[PATCH v4 24/36] KVM: s390: protvirt: Do only reset registers that are accessible

Christian Borntraeger
2020-02-24T11:41:16Z

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: 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 | 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 6ab4c88f2e1d..c734e89235f9 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -3499,14 +3499,16 @@ 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_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)
--
2.25.0