Re: [Qemu-devel] [PATCH 12/15] s390x: reduce TARGET_PHYS_ADDR_SPACE_BITS to 62

[Andreas Färber]

Am 24.05.2013 19:03, schrieb Paolo Bonzini:
> With the next patch, the memory API will complain if the
> TARGET_PHYS_ADDR_SPACE_BITS gets dangerously close to an
> overflow.  s390x can handle up to 64 bit of physical address
> space from its page tables, but we never use that much.  Just
> decrease the value.
> 
> Cc: Alexander Graf <address@hidden>
> Signed-off-by: Paolo Bonzini <address@hidden>

Didn't Avi introduce 128-bit arithmetic into QEMU to avoid 64-bit values
overflowing? Why are you limiting Memory API to 62-bit now?

Andreas

> ---
>  target-s390x/cpu.h | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h
> index 0ce82cf..6304c4d 100644
> --- a/target-s390x/cpu.h
> +++ b/target-s390x/cpu.h
> @@ -34,7 +34,10 @@
>  #include "exec/cpu-defs.h"
>  #define TARGET_PAGE_BITS 12
>  
> -#define TARGET_PHYS_ADDR_SPACE_BITS 64
> +/* Actually 64-bits, limited by the memory API to 62 bits.  We
> + * never use that much.
> + */
> +#define TARGET_PHYS_ADDR_SPACE_BITS 62
>  #define TARGET_VIRT_ADDR_SPACE_BITS 64
>  
>  #include "exec/cpu-all.h"
> 


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