Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:
 "Two fixes: a quirk for KVM guests running on certain AMD CPUs, and a
  KASAN related build fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/CPU/AMD: Don't force the CPB cap when running under a hypervisor
  x86/boot: Provide KASAN compatible aliases for string routines

1 files changed, 5 insertions, 2 deletions

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 80a405c2048a..8d4e50428b68 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -824,8 +824,11 @@ static void init_amd_zn(struct cpuinfo_x86 *c)
 {
         set_cpu_cap(c, X86_FEATURE_ZEN);
 
-        /* Fix erratum 1076: CPB feature bit not being set in CPUID. */
-        if (!cpu_has(c, X86_FEATURE_CPB))
+        /*
+         * Fix erratum 1076: CPB feature bit not being set in CPUID.
+         * Always set it, except when running under a hypervisor.
+         */
+        if (!cpu_has(c, X86_FEATURE_HYPERVISOR) && !cpu_has(c, X86_FEATURE_CPB))
                 set_cpu_cap(c, X86_FEATURE_CPB);
 }