On Mon, Nov 11, 2024, Ivan Orlov wrote:
Extend the 'set_memory_region_test' with a test case which covers the MMIO during vectoring error handling. The test case
- Sets an IDT descriptor base to point to an MMIO address
- Generates a #GP in the guest
- Verifies that we got a correct exit reason and suberror code
- Verifies that we got a corrent reported GPA in internal.data[3]
Also, add a definition of non-canonical address to processor.h
Signed-off-by: Ivan Orlov iorlov@amazon.com
V1 -> V2:
- Get rid of pronouns, redundant comments and incorrect wording
- Define noncanonical address in processor.h
- Fix indentation and wrap lines at 80 columns
.../selftests/kvm/include/x86_64/processor.h | 2 + .../selftests/kvm/set_memory_region_test.c | 51 +++++++++++++++++++ 2 files changed, 53 insertions(+)
diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h index 1a60c99b5833..997df5003edb 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -1165,6 +1165,8 @@ void vm_install_exception_handler(struct kvm_vm *vm, int vector, /* If a toddler were to say "abracadabra". */ #define KVM_EXCEPTION_MAGIC 0xabacadabaULL +#define NONCANONICAL 0xaaaaaaaaaaaaaaaaull
Uber nit, I much prefer to place this definition at the top of the header. More specifically, it needs to not be in the middle of the selftest's exception fixup code.
/*
- KVM selftest exception fixup uses registers to coordinate with the exception
- handler, versus the kernel's in-memory tables and KVM-Unit-Tests's in-memory
diff --git a/tools/testing/selftests/kvm/set_memory_region_test.c b/tools/testing/selftests/kvm/set_memory_region_test.c index a1c53cc854a5..d65a9f20aa1a 100644 --- a/tools/testing/selftests/kvm/set_memory_region_test.c +++ b/tools/testing/selftests/kvm/set_memory_region_test.c @@ -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;
Now I'm curious what happens if this uses vcpu_arch_put_guest(), i.e. if the test forces KVM to emulate the write.
No action needed, the test is a-ok as-is. I'm really just curious :-)