[PATCH] KVM: MMU: Report nx faults to the guest
With the recent guest page fault change, we perform access checks on our
own instead of relying on the cpu. This means we have to perform the nx
checks as well.
Software like the google toolbar on windows appears to rely on this
somehow.
Signed-off-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h
index afcd2a8..149fa45 100644
--- a/drivers/kvm/paging_tmpl.h
+++ b/drivers/kvm/paging_tmpl.h
@@ -71,7 +71,7 @@
*/
static int FNAME(walk_addr)(struct guest_walker *walker,
struct kvm_vcpu *vcpu, gva_t addr,
- int write_fault, int user_fault)
+ int write_fault, int user_fault, int fetch_fault)
{
hpa_t hpa;
struct kvm_memory_slot *slot;
@@ -123,6 +123,11 @@
if (user_fault && !(*ptep & PT_USER_MASK))
goto access_error;
+#if PTTYPE == 64
+ if (fetch_fault && is_nx(vcpu) && (*ptep & PT64_NX_MASK))
+ goto access_error;
+#endif
+
if (!(*ptep & PT_ACCESSED_MASK))
*ptep |= PT_ACCESSED_MASK; /* avoid rmw */
@@ -169,6 +174,8 @@
walker->error_code |= PFERR_WRITE_MASK;
if (user_fault)
walker->error_code |= PFERR_USER_MASK;
+ if (fetch_fault)
+ walker->error_code |= PFERR_FETCH_MASK;
return 0;
}
@@ -372,6 +379,7 @@
{
int write_fault = error_code & PFERR_WRITE_MASK;
int user_fault = error_code & PFERR_USER_MASK;
+ int fetch_fault = error_code & PFERR_FETCH_MASK;
struct guest_walker walker;
u64 *shadow_pte;
int fixed;
@@ -388,7 +396,8 @@
/*
* Look up the shadow pte for the faulting address.
*/
- r = FNAME(walk_addr)(&walker, vcpu, addr, write_fault, user_fault);
+ r = FNAME(walk_addr)(&walker, vcpu, addr, write_fault, user_fault,
+ fetch_fault);
/*
* The page is not mapped by the guest. Let the guest handle it.
@@ -437,7 +446,7 @@
pt_element_t guest_pte;
gpa_t gpa;
- FNAME(walk_addr)(&walker, vcpu, vaddr, 0, 0);
+ FNAME(walk_addr)(&walker, vcpu, vaddr, 0, 0, 0);
guest_pte = *walker.ptep;
FNAME(release_walker)(&walker);