From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752096AbdJFNNn (ORCPT ); Fri, 6 Oct 2017 09:13:43 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:59634 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750950AbdJFNNl (ORCPT ); Fri, 6 Oct 2017 09:13:41 -0400 Subject: Re: [PATCH v1 2/2] kvm: arm64: handle single-step of userspace mmio 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: Russell King , Catalin Marinas , Will Deacon , open list References: <20171006113921.24880-1-alex.bennee@linaro.org> <20171006113921.24880-3-alex.bennee@linaro.org> From: Julien Thierry Message-ID: Date: Fri, 6 Oct 2017 14:13:38 +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: <20171006113921.24880-3-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: > The system state of KVM when using userspace emulation is not complete > until we return into KVM_RUN. To handle mmio related updates we wait > until they have been committed and then schedule our KVM_EXIT_DEBUG. > > I've introduced a new function kvm_arm_maybe_return_debug() to wrap up > the differences between arm/arm64 which is currently null for arm. > > Signed-off-by: Alex Bennée > --- > arch/arm/include/asm/kvm_host.h | 2 ++ > arch/arm64/include/asm/kvm_host.h | 1 + > arch/arm64/kvm/debug.c | 21 +++++++++++++++++++++ > arch/arm64/kvm/handle_exit.c | 9 +++------ > virt/kvm/arm/arm.c | 2 +- > virt/kvm/arm/mmio.c | 3 ++- > 6 files changed, 30 insertions(+), 8 deletions(-) > > diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h > index 4a879f6ff13b..aec943f6d123 100644 > --- a/arch/arm/include/asm/kvm_host.h > +++ b/arch/arm/include/asm/kvm_host.h > @@ -285,6 +285,8 @@ static inline void kvm_arm_init_debug(void) {} > static inline void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) {} > static inline void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) {} > static inline void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu) {} > +static inline int kvm_arm_maybe_return_debug(struct kvm_vcpu *vcpu, > + struct kvm_run *run) {} > This function should return 1. > int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu, > struct kvm_device_attr *attr); > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index e923b58606e2..fa67d21662f6 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -369,6 +369,7 @@ void kvm_arm_init_debug(void); > void kvm_arm_setup_debug(struct kvm_vcpu *vcpu); > void kvm_arm_clear_debug(struct kvm_vcpu *vcpu); > void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu); > +int kvm_arm_maybe_return_debug(struct kvm_vcpu *vcpu, struct kvm_run *run); I feel the name could be a little bit more explicit: kvm_arm_trap_need_step_debug, kvm_arm_trap_step_return_debug, kvm_arm_trap_need_return_debug. At least, I think it would be nice that the name reflect that this check is meant for emulated instructions. Otherwise: Reviewed-by: Julien Thierry Thanks, -- Julien Thierry