Re: [PATCH 2/4] KVM: s390: selftests: Use TAP interface in the sync_regs test

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

On Thu, 14 Apr 2022 12:53:20 +0200
Thomas Huth <thuth@redhat.com> wrote:

> The sync_regs test currently does not have any output (unless one
> of the TEST_ASSERT statement fails), so it's hard to say for a user
> whether a certain new sub-test has been included in the binary or
> not. Let's make this a little bit more user-friendly and include
> some TAP output via the kselftests.h interface.
> To be able to distinguish the different sub-tests more easily, we
> also break up the huge main() function here in more fine grained
> parts.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>  .../selftests/kvm/s390x/sync_regs_test.c      | 86 ++++++++++++++-----
>  1 file changed, 65 insertions(+), 21 deletions(-)
> 
> diff --git a/tools/testing/selftests/kvm/s390x/sync_regs_test.c b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
> index caf7b8859a94..d5ddcbb82d12 100644
> --- a/tools/testing/selftests/kvm/s390x/sync_regs_test.c
> +++ b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
> @@ -21,6 +21,7 @@
>  #include "test_util.h"
>  #include "kvm_util.h"
>  #include "diag318_test_handler.h"
> +#include "kselftest.h"
>  
>  #define VCPU_ID 5
>  
> @@ -74,27 +75,9 @@ static void compare_sregs(struct kvm_sregs *left, struct kvm_sync_regs *right)
>  #define TEST_SYNC_FIELDS   (KVM_SYNC_GPRS|KVM_SYNC_ACRS|KVM_SYNC_CRS|KVM_SYNC_DIAG318)
>  #define INVALID_SYNC_FIELD 0x80000000
>  
> -int main(int argc, char *argv[])
> +void test_read_invalid(struct kvm_vm *vm, struct kvm_run *run)
>  {
> -	struct kvm_vm *vm;
> -	struct kvm_run *run;
> -	struct kvm_regs regs;
> -	struct kvm_sregs sregs;
> -	int rv, cap;
> -
> -	/* Tell stdout not to buffer its content */
> -	setbuf(stdout, NULL);
> -
> -	cap = kvm_check_cap(KVM_CAP_SYNC_REGS);
> -	if (!cap) {
> -		print_skip("CAP_SYNC_REGS not supported");
> -		exit(KSFT_SKIP);
> -	}
> -
> -	/* Create VM */
> -	vm = vm_create_default(VCPU_ID, 0, guest_code);
> -
> -	run = vcpu_state(vm, VCPU_ID);
> +	int rv;
>  
>  	/* Request reading invalid register set from VCPU. */
>  	run->kvm_valid_regs = INVALID_SYNC_FIELD;
> @@ -110,6 +93,11 @@ int main(int argc, char *argv[])
>  		    "Invalid kvm_valid_regs did not cause expected KVM_RUN error: %d\n",
>  		    rv);
>  	vcpu_state(vm, VCPU_ID)->kvm_valid_regs = 0;
> +}
> +
> +void test_set_invalid(struct kvm_vm *vm, struct kvm_run *run)
> +{
> +	int rv;
>  
>  	/* Request setting invalid register set into VCPU. */
>  	run->kvm_dirty_regs = INVALID_SYNC_FIELD;
> @@ -125,6 +113,13 @@ int main(int argc, char *argv[])
>  		    "Invalid kvm_dirty_regs did not cause expected KVM_RUN error: %d\n",
>  		    rv);
>  	vcpu_state(vm, VCPU_ID)->kvm_dirty_regs = 0;
> +}
> +
> +void test_req_and_verify_all_valid_regs(struct kvm_vm *vm, struct kvm_run *run)
> +{
> +	struct kvm_sregs sregs;
> +	struct kvm_regs regs;
> +	int rv;
>  
>  	/* Request and verify all valid register sets. */
>  	run->kvm_valid_regs = TEST_SYNC_FIELDS;
> @@ -146,6 +141,13 @@ int main(int argc, char *argv[])
>  
>  	vcpu_sregs_get(vm, VCPU_ID, &sregs);
>  	compare_sregs(&sregs, &run->s.regs);
> +}
> +
> +void test_set_and_verify_various_reg_values(struct kvm_vm *vm, struct kvm_run *run)
> +{
> +	struct kvm_sregs sregs;
> +	struct kvm_regs regs;
> +	int rv;
>  
>  	/* Set and verify various register values */
>  	run->s.regs.gprs[11] = 0xBAD1DEA;
> @@ -180,6 +182,11 @@ int main(int argc, char *argv[])
>  
>  	vcpu_sregs_get(vm, VCPU_ID, &sregs);
>  	compare_sregs(&sregs, &run->s.regs);
> +}
> +
> +void test_clear_kvm_dirty_regs_bits(struct kvm_vm *vm, struct kvm_run *run)
> +{
> +	int rv;
>  
>  	/* Clear kvm_dirty_regs bits, verify new s.regs values are
>  	 * overwritten with existing guest values.
> @@ -200,8 +207,45 @@ int main(int argc, char *argv[])
>  	TEST_ASSERT(run->s.regs.diag318 != 0x4B1D,
>  		    "diag318 sync regs value incorrect 0x%llx.",
>  		    run->s.regs.diag318);
> +}
> +
> +struct testdef {
> +	const char *name;
> +	void (*test)(struct kvm_vm *vm, struct kvm_run *run);
> +} testlist[] = {
> +	{ "read invalid", test_read_invalid },
> +	{ "set invalid", test_set_invalid },
> +	{ "request+verify all valid regs", test_req_and_verify_all_valid_regs },
> +	{ "set+verify various regs", test_set_and_verify_various_reg_values },
> +	{ "clear kvm_dirty_regs bits", test_clear_kvm_dirty_regs_bits },
> +};
> +
> +int main(int argc, char *argv[])
> +{
> +	static struct kvm_run *run;
> +	static struct kvm_vm *vm;
> +	int idx;
> +
> +	/* Tell stdout not to buffer its content */
> +	setbuf(stdout, NULL);
> +
> +	if (!kvm_check_cap(KVM_CAP_SYNC_REGS))
> +		ksft_exit_skip("CAP_SYNC_REGS not supported");

I'm not an expert on the TAP format, but wouldn't it be more meaningful
to print the header first? (like you do in the previous patch)

> +
> +	/* Create VM */
> +	vm = vm_create_default(VCPU_ID, 0, guest_code);
> +
> +	run = vcpu_state(vm, VCPU_ID);
> +
> +	ksft_print_header();
> +	ksft_set_plan(ARRAY_SIZE(testlist));
> +
> +	for (idx = 0; idx < ARRAY_SIZE(testlist); idx++) {
> +		testlist[idx].test(vm, run);
> +		ksft_test_result_pass("%s\n", testlist[idx].name);
> +	}
>  
>  	kvm_vm_free(vm);
>  
> -	return 0;
> +	ksft_finished();
>  }