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 <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
Cc: the arch/x86 maintainers <x86@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Jeremy Fitzhardinge 2008-06-16 15:01:53 -07:00 committed by Ingo Molnar
parent 6673cf63e5
commit eb179e443d
2 changed files with 6 additions and 3 deletions

View File

@ -1280,6 +1280,11 @@ 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();

View File

@ -343,10 +343,8 @@ 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 };
}