From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:34243 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726193AbgBRInE (ORCPT ); Tue, 18 Feb 2020 03:43:04 -0500 Subject: Re: [PATCH v2 26/42] KVM: s390: protvirt: Do only reset registers that are accessible References: <20200214222658.12946-1-borntraeger@de.ibm.com> <20200214222658.12946-27-borntraeger@de.ibm.com> From: David Hildenbrand Message-ID: <9b66eb07-9755-4afe-6837-6197acd5fa09@redhat.com> Date: Tue, 18 Feb 2020 09:42:53 +0100 MIME-Version: 1.0 In-Reply-To: <20200214222658.12946-27-borntraeger@de.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: Christian Borntraeger , Janosch Frank Cc: KVM , Cornelia Huck , Thomas Huth , Ulrich Weigand , Claudio Imbrenda , linux-s390 , Michael Mueller , Vasily Gorbik , Janosch Frank On 14.02.20 23:26, Christian Borntraeger wrote: > From: Janosch Frank > > For protected VMs the hypervisor can not access guest breaking event > address, program parameter, bpbc and todpr. Do not reset those fields > as the control block does not provide access to these fields. > > Signed-off-by: Janosch Frank > [borntraeger@de.ibm.com: patch merging, splitting, fixing] > Signed-off-by: Christian Borntraeger > --- > arch/s390/kvm/kvm-s390.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index d20a7fa9d480..5b551cc73540 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -3442,14 +3442,16 @@ static void kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu) > kvm_s390_set_prefix(vcpu, 0); > kvm_s390_set_cpu_timer(vcpu, 0); > vcpu->arch.sie_block->ckc = 0; > - vcpu->arch.sie_block->todpr = 0; > memset(vcpu->arch.sie_block->gcr, 0, sizeof(vcpu->arch.sie_block->gcr)); > vcpu->arch.sie_block->gcr[0] = CR0_INITIAL_MASK; > vcpu->arch.sie_block->gcr[14] = CR14_INITIAL_MASK; > vcpu->run->s.regs.fpc = 0; > - vcpu->arch.sie_block->gbea = 1; > - vcpu->arch.sie_block->pp = 0; > - vcpu->arch.sie_block->fpf &= ~FPF_BPBC; > + if (!kvm_s390_pv_handle_cpu(vcpu)) { Shouldn't we instead check if the VM is in PV mode? (with changed lifecycle handling). Easier to understand. (side not: the name kvm_s390_pv_handle_cpu() is very confusing. I'd suggest kvm_s390_pv_cpu_get_handle(). Will reply to the other patch) > + vcpu->arch.sie_block->gbea = 1; > + vcpu->arch.sie_block->pp = 0; > + vcpu->arch.sie_block->fpf &= ~FPF_BPBC; > + vcpu->arch.sie_block->todpr = 0; > + } > } > > static void kvm_arch_vcpu_ioctl_clear_reset(struct kvm_vcpu *vcpu) > -- Thanks, David / dhildenb