[PATCH 02/15] ARM: Add page table and page defines needed by KVM

Christoffer Dall c.dall at virtualopensystems.com
Tue Sep 18 11:10:04 EDT 2012


On Tue, Sep 18, 2012 at 11:07 AM, Catalin Marinas
<catalin.marinas at arm.com> wrote:
> On Tue, Sep 18, 2012 at 04:05:13PM +0100, Christoffer Dall wrote:
>> On Tue, Sep 18, 2012 at 10:06 AM, Catalin Marinas
>> <catalin.marinas at arm.com> wrote:
>> > On 18 September 2012 13:47, Will Deacon <will.deacon at arm.com> wrote:
>> >> On Sat, Sep 15, 2012 at 04:34:43PM +0100, Christoffer Dall wrote:
>> >>> +#define L_PTE2_SHARED                L_PTE_SHARED
>> >>> +#define L_PTE2_READ          (_AT(pteval_t, 1) << 6) /* HAP[0] */
>> >>> +#define L_PTE2_WRITE         (_AT(pteval_t, 1) << 7) /* HAP[1] */
>> >>
>> >> This is actually HAP[2:1], not HAP[1:0]. Also, can you follow what we do for
>> >> stage 1 translation and name these RDONLY and WRONLY (do you even use
>> >> that?).
>> >
>> > We can't use RDONLY as this would have value 0 as the HAP attributes
>> > (stage 2 overriding stage 1 translation attributes). Unless you add 4
>> > definitions like NOACCESS, RDONLY, WRONLY and RDWR to cover all the
>> > bit combinations.
>> >
>> >>> +#define L_PTE2_NORM_WB               (_AT(pteval_t, 3) << 4) /* MemAttr[3:2] */
>> >>> +#define L_PTE2_INNER_WB              (_AT(pteval_t, 3) << 2) /* MemAttr[1:0] */
>> >>
>> >> Another minor nit: PTE2 looks awful. Maybe L_PTE_HYP_* instead?
>> >
>> > L_PTE_HYP may be confused with the Stage 1 Hyp translation which is
>> > different from the guest Stage 2.
>>
>> exactly, it's misleading, how about L_PTE_STAGE2, a little verbose,
>> but clear...?
>
> I don't mind any (apart from L_PTE_HYP_ would be confusing) for stage 2.
> You could just use S2 to make it shorter.
>
I'm good with that, done.

-Christoffer



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