Re: [PATCH v2 6/6] selftests: KVM: Add test case for MMIO during vectoring

On Wed, Dec 11, 2024 at 10:19:40AM -0800, Sean Christopherson wrote:

...

+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 :-)

:) Just tried enabling `force_emulation_prefix` kvm parameter and replacing the write with

vcpu_arch_put_guest(*((uint8_t *)NONCANONICAL), 0x1);

And the test simply passes (so it returns the same internal error with suberror=3, patches applied)

-- Kind regards, Ivan Orlov