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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C986AC00140 for ; Tue, 9 Aug 2022 00:34:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244729AbiHIAee (ORCPT ); Mon, 8 Aug 2022 20:34:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36776 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244690AbiHIAec (ORCPT ); Mon, 8 Aug 2022 20:34:32 -0400 Received: from mail-pf1-x42c.google.com (mail-pf1-x42c.google.com [IPv6:2607:f8b0:4864:20::42c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C29C19C17 for ; Mon, 8 Aug 2022 17:34:29 -0700 (PDT) Received: by mail-pf1-x42c.google.com with SMTP id f28so9500186pfk.1 for ; Mon, 08 Aug 2022 17:34:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc; bh=6C9ArOHrYaAILM0KZ4kBvP+nUNIqPYA+uHHXGsdeawA=; b=P7WoNvVpS3okL4YI3o5uz9544qztcUEr1d+LExJylyHYHQZklqf4z8S2h44Nc5Rqre qNENlB9cRxxMXJSQLaVPA0ibUYmjuaUJxWHlEQg7XuwMMHiCKjfD800w6HWCWFW97jG/ ipFPUBO9QJxq33W2C+jnkG+6srCtqkLKyelalaRu86/MhVjtgfzdbu2VciP74lTDXia9 tcw8AMqrymPwqEMiio9pnZkOQSBjcxgOGJcbHeqKSwXLqqqiqfSq/J4xmKGbmk8N1IHN DNkD36mh4S1SoQfCQvhfZ0UTfN6afTiLMOCwOk8MufKvKKOHJeMYrKKHKZ0GG2/hN1yX s3pw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc; bh=6C9ArOHrYaAILM0KZ4kBvP+nUNIqPYA+uHHXGsdeawA=; b=b+CXnkGr55ZVVoTqmtTjIz6O+Y3hOvrUTQOn4oIWYR1jJDMpTdsAw1Fdd+Pb/wyjPZ YiERBmU0uSREQ7LhGBoRJRheTfbFo2dKcVDLt7YNTjijc2jNZ5RiDvzznMMHwVdwHTiR jwby6XT1/s6KTp5m2GxgaXNJxI1cQzaela4tZ/8UZGqOOlB1hgH4taLurfsvkoN42eZ5 bZaN7QLVJxx1VN82gxqbFFgv65xCGBKQ3f0geeS/kQLt9R0kZa2GALw2somDrWHgAv1l KWyp99z+pBFUKvNbyjPS2i6ublZ12ivogv/87NEGSxkUw74GhieNB9fnU01QZORs6j8D 1Dvw== X-Gm-Message-State: ACgBeo1/b2+IWOV5ZwxYg9PIShVPxvQR9UPRGMNShtVjwtLJ3+BJJFIq ZRVAvcAiLO32Dm1uIrEwNvjMHw== X-Google-Smtp-Source: AA6agR4Gz5g5vG/l/tZyqtSjI3vc8zXtknoeHx9hIKW+yKI0a0eBaFzsrwCevFsok5EYWzWVjhoKBA== X-Received: by 2002:a63:ea11:0:b0:41d:9296:21e6 with SMTP id c17-20020a63ea11000000b0041d929621e6mr4696671pgi.603.1660005268964; Mon, 08 Aug 2022 17:34:28 -0700 (PDT) Received: from google.com (7.104.168.34.bc.googleusercontent.com. [34.168.104.7]) by smtp.gmail.com with ESMTPSA id o13-20020a17090a420d00b001f260b1954bsm8740402pjg.13.2022.08.08.17.34.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 08 Aug 2022 17:34:28 -0700 (PDT) Date: Tue, 9 Aug 2022 00:34:24 +0000 From: Sean Christopherson To: Coleman Dietsch Cc: kvm@vger.kernel.org, Paolo Bonzini , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H . Peter Anvin" , linux-kernel@vger.kernel.org, skhan@linuxfoundation.org, Pavel Skripkin , linux-kernel-mentees@lists.linuxfoundation.org, stable@vger.kernel.org, syzbot+e54f930ed78eb0f85281@syzkaller.appspotmail.com Subject: Re: [PATCH v3 2/2] KVM: x86/xen: Stop Xen timer before changing IRQ Message-ID: References: <20220808190607.323899-2-dietschc@csp.edu> <20220808190607.323899-3-dietschc@csp.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220808190607.323899-3-dietschc@csp.edu> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Mon, Aug 08, 2022, Coleman Dietsch wrote: > Stop Xen timer (if it's running) prior to changing the IRQ vector and > potentially (re)starting the timer. Changing the IRQ vector while the > timer is still running can result in KVM injecting a garbage event, e.g. > vm_xen_inject_timer_irqs() could see a non-zero xen.timer_pending from > a previous timer but inject the new xen.timer_virq. > > Fixes: 536395260582 ("KVM: x86/xen: handle PV timers oneshot mode") > Cc: stable@vger.kernel.org > Link: https://syzkaller.appspot.com/bug?id=8234a9dfd3aafbf092cc5a7cd9842e3ebc45fc42 > Reported-by: syzbot+e54f930ed78eb0f85281@syzkaller.appspotmail.com > Signed-off-by: Coleman Dietsch > --- Reviewed-by: Sean Christopherson