kvm: Move guest entry/exit APIs to context_tracking

The kvm_host.h header file doesn't handle well
inclusion when archs don't support KVM.

This results in build crashes for such archs when they
want to implement context tracking because this subsystem
includes kvm_host.h in order to implement the
guest_enter/exit APIs but it doesn't handle KVM off case.

To fix this, move the guest_enter()/guest_exit()
declarations and generic implementation to the context
tracking headers. These generic APIs actually belong to
this subsystem, besides other domains boundary tracking
like user_enter() et al.

KVM now properly becomes a user of this library, not the
other buggy way around.

Reported-by: Kevin Hilman <khilman@linaro.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index 365f4a61bf0408c12b3b3dbeb1743c8a2b616c35..fc09d7b0dacfc00feef340cc03c06b207feed870 100644 (file)
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -3,6 +3,7 @@
 
 #include <linux/sched.h>
 #include <linux/percpu.h>
+#include <linux/vtime.h>
 #include <asm/ptrace.h>
 
 struct context_tracking {
@@ -19,6 +20,26 @@ struct context_tracking {
        } state;
 };
 
+static inline void __guest_enter(void)
+{
+       /*
+        * This is running in ioctl context so we can avoid
+        * the call to vtime_account() with its unnecessary idle check.
+        */
+       vtime_account_system(current);
+       current->flags |= PF_VCPU;
+}
+
+static inline void __guest_exit(void)
+{
+       /*
+        * This is running in ioctl context so we can avoid
+        * the call to vtime_account() with its unnecessary idle check.
+        */
+       vtime_account_system(current);
+       current->flags &= ~PF_VCPU;
+}
+
 #ifdef CONFIG_CONTEXT_TRACKING
 DECLARE_PER_CPU(struct context_tracking, context_tracking);
 
@@ -35,6 +56,9 @@ static inline bool context_tracking_active(void)
 extern void user_enter(void);
 extern void user_exit(void);
 
+extern void guest_enter(void);
+extern void guest_exit(void);
+
 static inline enum ctx_state exception_enter(void)
 {
        enum ctx_state prev_ctx;
@@ -57,6 +81,17 @@ extern void context_tracking_task_switch(struct task_struct *prev,
 static inline bool context_tracking_in_user(void) { return false; }
 static inline void user_enter(void) { }
 static inline void user_exit(void) { }
+
+static inline void guest_enter(void)
+{
+       __guest_enter();
+}
+
+static inline void guest_exit(void)
+{
+       __guest_exit();
+}
+
 static inline enum ctx_state exception_enter(void) { return 0; }
 static inline void exception_exit(enum ctx_state prev_ctx) { }
 static inline void context_tracking_task_switch(struct task_struct *prev,

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index f0eea07d2c2bb5168820443639af6e85a9d47850..8db53cfaccdb64fdbd18d29935e698d101bf5bf1 100644 (file)
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -23,6 +23,7 @@
 #include <linux/ratelimit.h>
 #include <linux/err.h>
 #include <linux/irqflags.h>
+#include <linux/context_tracking.h>
 #include <asm/signal.h>
 
 #include <linux/kvm.h>
@@ -760,42 +761,6 @@ static inline int kvm_iommu_unmap_guest(struct kvm *kvm)
 }
 #endif
 
-static inline void __guest_enter(void)
-{
-       /*
-        * This is running in ioctl context so we can avoid
-        * the call to vtime_account() with its unnecessary idle check.
-        */
-       vtime_account_system(current);
-       current->flags |= PF_VCPU;
-}
-
-static inline void __guest_exit(void)
-{
-       /*
-        * This is running in ioctl context so we can avoid
-        * the call to vtime_account() with its unnecessary idle check.
-        */
-       vtime_account_system(current);
-       current->flags &= ~PF_VCPU;
-}
-
-#ifdef CONFIG_CONTEXT_TRACKING
-extern void guest_enter(void);
-extern void guest_exit(void);
-
-#else /* !CONFIG_CONTEXT_TRACKING */
-static inline void guest_enter(void)
-{
-       __guest_enter();
-}
-
-static inline void guest_exit(void)
-{
-       __guest_exit();
-}
-#endif /* !CONFIG_CONTEXT_TRACKING */
-
 static inline void kvm_guest_enter(void)
 {
        unsigned long flags;

diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index 65349f07b8782a19f13014e66b8ff8ac0e7a5ecf..85bdde1137eb742bea00fad4ea351fab42f9d1d9 100644 (file)
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -15,7 +15,6 @@
  */
 
 #include <linux/context_tracking.h>
-#include <linux/kvm_host.h>
 #include <linux/rcupdate.h>
 #include <linux/sched.h>
 #include <linux/hardirq.h>