diff mbox

[3/2] context_tracking: move rcu_virt_note_context_switch out of kvm_host.h

Message ID 1466434712-31440-4-git-send-email-pbonzini@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Paolo Bonzini June 20, 2016, 2:58 p.m. UTC 
Make kvm_guest_{enter,exit} and __kvm_guest_{enter,exit} trivial wrappers
around the code in context_tracking.h.  Name the context_tracking.h functions
consistently with what those for kernel<->user switch.

Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 include/linux/context_tracking.h | 38 ++++++++++++++++++++++++++++++++++----
 include/linux/kvm_host.h         | 25 ++++---------------------
 2 files changed, 38 insertions(+), 25 deletions(-)

Comments

Rik van Riel June 20, 2016, 8:23 p.m. UTC | #1 
On Mon, 2016-06-20 at 16:58 +0200, Paolo Bonzini wrote:
> Make kvm_guest_{enter,exit} and __kvm_guest_{enter,exit} trivial
> wrappers
> around the code in context_tracking.h.  Name the context_tracking.h
> functions
> consistently with what those for kernel<->user switch.
> 
> Cc: Andy Lutomirski <luto@kernel.org>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Rik van Riel <riel@redhat.com>
> Cc: H. Peter Anvin <hpa@zytor.com>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> 

Yay. I remember being confused by this when going
through the context tracking code last year.

Reviewed-by: Rik van Riel <riel@redhat.com>
diff mbox

Patch

diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index d9aef2a0ec8e..c78fc27418f2 100644
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -99,7 +99,8 @@  static inline void context_tracking_init(void) { }
 
 
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
-static inline void guest_enter(void)
+/* must be called with irqs disabled */
+static inline void guest_enter_irqoff(void)
 {
 	if (vtime_accounting_cpu_enabled())
 		vtime_guest_enter(current);
@@ -108,9 +109,19 @@  static inline void guest_enter(void)
 
 	if (context_tracking_is_enabled())
 		__context_tracking_enter(CONTEXT_GUEST);
+
+	/* 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_cpu_is_enabled())
+		rcu_virt_note_context_switch(smp_processor_id());
 }
 
-static inline void guest_exit(void)
+static inline void guest_exit_irqoff(void)
 {
 	if (context_tracking_is_enabled())
 		__context_tracking_exit(CONTEXT_GUEST);
@@ -122,7 +133,7 @@  static inline void guest_exit(void)
 }
 
 #else
-static inline void guest_enter(void)
+static inline void guest_enter_irqoff(void)
 {
 	/*
 	 * This is running in ioctl context so its safe
@@ -131,9 +142,10 @@  static inline void guest_enter(void)
 	 */
 	vtime_account_system(current);
 	current->flags |= PF_VCPU;
+	rcu_virt_note_context_switch(smp_processor_id());
 }
 
-static inline void guest_exit(void)
+static inline void guest_exit_irqoff(void)
 {
 	/* Flush the guest cputime we spent on the guest */
 	vtime_account_system(current);
@@ -141,4 +153,22 @@  static inline void guest_exit(void)
 }
 #endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */
 
+static inline void guest_enter(void)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	guest_enter_irqoff();
+	local_irq_restore(flags);
+}
+
+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 1c9c973a7dd9..30c9224545b1 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -870,40 +870,23 @@  static inline void kvm_iommu_unmap_pages(struct kvm *kvm,
 /* must be called with irqs disabled */
 static inline void __kvm_guest_enter(void)
 {
-	guest_enter();
-	/* 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_cpu_is_enabled())
-		rcu_virt_note_context_switch(smp_processor_id());
+	guest_enter_irqoff();
 }
 
 /* must be called with irqs disabled */
 static inline void __kvm_guest_exit(void)
 {
-	guest_exit();
+	guest_exit_irqoff();
 }
 
 static inline void kvm_guest_enter(void)
 {
-	unsigned long flags;
-
-	local_irq_save(flags);
-	__kvm_guest_enter();
-	local_irq_restore(flags);
+	guest_enter();
 }
 
 static inline void kvm_guest_exit(void)
 {
-	unsigned long flags;
-
-	local_irq_save(flags);
-	__kvm_guest_exit();
-	local_irq_restore(flags);
+	guest_exit();
 }
 
 /*