KVM: selftests: aarch64: Level-sensitive interrupts tests in vgic_irq

Add a cmdline arg for using level-sensitive interrupts (vs the default
edge-triggered). Then move the handler into a generic handler function
that takes the type of interrupt (level vs. edge) as an arg.  When
handling line-sensitive interrupts it sets the line to low after
acknowledging the IRQ.
Signed-off-by: Ricardo Koller <ricarkol@google.com>
Acked-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211109023906.1091208-12-ricarkol@google.com

tools/testing/selftests/kvm/aarch64/vgic_irq.c

@@ -30,6 +30,7 @@
 struct test_args {
 	uint32_t nr_irqs; /* number of KVM supported IRQs. */
 	bool eoi_split; /* 1 is eoir+dir, 0 is eoir only */
+	bool level_sensitive; /* 1 is level, 0 is edge */
 };
 
 /*
@@ -57,27 +58,31 @@ static void *redist = (void *)GICR_BASE_GPA;
 
 typedef enum {
 	KVM_INJECT_EDGE_IRQ_LINE = 1,
+	KVM_SET_IRQ_LINE,
+	KVM_SET_IRQ_LINE_HIGH,
 } kvm_inject_cmd;
 
 struct kvm_inject_args {
 	kvm_inject_cmd cmd;
 	uint32_t first_intid;
 	uint32_t num;
+	int level;
 };
 
 /* Used on the guest side to perform the hypercall. */
-static void kvm_inject_call(kvm_inject_cmd cmd, uint32_t first_intid, uint32_t num);
-
-#define KVM_INJECT(cmd, intid)							\
-	kvm_inject_call(cmd, intid, 1)
-
-#define KVM_INJECT_MULTI(cmd, intid, num)					\
-	kvm_inject_call(cmd, intid, num)
+static void kvm_inject_call(kvm_inject_cmd cmd, uint32_t first_intid,
+			uint32_t num, int level);
 
 /* Used on the host side to get the hypercall info. */
 static void kvm_inject_get_call(struct kvm_vm *vm, struct ucall *uc,
 		struct kvm_inject_args *args);
 
+#define KVM_INJECT(cmd, intid)							\
+	kvm_inject_call(cmd, intid, 1, -1 /* not used */)
+
+#define KVM_INJECT_MULTI(cmd, intid, num)					\
+	kvm_inject_call(cmd, intid, num, -1 /* not used */)
+
 struct kvm_inject_desc {
 	kvm_inject_cmd cmd;
 	/* can inject PPIs, PPIs, and/or SPIs. */
@@ -90,6 +95,12 @@ static struct kvm_inject_desc inject_edge_fns[] = {
 	{ 0, },
 };
 
+static struct kvm_inject_desc inject_level_fns[] = {
+	/*                                      sgi    ppi    spi */
+	{ KVM_SET_IRQ_LINE_HIGH,		false, true,  true },
+	{ 0, },
+};
+
 #define for_each_inject_fn(t, f)						\
 	for ((f) = (t); (f)->cmd; (f)++)
 
@@ -114,7 +125,9 @@ static uint64_t gic_read_ap1r0(void)
 	return reg;
 }
 
-static void guest_irq_generic_handler(bool eoi_split)
+static void guest_set_irq_line(uint32_t intid, uint32_t level);
+
+static void guest_irq_generic_handler(bool eoi_split, bool level_sensitive)
 {
 	uint32_t intid = gic_get_and_ack_irq();
 
@@ -123,7 +136,11 @@ static void guest_irq_generic_handler(bool eoi_split)
 
 	GUEST_ASSERT(gic_irq_get_active(intid));
 
-	GUEST_ASSERT(!gic_irq_get_pending(intid));
+	if (!level_sensitive)
+		GUEST_ASSERT(!gic_irq_get_pending(intid));
+
+	if (level_sensitive)
+		guest_set_irq_line(intid, 0);
 
 	GUEST_ASSERT(intid < MAX_SPI);
 	irqnr_received[intid] += 1;
@@ -138,12 +155,14 @@ static void guest_irq_generic_handler(bool eoi_split)
 	GUEST_ASSERT(!gic_irq_get_pending(intid));
 }
 
-static void kvm_inject_call(kvm_inject_cmd cmd, uint32_t first_intid, uint32_t num)
+static void kvm_inject_call(kvm_inject_cmd cmd, uint32_t first_intid,
+			uint32_t num, int level)
 {
 	struct kvm_inject_args args = {
 		.cmd = cmd,
 		.first_intid = first_intid,
 		.num = num,
+		.level = level,
 	};
 	GUEST_SYNC(&args);
 }
@@ -158,19 +177,21 @@ do { 										\
 #define CAT_HELPER(a, b) a ## b
 #define CAT(a, b) CAT_HELPER(a, b)
 #define PREFIX guest_irq_handler_
-#define GUEST_IRQ_HANDLER_NAME(split) CAT(PREFIX, split)
-#define GENERATE_GUEST_IRQ_HANDLER(split)					\
-static void CAT(PREFIX, split)(struct ex_regs *regs)				\
+#define GUEST_IRQ_HANDLER_NAME(split, lev) CAT(PREFIX, CAT(split, lev))
+#define GENERATE_GUEST_IRQ_HANDLER(split, lev)					\
+static void CAT(PREFIX, CAT(split, lev))(struct ex_regs *regs)			\
 {										\
-	guest_irq_generic_handler(split);					\
+	guest_irq_generic_handler(split, lev);					\
 }
 
-GENERATE_GUEST_IRQ_HANDLER(0);
-GENERATE_GUEST_IRQ_HANDLER(1);
+GENERATE_GUEST_IRQ_HANDLER(0, 0);
+GENERATE_GUEST_IRQ_HANDLER(0, 1);
+GENERATE_GUEST_IRQ_HANDLER(1, 0);
+GENERATE_GUEST_IRQ_HANDLER(1, 1);
 
-static void (*guest_irq_handlers[2])(struct ex_regs *) = {
-	GUEST_IRQ_HANDLER_NAME(0),
-	GUEST_IRQ_HANDLER_NAME(1),
+static void (*guest_irq_handlers[2][2])(struct ex_regs *) = {
+	{GUEST_IRQ_HANDLER_NAME(0, 0), GUEST_IRQ_HANDLER_NAME(0, 1),},
+	{GUEST_IRQ_HANDLER_NAME(1, 0), GUEST_IRQ_HANDLER_NAME(1, 1),},
 };
 
 static void reset_priorities(struct test_args *args)
@@ -181,6 +202,11 @@ static void reset_priorities(struct test_args *args)
 		gic_set_priority(i, IRQ_DEFAULT_PRIO_REG);
 }
 
+static void guest_set_irq_line(uint32_t intid, uint32_t level)
+{
+	kvm_inject_call(KVM_SET_IRQ_LINE, intid, 1, level);
+}
+
 static void guest_inject(struct test_args *args,
 		uint32_t first_intid, uint32_t num,
 		kvm_inject_cmd cmd)
@@ -257,10 +283,12 @@ static void test_inject_preemption(struct test_args *args,
 	for (i = 0; i < num; i++) {
 		uint32_t tmp;
 		intid = i + first_intid;
-		kvm_inject_call(cmd, intid, 1);
+		KVM_INJECT(cmd, intid);
 		/* Each successive IRQ will preempt the previous one. */
 		tmp = wait_for_and_activate_irq();
 		GUEST_ASSERT_EQ(tmp, intid);
+		if (args->level_sensitive)
+			guest_set_irq_line(intid, 0);
 	}
 
 	/* finish handling the IRQs starting with the highest priority one. */
@@ -321,22 +349,29 @@ static void test_preemption(struct test_args *args, struct kvm_inject_desc *f)
 static void guest_code(struct test_args args)
 {
 	uint32_t i, nr_irqs = args.nr_irqs;
-	struct kvm_inject_desc *f;
+	bool level_sensitive = args.level_sensitive;
+	struct kvm_inject_desc *f, *inject_fns;
 
 	gic_init(GIC_V3, 1, dist, redist);
 
 	for (i = 0; i < nr_irqs; i++)
 		gic_irq_enable(i);
 
+	for (i = MIN_SPI; i < nr_irqs; i++)
+		gic_irq_set_config(i, !args.level_sensitive);
+
 	gic_set_eoi_split(args.eoi_split);
 
 	reset_priorities(&args);
 	gic_set_priority_mask(CPU_PRIO_MASK);
 
+	inject_fns  = level_sensitive ? inject_level_fns
+				      : inject_edge_fns;
+
 	local_irq_enable();
 
