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[v4,30/36] KVM: s390: protvirt: Mask PSW interrupt bits for interception 104 and 112

Message ID 20200224114107.4646-31-borntraeger@de.ibm.com (mailing list archive)
State New, archived
Headers show
Series KVM: s390: Add support for protected VMs | expand

Commit Message

Christian Borntraeger Feb. 24, 2020, 11:41 a.m. UTC 
From: Janosch Frank <frankja@linux.ibm.com>

We're not allowed to inject interrupts on intercepts that leave the
guest state in an "in-between" state where the next SIE entry will do a
continuation, namely secure instruction interception (104) and secure
prefix interception (112).
As our PSW is just a copy of the real one that will be replaced on the
next exit, we can mask out the interrupt bits in the PSW to make sure
that we do not inject anything.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.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 | 11 +++++++++++
 1 file changed, 11 insertions(+)
diff mbox series

Patch

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 9c0ab66128fd..c9045de90081 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -4085,6 +4085,7 @@  static int vcpu_post_run(struct kvm_vcpu *vcpu, int exit_reason)
 	return vcpu_post_run_fault_in_sie(vcpu);
 }
 
+#define PSW_INT_MASK (PSW_MASK_EXT | PSW_MASK_IO | PSW_MASK_MCHECK)
 static int __vcpu_run(struct kvm_vcpu *vcpu)
 {
 	int rc, exit_reason;
@@ -4121,6 +4122,16 @@  static int __vcpu_run(struct kvm_vcpu *vcpu)
 			memcpy(vcpu->run->s.regs.gprs,
 			       sie_page->pv_grregs,
 			       sizeof(sie_page->pv_grregs));
+			/*
+			 * We're not allowed to inject interrupts on intercepts
+			 * that leave the guest state in an "in-between" state
+			 * where the next SIE entry will do a continuation.
+			 * Fence interrupts in our "internal" PSW.
+			 */
+			if (vcpu->arch.sie_block->icptcode == ICPT_PV_INSTR ||
+			    vcpu->arch.sie_block->icptcode == ICPT_PV_PREF) {
+				vcpu->arch.sie_block->gpsw.mask &= ~PSW_INT_MASK;
+			}
 		}
 		local_irq_disable();
 		__enable_cpu_timer_accounting(vcpu);