Re: [kvm-unit-tests PATCH v6 1/8] lib: s390x: introduce bitfield for PSW mask

Janosch Frank
2023-09-05T16:03:25Z

On 9/4/23 10:22, Nico Boehr wrote:
> Changing the PSW mask is currently little clumsy, since there is only the
> PSW_MASK_* defines. This makes it hard to change e.g. only the address
> space in the current PSW without a lot of bit fiddling.
>
> Introduce a bitfield for the PSW mask. This makes this kind of
> modifications much simpler and easier to read.
>
> Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
> ---
> lib/s390x/asm/arch_def.h | 26 +++++++++++++++++++++++++-
> s390x/selftest.c | 34 ++++++++++++++++++++++++++++++++++
> 2 files changed, 59 insertions(+), 1 deletion(-)
>
> diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
> index bb26e008cc68..5a712f97f129 100644
> --- a/lib/s390x/asm/arch_def.h
> +++ b/lib/s390x/asm/arch_def.h
> @@ -37,12 +37,36 @@ struct stack_frame_int {
> };
>
> struct psw {
> - uint64_t mask;
> + union {
> + uint64_t mask;
> + struct {
> + uint64_t reserved00:1;
> + uint64_t per:1;
> + uint64_t reserved02:3;
> + uint64_t dat:1;
> + uint64_t io:1;
> + uint64_t ext:1;
> + uint64_t key:4;
> + uint64_t reserved12:1;
> + uint64_t mchk:1;
> + uint64_t wait:1;
> + uint64_t pstate:1;
> + uint64_t as:2;
> + uint64_t cc:2;
> + uint64_t prg_mask:4;
> + uint64_t reserved24:7;
> + uint64_t ea:1;
> + uint64_t ba:1;
> + uint64_t reserved33:31;
> + };
> + };
> uint64_t addr;
> };
> +_Static_assert(sizeof(struct psw) == 16, "PSW size");
>
> #define PSW(m, a) ((struct psw){ .mask = (m), .addr = (uint64_t)(a) })
>
> +

We can fix this up when picking.

Other than that:
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>