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=-5.5 required=3.0 tests=MAILING_LIST_MULTI, SIGNED_OFF_BY,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 7AF3DC31E40 for ; Tue, 6 Aug 2019 08:35:57 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 09E90206A2 for ; Tue, 6 Aug 2019 08:35:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 09E90206A2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 64E904A531; Tue, 6 Aug 2019 04:35:56 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id W0k6Mqa8cPUk; Tue, 6 Aug 2019 04:35:55 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 423E34A54A; Tue, 6 Aug 2019 04:35:55 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 71C444A531 for ; Tue, 6 Aug 2019 04:35:54 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id WYjZ4pnV9Ot0 for ; Tue, 6 Aug 2019 04:35:53 -0400 (EDT) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 6A9734A4E6 for ; Tue, 6 Aug 2019 04:35:53 -0400 (EDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E8EB3337; Tue, 6 Aug 2019 01:35:52 -0700 (PDT) Received: from [10.1.197.61] (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DF5A73F706; Tue, 6 Aug 2019 01:35:51 -0700 (PDT) Subject: Re: [PATCH 1/2] KVM: arm64: Don't write junk to sysregs on reset To: Zenghui Yu , kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org References: <20190805121555.130897-1-maz@kernel.org> <20190805121555.130897-2-maz@kernel.org> <01b74492-c59f-dfd9-e439-752e6b1c53dc@huawei.com> From: Marc Zyngier Organization: Approximate Message-ID: <7b36f1dd-e44f-af75-0e51-8f6e705e81f6@kernel.org> Date: Tue, 6 Aug 2019 09:35:50 +0100 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <01b74492-c59f-dfd9-e439-752e6b1c53dc@huawei.com> Content-Language: en-US X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On 06/08/2019 07:29, Zenghui Yu wrote: > Hi Marc, > > On 2019/8/5 20:15, Marc Zyngier wrote: >> At the moment, the way we reset system registers is mildly insane: >> We write junk to them, call the reset functions, and then check that >> we have something else in them. >> >> The "fun" thing is that this can happen while the guest is running >> (PSCI, for example). If anything in KVM has to evaluate the state >> of a system register while junk is in there, bad thing may happen. >> >> Let's stop doing that. Instead, we track that we have called a >> reset function for that register, and assume that the reset >> function has done something. This requires fixing a couple of >> sysreg refinition in the trap table. >> >> In the end, the very need of this reset check is pretty dubious, >> as it doesn't check everything (a lot of the sysregs leave outside of >> the sys_regs[] array). It may well be axed in the near future. >> >> Signed-off-by: Marc Zyngier > > (Regardless of whether this check is needed or not,) I tested this patch > with kvm-unit-tests: > > for i in {1..100}; do QEMU=/path/to/qemu-system-aarch64 accel=kvm > arch=arm64 ./run_tests.sh; done > > And all the tests passed! Great! Can I take this as a 'Tested-by:'? Thanks, M. -- Jazz is not dead, it just smells funny... _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm