On Thu, Jan 24, 2013 at 12:02 PM, Catalin Marinas <catalin.marinas@xxxxxxx> wrote: > On Thu, Jan 24, 2013 at 04:05:33PM +0000, Christoffer Dall wrote: >> On Thu, Jan 24, 2013 at 6:39 AM, Catalin Marinas >> <catalin.marinas@xxxxxxx> wrote: >> > On Wed, Jan 16, 2013 at 05:57:26PM +0000, Christoffer Dall wrote: >> >> diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h >> >> index a3f3792..6ef8afd 100644 >> >> --- a/arch/arm/include/asm/pgtable-3level.h >> >> +++ b/arch/arm/include/asm/pgtable-3level.h >> >> @@ -104,11 +104,29 @@ >> >> */ >> >> #define L_PGD_SWAPPER (_AT(pgdval_t, 1) << 55) /* swapper_pg_dir entry */ >> >> >> >> +/* >> >> + * 2nd stage PTE definitions for LPAE. >> >> + */ >> >> +#define L_PTE_S2_MT_UNCACHED (_AT(pteval_t, 0x5) << 2) /* MemAttr[3:0] */ >> >> +#define L_PTE_S2_MT_WRITETHROUGH (_AT(pteval_t, 0xa) << 2) /* MemAttr[3:0] */ >> >> +#define L_PTE_S2_MT_WRITEBACK (_AT(pteval_t, 0xf) << 2) /* MemAttr[3:0] */ >> >> +#define L_PTE_S2_RDONLY (_AT(pteval_t, 1) << 6) /* HAP[1] */ >> >> +#define L_PTE_S2_RDWR (_AT(pteval_t, 2) << 6) /* HAP[2:1] */ >> > >> > Why is this called L_PTE_S2_RDWR? The ARM ARM shows HAP[2:1] as 0b11 for >> > read/write and 0b10 for WRONLY. >> >> it should be >> >> +#define L_PTE_S2_RDWR (_AT(pteval_t, 3) << 6) /* HAP[2:1] */ > > OK. > >> >> >> --- a/arch/arm/include/asm/pgtable.h >> >> +++ b/arch/arm/include/asm/pgtable.h >> >> @@ -70,6 +70,9 @@ extern void __pgd_error(const char *file, int line, pgd_t); >> >> >> >> extern pgprot_t pgprot_user; >> >> extern pgprot_t pgprot_kernel; >> >> +extern pgprot_t pgprot_hyp_device; >> >> +extern pgprot_t pgprot_s2; >> >> +extern pgprot_t pgprot_s2_device; >> >> >> >> #define _MOD_PROT(p, b) __pgprot(pgprot_val(p) | (b)) >> >> >> >> @@ -82,6 +85,10 @@ extern pgprot_t pgprot_kernel; >> >> #define PAGE_READONLY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY) >> >> #define PAGE_KERNEL _MOD_PROT(pgprot_kernel, L_PTE_XN) >> >> #define PAGE_KERNEL_EXEC pgprot_kernel >> >> +#define PAGE_HYP _MOD_PROT(pgprot_kernel, L_PTE_HYP) >> >> +#define PAGE_HYP_DEVICE _MOD_PROT(pgprot_hyp_device, L_PTE_HYP) >> >> +#define PAGE_S2 _MOD_PROT(pgprot_s2, L_PTE_S2_RDONLY) >> >> +#define PAGE_S2_DEVICE _MOD_PROT(pgprot_s2_device, L_PTE_USER | L_PTE_S2_RDONLY) >> > >> > Are these S2 read-only by default? >> >> not sure I understand what you're asking here? > > Why do you pass L_PTE_S2_RDONLY? Do you need to restrict guest writes > via the stage 2 attributes? > yes, for example when KSM merges two pages, then it must be mapped read-only to the guest so that we catch writes and perform COW. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
