1 files changed, 362 insertions, 0 deletions

diff --git a/tools/testing/selftests/kvm/irq_test.c b/tools/testing/selftests/kvm/irq_test.c
new file mode 100644
index 000000000000..240f6f0fdbe4
--- /dev/null
+++ b/tools/testing/selftests/kvm/irq_test.c
@@ -0,0 +1,362 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "kvm_util.h"
+#include "test_util.h"
+#include "apic.h"
+#include "processor.h"
+#include "proc_util.h"
+
+#include <libvfio.h>
+#include <linux/sizes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <sys/eventfd.h>
+#include <sys/sysinfo.h>
+
+static u64 timeout_ns = 2ULL * 1000 * 1000 * 1000;
+static bool guest_ready_for_irqs[KVM_MAX_VCPUS];
+static bool guest_received_irq[KVM_MAX_VCPUS];
+static bool guest_received_nmi[KVM_MAX_VCPUS];
+static bool x2apic = true;
+static bool irq_affinity;
+static bool done;
+
+#define GUEST_RECEIVED_IRQ(__vcpu)	\
+	SYNC_FROM_GUEST_AND_READ((__vcpu)->vm, guest_received_irq[(__vcpu)->id])
+#define GUEST_RECEIVED_NMI(__vcpu)	\
+	SYNC_FROM_GUEST_AND_READ((__vcpu)->vm, guest_received_nmi[(__vcpu)->id])
+
+#define GUEST_RECEIVED_INTERRUPT(__vcpu, __nmi)	\
+	((__nmi) ? GUEST_RECEIVED_NMI(__vcpu) : GUEST_RECEIVED_IRQ(__vcpu))
+
+static u32 guest_get_vcpu_id(void)
+{
+	if (x2apic)
+		return x2apic_read_reg(APIC_ID);
+	else
+		return xapic_read_reg(APIC_ID) >> 24;
+}
+
+static void guest_irq_handler(struct ex_regs *regs)
+{
+	WRITE_ONCE(guest_received_irq[guest_get_vcpu_id()], true);
+
+	if (x2apic)
+		x2apic_write_reg(APIC_EOI, 0);
+	else
+		xapic_write_reg(APIC_EOI, 0);
+}
+
+static void guest_nmi_handler(struct ex_regs *regs)
+{
+	WRITE_ONCE(guest_received_nmi[guest_get_vcpu_id()], true);
+}
+
+static void guest_code(void)
+{
+	if (x2apic)
+		x2apic_enable();
+	else
+		xapic_enable();
+
+	sti_nop();
+
+	WRITE_ONCE(guest_ready_for_irqs[guest_get_vcpu_id()], true);
+
+	while (!READ_ONCE(done))
+		cpu_relax();
+
+	GUEST_DONE();
+}
+
+static void *vcpu_thread_main(void *arg)
+{
+	struct kvm_vcpu *vcpu = arg;
+	struct ucall uc;
+
+	vcpu_run(vcpu);
+	TEST_ASSERT_EQ(UCALL_DONE, get_ucall(vcpu, &uc));
+
+	return NULL;
+}
+
+static int vfio_setup_msi(struct vfio_pci_device *device)
+{
+	const int flags = MAP_SHARED | MAP_ANONYMOUS;
+	const int prot = PROT_READ | PROT_WRITE;
+	struct iova_allocator *allocator;
+	struct dma_region *region;
+
+	/* Sanity check that the device+driver can actually send MSIs. */
+	TEST_REQUIRE(device->driver.ops);
+	TEST_REQUIRE(device->driver.ops->send_msi);
+
+	/*
+	 * Set up a DMA-able region for the driver to use.   Very few devices
+	 * provide a way to arbitrarily send interrupts (MSIs), e.g. by writing
+	 * an MMIO register.  Instead, most devices send MSIs when an action is
+	 * completed, and practically all actions involve DMA of some form.
+	 */
+	allocator = iova_allocator_init(device->iommu);
+
+	region = &device->driver.region;
+	region->size = SZ_2M;
+	region->iova = iova_allocator_alloc(allocator, region->size);
+	region->vaddr = kvm_mmap(region->size, prot, flags, -1);
+	TEST_ASSERT(region->vaddr != MAP_FAILED, "mmap() failed\n");
+	iommu_map(device->iommu, region);
+
+	iova_allocator_cleanup(allocator);
+
+	vfio_pci_driver_init(device);
+
+	return device->driver.msi;
+}
+
+static void trigger_interrupt(struct vfio_pci_device *device, int eventfd)
+{
+	if (device)
+		vfio_pci_driver_send_msi(device);
+	else
+		eventfd_write(eventfd, 1);
+}
+
+
+static void kvm_route_msi(struct kvm_vm *vm, u32 gsi, struct kvm_vcpu *vcpu,
+			  u8 vector, bool use_nmi)
+{
+	struct {
+		struct kvm_irq_routing header;
+		struct kvm_irq_routing_entry entry;
+	} routing = {
+		.header.nr = 1,
+		.entry = {
+			.gsi = gsi,
+			.type = KVM_IRQ_ROUTING_MSI,
+			.u.msi.address_lo = 0xFEE00000 | (vcpu->id & GENMASK(7, 0)) << 12,
+			.u.msi.address_hi = vcpu->id & GENMASK(31, 8),
+			.u.msi.data = use_nmi ? NMI_VECTOR | (4 << 8) : vector,
+		},
+	};
+
+	vm_ioctl(vm, KVM_SET_GSI_ROUTING, &routing.header);
+}
+
+static void kvm_set_empty_gsi_routing(struct kvm_vm *vm)
+{
+	struct kvm_irq_routing routing = {};
+
+	vm_ioctl(vm, KVM_SET_GSI_ROUTING, &routing);
+}
+
+static const char *probe_iommu_type(void)
+{
+	int io_fd;
+
+	io_fd = open("/dev/iommu", O_RDONLY);
+	if (io_fd >= 0) {
+		close(io_fd);
+		return MODE_IOMMUFD;
+	}
+
+	io_fd = __open_path_or_exit("/dev/vfio/vfio", O_RDONLY,
+				    "Is VFIO (or IOMMUFD) loaded and enabled?");
+	close(io_fd);
+	return MODE_VFIO_TYPE1_IOMMU;
+}
+
+static void help(const char *name)
+{
+	printf("Usage: %s [-a] [-d <segment:bus:device.function>] [-e] [-h] [-i nr_irqs] [-m] [-n] [-t iommu_type] [-v nr_vcpus] [-x]\n", name);
+	printf("\n");
+	printf("Tests KVM interrupt routing and delivery via irqfd.\n");
+	printf("-a	Affine the device's host IRQ to a random physical CPU\n");
+	printf("-d	Use a VFIO device to send MSI-X interrupts instead of manually signaling the eventfd\n");
+	printf("-e	Set empty GSI routing in-between some interrupts\n");
+	printf("-i	The number of IRQs to generate during the test\n");
+	printf("-m	Pin target vCPU to random physical CPU before triggering interrupt\n");
+	printf("-n	Deliver 50 percent of IRQs as non-maskable interrupts\n");
+	printf("-t	Override the IOMMU type to use (vfio_type1_iommu or iommufd)\n");
+	printf("-v	Number of vCPUS to run\n");
+	printf("-x	Use xAPIC mode instead of x2APIC mode in the guest\n");
+	printf("\n");
+	exit(KSFT_FAIL);
+}
+
+int main(int argc, char **argv)
+{
+	/*
+	 * Pick a random vector and a random GSI to use for device IRQ.
+	 *
+	 * Pick an IRQ vector in range [32, UINT8_MAX]. Min value is 32 because
+	 * Linux/x86 reserves vectors 0-31 for exceptions and architecture
+	 * defined NMIs and interrupts.
+	 *
+	 * Pick a GSI in range [24, KVM_MAX_IRQ_ROUTES - 1]. The min value is 24
+	 * because KVM reserves GSIs 0-15 for legacy ISA IRQs and 16-23 only go
+	 * to the IOAPIC. The max is KVM_MAX_IRQ_ROUTES - 1, because
+	 * KVM_MAX_IRQ_ROUTES is exclusive.
+	 */
+	u32 gsi = kvm_random_u64_in_range(&kvm_rng, 24, KVM_MAX_IRQ_ROUTES - 1);
+	u8 vector = kvm_random_u64_in_range(&kvm_rng, 32, UINT8_MAX);
+
+	pthread_t vcpu_threads[KVM_MAX_VCPUS];
+	struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
+	struct vfio_pci_device *device = NULL;
+	int nr_irqs = 1000, nr_vcpus = 1;
+	bool set_empty_routing = false;
+	const char *device_bdf = NULL;
+	const char *iommu_type = NULL;
+	int i, j, c, msix, eventfd;
+	bool migrate_vcpus = false;
+	cpu_set_t available_cpus;
+	bool use_nmi = false;
+	struct iommu *iommu;
+	struct kvm_vm *vm;
+	int irq, irq_cpu;
+
+	while ((c = getopt(argc, argv, "ad:ehi:mnt:v:x")) != -1) {
+		switch (c) {
+		case 'a':
+			irq_affinity = true;
+			break;
+		case 'd':
