Re: [PATCH v3 4/4] pc-bios/s390x: Fix reset psw mask

[Christian Borntraeger <borntraeger@de.ibm.com>]

On 03.12.19 14:28, Janosch Frank wrote:
> We need to set the short psw indication bit in the reset psw, as it is
> a short psw.
> 
> fixes: 9629823290 ("pc-bios/s390-ccw: do a subsystem reset before running the guest")
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>

We should also add 
commit 24bb1fa36ff7b25ee774dbe4a18830dc782b54bf (HEAD, github-cohuck/s390-next)
Author:     Janosch Frank <frankja@linux.ibm.com>
AuthorDate: Fri Nov 29 09:20:23 2019 -0500
Commit:     Cornelia Huck <cohuck@redhat.com>
CommitDate: Mon Dec 2 09:58:57 2019 +0100

    s390x: Properly fetch and test the short psw on diag308 subc 0/1

or whatever the final commit id will be. While this patch is not "broken"
it exposes the bug.



> ---
>  pc-bios/s390-ccw/jump2ipl.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/pc-bios/s390-ccw/jump2ipl.c b/pc-bios/s390-ccw/jump2ipl.c
> index 266f1502b9..da13c43cc0 100644
> --- a/pc-bios/s390-ccw/jump2ipl.c
> +++ b/pc-bios/s390-ccw/jump2ipl.c
> @@ -12,11 +12,11 @@
>  #define KERN_IMAGE_START 0x010000UL
>  #define PSW_MASK_64 0x0000000100000000ULL
>  #define PSW_MASK_32 0x0000000080000000ULL
> -#define IPL_PSW_MASK (PSW_MASK_32 | PSW_MASK_64)
> +#define PSW_MASK_SHORTPSW 0x0008000000000000ULL
> +#define RESET_PSW_MASK (PSW_MASK_SHORTPSW | PSW_MASK_32 | PSW_MASK_64)
>  
>  typedef struct ResetInfo {
> -    uint32_t ipl_mask;
> -    uint32_t ipl_addr;
> +    uint64_t ipl_psw;
>      uint32_t ipl_continue;
>  } ResetInfo;
>  
> @@ -50,7 +50,9 @@ void jump_to_IPL_code(uint64_t address)
>      ResetInfo *current = 0;
>  
>      save = *current;
> -    current->ipl_addr = (uint32_t) (uint64_t) &jump_to_IPL_2;
> +
> +    current->ipl_psw = (uint64_t) &jump_to_IPL_2;
> +    current->ipl_psw |= RESET_PSW_MASK;
>      current->ipl_continue = address & 0x7fffffff;
>  
>      debug_print_int("set IPL addr to", current->ipl_continue);
> @@ -82,7 +84,7 @@ void jump_to_low_kernel(void)
>      }
>  
>      /* Trying to get PSW at zero address */
> -    if (*((uint64_t *)0) & IPL_PSW_MASK) {
> +    if (*((uint64_t *)0) & RESET_PSW_MASK) {
>          jump_to_IPL_code((*((uint64_t *)0)) & 0x7fffffff);
>      }
>  
>