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Commit ebaac173 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

context_tracking: move rcu_virt_note_context_switch out of kvm_host.h 



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: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarRik van Riel <riel@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent fb6cec14

include/linux/context_tracking.h

+34 −4
Original line number Diff line number Diff line
@@ -84,7 +84,8 @@ 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);
@@ -93,9 +94,19 @@ 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);
@@ -107,7 +118,7 @@ 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
@@ -116,9 +127,10 @@ 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);
@@ -126,4 +138,22 @@ 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

include/linux/kvm_host.h

+4 −21
Original line number Diff line number Diff line
@@ -878,40 +878,23 @@ 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();

}



/*