Re: [Qemu-devel] [qemu-s390x] [PATCH-for-4.2 v1 1/6] s390x/mmu: ASC selection in s390_cpu_get_phys_page_debug()

[Thomas Huth <thuth@redhat.com>]

On 8/12/19 1:27 PM, David Hildenbrand wrote:
> Let's select the ASC before calling the function. This is a prepararion
> to remove the ASC magic depending on the access mode from mmu_translate.
> 
> There is currently no way to distinguish if we have code or data access.
> For now, we were using code access, because especially when debugging with
> the gdbstub, we want to read and disassemble what we single-step.

IMHO we should add a "instruction" bit to MemTxAttrs and then use the
...page_attrs_debug() interface instead. But ok, that's likely really
something for a separate clean-up, so for the time being:

Reviewed-by: Thomas Huth <thuth@redhat.com>

> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  target/s390x/helper.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/target/s390x/helper.c b/target/s390x/helper.c
> index 13ae9909ad..c5fb8966b6 100644
> --- a/target/s390x/helper.c
> +++ b/target/s390x/helper.c
> @@ -58,6 +58,11 @@ hwaddr s390_cpu_get_phys_page_debug(CPUState *cs, vaddr vaddr)
>          vaddr &= 0x7fffffff;
>      }
>  
> +    /* We want to read the code (e.g., see what we are single-stepping).*/
> +    if (asc != PSW_ASC_HOME) {
> +        asc = PSW_ASC_PRIMARY;
> +    }
> +
>      if (mmu_translate(env, vaddr, MMU_INST_FETCH, asc, &raddr, &prot, false)) {
>          return -1;
>      }
>