From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Aneesh Kumar K.V" Subject: Re: [PATCH V4] POWERPC: BOOK3S: KVM: Use the saved dar value and generic make_dsisr Date: Mon, 05 May 2014 20:33:11 +0530 Message-ID: <87d2fs9sk0.fsf@linux.vnet.ibm.com> References: <1399224075-18041-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <536773C2.1070502@suse.de> <87tx949u9d.fsf@linux.vnet.ibm.com> <5367A39D.9080709@suse.de> Mime-Version: 1.0 Content-Type: text/plain Cc: Benjamin Herrenschmidt , Paul Mackerras , linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org, kvm@vger.kernel.org To: Olof Johansson , Alexander Graf Return-path: In-Reply-To: Sender: kvm-ppc-owner@vger.kernel.org List-Id: kvm.vger.kernel.org Olof Johansson writes: > 2014-05-05 7:43 GMT-07:00 Alexander Graf : > >> On 05/05/2014 04:26 PM, Aneesh Kumar K.V wrote: >> >>> Alexander Graf writes: >>> >>> On 05/04/2014 07:21 PM, Aneesh Kumar K.V wrote: >>>> >>>>> Although it's optional IBM POWER cpus always had DAR value set on >>>>> alignment interrupt. So don't try to compute these values. >>>>> >>>>> Signed-off-by: Aneesh Kumar K.V >>>>> --- >>>>> Changes from V3: >>>>> * Use make_dsisr instead of checking feature flag to decide whether to >>>>> use >>>>> saved dsisr or not >>>>> >>>>> .... >>> >>> ulong kvmppc_alignment_dar(struct kvm_vcpu *vcpu, unsigned int inst) >>>>> { >>>>> +#ifdef CONFIG_PPC_BOOK3S_64 >>>>> + return vcpu->arch.fault_dar; >>>>> >>>> How about PA6T and G5s? >>>> >>>> >>>> Paul mentioned that BOOK3S always had DAR value set on alignment >>> interrupt. And the patch is to enable/collect correct DAR value when >>> running with Little Endian PR guest. Now to limit the impact and to >>> enable Little Endian PR guest, I ended up doing the conditional code >>> only for book3s 64 for which we know for sure that we set DAR value. >>> >> >> Yes, and I'm asking whether we know that this statement holds true for >> PA6T and G5 chips which I wouldn't consider IBM POWER. Since the G5 is at >> least developed by IBM, I'd assume its semantics here are similar to >> POWER4, but for PA6T I wouldn't be so sure. >> >> > Thanks for looking out for us, obviously IBM doesn't (based on the reply a > minute ago). The reason I deferred the question to Paul is really because I don't know enough about PA6T and G5 to comment. I intentionally restricted the changes to BOOK3S_64 because I wanted to make sure I don't break anything else. It is in no way to hint that others don't care. -aneesh