Re: [kvm-unit-tests PATCH v2 1/4] x86: nSVM: Move common functionality of the main() to helper run_svm_tests

[Sean Christopherson <seanjc@google.com>]

On Thu, Mar 24, 2022, Manali Shukla wrote:
> nSVM tests are "incompatible" with usermode due to __setup_vm()
> call in main function.
> 
> If __setup_vm() is replaced with setup_vm() in main function, KUT
> will build the test with PT_USER_MASK set on all PTEs.
> 
> nNPT tests will be moved to their own file so that the tests
> don't need to fiddle with page tables midway through.
> 
> The quick and dirty approach would be to turn the current main()
> into a small helper, minus its call to __setup_vm() and call the
> helper function run_svm_tests() from main() function.
> 
> No functional change intended.
> 
> Suggested-by: Sean Christopherson <seanjc@google.com>
> Signed-off-by: Manali Shukla <manali.shukla@amd.com>
> ---
>  x86/svm.c | 14 +++++++++-----
>  x86/svm.h |  1 +
>  2 files changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/x86/svm.c b/x86/svm.c
> index 3f94b2a..e93e780 100644
> --- a/x86/svm.c
> +++ b/x86/svm.c
> @@ -406,17 +406,13 @@ test_wanted(const char *name, char *filters[], int filter_count)
>          }
>  }
>  
> -int main(int ac, char **av)
> +int run_svm_tests(int ac, char **av)
>  {
> -	/* Omit PT_USER_MASK to allow tested host.CR4.SMEP=1. */
> -	pteval_t opt_mask = 0;
>  	int i = 0;
>  
>  	ac--;
>  	av++;
>  
> -	__setup_vm(&opt_mask);
> -
>  	if (!this_cpu_has(X86_FEATURE_SVM)) {
>  		printf("SVM not availble\n");
>  		return report_summary();
> @@ -453,3 +449,11 @@ int main(int ac, char **av)
>  
>  	return report_summary();
>  }
> +
> +int main(int ac, char **av)
> +{
> +    pteval_t opt_mask = 0;

Please use tabs, not spaces.  Looks like this file is an unholy mess of tabs and
spaces.  And since we're riping this file apart, let's take the opportunity to
clean it up.  How about after moving code to svm_npt.c, go through and replace
all spaces with tabs and fixup indentation as appropriate in this file?

> +
> +    __setup_vm(&opt_mask);
> +    return run_svm_tests(ac, av);
> +}
> diff --git a/x86/svm.h b/x86/svm.h
> index f74b13a..9ab3aa5 100644
> --- a/x86/svm.h
> +++ b/x86/svm.h
> @@ -398,6 +398,7 @@ struct regs {
>  
>  typedef void (*test_guest_func)(struct svm_test *);
>  
> +int run_svm_tests(int ac, char **av);
>  u64 *npt_get_pte(u64 address);
>  u64 *npt_get_pde(u64 address);
>  u64 *npt_get_pdpe(void);
> -- 
> 2.30.2
>