From patchwork Fri Mar  2 10:12:12 2012
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Subject: [RFC,04/16,v8] Add API to check whether paging mode is enabled
Date: Fri, 02 Mar 2012 00:12:12 -0000
From: Wen Congyang <wency@cn.fujitsu.com>
X-Patchwork-Id: 144192
Message-Id: <4F509CFC.8010800@cn.fujitsu.com>
To: qemu-devel <qemu-devel@nongnu.org>, Jan Kiszka <jan.kiszka@siemens.com>, 
 Dave Anderson <anderson@redhat.com>,
 HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>,
 Luiz Capitulino <lcapitulino@redhat.com>, Eric Blake <eblake@redhat.com>

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>

---
cpu-all.h                         |    6 ++++++
 target-i386/arch_memory_mapping.c |    7 ++++++-
 2 files changed, 12 insertions(+), 1 deletions(-)

diff --git a/cpu-all.h b/cpu-all.h
index cb72680..01c3c23 100644
--- a/cpu-all.h
+++ b/cpu-all.h
@@ -526,11 +526,17 @@ int cpu_memory_rw_debug(CPUState *env, target_ulong addr,
 
 #if defined(CONFIG_HAVE_GET_MEMORY_MAPPING)
 int cpu_get_memory_mapping(MemoryMappingList *list, CPUState *env);
+bool cpu_paging_enabled(CPUState *env);
 #else
 static inline int cpu_get_memory_mapping(MemoryMappingList *list, CPUState *env)
 {
     return -1;
 }
+
+static inline bool cpu_paging_enabled(CPUState *env)
+{
+    return true;
+}
 #endif
 
 #endif /* CPU_ALL_H */
diff --git a/target-i386/arch_memory_mapping.c b/target-i386/arch_memory_mapping.c
index 10d9b2c..824f293 100644
--- a/target-i386/arch_memory_mapping.c
+++ b/target-i386/arch_memory_mapping.c
@@ -233,7 +233,7 @@ static void walk_pml4e(MemoryMappingList *list,
 
 int cpu_get_memory_mapping(MemoryMappingList *list, CPUState *env)
 {
-    if (!(env->cr[0] & CR0_PG_MASK)) {
+    if (!cpu_paging_enabled(env)) {
         /* paging is disabled */
         return 0;
     }
@@ -264,3 +264,8 @@ int cpu_get_memory_mapping(MemoryMappingList *list, CPUState *env)
 
     return 0;
 }
+
+bool cpu_paging_enabled(CPUState *env)
+{
+    return env->cr[0] & CR0_PG_MASK;
+}