Re: [Qemu-devel] [PATCH v6 13/19] cputlb: atomically update tlb fields used by tlb_reset_dirty

[Alex Bennée]

Richard Henderson <address@hidden> writes:

> On 11/09/2016 03:57 PM, Alex Bennée wrote:
>> +/* We currently can't handle more than 16 bits in the MMUIDX bitmask.
>> + */
>> +QEMU_BUILD_BUG_ON(NB_MMU_MODES > 16);
>
> We already assert <= 12 in exec/cpu_ldst.h.  Although really any such assert
> belongs in exec/cpu-defs.h, where we define CPU_TLB_BITS et al.
>
> That said, what's the technical restriction here?

Really we just need to ensure that we don't run out of bits to convert
the MMUIDX var args into the bottom bit of a page aligned address. We
already have:

  QEMU_BUILD_BUG_ON(NB_MMU_MODES > TARGET_PAGE_BITS_MIN);

So I guess I can drop the other one.

--
Alex Bennée