Keep track of the last time a cpu ran guest_exit(), and provide a helper to make this information available to other files.
Signed-off-by: Leonardo Bras <[email protected]> --- include/linux/kvm_host.h | 13 +++++++++++++ virt/kvm/kvm_main.c | 3 +++ 2 files changed, 16 insertions(+) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 48f31dcd318a..be90d83d631a 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -470,31 +470,44 @@ static __always_inline void guest_state_enter_irqoff(void) { instrumentation_begin(); trace_hardirqs_on_prepare(); lockdep_hardirqs_on_prepare(); instrumentation_end(); guest_context_enter_irqoff(); lockdep_hardirqs_on(CALLER_ADDR0); } +DECLARE_PER_CPU(unsigned long, kvm_last_guest_exit); + +/* + * Returns time (jiffies) for the last guest exit in current cpu + */ +static inline unsigned long guest_exit_last_time(void) +{ + return this_cpu_read(kvm_last_guest_exit); +} + /* * Exit guest context and exit an RCU extended quiescent state. * * Between guest_context_enter_irqoff() and guest_context_exit_irqoff() it is * unsafe to use any code which may directly or indirectly use RCU, tracing * (including IRQ flag tracing), or lockdep. All code in this period must be * non-instrumentable. */ static __always_inline void guest_context_exit_irqoff(void) { context_tracking_guest_exit(); + + /* Keeps track of last guest exit */ + this_cpu_write(kvm_last_guest_exit, jiffies); } /* * Stop accounting time towards a guest. * Must be called after exiting guest context. */ static __always_inline void guest_timing_exit_irqoff(void) { instrumentation_begin(); /* Flush the guest cputime we spent on the guest */ diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index fb49c2a60200..732b1ab43ac9 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -103,20 +103,23 @@ EXPORT_SYMBOL_GPL(halt_poll_ns_shrink); */ DEFINE_MUTEX(kvm_lock); LIST_HEAD(vm_list); static struct kmem_cache *kvm_vcpu_cache; static __read_mostly struct preempt_ops kvm_preempt_ops; static DEFINE_PER_CPU(struct kvm_vcpu *, kvm_running_vcpu); +DEFINE_PER_CPU(unsigned long, kvm_last_guest_exit); +EXPORT_SYMBOL_GPL(kvm_last_guest_exit); + struct dentry *kvm_debugfs_dir; EXPORT_SYMBOL_GPL(kvm_debugfs_dir); static const struct file_operations stat_fops_per_vm; static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl, unsigned long arg); #ifdef CONFIG_KVM_COMPAT static long kvm_vcpu_compat_ioctl(struct file *file, unsigned int ioctl, unsigned long arg); -- 2.44.0
