[PATCH v4 7/8] context_tracking: KVM: Move guest enter/exit wrappers to KVM's domain

From: Sean Christopherson
Date: Tue May 04 2021 - 20:28:13 EST


Move the guest enter/exit wrappers to kvm_host.h so that KVM can manage
its context tracking vs. vtime accounting without bleeding too many KVM
details into the context tracking code.

No functional change intended.

Cc: Frederic Weisbecker <frederic@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
include/linux/context_tracking.h | 45 --------------------------------
include/linux/kvm_host.h | 45 ++++++++++++++++++++++++++++++++
2 files changed, 45 insertions(+), 45 deletions(-)

diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index aa58c2ac67ca..4d7fced3a39f 100644
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -118,49 +118,4 @@ extern void context_tracking_init(void);
static inline void context_tracking_init(void) { }
#endif /* CONFIG_CONTEXT_TRACKING_FORCE */

-/* 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();
- vtime_account_guest_enter();
- instrumentation_end();
-
- /*
- * 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_guest_enter()) {
- instrumentation_begin();
- rcu_virt_note_context_switch(smp_processor_id());
- instrumentation_end();
- }
-}
-
-static __always_inline void guest_exit_irqoff(void)
-{
- context_tracking_guest_exit();
-
- instrumentation_begin();
- /* Flush the guest cputime we spent on the guest */
- vtime_account_guest_exit();
- instrumentation_end();
-}
-
-static inline void guest_exit(void)
-{
- unsigned long flags;
-
- local_irq_save(flags);
- guest_exit_irqoff();
- local_irq_restore(flags);
-}
-
#endif
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index a9a7bcf6ebee..a6f47ed8b1e6 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -338,6 +338,51 @@ struct kvm_vcpu {
struct kvm_dirty_ring dirty_ring;
};

+/* 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();
+ vtime_account_guest_enter();
+ instrumentation_end();
+
+ /*
+ * 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_guest_enter()) {
+ instrumentation_begin();
+ rcu_virt_note_context_switch(smp_processor_id());
+ instrumentation_end();
+ }
+}
+
+static __always_inline void guest_exit_irqoff(void)
+{
+ context_tracking_guest_exit();
+
+ instrumentation_begin();
+ /* Flush the guest cputime we spent on the guest */
+ vtime_account_guest_exit();
+ instrumentation_end();
+}
+
+static inline void guest_exit(void)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ guest_exit_irqoff();
+ local_irq_restore(flags);
+}
+
static inline int kvm_vcpu_exiting_guest_mode(struct kvm_vcpu *vcpu)
{
/*
--
2.31.1.527.g47e6f16901-goog