[Looping in Catalin, as we just had an interesting discussion about this] Hi Anup, On 09/05/13 06:53, Anup Patel wrote: > We cannot use existing stage1 PTE_ATTRINDX() macro for specifying > stage2 memory type because stage1 ATTRINDX = PTE[4:2] and stage2 > MEMATTR = PTE[5:2]. You're right, this is a bug. But... > This patch adds bit definetions for specifying device, noncacheable, > writethrough, and writeback memory types in stage2 PTE and also uses > it in PAGE_S2 and PAGE_S2_DEVICE. ... I have the feeling we don't need most of this: Stage-2 memory attributes can only restrict what the guest puts in its Stage-1. Which means that unless we really need to play some ugly tricks on the guest (which we don't), it is probably best to leave everything as Normal, Outer Write-Back, Inner Write-Back. So I think the right fix is to get rid of of PAGE_S2_DEVICE, use PAGE_S2 for everything, and set MemAttr[3:0] to 0b1111. I'll try that and cook a separate patch if it looks good enough (it is likely to impact the 32bit code as well...). > Signed-off-by: Anup Patel <anup.patel@xxxxxxxxxx> > Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@xxxxxxxxxx> > --- > arch/arm64/include/asm/pgtable-hwdef.h | 4 ++++ > arch/arm64/include/asm/pgtable.h | 6 ++++-- > arch/arm64/mm/mmu.c | 9 +++++++++ > 3 files changed, 17 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h > index c49cd61..555babb 100644 > --- a/arch/arm64/include/asm/pgtable-hwdef.h > +++ b/arch/arm64/include/asm/pgtable-hwdef.h > @@ -73,6 +73,10 @@ > */ > #define PTE_S2_RDONLY (_AT(pteval_t, 1) << 6) /* HAP[1] */ > #define PTE_S2_RDWR (_AT(pteval_t, 3) << 6) /* HAP[2:1] */ > +#define PTE_S2_MT_DEVICE (_AT(pteval_t, 0x0) << 2) /* MemAttr[3:0] */ > +#define PTE_S2_MT_UNCACHED (_AT(pteval_t, 0x5) << 2) /* MemAttr[3:0] */ > +#define PTE_S2_MT_WRITETHROUGH (_AT(pteval_t, 0xa) << 2) /* MemAttr[3:0] */ > +#define PTE_S2_MT_WRITEBACK (_AT(pteval_t, 0xf) << 2) /* MemAttr[3:0] */ > > /* > * EL2/HYP PTE/PMD definitions > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index 43ce724..3003fd0 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -60,6 +60,8 @@ extern void __pgd_error(const char *file, int line, unsigned long val); > #define _PAGE_DEFAULT PTE_TYPE_PAGE | PTE_AF > > extern pgprot_t pgprot_default; > +extern pgprot_t pgprot_s2; > +extern pgprot_t pgprot_s2_device; > > #define __pgprot_modify(prot,mask,bits) \ > __pgprot((pgprot_val(prot) & ~(mask)) | (bits)) > @@ -79,8 +81,8 @@ extern pgprot_t pgprot_default; > #define PAGE_HYP _MOD_PROT(pgprot_default, PTE_HYP) > #define PAGE_HYP_DEVICE _MOD_PROT(__pgprot(PROT_DEVICE_nGnRE), PTE_HYP) > > -#define PAGE_S2 _MOD_PROT(pgprot_default, PTE_S2_RDONLY) > -#define PAGE_S2_DEVICE __pgprot_modify(__pgprot(PROT_DEVICE_nGnRE), PTE_PXN, PTE_S2_RDWR) > +#define PAGE_S2 _MOD_PROT(pgprot_s2, PTE_USER | PTE_S2_RDONLY) > +#define PAGE_S2_DEVICE _MOD_PROT(pgprot_s2_device, PTE_USER | PTE_S2_RDWR) Beware, you are reintroducing a bug I fixed a while ago (Stage-2 has no USER bit). Thanks, M. -- Jazz is not dead. It just smells funny... _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
