Re: [Qemu-devel] [PATCH 4/5] target-arm: get_phys_addr_lpae: more xn control

[Peter Maydell]

On 10 March 2015 at 16:48, Andrew Jones <address@hidden> wrote:
> On Tue, Mar 10, 2015 at 03:56:11PM +0000, Peter Maydell wrote:

>> For instance, you're missing a shift here on the ap bits, because
>> get_rw_prot needs AP[2:0] and 'ap' here is AP[2:1].
>
> Don't need the shift because get_rw_prot supports the 2-bit format.

No it doesn't...

>> Doesn't this lose us the "you need read permission to execute"
>> check (for 32-bit)? Something in here should be doing a
>> PAGE_READ check to see if we can have PAGE_EXEC.
>
> It's there. It's the '!user_rw' and the '!prot_rw'

Ah yes, and that works because you can't have a page which
is writable but not readable (which is what I'd forgotten).

-- PMM