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yaml --- r: 356150 b: refs/heads/master c: 52d3d06 h: refs/heads/master v: v3
git-mirror · Feb 19, 2013 · 1decbb8 · 1decbb8
1 parent d4de5aa
commit 1decbb8
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Showing 2 changed files with 8 additions and 6 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: f0322bd341fd63261527bf84afd3272bcc2e8dd3
+refs/heads/master: 52d3d06e706bdde3d6c5c386deb065c3b4c51618
diff --git a/trunk/arch/x86/kernel/cpu/amd.c b/trunk/arch/x86/kernel/cpu/amd.c
@@ -723,12 +723,14 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
 		 * performance degradation for certain nested-paging guests.
 		 * Prevent this conversion by clearing bit 24 in
 		 * MSR_AMD64_BU_CFG2.
+		 *
+		 * NOTE: we want to use the _safe accessors so as not to #GP kvm
+		 * guests on older kvm hosts.
 		 */
-		if (c->x86 == 0x10) {
-			rdmsrl(MSR_AMD64_BU_CFG2, value);
-			value &= ~(1ULL << 24);
-			wrmsrl(MSR_AMD64_BU_CFG2, value);
-		}
+
+		rdmsrl_safe(MSR_AMD64_BU_CFG2, &value);
+		value &= ~(1ULL << 24);
+		wrmsrl_safe(MSR_AMD64_BU_CFG2, value);
 	}
 
 	rdmsr_safe(MSR_AMD64_PATCH_LEVEL, &c->microcode, &dummy);