Re: [kvm-unit-tests PATCH 4/5] s390x: Use library functions for snippet exit

[Claudio Imbrenda <imbrenda@linux.ibm.com>]

On Wed, 13 Dec 2023 13:49:41 +0100
Nina Schoetterl-Glausch <nsg@linux.ibm.com> wrote:

> Replace the existing code for exiting from snippets with the newly
> introduced library functionality.
> This causes additional report()s, otherwise no change in functionality
> intended.
> 
> Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
> ---
>  s390x/sie-dat.c            | 10 ++--------
>  s390x/snippets/c/sie-dat.c | 19 +------------------
>  2 files changed, 3 insertions(+), 26 deletions(-)
> 
> diff --git a/s390x/sie-dat.c b/s390x/sie-dat.c
> index 9e60f26e..6b6e6868 100644
> --- a/s390x/sie-dat.c
> +++ b/s390x/sie-dat.c
> @@ -27,23 +27,17 @@ static void test_sie_dat(void)
>  	uint64_t test_page_gpa, test_page_hpa;
>  	uint8_t *test_page_hva, expected_val;
>  	bool contents_match;
> -	uint8_t r1;
>  
>  	/* guest will tell us the guest physical address of the test buffer */
>  	sie(&vm);
> -	assert(vm.sblk->icptcode == ICPT_INST &&
> -	       (vm.sblk->ipa & 0xff00) == 0x8300 && vm.sblk->ipb == 0x9c0000);
> -
> -	r1 = (vm.sblk->ipa & 0xf0) >> 4;
> -	test_page_gpa = vm.save_area.guest.grs[r1];
> +	assert(snippet_get_force_exit_value(&vm, &test_page_gpa));

but the function inside the assert will already report a failure, right?
then why the assert? (the point I'm trying to make is that the function
should not report stuff, see my comments in the previous patch)

>  	test_page_hpa = virt_to_pte_phys(guest_root, (void*)test_page_gpa);
>  	test_page_hva = __va(test_page_hpa);
>  	report_info("test buffer gpa=0x%lx hva=%p", test_page_gpa, test_page_hva);
>  
>  	/* guest will now write to the test buffer and we verify the contents */
>  	sie(&vm);
> -	assert(vm.sblk->icptcode == ICPT_INST &&
> -	       vm.sblk->ipa == 0x8300 && vm.sblk->ipb == 0x440000);
> +	assert(snippet_check_force_exit(&vm));
>  
>  	contents_match = true;
>  	for (unsigned int i = 0; i < GUEST_TEST_PAGE_COUNT; i++) {
> diff --git a/s390x/snippets/c/sie-dat.c b/s390x/snippets/c/sie-dat.c
> index ecfcb60e..414afd42 100644
> --- a/s390x/snippets/c/sie-dat.c
> +++ b/s390x/snippets/c/sie-dat.c
> @@ -9,28 +9,11 @@
>   */
>  #include <libcflat.h>
>  #include <asm-generic/page.h>
> +#include <snippet-guest.h>
>  #include "sie-dat.h"
>  
>  static uint8_t test_pages[GUEST_TEST_PAGE_COUNT * PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
>  
> -static inline void force_exit(void)
> -{
> -	asm volatile("diag	0,0,0x44\n"
> -		     :
> -		     :
> -		     : "memory"
> -	);
> -}
> -
> -static inline void force_exit_value(uint64_t val)
> -{
> -	asm volatile("diag	%[val],0,0x9c\n"
> -		     :
> -		     : [val] "d"(val)
> -		     : "memory"
> -	);
> -}
> -
>  int main(void)
>  {
>  	uint8_t *invalid_ptr;