context_tracking: Consolidate guest enter/exit wrappers

Consolidate the guest enter/exit wrappers, providing and tweaking stubs
as needed.  This will allow moving the wrappers under KVM without having
to bleed #ifdefs into the soon-to-be KVM code.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210505002735.1684165-7-seanjc@google.com

diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index 56c648bdbde8f74ea80abf4ba416c1bd28e07633..aa58c2ac67ca51a014622c8ebbe60158ac53b62a 100644 (file)
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -71,6 +71,19 @@ static inline void exception_exit(enum ctx_state prev_ctx)
        }
 }
 
+static __always_inline bool context_tracking_guest_enter(void)
+{
+       if (context_tracking_enabled())
+               __context_tracking_enter(CONTEXT_GUEST);
+
+       return context_tracking_enabled_this_cpu();
+}
+
+static __always_inline void context_tracking_guest_exit(void)
+{
+       if (context_tracking_enabled())
+               __context_tracking_exit(CONTEXT_GUEST);
+}
 
 /**
  * ct_state() - return the current context tracking state if known
@@ -92,6 +105,9 @@ static inline void user_exit_irqoff(void) { }
 static inline enum ctx_state exception_enter(void) { return 0; }
 static inline void exception_exit(enum ctx_state prev_ctx) { }
 static inline enum ctx_state ct_state(void) { return CONTEXT_DISABLED; }
+static inline bool context_tracking_guest_enter(void) { return false; }
+static inline void context_tracking_guest_exit(void) { }
+
 #endif /* !CONFIG_CONTEXT_TRACKING */
 
 #define CT_WARN_ON(cond) WARN_ON(context_tracking_enabled() && (cond))
@@ -102,74 +118,41 @@ extern void context_tracking_init(void);
 static inline void context_tracking_init(void) { }
 #endif /* CONFIG_CONTEXT_TRACKING_FORCE */
 
-
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
 /* must be called with irqs disabled */
 static __always_inline void guest_enter_irqoff(void)
 {
+       /*
+        * This is running in ioctl context so its safe to assume that it's the
+        * stime pending cputime to flush.
+        */
        instrumentation_begin();
-       if (vtime_accounting_enabled_this_cpu())
-               vtime_guest_enter(current);
-       else
-               current->flags |= PF_VCPU;
+       vtime_account_guest_enter();
        instrumentation_end();
 
-       if (context_tracking_enabled())
-               __context_tracking_enter(CONTEXT_GUEST);
-
-       /* KVM does not hold any references to rcu protected data when it
+       /*
+        * KVM does not hold any references to rcu protected data when it
         * switches CPU into a guest mode. In fact switching to a guest mode
         * is very similar to exiting to userspace from rcu point of view. In
         * addition CPU may stay in a guest mode for quite a long time (up to
         * one time slice). Lets treat guest mode as quiescent state, just like
         * we do with user-mode execution.
         */
-       if (!context_tracking_enabled_this_cpu()) {
+       if (!context_tracking_guest_enter()) {
                instrumentation_begin();
                rcu_virt_note_context_switch(smp_processor_id());
                instrumentation_end();
        }
 }
 
-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();
-       vtime_account_guest_exit();
-       instrumentation_end();
-}
-
-#else
-static __always_inline void guest_enter_irqoff(void)
-{
-       /*
-        * This is running in ioctl context so its safe
-        * to assume that it's the stime pending cputime
-        * to flush.
-        */
-       instrumentation_begin();
-       vtime_account_guest_enter();
-       rcu_virt_note_context_switch(smp_processor_id());
-       instrumentation_end();
-}
-
-static __always_inline void context_tracking_guest_exit(void) { }
-
-static __always_inline void guest_exit_irqoff(void)
-{
        instrumentation_begin();
        /* Flush the guest cputime we spent on the guest */
        vtime_account_guest_exit();
        instrumentation_end();
 }
-#endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */
 
 static inline void guest_exit(void)
 {