From: Hao Zhang Add a regression test for level-triggered I/O APIC interrupt delivery when no local APIC can accept the interrupt. remote_irr tracks that a level-triggered interrupt has been accepted by a local APIC and that the I/O APIC must wait for the corresponding EOI before delivering the interrupt again. If no local APIC accepts the interrupt, remote_irr must remain clear, as no EOI will ever be generated. Configure an I/O APIC redirection entry and inject an I/O APIC-only GSI before creating any vCPUs. Verify that KVM_IRQ_LINE_STATUS reports failed delivery and that KVM_GET_IRQCHIP reports remote_irr clear. This covers the case where failed delivery returns a negative value and must not be treated as a successful delivery for remote_irr tracking. Signed-off-by: Hao Zhang --- tools/testing/selftests/kvm/Makefile.kvm | 1 + .../testing/selftests/kvm/x86/ioapic_state_test.c | 70 ++++++++++++++++++++++ 2 files changed, 71 insertions(+) create mode 100644 tools/testing/selftests/kvm/x86/ioapic_state_test.c diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm index 6fc34e9bf8e1..89e3f82e75b0 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -86,6 +86,7 @@ TEST_GEN_PROGS_x86 += x86/hyperv_features TEST_GEN_PROGS_x86 += x86/hyperv_ipi TEST_GEN_PROGS_x86 += x86/hyperv_svm_test TEST_GEN_PROGS_x86 += x86/hyperv_tlb_flush +TEST_GEN_PROGS_x86 += x86/ioapic_state_test TEST_GEN_PROGS_x86 += x86/kvm_clock_test TEST_GEN_PROGS_x86 += x86/kvm_pv_test TEST_GEN_PROGS_x86 += x86/kvm_buslock_test diff --git a/tools/testing/selftests/kvm/x86/ioapic_state_test.c b/tools/testing/selftests/kvm/x86/ioapic_state_test.c new file mode 100644 index 000000000000..3e1badcc391c --- /dev/null +++ b/tools/testing/selftests/kvm/x86/ioapic_state_test.c @@ -0,0 +1,70 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Regression tests for in-kernel I/O APIC state. + */ + +#include "kvm_util.h" +#include "test_util.h" + +#define TEST_IOAPIC_PIN 16 +#define TEST_VECTOR 0x50 +#define NO_SUCH_APIC_ID 0xfe + +static void get_ioapic(struct kvm_vm *vm, struct kvm_irqchip *irqchip) +{ + int r; + + irqchip->chip_id = KVM_IRQCHIP_IOAPIC; + r = __vm_ioctl(vm, KVM_GET_IRQCHIP, irqchip); + if (r && errno == ENXIO) + __TEST_REQUIRE(0, "In-kernel I/O APIC not available"); + + TEST_ASSERT(!r, KVM_IOCTL_ERROR(KVM_GET_IRQCHIP, r)); +} + +static void set_ioapic(struct kvm_vm *vm, struct kvm_irqchip *irqchip) +{ + irqchip->chip_id = KVM_IRQCHIP_IOAPIC; + vm_ioctl(vm, KVM_SET_IRQCHIP, irqchip); +} + +static void test_no_remote_irr_for_undelivered_interrupt(void) +{ + struct kvm_irq_level irq = { + .irq = TEST_IOAPIC_PIN, + .level = 1, + }; + struct kvm_irqchip irqchip; + struct kvm_vm *vm; + + vm = vm_create_barebones(); + vm_create_irqchip(vm); + + get_ioapic(vm, &irqchip); + + irqchip.chip.ioapic.redirtbl[TEST_IOAPIC_PIN].fields.vector = TEST_VECTOR; + irqchip.chip.ioapic.redirtbl[TEST_IOAPIC_PIN].fields.dest_id = NO_SUCH_APIC_ID; + irqchip.chip.ioapic.redirtbl[TEST_IOAPIC_PIN].fields.dest_mode = 0; + irqchip.chip.ioapic.redirtbl[TEST_IOAPIC_PIN].fields.trig_mode = 1; + irqchip.chip.ioapic.redirtbl[TEST_IOAPIC_PIN].fields.mask = 0; + irqchip.chip.ioapic.redirtbl[TEST_IOAPIC_PIN].fields.remote_irr = 0; + + set_ioapic(vm, &irqchip); + + vm_ioctl(vm, KVM_IRQ_LINE_STATUS, &irq); + TEST_ASSERT(irq.status == -1, + "Expected failed interrupt delivery, got %d", irq.status); + + get_ioapic(vm, &irqchip); + TEST_ASSERT(!irqchip.chip.ioapic.redirtbl[TEST_IOAPIC_PIN].fields.remote_irr, + "KVM set remote_irr for a level-triggered interrupt that wasn't delivered"); + + kvm_vm_free(vm); +} + +int main(void) +{ + test_no_remote_irr_for_undelivered_interrupt(); + + return 0; +} -- 2.15.0