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Diffstat (limited to 'arch/x86/xen/enlighten.c')
-rw-r--r--arch/x86/xen/enlighten.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 23a4d80fb39e..dfbf70e65860 100644
--- a/arch/x86/xen/enlighten.c
+++ b/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;
}