On Tue, Sep 21, 2021 at 05:11:21PM +0000, Oliver Upton wrote:
> The SMC64 calling convention passes a function identifier in w0 and its
> parameters in x1-x17. Given this, there are two deviations in the
> SMC64 call performed by the steal_time test: the function identifier is
> assigned to a 64 bit register and the parameter is only 32 bits wide.
>
> Align the call with the SMCCC by using a 32 bit register to handle the
> function identifier and increasing the parameter width to 64 bits.
>
> Suggested-by: Andrew Jones <drjones@xxxxxxxxxx>
> Signed-off-by: Oliver Upton <oupton@xxxxxxxxxx>
> ---
> tools/testing/selftests/kvm/steal_time.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/steal_time.c b/tools/testing/selftests/kvm/steal_time.c
> index ecec30865a74..aafaa8e38b7c 100644
> --- a/tools/testing/selftests/kvm/steal_time.c
> +++ b/tools/testing/selftests/kvm/steal_time.c
> @@ -118,12 +118,12 @@ struct st_time {
> uint64_t st_time;
> };
>
> -static int64_t smccc(uint32_t func, uint32_t arg)
> +static int64_t smccc(uint32_t func, uint64_t arg)
> {
> unsigned long ret;
>
> asm volatile(
> - "mov x0, %1\n"
> + "mov w0, %w1\n"
> "mov x1, %2\n"
> "hvc #0\n"
> "mov %0, x0\n"
> --
> 2.33.0.464.g1972c5931b-goog
>
Reviewed-by: Andrew Jones <drjones@xxxxxxxxxx>
