Re: [PATCH 10 of 10] xen: mask out PWT too

Jan Beulich
2008-01-09T09:17:16Z

That's somewhat ugly, as it will need to be undone/modified for Dom0 and
physical device access support. Jan

>>> Jeremy Fitzhardinge <jeremy@goop.org> 08.01.08 23:00 >>>
The hypervisor doesn't allow PCD or PWT to be set on guest ptes, so
make sure they're masked out. Also, fix up some previous mispatching.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>

---
arch/x86/xen/mmu.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -244,7 +244,7 @@ pte_t xen_make_pte(unsigned long long pt
if (pte & 1)
pte = phys_to_machine(XPADDR(pte)).maddr;

- pte &= ~_PAGE_PCD;
+ pte &= ~(_PAGE_PCD | _PAGE_PWT);

return (pte_t){ .pte = pte };
}
@@ -293,9 +293,7 @@ pte_t xen_make_pte(unsigned long pte)
if (pte & _PAGE_PRESENT)
pte = phys_to_machine(XPADDR(pte)).maddr;

- pte &= ~_PAGE_PCD;
-
- pte &= ~_PAGE_PCD;
+ pte &= ~(_PAGE_PCD | _PAGE_PWT);

return (pte_t){ pte };
}