Extend the 'set_memory_region_test' with a test case which covers the MMIO during event delivery error handling. The test case
1) Tries to set an IDT descriptor base to point to an MMIO address 2) Generates a #GP 3) Verifies that we got a correct exit reason (KVM_EXIT_INTERNAL_ERROR) and suberror code (KVM_INTERNAL_ERROR_DELIVERY_EV) 4) Verifies that we got a corrent "faulty" GPA in internal.data[3]
Signed-off-by: Ivan Orlov iorlov@amazon.com --- .../selftests/kvm/set_memory_region_test.c | 46 +++++++++++++++++++ 1 file changed, 46 insertions(+)
diff --git a/tools/testing/selftests/kvm/set_memory_region_test.c b/tools/testing/selftests/kvm/set_memory_region_test.c index a8267628e9ed..e9e97346edf1 100644 --- a/tools/testing/selftests/kvm/set_memory_region_test.c +++ b/tools/testing/selftests/kvm/set_memory_region_test.c @@ -553,6 +553,51 @@ static void test_add_overlapping_private_memory_regions(void) close(memfd); kvm_vm_free(vm); } + +static const struct desc_ptr faulty_idt_desc = { + .address = MEM_REGION_GPA, + .size = 0xFFF, +}; + +static void guest_code_faulty_idt_desc(void) +{ + __asm__ __volatile__("lidt %0"::"m"(faulty_idt_desc)); + + /* Generate a #GP by dereferencing a non-canonical address */ + *((uint8_t *)0xDEADBEEFDEADBEEFULL) = 0x1; + + /* We should never reach this point */ + GUEST_ASSERT(0); +} + +/* + * This test tries to point the IDT descriptor base to an MMIO address. This action + * should cause a KVM internal error, so the VMM could handle such situations gracefully. + */ +static void test_faulty_idt_desc(void) +{ + struct kvm_vm *vm; + struct kvm_vcpu *vcpu; + + pr_info("Testing a faulty IDT descriptor pointing to an MMIO address\n"); + + vm = vm_create_with_one_vcpu(&vcpu, guest_code_faulty_idt_desc); + virt_map(vm, MEM_REGION_GPA, MEM_REGION_GPA, 1); + + vcpu_run(vcpu); + TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_INTERNAL_ERROR); + TEST_ASSERT(vcpu->run->internal.suberror == KVM_INTERNAL_ERROR_DELIVERY_EV, + "Unexpected suberror = %d", vcpu->run->internal.suberror); + TEST_ASSERT(vcpu->run->internal.ndata > 4, "Unexpected internal error data array size = %d", + vcpu->run->internal.ndata); + + /* The "faulty" GPA address should be = IDT base + offset of the GP vector */ + TEST_ASSERT(vcpu->run->internal.data[3] == MEM_REGION_GPA + + GP_VECTOR * sizeof(struct idt_entry), + "Unexpected GPA = %llx", vcpu->run->internal.data[3]); + + kvm_vm_free(vm); +} #endif
int main(int argc, char *argv[]) @@ -568,6 +613,7 @@ int main(int argc, char *argv[]) * KVM_RUN fails with ENOEXEC or EFAULT. */ test_zero_memory_regions(); + test_faulty_idt_desc(); #endif
test_invalid_memory_region_flags();