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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 81DE0C43331 for ; Fri, 3 Apr 2020 12:54:14 +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 4CBA020659 for ; Fri, 3 Apr 2020 12:54:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="CEn1O+5e" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4CBA020659 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:55034 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jKLpt-0007hA-Fz for qemu-devel@archiver.kernel.org; Fri, 03 Apr 2020 08:54:13 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:56542) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jKLp8-0006o6-98 for qemu-devel@nongnu.org; Fri, 03 Apr 2020 08:53:28 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jKLp6-0006HS-PS for qemu-devel@nongnu.org; Fri, 03 Apr 2020 08:53:25 -0400 Received: from mail-ot1-x341.google.com ([2607:f8b0:4864:20::341]:41427) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1jKLp6-0006Gz-JB for qemu-devel@nongnu.org; Fri, 03 Apr 2020 08:53:24 -0400 Received: by mail-ot1-x341.google.com with SMTP id f52so7080633otf.8 for ; Fri, 03 Apr 2020 05:53:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=nrlvADXxGbT+s6lAZobU7zynwUwqGGeUpsEGsLb7j8I=; b=CEn1O+5eaZ8zjImeCZm8YuxwZnuiygnUjAIhsf2opiY6o+o/93GaxYw/mP09dAgtZI THQYxp64FJO6SF1Ct3jz12M6Bz7staXYDOzhHrcI8V70YvHiwkBO38/4hJmkE6Nc3cku a8zxGtrDj/U8cm1Yz51vqScKrfFjFulRL7a35IVb3UYPar8P5bFKWtSkufcxWpMHOc9g GxPru1tsxQNG/7yOxtAm9uj+iq+enk8T0I0CQyM+ASgBFDL8C+Cyzwnq1lVJlL+Iy8FE cxr173jrQPp459/ej2HxX9NYI0wjEfR8OkMAwrspNU9EAHsu0eH3xgFfshH2QxWvnAKr qZDQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=nrlvADXxGbT+s6lAZobU7zynwUwqGGeUpsEGsLb7j8I=; b=D1stdFWb5Sp4kLfIxiDiGBtfGSiVTdyNF80HthZdOnsYC71TepGT+O6LeMtaahHNdS Iiig56SIUxCS1kPUSygiokcDY38GTZiXfqtj7isjffPV3Q3+Djk/CJWDeQ+rZkv1WHK+ ubB5DDR8YjzvT3jGFvo0zT4Doj+6NwzsxOkPn1HjZPOzqdiuBKEf3m+lsorOX/8aC79s P+oxuhDcA8hYgCWwhAWJfQ9M+tgCL3IB9E4DdIU5lXYFm2hCnAHvsw7hJp5sTHQDybgu iPvsGlgh7KE7cdHvFldXL/SKLPY5Cett6KWUgfcLNqlGgAyVNoSh2fKKQVuoe1DdbiFD qouQ== X-Gm-Message-State: AGi0Puaxf05Ib5LndXNMQa5YNyMSpADkECc90vijLBiOMlJhuDIGYTNi BqJSUFL5ugC/xhpN2HTbOHXHMVKVUt+cPyTGjXVq9A== X-Google-Smtp-Source: APiQypLbjH41uZGse9rWQFFa8/m8YD4Q84Sn2aKbNTXszPyT9itlCOYT4RQ8zU1KlhSY310yCgWIjh9wZ8ZWxCyeEZY= X-Received: by 2002:a9d:1920:: with SMTP id j32mr5886060ota.221.1585918403126; Fri, 03 Apr 2020 05:53:23 -0700 (PDT) MIME-Version: 1.0 References: <20200403165657.20566-1-yan.y.zhao@intel.com> In-Reply-To: <20200403165657.20566-1-yan.y.zhao@intel.com> From: Peter Maydell Date: Fri, 3 Apr 2020 13:53:12 +0100 Message-ID: Subject: Re: [PATCH v2 0/3] drop writes to read-only ram device & vfio regions To: Yan Zhao Content-Type: text/plain; charset="UTF-8" X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2607:f8b0:4864:20::341 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: Paolo Bonzini , Alex Williamson , =?UTF-8?Q?Philippe_Mathieu=2DDaud=C3=A9?= , QEMU Developers , xin.zeng@intel.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, 3 Apr 2020 at 09:13, Yan Zhao wrote: > > patch 1 modifies handler of ram device memory regions to drop guest writes > to read-only ram device memory regions > > patch 2 modifies handler of non-mmap'd read-only vfio regions to drop guest > writes to those regions > > patch 3 let mmap'd read-only vfio regions be able to generate vmexit for > guest write. so, without patch 1, host qemu would crash on guest write to > this read-only region. with patch 1, host qemu would drop the writes. Just FYI, there seems to be a minor clock or timezone issue with however you're sending these emails: the Date header you sent reads "Date: Fri, 3 Apr 2020 16:56:57 +0000" but that time in the UTC +0000 timezone is (as I write this) still several hours in the future. This isn't a big deal but you probably want to look into fixing it. (Noticed because the wrong-date makes your patches stick to the top of the https://patchew.org/QEMU/ list even after other patches arrive after them.) thanks -- PMM