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context_tracking: KVM: Move guest enter/exit wrappers to KVM's domain
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.

Signed-off-by: Sean Christopherson <seanjc@google.com>
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sean-jc authored and intel-lab-lkp committed Apr 13, 2021
1 parent 3f33989 commit 812e089ce79e0e9d5a7b8063fbdb4496174f30f5
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Showing 2 changed files with 45 additions and 45 deletions.
@@ -126,49 +126,4 @@ 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_irqoff()) {
instrumentation_begin();
rcu_virt_note_context_switch(smp_processor_id());
instrumentation_end();
}
}

static __always_inline void guest_exit_irqoff(void)
{
context_tracking_guest_exit_irqoff();

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
@@ -332,6 +332,51 @@ 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_irqoff()) {
instrumentation_begin();
rcu_virt_note_context_switch(smp_processor_id());
instrumentation_end();
}
}

static __always_inline void guest_exit_irqoff(void)
{
context_tracking_guest_exit_irqoff();

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)
{
/*

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