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-rw-r--r--arch/s390/kvm/Kconfig1
-rw-r--r--arch/s390/kvm/intercept.c32
-rw-r--r--arch/s390/kvm/kvm-s390.c1
3 files changed, 25 insertions, 9 deletions
diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig
index 33f4ff909476..45fdf2a9b2e3 100644
--- a/arch/s390/kvm/Kconfig
+++ b/arch/s390/kvm/Kconfig
@@ -31,7 +31,6 @@ config KVM
select HAVE_KVM_IRQ_ROUTING
select HAVE_KVM_INVALID_WAKEUPS
select HAVE_KVM_NO_POLL
- select SRCU
select KVM_VFIO
select INTERVAL_TREE
select MMU_NOTIFIER
diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index 0ee02dae14b2..2cda8d9d7c6e 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -271,10 +271,18 @@ static int handle_prog(struct kvm_vcpu *vcpu)
* handle_external_interrupt - used for external interruption interceptions
* @vcpu: virtual cpu
*
- * This interception only occurs if the CPUSTAT_EXT_INT bit was set, or if
- * the new PSW does not have external interrupts disabled. In the first case,
- * we've got to deliver the interrupt manually, and in the second case, we
- * drop to userspace to handle the situation there.
+ * This interception occurs if:
+ * - the CPUSTAT_EXT_INT bit was already set when the external interrupt
+ * occurred. In this case, the interrupt needs to be injected manually to
+ * preserve interrupt priority.
+ * - the external new PSW has external interrupts enabled, which will cause an
+ * interruption loop. We drop to userspace in this case.
+ *
+ * The latter case can be detected by inspecting the external mask bit in the
+ * external new psw.
+ *
+ * Under PV, only the latter case can occur, since interrupt priorities are
+ * handled in the ultravisor.
*/
static int handle_external_interrupt(struct kvm_vcpu *vcpu)
{
@@ -285,10 +293,18 @@ static int handle_external_interrupt(struct kvm_vcpu *vcpu)
vcpu->stat.exit_external_interrupt++;
- rc = read_guest_lc(vcpu, __LC_EXT_NEW_PSW, &newpsw, sizeof(psw_t));
- if (rc)
- return rc;
- /* We can not handle clock comparator or timer interrupt with bad PSW */
+ if (kvm_s390_pv_cpu_is_protected(vcpu)) {
+ newpsw = vcpu->arch.sie_block->gpsw;
+ } else {
+ rc = read_guest_lc(vcpu, __LC_EXT_NEW_PSW, &newpsw, sizeof(psw_t));
+ if (rc)
+ return rc;
+ }
+
+ /*
+ * Clock comparator or timer interrupt with external interrupt enabled
+ * will cause interrupt loop. Drop to userspace.
+ */
if ((eic == EXT_IRQ_CLK_COMP || eic == EXT_IRQ_CPU_TIMER) &&
(newpsw.mask & PSW_MASK_EXT))
return -EOPNOTSUPP;
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 4c3edccb9911..17b81659cdb2 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -573,6 +573,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_S390_VCPU_RESETS:
case KVM_CAP_SET_GUEST_DEBUG:
case KVM_CAP_S390_DIAG318:
+ case KVM_CAP_IRQFD_RESAMPLE:
r = 1;
break;
case KVM_CAP_SET_GUEST_DEBUG2: