From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752022AbdJFNPZ (ORCPT ); Fri, 6 Oct 2017 09:15:25 -0400 Received: from foss.arm.com ([217.140.101.70]:59708 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750950AbdJFNPY (ORCPT ); Fri, 6 Oct 2017 09:15:24 -0400 Subject: Re: [PATCH v1 1/2] KVM: arm64: handle single-stepping trapped instructions To: =?UTF-8?Q?Alex_Benn=c3=a9e?= , kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, christoffer.dall@linaro.org, marc.zyngier@arm.com Cc: Catalin Marinas , Will Deacon , open list References: <20171006113921.24880-1-alex.bennee@linaro.org> <20171006113921.24880-2-alex.bennee@linaro.org> From: Julien Thierry Message-ID: Date: Fri, 6 Oct 2017 14:15:21 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20171006113921.24880-2-alex.bennee@linaro.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/10/17 12:39, Alex Bennée wrote: > If we are using guest debug to single-step the guest we need to ensure > we exit after emulating the instruction. This only affects > instructions completely emulated by the kernel. For userspace emulated > instructions we need to exit and return to complete the emulation. > > We fake debug.arch.hsr to contain ESR_ELx_EC_SOFTSTP_LOW so QEMU knows > it was a single-step event (and without altering the userspace ABI). > > Signed-off-by: Alex Bennée Reviewed-by: Julien Thierry Thanks, -- Julien Thierry