From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Thierry Subject: Re: [PATCH v1 1/2] KVM: arm64: handle single-stepping trapped instructions Date: Fri, 6 Oct 2017 14:15:21 +0100 Message-ID: References: <20171006113921.24880-1-alex.bennee@linaro.org> <20171006113921.24880-2-alex.bennee@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20171006113921.24880-2-alex.bennee@linaro.org> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org 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 List-Id: kvmarm@lists.cs.columbia.edu 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