KVM: VMX: Enable XSAVE/XRSTOR for guest

This patch enable guest to use XSAVE/XRSTOR instructions.

We assume that host_xcr0 would use all possible bits that OS supported.

And we loaded xcr0 in the same way we handled fpu - do it as late as we can.

Signed-off-by: Dexuan Cui <dexuan.cui@intel.com>
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 2c62319..2d96555 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -88,7 +88,7 @@
 	int srcu_idx;
 
 	int fpu_active;
-	int guest_fpu_loaded;
+	int guest_fpu_loaded, guest_xcr0_loaded;
 	wait_queue_head_t wq;
 	int sigset_active;
 	sigset_t sigset;