From 1decbb85cb22a99011ff1de00d9f77f60edfc980 Mon Sep 17 00:00:00 2001
From: Borislav Petkov <bp@suse.de>
Date: Tue, 19 Feb 2013 19:33:12 +0100
Subject: [PATCH] --- yaml --- r: 356150 b: refs/heads/master c:
 52d3d06e706bdde3d6c5c386deb065c3b4c51618 h: refs/heads/master v: v3

---
 [refs]                          |  2 +-
 trunk/arch/x86/kernel/cpu/amd.c | 12 +++++++-----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/[refs] b/[refs]
index 20addbfef855..eda0616ba73c 100644
--- 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
index 721ef3208eb5..163af4a91d09 100644
--- 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);