From 3835b39f99717a4f2c67057b1e263ff1d9e2ee83 Mon Sep 17 00:00:00 2001
From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Date: Thu, 22 Oct 2009 16:41:15 -0700
Subject: [PATCH] --- yaml --- r: 168266 b: refs/heads/master c:
 82d6469916c6fcfa345636a49004c9d1753905d1 h: refs/heads/master v: v3

---
 [refs]                         |  2 +-
 trunk/arch/x86/xen/enlighten.c | 11 ++++++++++-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 3b2306ed1699..152992053001 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 7825cf10e31c64ece3cac66fb01a742f1094da51
+refs/heads/master: 82d6469916c6fcfa345636a49004c9d1753905d1
diff --git a/trunk/arch/x86/xen/enlighten.c b/trunk/arch/x86/xen/enlighten.c
index 23a4d80fb39e..dfbf70e65860 100644
--- a/trunk/arch/x86/xen/enlighten.c
+++ b/trunk/arch/x86/xen/enlighten.c
@@ -178,6 +178,7 @@ static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0;
 static void xen_cpuid(unsigned int *ax, unsigned int *bx,
 		      unsigned int *cx, unsigned int *dx)
 {
+	unsigned maskebx = ~0;
 	unsigned maskecx = ~0;
 	unsigned maskedx = ~0;
 
@@ -185,9 +186,16 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx,
 	 * Mask out inconvenient features, to try and disable as many
 	 * unsupported kernel subsystems as possible.
 	 */
-	if (*ax == 1) {
+	switch (*ax) {
+	case 1:
 		maskecx = cpuid_leaf1_ecx_mask;
 		maskedx = cpuid_leaf1_edx_mask;
+		break;
+
+	case 0xb:
+		/* Suppress extended topology stuff */
+		maskebx = 0;
+		break;
 	}
 
 	asm(XEN_EMULATE_PREFIX "cpuid"
@@ -197,6 +205,7 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx,
 		  "=d" (*dx)
 		: "0" (*ax), "2" (*cx));
 
+	*bx &= maskebx;
 	*cx &= maskecx;
 	*dx &= maskedx;
 }