Re: [PATCH] selftests: kvm: Check whether SIDA memop fails for normal guests

[Shuah Khan <skhan@linuxfoundation.org>]

On 2/15/22 12:48 AM, Thomas Huth wrote:
> Commit 2c212e1baedc ("KVM: s390: Return error on SIDA memop on normal
> guest") fixed the behavior of the SIDA memops for normal guests. It
> would be nice to have a way to test whether the current kernel has
> the fix applied or not. Thus add a check to the KVM selftests for
> these two memops.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>   tools/testing/selftests/kvm/s390x/memop.c | 15 +++++++++++++++
>   1 file changed, 15 insertions(+)
> 
> diff --git a/tools/testing/selftests/kvm/s390x/memop.c b/tools/testing/selftests/kvm/s390x/memop.c
> index 9f49ead380ab..d19c3ffdea3f 100644
> --- a/tools/testing/selftests/kvm/s390x/memop.c
> +++ b/tools/testing/selftests/kvm/s390x/memop.c
> @@ -160,6 +160,21 @@ int main(int argc, char *argv[])
>   	run->psw_mask &= ~(3UL << (63 - 17));   /* Disable AR mode */
>   	vcpu_run(vm, VCPU_ID);                  /* Run to sync new state */
>   
> +	/* Check that the SIDA calls are rejected for non-protected guests */
> +	ksmo.gaddr = 0;
> +	ksmo.flags = 0;
> +	ksmo.size = 8;
> +	ksmo.op = KVM_S390_MEMOP_SIDA_READ;
> +	ksmo.buf = (uintptr_t)mem1;
> +	ksmo.sida_offset = 0x1c0;
> +	rv = _vcpu_ioctl(vm, VCPU_ID, KVM_S390_MEM_OP, &ksmo);
> +	TEST_ASSERT(rv == -1 && errno == EINVAL,
> +		    "ioctl does not reject SIDA_READ in non-protected mode");

Printing what passed would be a good addition to understand the tests that
get run and expected to pass.

> +	ksmo.op = KVM_S390_MEMOP_SIDA_WRITE;
> +	rv = _vcpu_ioctl(vm, VCPU_ID, KVM_S390_MEM_OP, &ksmo);
> +	TEST_ASSERT(rv == -1 && errno == EINVAL,
> +		    "ioctl does not reject SIDA_WRITE in non-protected mode");
> +

Same here.

>   	kvm_vm_free(vm);
>   
>   	return 0;
> 

Something to consider in a follow-on patch and future changes to these tests.

Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>

thanks,
-- Shuah