSZtjXQsnY7uyciXP9lxpfoqDoAPeKJljoqJYUuqpmgA ik27B7KQ7YPMDoPAmKl+5zBP7AVVrH4AcDY4px+r1UCtsVxRzQ6DTdLCxg2MErdDIeZA Ff8g== X-Gm-Message-State: AOAM532on6HktJ37yoUC33P+mYHidTbN0/ROHAfSiHmG2BtjMqsNX4Dv QQ5vkv0qVVfCsxIiI9P/KR3O85D/vTFHukbcbLbZpOCnr40ASt1uSjZ9llmUjv+wZagcosL0znm WbXDAA8jA1dvujKM= X-Received: by 2002:a7b:c847:: with SMTP id c7mr2515272wml.1.1629967249361; Thu, 26 Aug 2021 01:40:49 -0700 (PDT) X-Google-Smtp-Source: ABdhPJx0QXe34ABhBHK/upXt8k/pUom5ZnBnA0pHPGI1CVp5sElhIOWjugkuGAIYU8i97+oduk1xHA== X-Received: by 2002:a7b:c847:: with SMTP id c7mr2515250wml.1.1629967249106; Thu, 26 Aug 2021 01:40:49 -0700 (PDT) Received: from [192.168.1.36] (163.red-83-52-55.dynamicip.rima-tde.net. [83.52.55.163]) by smtp.gmail.com with ESMTPSA id b2sm2014305wmd.3.2021.08.26.01.40.48 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 26 Aug 2021 01:40:48 -0700 (PDT) Subject: Re: [PATCH] hw/virtio: Update vring after modifying its queue size To: Jason Wang References: <20210825224256.1750286-1-philmd@redhat.com> From: =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= Message-ID: <6824eed8-30e6-dbbf-4a4f-92e394c5430c@redhat.com> Date: Thu, 26 Aug 2021 10:40:47 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=philmd@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=philmd@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -57 X-Spam_score: -5.8 X-Spam_bar: ----- X-Spam_report: (-5.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.745, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-2.24, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, WEIRD_PORT=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Michael S. Tsirkin" , Cornelia Huck , Li Qiang , qemu-devel , Qiuhao Li , Alexander Bulekov , Stefan Hajnoczi , Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 8/26/21 5:28 AM, Jason Wang wrote: > On Thu, Aug 26, 2021 at 6:43 AM Philippe Mathieu-Daudé > wrote: >> >> When a ring queue size is modified, we need to call >> virtio_queue_update_rings() to re-init the memory region >> caches. Otherwise the region might have outdated memory >> size, and later load/store access might trigger an >> assertion, such: >> >> qemu-system-i386: include/exec/memory_ldst_cached.h.inc:30: uint16_t address_space_lduw_le_cached(MemoryRegionCache *, hwaddr, MemTxAttrs, MemTxResult *): >> Assertion `addr < cache->len && 2 <= cache->len - addr' failed. >> Thread 1 "qemu-system-i38" received signal SIGABRT, Aborted. >> 0x00007ffff4d312a2 in raise () from /lib64/libc.so.6 >> (gdb) bt >> #1 0x00007ffff4d1a8a4 in abort () at /lib64/libc.so.6 >> #4 0x0000555558f2b8ec in address_space_lduw_le_cached (cache=0x61300010a7c0, addr=134, attrs=..., result=0x0) at include/exec/memory_ldst_cached.h.inc:30 >> #5 0x0000555558f2ac6b in lduw_le_phys_cached (cache=0x61300010a7c0, addr=134) at include/exec/memory_ldst_phys.h.inc:67 >> #6 0x0000555558f2a3cd in virtio_lduw_phys_cached (vdev=0x62d00003a680, cache=0x61300010a7c0, pa=134) at include/hw/virtio/virtio-access.h:166 >> #7 0x0000555558f300ea in vring_avail_ring (vq=0x7fffdd55d8a0, i=65) at hw/virtio/virtio.c:326 >> #8 0x0000555558f33b10 in vring_get_used_event (vq=0x7fffdd55d8a0) at hw/virtio/virtio.c:332 >> #9 0x0000555558f33677 in virtio_split_should_notify (vdev=0x62d00003a680, vq=0x7fffdd55d8a0) at hw/virtio/virtio.c:2471 >> #10 0x0000555558f1859f in virtio_should_notify (vdev=0x62d00003a680, vq=0x7fffdd55d8a0) at hw/virtio/virtio.c:2523 >> #11 0x0000555558f188cc in virtio_notify (vdev=0x62d00003a680, vq=0x7fffdd55d8a0) at hw/virtio/virtio.c:2565 >> #12 0x0000555557c2bd52 in virtio_input_handle_sts (vdev=0x62d00003a680, vq=0x7fffdd55d8a0) at hw/input/virtio-input.c:100 >> #13 0x0000555558f16df7 in virtio_queue_notify (vdev=0x62d00003a680, n=1) at hw/virtio/virtio.c:2363 >> #14 0x00005555583f45c0 in virtio_pci_notify_write (opaque=0x62d000032400, addr=7, val=0, size=1) at hw/virtio/virtio-pci.c:1369 >> #15 0x0000555558b80b04 in memory_region_write_accessor (mr=0x62d000033190, addr=7, value=0x7fffffff8eb0, size=1, shift=0, mask=255, attrs=...) at softmmu/memory.c:492 >> >> Reported-by: Qiuhao Li >> Fixes: ab223c9518e ("virtio: allow virtio-1 queue layout") >> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/302 >> BugLink: https://bugs.launchpad.net/qemu/+bug/1913510 >> Signed-off-by: Philippe Mathieu-Daudé >> --- >> hw/virtio/virtio.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c >> index 874377f37a7..04ffe5f420e 100644 >> --- a/hw/virtio/virtio.c >> +++ b/hw/virtio/virtio.c >> @@ -2255,6 +2255,7 @@ void virtio_queue_set_num(VirtIODevice *vdev, int n, int num) >> return; >> } >> vdev->vq[n].vring.num = num; >> + virtio_queue_update_rings(vdev, n); >> } >> > > Spec said: > > " > The driver MUST configure the other virtqueue fields before enabling > the virtqueue with queue_enable. > " > > So I think we should forbid the num to be changed if the virtqueue is ready? Alright. virtio_pci_common_write() doesn't report errors although.