diff mbox series

[GIT,PULL,24/36] KVM: s390: protvirt: Do only reset registers that are accessible

Message ID 20200309085126.3334302-25-borntraeger@de.ibm.com (mailing list archive)
State New, archived
Headers show
Series [GIT,PULL,01/36] s390/protvirt: introduce host side setup | expand

Commit Message

Christian Borntraeger March 9, 2020, 8:51 a.m. UTC 
From: Janosch Frank <frankja@linux.ibm.com>

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 <frankja@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
[borntraeger@de.ibm.com: patch merging, splitting, fixing]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 arch/s390/kvm/kvm-s390.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 797b4031ed4d..1c7bbc2497a2 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -3502,14 +3502,21 @@  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;
+	/*
+	 * Do not reset these registers in the protected case, as some of
+	 * them are overlayed and they are not accessible in this case
+	 * anyway.
+	 */
+	if (!kvm_s390_pv_cpu_is_protected(vcpu)) {
+		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)