From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Graf Subject: Re: [PATCH V4] POWERPC: BOOK3S: KVM: Use the saved dar value and generic make_dsisr Date: Tue, 06 May 2014 16:21:16 +0200 Message-ID: <5368EFDC.7020701@suse.de> References: <1399224075-18041-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <536773C2.1070502@suse.de> <20140506004133.GA12595@iris.ozlabs.ibm.com> <536887EF.2070201@suse.de> <87zjivq9mb.fsf@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Paul Mackerras , benh@kernel.crashing.org, linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org, kvm@vger.kernel.org To: "Aneesh Kumar K.V" Return-path: In-Reply-To: <87zjivq9mb.fsf@linux.vnet.ibm.com> Sender: kvm-ppc-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 05/06/2014 04:12 PM, Aneesh Kumar K.V wrote: > Alexander Graf writes: > >> On 06.05.14 02:41, Paul Mackerras wrote: >>> On Mon, May 05, 2014 at 01:19:30PM +0200, Alexander Graf wrote: >>>> On 05/04/2014 07:21 PM, Aneesh Kumar K.V wrote: >>>>> +#ifdef CONFIG_PPC_BOOK3S_64 >>>>> + return vcpu->arch.fault_dar; >>>> How about PA6T and G5s? >>> G5 sets DAR on an alignment interrupt. >>> >>> As for PA6T, I don't know for sure, but if it doesn't, ordinary >>> alignment interrupts wouldn't be handled properly, since the code in >>> arch/powerpc/kernel/align.c assumes DAR contains the address being >>> accessed on all PowerPC CPUs. >> Now that's a good point. If we simply behave like Linux, I'm fine. This >> definitely deserves a comment on the #ifdef in the code. > > How about ? > > #ifdef CONFIG_PPC_BOOK3S_64 > /* > * Linux always expect a valid dar as per alignment > * interrupt handling code (fix_alignment()). Don't compute the dar > * value here, instead used the saved dar value. Right now we restrict > * this only for BOOK3S-64. > */ /* Linux's fix_alignment() assumes that DAR is valid, so can we */ Alex > return vcpu->arch.fault_dar; > #else > > > -aneesh >