xen: mask unwanted pte bits in __supported_pte_mask

[linux-kernel-docs/linux-2.6.git] / arch / x86 / xen / enlighten.c

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index c8a56e4..c048de3 100644 (file)
--- 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();