xen: mask the MTRR feature from the cpuid

We don't want Linux to think that the cpu supports MTRRs when running
under Xen because MTRR operations could only be performed through
hypercalls.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 9efb0044625076d32d0341009520382e67fe7f5b..d48a32b10a3cdbd6c3bb8b9af75de8a3a55c0ab1 100644 (file)
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -243,6 +243,7 @@ static __init void xen_init_cpuid_mask(void)
        cpuid_leaf1_edx_mask =
                ~((1 << X86_FEATURE_MCE)  |  /* disable MCE */
                  (1 << X86_FEATURE_MCA)  |  /* disable MCA */
+                 (1 << X86_FEATURE_MTRR) |  /* disable MTRR */
                  (1 << X86_FEATURE_ACC));   /* thermal monitoring */
 
        if (!xen_initial_domain())