Thank you Andrew Cooper, this patch indeed resolve my issue and two point need modify.
The code need move ahead of "break;" @@ -1101,6 +1101,9 @@ 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); break; + + a &= (uint32_t)pv_xfeature_mask; + d &= (uint32_t)(pv_xfeature_mask >> 32); } extraneous space after "&". - sanitise_featureset(hvm_featureset); + sanitise_featureset(hvm_featureset, & hvm_xfeature_mask); -----Original Message----- From: Andrew Cooper [mailto:andrew.coop...@citrix.com] Sent: Wednesday, June 1, 2016 5:04 PM To: Kang, Luwei <luwei.k...@intel.com>; xen-devel@lists.xen.org Cc: jbeul...@suse.com; Han, Huaitong <huaitong....@intel.com>; Wang, Yong Y <yong.y.w...@intel.com> Subject: Re: [PATCH] x86/cpuid: fix dom0 crash on skylake machine On 01/06/16 05:58, Luwei Kang wrote: > 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.k...@intel.com> > --- > 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; > } > While this does work, it undoes some of the work I started with my cpuid improvements in 4.7 Does the attached patch also resolve your issue? ~Andrew _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel