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While this adds coverage for NMI injection, the primary goal is to validate KVM's handling of non-postable interrupt delivery (AMD and Intel IOMMUs only support posting fixed IRQs targeting a single vCPU). KVM has historically bungled handling transitions between posted and remapped modes. Use NMIs to stress the transitions, because they are a reliable, architectural way to force these code paths. Signed-off-by: David Matlack Co-developed-by: Josh Hilke Signed-off-by: Josh Hilke [sean: add GUEST_RECEIVED_INTERRUPT(), massage changelog] Signed-off-by: Sean Christopherson --- tools/testing/selftests/kvm/irq_test.c | 48 ++++++++++++++++++++------ 1 file changed, 37 insertions(+), 11 deletions(-) diff --git a/tools/testing/selftests/kvm/irq_test.c b/tools/testing/selftests/kvm/irq_test.c index 2cfb6c24e8d6..d2d861119854 100644 --- a/tools/testing/selftests/kvm/irq_test.c +++ b/tools/testing/selftests/kvm/irq_test.c @@ -17,11 +17,17 @@ 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 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) { @@ -35,6 +41,11 @@ static void guest_irq_handler(struct ex_regs *regs) x2apic_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) { x2apic_enable(); @@ -91,7 +102,7 @@ static void trigger_interrupt(struct vfio_pci_device *device, int eventfd) static void kvm_route_msi(struct kvm_vm *vm, u32 gsi, struct kvm_vcpu *vcpu, - u8 vector) + u8 vector, bool use_nmi) { struct { struct kvm_irq_routing header; @@ -102,7 +113,7 @@ static void kvm_route_msi(struct kvm_vm *vm, u32 gsi, struct kvm_vcpu *vcpu, .gsi = gsi, .type = KVM_IRQ_ROUTING_MSI, .u.msi.address_lo = 0xFEE00000 | (vcpu->id << 12), - .u.msi.data = vector, + .u.msi.data = use_nmi ? NMI_VECTOR | (4 << 8) : vector, }, }; @@ -134,13 +145,14 @@ static const char *probe_iommu_type(void) static void help(const char *name) { - printf("Usage: %s [-a] [-d ] [-e] [-h] [-i nr_irqs] [-t iommu_type]\n", name); + printf("Usage: %s [-a] [-d ] [-e] [-h] [-i nr_irqs] [-n] [-t iommu_type]\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("-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("\n"); exit(KSFT_FAIL); @@ -171,11 +183,12 @@ int main(int argc, char **argv) const char *device_bdf = NULL; const char *iommu_type = NULL; int i, j, c, msix, eventfd; + bool use_nmi = false; struct iommu *iommu; struct kvm_vm *vm; int irq, irq_cpu; - while ((c = getopt(argc, argv, "ad:ehi:t:")) != -1) { + while ((c = getopt(argc, argv, "ad:ehi:nt:")) != -1) { switch (c) { case 'a': irq_affinity = true; @@ -189,6 +202,9 @@ int main(int argc, char **argv) case 'i': nr_irqs = atoi_positive("Number of IRQs", optarg); break; + case 'n': + use_nmi = true; + break; case 't': iommu_type = optarg; break; @@ -202,6 +218,7 @@ int main(int argc, char **argv) vm = vm_create_with_vcpus(nr_vcpus, guest_code, vcpus); vm_install_exception_handler(vm, vector, guest_irq_handler); + vm_install_exception_handler(vm, NMI_VECTOR, guest_nmi_handler); if (device_bdf) { if (!iommu_type) @@ -240,36 +257,45 @@ int main(int argc, char **argv) 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); + 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); } - for (j = 0; j < nr_vcpus; j++) + 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_IRQ(vcpu) && + while (!GUEST_RECEIVED_INTERRUPT(vcpu, do_use_nmi) && timespec_to_ns(timespec_elapsed(start)) <= timeout_ns) cpu_relax(); - TEST_ASSERT(GUEST_RECEIVED_IRQ(vcpu), - "vCPU %d timed out waiting for IRQ (vector 0x%x) from GSI %d (via CPU %d)\n", - vcpu->id, vector, gsi, irq_cpu); + 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); - WRITE_AND_SYNC_TO_GUEST(vm, guest_received_irq[vcpu->id], false); + 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); -- 2.54.0.1136.gdb2ca164c4-goog