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=-4.0 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 30F63C433ED for ; Wed, 28 Apr 2021 14:36:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F239F6143E for ; Wed, 28 Apr 2021 14:36:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237045AbhD1Og5 (ORCPT ); Wed, 28 Apr 2021 10:36:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:53790 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235864AbhD1Og4 (ORCPT ); Wed, 28 Apr 2021 10:36:56 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A00E86143B; Wed, 28 Apr 2021 14:36:11 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1lblIP-009s5K-EV; Wed, 28 Apr 2021 15:36:09 +0100 Date: Wed, 28 Apr 2021 15:36:08 +0100 Message-ID: <87k0omo4rr.wl-maz@kernel.org> From: Marc Zyngier To: Alexandru Elisei Cc: Alex =?UTF-8?B?QmVubsOpZQ==?= , kvm@vger.kernel.org, shashi.mallela@linaro.org, eric.auger@redhat.com, qemu-arm@nongnu.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, christoffer.dall@arm.com Subject: Re: [kvm-unit-tests PATCH v1 1/4] arm64: split its-trigger test into KVM and TCG variants In-Reply-To: <996210ae-9c63-54ff-1a65-6dbd63da74d2@arm.com> References: <20210428101844.22656-1-alex.bennee@linaro.org> <20210428101844.22656-2-alex.bennee@linaro.org> <87fszasjdg.fsf@linaro.org> <996210ae-9c63-54ff-1a65-6dbd63da74d2@arm.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: alexandru.elisei@arm.com, alex.bennee@linaro.org, kvm@vger.kernel.org, shashi.mallela@linaro.org, eric.auger@redhat.com, qemu-arm@nongnu.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, christoffer.dall@arm.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, 28 Apr 2021 15:00:15 +0100, Alexandru Elisei wrote: > > I interpret that as that an INVALL guarantees that a change is > visible, but it the change can become visible even without the > INVALL. Yes. Expecting the LPI to be delivered or not in the absence of an invalidate when its configuration has been altered is wrong. The architecture doesn't guarantee anything of the sort. > The test relies on the fact that changes to the LPI tables are not > visible *under KVM* until the INVALL command, but that's not > necessarily the case on real hardware. To match the spec, I think > the test "dev2/eventid=20 still does not trigger any LPI" should be > removed and the stats reset should take place before the > configuration for LPI 8195 is set to the default. If that's what the test expects (I haven't tried to investigate), it should be dropped completely, rather than trying to sidestep it for TCG. Thanks, M. -- Without deviation from the norm, progress is not possible.