From 2ccced7b73c5d2d52febbaced473deeac9042c47 Mon Sep 17 00:00:00 2001 From: Tim Deegan Date: Wed, 21 Mar 2007 17:17:08 +0000 Subject: [PATCH] [XEN] Shadow: check the _PAGE_PRESENT bit in fast-path MMIO shadow ptes otherwise the fast-path code is not safe against some kinds of concurrent shadow updates. Signed-off-by: Tim Deegan --- xen/arch/x86/mm/shadow/types.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/xen/arch/x86/mm/shadow/types.h b/xen/arch/x86/mm/shadow/types.h index 400514f241..8397e7ae2c 100644 --- a/xen/arch/x86/mm/shadow/types.h +++ b/xen/arch/x86/mm/shadow/types.h @@ -597,7 +597,7 @@ accumulate_guest_flags(struct vcpu *v, walk_t *gw) * have reserved bits that we can use for this. */ -#define SH_L1E_MAGIC 0xffffffff00000000ULL +#define SH_L1E_MAGIC 0xffffffff00000001ULL static inline int sh_l1e_is_magic(shadow_l1e_t sl1e) { return ((sl1e.l1 & SH_L1E_MAGIC) == SH_L1E_MAGIC); -- 2.30.2