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=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,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 29410C433E0 for ; Tue, 26 Jan 2021 17:07:40 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 CF3F3229C9 for ; Tue, 26 Jan 2021 17:07:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CF3F3229C9 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.75354.135659 (Exim 4.92) (envelope-from ) id 1l4RoM-00019A-Gq; Tue, 26 Jan 2021 17:07:26 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 75354.135659; Tue, 26 Jan 2021 17:07:26 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1l4RoM-000193-Di; Tue, 26 Jan 2021 17:07:26 +0000 Received: by outflank-mailman (input) for mailman id 75354; Tue, 26 Jan 2021 17:07:24 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1l4RoK-00018x-QJ for xen-devel@lists.xenproject.org; Tue, 26 Jan 2021 17:07:24 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id d360b26e-3326-4be9-bf3d-dc6784222cd2; Tue, 26 Jan 2021 17:07:23 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id B4E4CAB92; Tue, 26 Jan 2021 17:07:22 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: d360b26e-3326-4be9-bf3d-dc6784222cd2 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1611680842; h=from:from:reply-to: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=12zF1yxqIS+nqv4aRBVRF0QF7ZcuJMMaeM4a5urbkqg=; b=h3kKwv6R/k49jfMQfdfiKRBc6MnkYtsNSJryVAT5r3uYWOuz2rFLtuH+63xXabtvHzCKUF 4DYsHpzXoDE62Agh+Mr96+RhldO1Vb2R6xqdutFSgFC5ME2d4GUuxH8/Vi5gz5n5kHiKWC iRma9M/vajyLAKZzvwPwD0d70DMldrc= Subject: Re: [PATCH v3 0/6] x86/intr: HVM guest interrupt handling fixes/cleanup To: Ian Jackson , Roger Pau Monne Cc: Andrew Cooper , Wei Liu , Kevin Tian , Paul Durrant , xen-devel@lists.xenproject.org References: <20210126134521.25784-1-roger.pau@citrix.com> From: Jan Beulich Message-ID: Date: Tue, 26 Jan 2021 18:07:23 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.1 MIME-Version: 1.0 In-Reply-To: <20210126134521.25784-1-roger.pau@citrix.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Ian, On 26.01.2021 14:45, Roger Pau Monne wrote: > The following series aims to fix some shortcomings of guest interrupt > handling when using passthrough devices. The first 5 patches are > bugfixes or cleanups, which I think should solve the issue(s) that > caused the dpci EOI timer to be introduced. However neither me nor > others seem to be able to reproduce the original issue, so it's hard to > tell. > > It's my opinion that we should remove the timer and see what explodes > (if anything). That's the only way we will be able to figure out what > the original issue was, and how to fix it without introducing yet > another per-guest-irq related timer. > > Thanks, Roger. > > Roger Pau Monne (6): > x86/vioapic: top word redir entry writes don't trigger interrupts > x86/vioapic: issue EOI to dpci when switching pin to edge trigger mode > x86/vpic: force int output to low when in init mode > x86/vpic: don't trigger unmask event until end of init > x86/vpic: issue dpci EOI for cleared pins at ICW1 > x86/dpci: remove the dpci EOI timer while half of this series was still submitted in time, I'd still like to raise the question of including part or all of it in 4.15. In particular the last change is one which I would prefer to see happen early in a release cycle. Risk assessment is pretty difficult, I'm afraid (Roger can correct me here), as at least some of what gets adjusted are cases we don't normally expect to be exercised. (FAOD patch 5 is still pending a R-b tag.) Roger, if you could give your own judgement on which of the changes you would view as more or less clear 4.15 candidates, this may help Ian take a decision. Jan