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

Catalin Marinas catalin.marinas at arm.com
Tue Sep 18 11:07:57 EDT 2012


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.

-- 
Catalin



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