[Xen-devel] [PATCH] x86/cpuid: fix dom0 crash on skylake machine

[Luwei Kang <luwei.kang@xxxxxxxxx>]

CPUID.0XD.0X0.EAX is from machine value for dom0, and dom0 kernel will xsetbv
with xfeatures_mask that is from CPUID.0XD.0X0.EAX, but handle_xsetbv has
ingored XSTATE_PKRU with hardware protection fault emulation, so dom0 kernel
will crash on skylake machine with PKRU support.

Signed-off-by: Luwei Kang <luwei.kang@xxxxxxxxx>
---
 xen/arch/x86/traps.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index 1ef8401..5e72e44 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -1100,6 +1100,9 @@ void pv_cpuid(struct cpu_user_regs *regs)
              */
             if ( !is_control_domain(currd) && !is_hardware_domain(currd) )
                 cpuid_count(leaf, subleaf, &tmp, &b, &tmp, &tmp);
+
+            /* PV is not supported by XSTATE_PKRU. */
+            a &= ~XSTATE_PKRU;
             break;
         }
 
-- 
2.7.4


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel