Re: [kvm-unit-tests PATCH v4 2/3] x86: Add support for running a nested guest multiple times in one test

[Sean Christopherson <seanjc@google.com>]

On Fri, Jan 21, 2022, Aaron Lewis wrote:
> KUT has a limit of only being able to run one nested guest per vmx test.
> This is limiting and not necessary.  Add support for allowing a test to
> run guest code multiple times.
> 
> Signed-off-by: Aaron Lewis <aaronlewis@google.com>
> ---
>  x86/vmx.c | 24 ++++++++++++++++++++++--
>  x86/vmx.h |  2 ++
>  2 files changed, 24 insertions(+), 2 deletions(-)
> 
> diff --git a/x86/vmx.c b/x86/vmx.c
> index f4fbb94..51eed8c 100644
> --- a/x86/vmx.c
> +++ b/x86/vmx.c
> @@ -1884,15 +1884,35 @@ void test_add_teardown(test_teardown_func func, void *data)
>  	step->data = data;
>  }
>  
> +static void __test_set_guest(test_guest_func func)
> +{
> +	assert(current->v2);
> +	v2_guest_main = func;
> +}
> +
>  /*
>   * Set the target of the first enter_guest call. Can only be called once per
>   * test. Must be called before first enter_guest call.
>   */
>  void test_set_guest(test_guest_func func)
>  {
> -	assert(current->v2);
>  	TEST_ASSERT_MSG(!v2_guest_main, "Already set guest func.");
> -	v2_guest_main = func;
> +	__test_set_guest(func);
> +}
> +
> +/*
> + * Set the target of the enter_guest call and reset the RIP so 'func' will
> + * start from the beginning.  This can be called multiple times per test.
> + */
> +void test_override_guest(test_guest_func func)
> +{
> +	__test_set_guest(func);
> +	init_vmcs_guest();
> +}
> +
> +void test_set_guest_finished(void)
> +{
> +	guest_finished = 1;

Adding test_set_guest_finished() should be a separate commit.

>  }
>  
>  static void check_for_guest_termination(union exit_reason exit_reason)
> diff --git a/x86/vmx.h b/x86/vmx.h
> index 4423986..11cb665 100644
> --- a/x86/vmx.h
> +++ b/x86/vmx.h
> @@ -1055,7 +1055,9 @@ void hypercall(u32 hypercall_no);
>  typedef void (*test_guest_func)(void);
>  typedef void (*test_teardown_func)(void *data);
>  void test_set_guest(test_guest_func func);
> +void test_override_guest(test_guest_func func);
>  void test_add_teardown(test_teardown_func func, void *data);
>  void test_skip(const char *msg);
> +void test_set_guest_finished(void);
>  
>  #endif
> -- 
> 2.35.0.rc0.227.g00780c9af4-goog
>