diff options
Diffstat (limited to 'xen/arch/x86/mm/shadow/types.h')
| -rw-r--r-- | xen/arch/x86/mm/shadow/types.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/xen/arch/x86/mm/shadow/types.h b/xen/arch/x86/mm/shadow/types.h index 8397e7ae2c..1595a25a5b 100644 --- a/xen/arch/x86/mm/shadow/types.h +++ b/xen/arch/x86/mm/shadow/types.h @@ -553,6 +553,9 @@ accumulate_guest_flags(struct vcpu *v, walk_t *gw) { u32 accumulated_flags; + if ( unlikely(!(guest_l1e_get_flags(gw->eff_l1e) & _PAGE_PRESENT)) ) + return 0; + // We accumulate the permission flags with bitwise ANDing. // This works for the PRESENT bit, RW bit, and USER bit. // For the NX bit, however, the polarity is wrong, so we accumulate the |