Re: [kvm-unit-tests PATCH v2 5/7] s390x: smp: Wait for cpu setup to finish

David Hildenbrand
2020-01-16T12:20:04Z

On 16.01.20 13:05, Janosch Frank wrote:
> We store the user provided psw address into restart new, so a psw
> restart does not lead us through setup again.
>
> Also we wait on smp_cpu_setup() until the cpu has finished setup
> before returning. This is necessary for z/VM and LPAR where sigp is
> asynchronous.
>
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
> lib/s390x/smp.c | 2 ++
> s390x/cstart64.S | 2 ++
> 2 files changed, 4 insertions(+)
>
> diff --git a/lib/s390x/smp.c b/lib/s390x/smp.c
> index f984a34..0a0bc1c 100644
> --- a/lib/s390x/smp.c
> +++ b/lib/s390x/smp.c
> @@ -199,6 +199,8 @@ int smp_cpu_setup(uint16_t addr, struct psw psw)
>
> /* Start processing */
> smp_cpu_restart_nolock(addr, NULL);
> + /* Wait until the cpu has finished setup and started the provided psw */
> + while (lc->restart_new_psw.addr != psw.addr) { mb(); }
> out:
> spin_unlock(&lock);
> return rc;
> diff --git a/s390x/cstart64.S b/s390x/cstart64.S
> index 86dd4c4..9af6bb3 100644
> --- a/s390x/cstart64.S
> +++ b/s390x/cstart64.S
> @@ -159,6 +159,8 @@ smp_cpu_setup_state:
> xgr %r1, %r1
> lmg %r0, %r15, GEN_LC_SW_INT_GRS
> lctlg %c0, %c0, GEN_LC_SW_INT_CRS
> + /* We should only go once through cpu setup and not for every restart */
> + stg %r14, GEN_LC_RESTART_NEW_PSW + 8
> br %r14
>
> pgm_int:
>

Reviewed-by: David Hildenbrand <david@redhat.com>

--
Thanks,

David / dhildenb