On Fri, Apr 30, 2021 at 04:24:04PM -0700, Ricardo Koller wrote:
> x86, the only arch implementing exception handling, reports unhandled
> vectors using port IO at a specific port number. This replicates what
> ucall already does.
>
> Introduce a new ucall type, UCALL_UNHANDLED, for guests to report
> unhandled exceptions. Then replace the x86 unhandled vector exception
> reporting to use it instead of port IO. This new ucall type will be
> used in the next commits by arm64 to report unhandled vectors as well.
>
> Tested: Forcing a page fault in the ./x86_64/xapic_ipi_test
> halter_guest_code() shows this:
>
> $ ./x86_64/xapic_ipi_test
> ...
> Unexpected vectored event in guest (vector:0xe)
>
> Signed-off-by: Ricardo Koller <ricarkol@xxxxxxxxxx>
> ---
> tools/testing/selftests/kvm/include/kvm_util.h | 1 +
> .../selftests/kvm/include/x86_64/processor.h | 2 --
> .../testing/selftests/kvm/lib/x86_64/processor.c | 15 ++++++---------
> 3 files changed, 7 insertions(+), 11 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
> index bea4644d645d..7880929ea548 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util.h
> @@ -347,6 +347,7 @@ enum {
> UCALL_SYNC,
> UCALL_ABORT,
> UCALL_DONE,
> + UCALL_UNHANDLED,
> };
>
> #define UCALL_MAX_ARGS 6
> diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
> index 12889d3e8948..ff4da2f95b13 100644
> --- a/tools/testing/selftests/kvm/include/x86_64/processor.h
> +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
> @@ -53,8 +53,6 @@
> #define CPUID_PKU (1ul << 3)
> #define CPUID_LA57 (1ul << 16)
>
> -#define UNEXPECTED_VECTOR_PORT 0xfff0u
> -
> /* General Registers in 64-Bit Mode */
> struct gpr64_regs {
> u64 rax;
> diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
> index e156061263a6..96e2bd9d66eb 100644
> --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
> +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
> @@ -1207,7 +1207,7 @@ static void set_idt_entry(struct kvm_vm *vm, int vector, unsigned long addr,
>
> void kvm_exit_unexpected_vector(uint32_t value)
> {
> - outl(UNEXPECTED_VECTOR_PORT, value);
> + ucall(UCALL_UNHANDLED, 1, value);
> }
>
> void route_exception(struct ex_regs *regs)
> @@ -1260,16 +1260,13 @@ void vm_install_vector_handler(struct kvm_vm *vm, int vector,
>
> void assert_on_unhandled_exception(struct kvm_vm *vm, uint32_t vcpuid)
> {
> - if (vcpu_state(vm, vcpuid)->exit_reason == KVM_EXIT_IO
> - && vcpu_state(vm, vcpuid)->io.port == UNEXPECTED_VECTOR_PORT
> - && vcpu_state(vm, vcpuid)->io.size == 4) {
> - /* Grab pointer to io data */
> - uint32_t *data = (void *)vcpu_state(vm, vcpuid)
> - + vcpu_state(vm, vcpuid)->io.data_offset;
> + struct ucall uc;
>
> + if (get_ucall(vm, vcpuid, &uc) == UCALL_UNHANDLED) {
> + uint64_t vector = uc.args[0];
> TEST_ASSERT(false,
> - "Unexpected vectored event in guest (vector:0x%x)",
> - *data);
> + "Unexpected vectored event in guest (vector:0x%lx)",
> + vector);
nit: Could have changed this TEST_ASSERT(false, ...) to TEST_FAIL while
touching it.
> }
> }
>
> --
> 2.31.1.527.g47e6f16901-goog
>
Reviewed-by: Andrew Jones <drjones@xxxxxxxxxx>
Thanks,
drew
