On 11/03/15 13:34, Paolo Bonzini wrote: > > > On 03/11/2015 02:14, Laszlo Ersek wrote: >> Anyway, with the following host kernel change, the AP startup problem >> goes away (tested on top of v4.3): >> >>>> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c >>>> index 9a9a198..4f978ad 100644 >>>> --- a/arch/x86/kvm/x86.c >>>> +++ b/arch/x86/kvm/x86.c >>>> @@ -622,7 +622,8 @@ int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long >>>> cr0) >>>> if ((cr0 ^ old_cr0) & update_bits) >>>> kvm_mmu_reset_context(vcpu); >>>> >>>> - if ((cr0 ^ old_cr0) & X86_CR0_CD) >>>> + if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_CD_NW_CLEARED) && >>>> + (cr0 ^ old_cr0) & X86_CR0_CD) >>>> kvm_zap_gfn_range(vcpu->kvm, 0, ~0ULL); >>>> >>>> return 0; >> (Honestly I just imitated fb279950ba here; I'm not making any better >> argument for this diff. But, independently, I wonder why this hunk >> didn't have the noncoherent DMA check either, originally.) > > Great job. I look forward to the testing results. > > It should also have the noncoherent DMA check, in fact, though that's > just an optimization and it would have masked the bug on your system.
Thank you! I'll wait for Janusz's results, and if stuff works, I'll post the patch with the update you're suggesting (zap only if the guest has noncoherent DMA and lacks the quirk). Laszlo > > Thanks, > > Paolo > >> Janusz, could you rebuild your host kernel with this patch, and share >> the results? (I'm also attaching the same as a formatted patch, so you >> can apply it with "git am" easily.) > _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
