[PATCH v3 25/37] KVM: s390: protvirt: Do only reset registers that are accessible

Christian Borntraeger
2020-02-20T10:40:30Z

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>
[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 436778d3dc14..db28a717a622 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -3478,14 +3478,16 @@ 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