 	/* Start the tests. */
-	for_each_inject_fn(inject_edge_fns, f) {
+	for_each_inject_fn(inject_fns, f) {
 		test_injection(&args, f);
 		test_preemption(&args, f);
 	}
@@ -351,6 +386,7 @@ static void run_guest_cmd(struct kvm_vm *vm, int gic_fd,
 	kvm_inject_cmd cmd = inject_args->cmd;
 	uint32_t intid = inject_args->first_intid;
 	uint32_t num = inject_args->num;
+	int level = inject_args->level;
 	uint32_t i;
 
 	assert(intid < UINT_MAX - num);
@@ -362,6 +398,14 @@ static void run_guest_cmd(struct kvm_vm *vm, int gic_fd,
 		for (i = intid; i < intid + num; i++)
 			kvm_arm_irq_line(vm, i, 0);
 		break;
+	case KVM_SET_IRQ_LINE:
+		for (i = intid; i < intid + num; i++)
+			kvm_arm_irq_line(vm, i, level);
+		break;
+	case KVM_SET_IRQ_LINE_HIGH:
+		for (i = intid; i < intid + num; i++)
+			kvm_arm_irq_line(vm, i, 1);
+		break;
 	default:
 		break;
 	}
@@ -380,11 +424,12 @@ static void kvm_inject_get_call(struct kvm_vm *vm, struct ucall *uc,
 
 static void print_args(struct test_args *args)
 {
-	printf("nr-irqs=%d eoi-split=%d\n",
-			args->nr_irqs, args->eoi_split);
+	printf("nr-irqs=%d level-sensitive=%d eoi-split=%d\n",
+			args->nr_irqs, args->level_sensitive,
+			args->eoi_split);
 }
 
-static void test_vgic(uint32_t nr_irqs, bool eoi_split)
+static void test_vgic(uint32_t nr_irqs, bool level_sensitive, bool eoi_split)
 {
 	struct ucall uc;
 	int gic_fd;
@@ -393,6 +438,7 @@ static void test_vgic(uint32_t nr_irqs, bool eoi_split)
 
 	struct test_args args = {
 		.nr_irqs = nr_irqs,
+		.level_sensitive = level_sensitive,
 		.eoi_split = eoi_split,
 	};
 
@@ -411,7 +457,7 @@ static void test_vgic(uint32_t nr_irqs, bool eoi_split)
 			GICD_BASE_GPA, GICR_BASE_GPA);
 
 	vm_install_exception_handler(vm, VECTOR_IRQ_CURRENT,
-			guest_irq_handlers[args.eoi_split]);
+		guest_irq_handlers[args.eoi_split][args.level_sensitive]);
 
 	while (1) {
 		vcpu_run(vm, VCPU_ID);
@@ -442,11 +488,12 @@ static void help(const char *name)
 {
 	printf(
 	"\n"
-	"usage: %s [-n num_irqs] [-e eoi_split]\n", name);
-	printf(" -n: specify the number of IRQs to configure the vgic with. "
+	"usage: %s [-n num_irqs] [-e eoi_split] [-l level_sensitive]\n", name);
+	printf(" -n: specify number of IRQs to setup the vgic with. "
 		"It has to be a multiple of 32 and between 64 and 1024.\n");
 	printf(" -e: if 1 then EOI is split into a write to DIR on top "
 		"of writing EOI.\n");
+	printf(" -l: specify whether the IRQs are level-sensitive (1) or not (0).");
 	puts("");
 	exit(1);
 }
@@ -455,13 +502,14 @@ int main(int argc, char **argv)
 {
 	uint32_t nr_irqs = 64;
 	bool default_args = true;
+	bool level_sensitive = false;
 	int opt;
 	bool eoi_split = false;
 
 	/* Tell stdout not to buffer its content */
 	setbuf(stdout, NULL);
 
-	while ((opt = getopt(argc, argv, "hn:e:")) != -1) {
+	while ((opt = getopt(argc, argv, "hn:e:l:")) != -1) {
 		switch (opt) {
 		case 'n':
 			nr_irqs = atoi(optarg);
@@ -472,6 +520,10 @@ int main(int argc, char **argv)
 			eoi_split = (bool)atoi(optarg);
 			default_args = false;
 			break;
+		case 'l':
+			level_sensitive = (bool)atoi(optarg);
+			default_args = false;
+			break;
 		case 'h':
 		default:
 			help(argv[0]);
@@ -483,10 +535,12 @@ int main(int argc, char **argv)
 	 * combinations.
 	 */
 	if (default_args) {
-		test_vgic(nr_irqs, false /* eoi_split */);
-		test_vgic(nr_irqs, true /* eoi_split */);
+		test_vgic(nr_irqs, false /* level */, false /* eoi_split */);
+		test_vgic(nr_irqs, false /* level */, true /* eoi_split */);
+		test_vgic(nr_irqs, true /* level */, false /* eoi_split */);
+		test_vgic(nr_irqs, true /* level */, true /* eoi_split */);
 	} else {
-		test_vgic(nr_irqs, eoi_split);
+		test_vgic(nr_irqs, level_sensitive, eoi_split);
 	}
 
 	return 0;