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Date: Mon, 12 Nov 2007 17:34:43 -0800 From: Jeremy Fitzhardinge <jeremy@...p.org> To: Linus Torvalds <torvalds@...ux-foundation.org> CC: Linux Kernel Mailing List <linux-kernel@...r.kernel.org> Subject: [PATCH] xen: mask _PAGE_PCD from ptes _PAGE_PCD maps a page with caching disabled, which is typically used for mapping harware registers. Xen never allows it to be set on a mapping, and unprivileged guests never need it since they can't see the real underlying hardware. However, some uncached mappings are made early when probing the (non-existent) APIC, and its OK to mask off the PCD flag in these cases. Signed-off-by: Jeremy Fitzhardinge <jeremy@...source.com> --- arch/x86/xen/mmu.c | 4 ++++ 1 file changed, 4 insertions(+) =================================================================== --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -244,6 +244,8 @@ pte_t xen_make_pte(unsigned long long pt if (pte & 1) pte = phys_to_machine(XPADDR(pte)).maddr; + pte &= ~_PAGE_PCD; + return (pte_t){ pte, pte >> 32 }; } @@ -290,6 +292,8 @@ pte_t xen_make_pte(unsigned long pte) { if (pte & _PAGE_PRESENT) pte = phys_to_machine(XPADDR(pte)).maddr; + + pte &= ~_PAGE_PCD; return (pte_t){ pte }; } - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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