selftests: KVM: testing the local IRQs resets

Local IRQs are reset by a normal cpu reset.  The initial cpu reset and
the clear cpu reset, as superset of the normal reset, both clear the
IRQs too.

Let's inject an interrupt to a vCPU before calling a reset and see if
it is gone after the reset.

We choose to inject only an emergency interrupt at this point and can
extend the test to other types of IRQs later.

Signed-off-by: Pierre Morel <[email protected]>
Signed-off-by: Janosch Frank <[email protected]>
[minor fixups]
Reviewed-by: Cornelia Huck <[email protected]>
Reviewed-by: Thomas Huth <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Borntraeger <[email protected]>

Author: Pierre Morel

tools/testing/selftests/kvm/s390x/resets.c

@@ -14,6 +14,9 @@
 #include "kvm_util.h"
 
 #define VCPU_ID 3
+#define LOCAL_IRQS 32
+
+struct kvm_s390_irq buf[VCPU_ID + LOCAL_IRQS];
 
 struct kvm_vm *vm;
 struct kvm_run *run;
@@ -53,6 +56,23 @@ static void test_one_reg(uint64_t id, uint64_t value)
 	TEST_ASSERT(eval_reg == value, "value == %s", value);
 }
 
+static void assert_noirq(void)
+{
+	struct kvm_s390_irq_state irq_state;
+	int irqs;
+
+	irq_state.len = sizeof(buf);
+	irq_state.buf = (unsigned long)buf;
+	irqs = _vcpu_ioctl(vm, VCPU_ID, KVM_S390_GET_IRQ_STATE, &irq_state);
+	/*
+	 * irqs contains the number of retrieved interrupts. Any interrupt
+	 * (notably, the emergency call interrupt we have injected) should
+	 * be cleared by the resets, so this should be 0.
+	 */
+	TEST_ASSERT(irqs >= 0, "Could not fetch IRQs: errno %d\n", errno);
+	TEST_ASSERT(!irqs, "IRQ pending");
+}
+
 static void assert_clear(void)
 {
 	struct kvm_sregs sregs;
@@ -94,6 +114,22 @@ static void assert_initial(void)
 static void assert_normal(void)
 {
 	test_one_reg(KVM_REG_S390_PFTOKEN, KVM_S390_PFAULT_TOKEN_INVALID);
+	assert_noirq();
+}
+
+static void inject_irq(int cpu_id)
+{
+	struct kvm_s390_irq_state irq_state;
+	struct kvm_s390_irq *irq = &buf[0];
+	int irqs;
+
+	/* Inject IRQ */
+	irq_state.len = sizeof(struct kvm_s390_irq);
+	irq_state.buf = (unsigned long)buf;
+	irq->type = KVM_S390_INT_EMERGENCY;
+	irq->u.emerg.code = cpu_id;
+	irqs = _vcpu_ioctl(vm, cpu_id, KVM_S390_SET_IRQ_STATE, &irq_state);
+	TEST_ASSERT(irqs >= 0, "Error injecting EMERGENCY IRQ errno %d\n", errno);
 }
 
 static void test_normal(void)
@@ -106,6 +142,8 @@ static void test_normal(void)
 
 	vcpu_run(vm, VCPU_ID);
 
+	inject_irq(VCPU_ID);
+
 	vcpu_ioctl(vm, VCPU_ID, KVM_S390_NORMAL_RESET, 0);
 	assert_normal();
 	kvm_vm_free(vm);
@@ -120,6 +158,8 @@ static void test_initial(void)
 
 	vcpu_run(vm, VCPU_ID);
 
+	inject_irq(VCPU_ID);
+
 	vcpu_ioctl(vm, VCPU_ID, KVM_S390_INITIAL_RESET, 0);
 	assert_normal();
 	assert_initial();
@@ -135,6 +175,8 @@ static void test_clear(void)
 
 	vcpu_run(vm, VCPU_ID);
 
+	inject_irq(VCPU_ID);
+
 	vcpu_ioctl(vm, VCPU_ID, KVM_S390_CLEAR_RESET, 0);
 	assert_normal();
 	assert_initial();