From: Janosch Frank <frankja@linux.ibm.com>
Date: Fri, 13 Dec 2019 08:26:06 -0500
Subject: KVM: s390: protvirt: Mask PSW interrupt bits for interception 104 and
 112
Git-commit: 3adae0b4ca64c08a6c05a54be0becf9d127d39dc
Patch-mainline: v5.7-rc1
References: jsc#SLE-7512 bsc#1165545

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>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 arch/s390/kvm/kvm-s390.c |   11 +++++++++++
 1 file changed, 11 insertions(+)

--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -4100,6 +4100,7 @@ static int vcpu_post_run(struct kvm_vcpu
 	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;
@@ -4136,6 +4137,16 @@ static int __vcpu_run(struct kvm_vcpu *v
 			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);