__kvm_set_xcr function does the CPL check when set xcr. __kvm_set_xcr is
called in two flows, one is invoked by guest, call stack shown as below,
handle_xsetbv(or xsetbv_interception)
kvm_set_xcr
__kvm_set_xcr
the other one is invoked by host, for example during system reset:
kvm_arch_vcpu_ioctl
kvm_vcpu_ioctl_x86_set_xcrs
__kvm_set_xcr
The former does need the CPL check, but the latter does not.
Cc: stable@vger.kernel.org
Signed-off-by: Zhang Haoyu <haoyu.zhang@huawei.com>
[Tweaks to commit message. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
764bcbc5a6