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KVM: selftests: Add test case for MMIO during vectoring on x86

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Extend the 'set_memory_region_test' with an x86-only test case which
covers emulated MMIO during event vectoring error handling. The test case

1) Sets an IDT descriptor base to point to an MMIO address
2) Generates a #GP in the guest
3) Verifies userspace gets the correct exit reason, suberror code, and
   GPA in internal.data[3]

Opportunistically add a definition for a non-canonical address to
processor.h so that the source of the #GP is somewhat self-documenting,
and so that future tests don't have to reinvent the wheel.

Signed-off-by: Ivan Orlov <iorlov@amazon.com>
Link: https://lore.kernel.org/r/20241217181458.68690-8-iorlov@amazon.com
[sean: massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Ivan Orlov
2024-12-17 18:14:58 +00:00
committed by Sean Christopherson
parent 4e9427aeb9
commit 62e41f6b4f
2 changed files with 53 additions and 0 deletions
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2
tools/testing/selftests/kvm/include/x86/processor.h
View File

@@ -27,6 +27,8 @@ extern uint64_t guest_tsc_khz;
#define MAX_NR_CPUID_ENTRIES 100
#endif
#define NONCANONICAL 0xaaaaaaaaaaaaaaaaull
/* Forced emulation prefix, used to invoke the emulator unconditionally. */
#define KVM_FEP "ud2; .byte 'k', 'v', 'm';"

51
tools/testing/selftests/kvm/set_memory_region_test.c
View File

@@ -553,6 +553,56 @@ static void test_add_overlapping_private_memory_regions(void)
close(memfd);
kvm_vm_free(vm);
}
static void guest_code_mmio_during_vectoring(void)
{
const struct desc_ptr idt_desc = {
.address = MEM_REGION_GPA,
.size = 0xFFF,
};
set_idt(&idt_desc);
/* Generate a #GP by dereferencing a non-canonical address */
*((uint8_t *)NONCANONICAL) = 0x1;
GUEST_ASSERT(0);
}
/*
* This test points the IDT descriptor base to an MMIO address. It should cause
* a KVM internal error when an event occurs in the guest.
*/
static void test_mmio_during_vectoring(void)
{
struct kvm_vcpu *vcpu;
struct kvm_run *run;
struct kvm_vm *vm;
u64 expected_gpa;
pr_info("Testing MMIO during vectoring error handling\n");
vm = vm_create_with_one_vcpu(&vcpu, guest_code_mmio_during_vectoring);
virt_map(vm, MEM_REGION_GPA, MEM_REGION_GPA, 1);
run = vcpu->run;
vcpu_run(vcpu);
TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_INTERNAL_ERROR);
TEST_ASSERT(run->internal.suberror == KVM_INTERNAL_ERROR_DELIVERY_EV,
"Unexpected suberror = %d", vcpu->run->internal.suberror);
TEST_ASSERT(run->internal.ndata != 4, "Unexpected internal error data array size = %d",
run->internal.ndata);
/* The reported GPA should be IDT base + offset of the GP vector */
expected_gpa = MEM_REGION_GPA + GP_VECTOR * sizeof(struct idt_entry);
TEST_ASSERT(run->internal.data[3] == expected_gpa,
"Unexpected GPA = %llx (expected %lx)",
vcpu->run->internal.data[3], expected_gpa);
kvm_vm_free(vm);
}
#endif
int main(int argc, char *argv[])
@@ -568,6 +618,7 @@ int main(int argc, char *argv[])
* KVM_RUN fails with ENOEXEC or EFAULT.
*/
test_zero_memory_regions();
test_mmio_during_vectoring();
#endif
test_invalid_memory_region_flags();