context_tracking: Move guest exit context tracking to separate helpers

stable inclusion
from stable-5.10.41
commit 5ae5e3f05831b7629cd33be0a8591905f0898599
bugzilla: 51890
CVE: NA

--------------------------------

commit 866a6dad upstream.

Provide separate context tracking helpers for guest exit, the standalone
helpers will be called separately by KVM x86 in later patches to fix
tick-based accounting.
Suggested-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NWanpeng Li <wanpengli@tencent.com>
Co-developed-by: NSean Christopherson <seanjc@google.com>
Signed-off-by: NSean Christopherson <seanjc@google.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210505002735.1684165-2-seanjc@google.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

include/linux/context_tracking.h

@@ -129,10 +129,15 @@ static __always_inline void guest_enter_irqoff(void)
 	}
 }
 
-static __always_inline void guest_exit_irqoff(void)
+static __always_inline void context_tracking_guest_exit(void)
 {
 	if (context_tracking_enabled())
 		__context_tracking_exit(CONTEXT_GUEST);
+}
+
+static __always_inline void guest_exit_irqoff(void)
+{
+	context_tracking_guest_exit();
 
 	instrumentation_begin();
 	if (vtime_accounting_enabled_this_cpu())
@@ -157,6 +162,8 @@ static __always_inline void guest_enter_irqoff(void)
 	instrumentation_end();
 }
 
+static __always_inline void context_tracking_guest_exit(void) { }
+
 static __always_inline void guest_exit_irqoff(void)
 {
 	instrumentation_begin();