Re: [PATCH v4 00/18] target/arm: sve load/store improvements

[Peter Maydell]

On Thu, 30 Apr 2020 at 17:28, Richard Henderson
<address@hidden> wrote:
>
> The goal here is to support MTE, but there's some cleanup to do.
>
> Technically, we have sufficient interfaces in cputlb.c now, but it
> requires multiple tlb lookups on different interfaces to do so.
>
> Adding probe_access_flags() allows probing the tlb and getting out
> some of the flags buried in the tlb comparator, such as TLB_MMIO
> and TLB_WATCHPOINT.  In addition, we get no-fault semantics,
> which we don't have via probe_acccess().
>
> Looking forward to MTE, we can examine the Tagged bit on a per-page
> basis and avoid dozens of mte_check calls that must be Unchecked.
> That comes later, in a new version of the MTE patch set, but I do
> add comments for where the checks should be added.
>
> Version 4 addresses some review comments.
> Only 2 patches still unreviewed:
>
> 0004-accel-tcg-Add-probe_access_flags.patch
> 0013-target-arm-Update-contiguous-first-fault-and-no-f.patch

I've reviewed patch 13, but I still don't understand why you've
made the size-related changes in patch 4, so I've continued
our conversation in the thread on the v3 version of that patch.

thanks
-- PMM