From 05345b0f006ac226d0d25d48fcb2d792ac44a071 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Mon, 16 Jun 2008 15:01:53 -0700 Subject: xen: mask unwanted pte bits in __supported_pte_mask [ Stable: this isn't a bugfix in itself, but it's a pre-requiste for "xen: don't drop NX bit" ] Signed-off-by: Jeremy Fitzhardinge Cc: Stable Kernel Cc: the arch/x86 maintainers Signed-off-by: Ingo Molnar --- arch/x86/xen/enlighten.c | 5 +++++ arch/x86/xen/mmu.c | 4 +--- 2 files changed, 6 insertions(+), 3 deletions(-) (limited to 'arch') diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index c8a56e457d61..c048de34d6a1 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1228,6 +1228,11 @@ asmlinkage void __init xen_start_kernel(void) if (xen_feature(XENFEAT_supervisor_mode_kernel)) pv_info.kernel_rpl = 0; + /* Prevent unwanted bits from being set in PTEs. */ + __supported_pte_mask &= ~_PAGE_GLOBAL; + if (!is_initial_xendomain()) + __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD); + /* set the limit of our address space */ xen_reserve_top(); diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 3525ef523a74..3f2a67fe6ad6 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -199,10 +199,8 @@ pgdval_t xen_pgd_val(pgd_t pgd) pte_t xen_make_pte(pteval_t pte) { - if (pte & _PAGE_PRESENT) { + if (pte & _PAGE_PRESENT) pte = phys_to_machine(XPADDR(pte)).maddr; - pte &= ~(_PAGE_PCD | _PAGE_PWT); - } return (pte_t){ .pte = pte }; } -- cgit v1.2.3-58-ga151 From ebb9cfe20fe167f29960a5e913193a684fac50bf Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Mon, 16 Jun 2008 15:01:56 -0700 Subject: xen: don't drop NX bit Because NX is now enforced properly, we must put the hypercall page into the .text segment so that it is executable. Signed-off-by: Jeremy Fitzhardinge Cc: Stable Kernel Cc: the arch/x86 maintainers Signed-off-by: Ingo Molnar --- arch/x86/xen/mmu.c | 54 +++++++++++++++++++++++++++---------------------- arch/x86/xen/xen-head.S | 2 +- 2 files changed, 31 insertions(+), 25 deletions(-) (limited to 'arch') diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 3f2a67fe6ad6..265601d5a6ae 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -179,46 +179,54 @@ out: preempt_enable(); } -pteval_t xen_pte_val(pte_t pte) +/* Assume pteval_t is equivalent to all the other *val_t types. */ +static pteval_t pte_mfn_to_pfn(pteval_t val) { - pteval_t ret = pte.pte; + if (val & _PAGE_PRESENT) { + unsigned long mfn = (val & PTE_MASK) >> PAGE_SHIFT; + pteval_t flags = val & ~PTE_MASK; + val = (mfn_to_pfn(mfn) << PAGE_SHIFT) | flags; + } - if (ret & _PAGE_PRESENT) - ret = machine_to_phys(XMADDR(ret)).paddr | _PAGE_PRESENT; + return val; +} - return ret; +static pteval_t pte_pfn_to_mfn(pteval_t val) +{ + if (val & _PAGE_PRESENT) { + unsigned long pfn = (val & PTE_MASK) >> PAGE_SHIFT; + pteval_t flags = val & ~PTE_MASK; + val = (pfn_to_mfn(pfn) << PAGE_SHIFT) | flags; + } + + return val; +} + +pteval_t xen_pte_val(pte_t pte) +{ + return pte_mfn_to_pfn(pte.pte); } pgdval_t xen_pgd_val(pgd_t pgd) { - pgdval_t ret = pgd.pgd; - if (ret & _PAGE_PRESENT) - ret = machine_to_phys(XMADDR(ret)).paddr | _PAGE_PRESENT; - return ret; + return pte_mfn_to_pfn(pgd.pgd); } pte_t xen_make_pte(pteval_t pte) { - if (pte & _PAGE_PRESENT) - pte = phys_to_machine(XPADDR(pte)).maddr; - - return (pte_t){ .pte = pte }; + pte = pte_pfn_to_mfn(pte); + return native_make_pte(pte); } pgd_t xen_make_pgd(pgdval_t pgd) { - if (pgd & _PAGE_PRESENT) - pgd = phys_to_machine(XPADDR(pgd)).maddr; - - return (pgd_t){ pgd }; + pgd = pte_pfn_to_mfn(pgd); + return native_make_pgd(pgd); } pmdval_t xen_pmd_val(pmd_t pmd) { - pmdval_t ret = native_pmd_val(pmd); - if (ret & _PAGE_PRESENT) - ret = machine_to_phys(XMADDR(ret)).paddr | _PAGE_PRESENT; - return ret; + return pte_mfn_to_pfn(pmd.pmd); } #ifdef CONFIG_X86_PAE void xen_set_pud(pud_t *ptr, pud_t val) @@ -265,9 +273,7 @@ void xen_pmd_clear(pmd_t *pmdp) pmd_t xen_make_pmd(pmdval_t pmd) { - if (pmd & _PAGE_PRESENT) - pmd = phys_to_machine(XPADDR(pmd)).maddr; - + pmd = pte_pfn_to_mfn(pmd); return native_make_pmd(pmd); } #else /* !PAE */ diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S index 288d587ce73c..3175e973fd0d 100644 --- a/arch/x86/xen/xen-head.S +++ b/arch/x86/xen/xen-head.S @@ -17,7 +17,7 @@ ENTRY(startup_xen) __FINIT -.pushsection .bss.page_aligned +.pushsection .text .align PAGE_SIZE_asm ENTRY(hypercall_page) .skip 0x1000 -- cgit v1.2.3-58-ga151