From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:58026 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726225AbgBRJ2S (ORCPT ); Tue, 18 Feb 2020 04:28:18 -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> <9b66eb07-9755-4afe-6837-6197acd5fa09@redhat.com> <1893c520-165d-6006-47cd-0e7498f39188@de.ibm.com> From: David Hildenbrand Message-ID: <88acfaf1-b8d1-da77-79b1-52be912fd53b@redhat.com> Date: Tue, 18 Feb 2020 10:28:08 +0100 MIME-Version: 1.0 In-Reply-To: <1893c520-165d-6006-47cd-0e7498f39188@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 18.02.20 10:20, Christian Borntraeger wrote: > > > On 18.02.20 09:42, David Hildenbrand wrote: >> 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. > > No. these ioctls are under the vcpu->mutex, so I am going to compare > against the per cpu variant. > > I will use kvm_s390_pv_cpu_is_protected instead to have the lockdep assertion. That's what I meant! -- Thanks, David / dhildenb