[Xen-changelog] [xen-4.1-testing] x86: don't expose SYSENTER on unknown CPUs

[Xen patchbot-4.1-testing <patchbot@xxxxxxx>]

# HG changeset patch
# User Jan Beulich <jbeulich@xxxxxxxx>
# Date 1348131144 -7200
# Node ID 4fc6e4f64024d1085ae397b38001d1194a5513be
# Parent  35bb0a4c9bc0b2481e34a3394fb914674a45f6e0
x86: don't expose SYSENTER on unknown CPUs

So far we only ever set up the respective MSRs on Intel CPUs, yet we
hide the feature only on a 32-bit hypervisor. That prevents booting of
PV guests on top of a 64-bit hypervisor making use of the instruction
on unknown CPUs (VIA in this case).

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Acked-by: Keir Fraser <keir@xxxxxxx>
xen-unstable changeset: 25764:4b0d263008cd
xen-unstable date: Mon Aug 20 06:40:01 UTC 2012
---


diff -r 35bb0a4c9bc0 -r 4fc6e4f64024 xen/arch/x86/cpu/common.c
--- a/xen/arch/x86/cpu/common.c Thu Sep 20 10:51:30 2012 +0200
+++ b/xen/arch/x86/cpu/common.c Thu Sep 20 10:52:24 2012 +0200
@@ -68,6 +68,7 @@ static void default_init(struct cpuinfo_
                else if (c->x86 == 3)
                        safe_strcpy(c->x86_model_id, "386");
        }
+        __clear_bit(X86_FEATURE_SEP, c->x86_capability);
 }
 
 static struct cpu_dev default_cpu = {

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