[Qemu-devel] [PULL 06/14] target-i386: Don't forbid NX bit on PAE PDEs and PTEs

[Paolo Bonzini <pbonzini@redhat.com>]

From: William Grant <wgrant@ubuntu.com>

Commit e8f6d00c30ed88910d0d985f4b2bf41654172ceb ("target-i386: raise
page fault for reserved physical address bits") added a check that the
NX bit is not set on PAE PDPEs, but it also added it to rsvd_mask for
the rest of the function. This caused any PDEs or PTEs with NX set to be
erroneously rejected, making PAE guests with NX support unusable.

Signed-off-by: William Grant <wgrant@ubuntu.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target-i386/helper.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/target-i386/helper.c b/target-i386/helper.c
index 47b982b..30cb0d0 100644
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -615,8 +615,8 @@ int x86_cpu_handle_mmu_fault(CPUState *cs, vaddr addr,
             if (!(pdpe & PG_PRESENT_MASK)) {
                 goto do_fault;
             }
-            rsvd_mask |= PG_HI_USER_MASK | PG_NX_MASK;
-            if (pdpe & rsvd_mask) {
+            rsvd_mask |= PG_HI_USER_MASK;
+            if (pdpe & (rsvd_mask | PG_NX_MASK)) {
                 goto do_fault_rsvd;
             }
             ptep = PG_NX_MASK | PG_USER_MASK | PG_RW_MASK;
-- 
1.8.3.1