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 4049DECAAD3 for ; Mon, 19 Sep 2022 09:37:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230175AbiISJg7 (ORCPT ); Mon, 19 Sep 2022 05:36:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55480 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229983AbiISJgs (ORCPT ); Mon, 19 Sep 2022 05:36:48 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 99DFF1D326 for ; Mon, 19 Sep 2022 02:36:47 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E1C15618F4 for ; Mon, 19 Sep 2022 09:36:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 48EC1C433D6; Mon, 19 Sep 2022 09:36:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1663580206; bh=gHaHELOcgDC33nJSx8H/UYvtibzcoOuoxqqzCmth6cw=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=dhGr/CeP7Oh6y7j98PxpsrujeFhZ6MKDylijKD7i1dx6LIBncP5rT+LC/mIdlzwfe SPzFUtuixMiSE31X/B+4fV2CcUkKLOSEaSx3PBN0Klr3b/4g8eQGfylWMlugrXqqLi UAhd4Z9p/xEfeADk4wTKeN5Jid/yBHphOu0wTb4CLF6Op772J2qU6CxYU2yNYT9Lxi Vj6KszWldc0vHsD3kNUCgqdgTxFAW/wDMOuEpAtyttkwBSsEWPBjk3SUjlJfCAMX/E 3mTlcP8U/WXl8r0Il5M5kNjE2rSfLZ7c6W1xgMiwHJ+4h9UHaXGBNbAYKQ99Zlrqka HBbWFQvc1b9Ng== Received: from 185-176-101-241.host.sccbroadband.ie ([185.176.101.241] helo=wait-a-minute.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1oaDCm-00B3zn-0M; Mon, 19 Sep 2022 10:36:44 +0100 Date: Mon, 19 Sep 2022 10:36:43 +0100 Message-ID: <87bkrbln84.wl-maz@kernel.org> From: Marc Zyngier To: Reiji Watanabe Cc: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, James Morse , Alexandru Elisei , Suzuki K Poulose , Paolo Bonzini , Ricardo Koller , Oliver Upton , Jing Zhang , Raghavendra Rao Anata Subject: Re: [PATCH v2 4/4] KVM: arm64: selftests: Add a test case for KVM_GUESTDBG_SINGLESTEP In-Reply-To: <20220917010600.532642-5-reijiw@google.com> References: <20220917010600.532642-1-reijiw@google.com> <20220917010600.532642-5-reijiw@google.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: 185.176.101.241 X-SA-Exim-Rcpt-To: reijiw@google.com, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, james.morse@arm.com, alexandru.elisei@arm.com, suzuki.poulose@arm.com, pbonzini@redhat.com, ricarkol@google.com, oliver.upton@linux.dev, jingzhangos@google.com, rananta@google.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 Sat, 17 Sep 2022 02:06:00 +0100, Reiji Watanabe wrote: > > Add a test case for KVM_GUESTDBG_SINGLESTEP to the debug-exceptions test. > The test enables single-step execution from userspace, and check if the > exit to userspace occurs for each instruction that is stepped. > Set the default number of the test iterations to a number of iterations > sufficient to always reproduce the problem that the previous patch fixes > on an Ampere Altra machine. A possibly more aggressive version of this test would be to force a (short lived) timer to fire on the same CPU, forcing an exit. This should hopefully result in a more predictable way to trigger the issue. But that's a reasonable test as a start. Thanks, M. -- Without deviation from the norm, progress is not possible.