+			device_bdf = optarg;
+			break;
+		case 'e':
+			set_empty_routing = true;
+			break;
+		case 'i':
+			nr_irqs = atoi_positive("Number of IRQs", optarg);
+			break;
+		case 'm':
+			migrate_vcpus = true;
+			break;
+		case 'n':
+			use_nmi = true;
+			break;
+		case 't':
+			iommu_type = optarg;
+			break;
+		case 'v':
+			nr_vcpus = atoi_positive("Number of vCPUS", optarg);
+			TEST_ASSERT(nr_vcpus <= KVM_MAX_VCPUS,
+				    "KVM selftests support at most %u vCPUs", KVM_MAX_VCPUS);
+			break;
+		case 'x':
+			x2apic = false;
+			break;
+		case 'h':
+		default:
+			help(argv[0]);
+		}
+	}
+
+	TEST_REQUIRE(kvm_arch_has_default_irqchip());
+
+	vm = vm_create_with_vcpus(nr_vcpus, guest_code, vcpus);
+	vm_enable_cap(vm, KVM_CAP_X2APIC_API, KVM_X2APIC_API_USE_32BIT_IDS |
+					      KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK);
+
+	vm_install_exception_handler(vm, vector, guest_irq_handler);
+	vm_install_exception_handler(vm, NMI_VECTOR, guest_nmi_handler);
+
+	if (!x2apic) {
+		TEST_ASSERT(nr_vcpus < 256, "xAPIC can only target IDs [0-254] (255 vCPUs)");
+		virt_pg_map(vm, APIC_DEFAULT_GPA, APIC_DEFAULT_GPA);
+	}
+
+	if (device_bdf) {
+		if (!iommu_type)
+			iommu_type = probe_iommu_type();
+		iommu = iommu_init(iommu_type);
+		device = vfio_pci_device_init(device_bdf, iommu);
+		msix = vfio_setup_msi(device);
+		irq = vfio_msix_to_host_irq(device_bdf, msix);
+		eventfd = device->msi_eventfds[msix];
+		printf("Using device %s MSI-X[%d] (IRQ-%u)\n", device_bdf, msix,
+		       irq);
+	} else {
+		TEST_ASSERT(!irq_affinity,
+			    "Setting IRQ affinity (-a) requires a backing device (-d)");
+
+		eventfd = kvm_new_eventfd();
+		irq = -1;
+	}
+
+	pr_info("Injecting interrupts for GSI %d (guest vector 0x%x) %d times\n",
+		gsi, vector, nr_irqs);
+
+	kvm_assign_irqfd(vm, gsi, eventfd);
+
+	sync_global_to_guest(vm, x2apic);
+
+	if (migrate_vcpus)
+		kvm_sched_getaffinity(0, sizeof(available_cpus), &available_cpus);
+
+	for (i = 0; i < nr_vcpus; i++)
+		pthread_create(&vcpu_threads[i], NULL, vcpu_thread_main, vcpus[i]);
+
+	for (i = 0; i < nr_vcpus; i++) {
+		struct kvm_vcpu *vcpu = vcpus[i];
+
+		while (!SYNC_FROM_GUEST_AND_READ(vm, guest_ready_for_irqs[vcpu->id]))
+			continue;
+	}
+
+	irq_cpu = -1;
+
+	for (i = 0; i < nr_irqs; i++) {
+		const bool do_set_empty_routing = set_empty_routing && (i & BIT(3));
+		const bool do_use_nmi = use_nmi && (i & BIT(2));
+		struct kvm_vcpu *vcpu = vcpus[i % nr_vcpus];
+		struct timespec start;
+
+		if (do_set_empty_routing)
+			kvm_set_empty_gsi_routing(vm);
+
+		kvm_route_msi(vm, gsi, vcpu, vector, do_use_nmi);
+
+		if (irq_affinity) {
+			irq_cpu = kvm_random_u64(&kvm_rng) % get_nprocs();
+			proc_irq_set_smp_affinity(irq, irq_cpu);
+		}
+
+		if (migrate_vcpus)
+			pin_task_to_random_cpu(vcpu_threads[i % nr_vcpus], &available_cpus);
+
+		for (j = 0; j < nr_vcpus; j++) {
+			TEST_ASSERT(!GUEST_RECEIVED_IRQ(vcpus[j]),
+				    "IRQ flag for vCPU %d not clear prior to test",
+				    vcpus[j]->id);
+			TEST_ASSERT(!GUEST_RECEIVED_NMI(vcpus[j]),
+				    "NMI flag for vCPU %d not clear prior to test",
+				    vcpus[j]->id);
+		}
+
+		trigger_interrupt(device, eventfd);
+
+		clock_gettime(CLOCK_MONOTONIC, &start);
+		while (!GUEST_RECEIVED_INTERRUPT(vcpu, do_use_nmi) &&
+		       timespec_to_ns(timespec_elapsed(start)) <= timeout_ns)
+			cpu_relax();
+
+		TEST_ASSERT(GUEST_RECEIVED_INTERRUPT(vcpu, do_use_nmi),
+			    "vCPU %d timed out waiting for %s (vector 0x%x) from GSI %d (via CPU %d)\n",
+			    vcpu->id, do_use_nmi ? "NMI" : "IRQ",
+			    do_use_nmi ? NMI_VECTOR : vector, gsi, irq_cpu);
+
+		if (do_use_nmi)
+			WRITE_AND_SYNC_TO_GUEST(vm, guest_received_nmi[vcpu->id], false);
+		else
+			WRITE_AND_SYNC_TO_GUEST(vm, guest_received_irq[vcpu->id], false);
+	}
+
+	WRITE_AND_SYNC_TO_GUEST(vm, done, true);
+
+	for (i = 0; i < nr_vcpus; i++)
+		pthread_join(vcpu_threads[i], NULL);
+
+	return 0;
+}