[PATCH] kvm: Two-way apic tpr synchronization

We report the value of cr8 to userspace on an exit.  Also let userspace change
cr8 when we re-enter the guest.  The lets 64-bit guest code maintain the tpr
correctly.

Thanks for Yaniv Kamay for the idea.

Signed-off-by: Dor Laor <dor.laor@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 1be148f..6a5f6f4 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -65,6 +65,8 @@
 	__u8 ready_for_interrupt_injection;
 	__u8 if_flag;
 	__u16 padding2;
+
+	/* in (pre_kvm_run), out (post_kvm_run) */
 	__u64 cr8;
 	__u64 apic_base;