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=-12.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,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 16CB3C433DB for ; Tue, 23 Feb 2021 09:27:37 +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 A31A064DE9 for ; Tue, 23 Feb 2021 09:27:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A31A064DE9 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=citrix.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.88658.166813 (Exim 4.92) (envelope-from ) id 1lETyY-0005Dw-OT; Tue, 23 Feb 2021 09:27:26 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 88658.166813; Tue, 23 Feb 2021 09:27:26 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lETyY-0005Dp-KE; Tue, 23 Feb 2021 09:27:26 +0000 Received: by outflank-mailman (input) for mailman id 88658; Tue, 23 Feb 2021 09:27:26 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lETyY-0005Di-1L for xen-devel@lists.xenproject.org; Tue, 23 Feb 2021 09:27:26 +0000 Received: from esa2.hc3370-68.iphmx.com (unknown [216.71.145.153]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id b7be0412-0d7f-41ab-904c-9595b6b1c5e7; Tue, 23 Feb 2021 09:27:24 +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: b7be0412-0d7f-41ab-904c-9595b6b1c5e7 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1614072444; h=subject:to:cc:references:from:message-id:date: mime-version:in-reply-to:content-transfer-encoding; bh=elkiEyw/x+p4Mzp82r1PU6gv61RdX2VzYrI0EcXBgiE=; b=As6UcGJK6bypwN1OEdqFVkppT+JLta/yNR3b8tIx/9GSesWdEfA5AD4W uQm/dwo/4rwPoGqnrQE0/8ZFpKcHCGD09eyB5yNpL+MpXGka4dLgX34l5 qc/lDpvFo8Ep8sb/UQY1IQ7426bp4SzyRIdWZIm45QELvLh9jupohnyJ2 k=; Authentication-Results: esa2.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none IronPort-SDR: r+v2a+pAcLkDXkvtq+LmVooxIXl9Yi1OFFOUqXQVl7OPoBQ/F1wR39/aL26u9L65xhinLzNmzD IkM5sCEPjCfpmf9zzrGZh3QpaL3V+Q5QWq+TyAXm2mwA4eOOjMRr16+CUyDyewQEuJfODY5MbN wFE9A627oR/uIUpbMpS8JESAt4rQ0ZHYTeHTVyqMz0CtZl4/Eu4i5+crISP29PhiJDm9wpiP9E 8gWCC28x4GMlXuCPvXKvUr/Ak6638Jo/O1FCh/AH4ug72oJzWRID7AuaDHkXLapWfmKY7SqObb oGk= X-SBRS: 5.1 X-MesageID: 37826829 X-Ironport-Server: esa2.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.81,199,1610427600"; d="scan'208";a="37826829" Subject: Re: [PATCH v3 2/8] xen/events: don't unmask an event channel when an eoi is pending To: Juergen Gross , , CC: Boris Ostrovsky , Stefano Stabellini , , Julien Grall References: <20210219154030.10892-1-jgross@suse.com> <20210219154030.10892-3-jgross@suse.com> From: Ross Lagerwall Message-ID: Date: Tue, 23 Feb 2021 09:26:49 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <20210219154030.10892-3-jgross@suse.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit On 2021-02-19 15:40, Juergen Gross wrote: > An event channel should be kept masked when an eoi is pending for it. > When being migrated to another cpu it might be unmasked, though. > > In order to avoid this keep three different flags for each event channel > to be able to distinguish "normal" masking/unmasking from eoi related > masking/unmasking and temporary masking. The event channel should only > be able to generate an interrupt if all flags are cleared. > > Cc: stable@vger.kernel.org > Fixes: 54c9de89895e0a36047 ("xen/events: add a new late EOI evtchn framework") > Reported-by: Julien Grall > Signed-off-by: Juergen Gross I tested this patch series backported to a 4.19 kernel and found that when doing a reboot loop of Windows with PV drivers, occasionally it will end up in a state with some event channels pending and masked in dom0 which breaks networking in the guest. The issue seems to have been introduced with this patch, though at first glance it appears correct. I haven't yet looked into why it is happening. Have you seen anything like this with this patch? Thanks, Ross