Commit 332967a3 authored by Andrew Jones's avatar Andrew Jones Committed by Paolo Bonzini
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x86: kvm: introduce periodic global clock updates 



commit 0061d53d introduced a mechanism to execute a global clock
update for a vm. We can apply this periodically in order to propagate
host NTP corrections. Also, if all vcpus of a vm are pinned, then
without an additional trigger, no guest NTP corrections can propagate
either, as the current trigger is only vcpu cpu migration.

Signed-off-by: default avatarAndrew Jones <drjones@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 7e44e449

arch/x86/include/asm/kvm_host.h

+1 −0
Original line number Diff line number Diff line
@@ -599,6 +599,7 @@ struct kvm_arch { 
	u64 master_kernel_ns;

	cycle_t master_cycle_now;

	struct delayed_work kvmclock_update_work;

	struct delayed_work kvmclock_sync_work;



	struct kvm_xen_hvm_config xen_hvm_config;

arch/x86/kvm/x86.c

+20 −0
Original line number Diff line number Diff line
@@ -1660,6 +1660,20 @@ static void kvm_gen_kvmclock_update(struct kvm_vcpu *v) 
					KVMCLOCK_UPDATE_DELAY);

}



#define KVMCLOCK_SYNC_PERIOD (300 * HZ)



static void kvmclock_sync_fn(struct work_struct *work)

{

	struct delayed_work *dwork = to_delayed_work(work);

	struct kvm_arch *ka = container_of(dwork, struct kvm_arch,

					   kvmclock_sync_work);

	struct kvm *kvm = container_of(ka, struct kvm, arch);



	schedule_delayed_work(&kvm->arch.kvmclock_update_work, 0);

	schedule_delayed_work(&kvm->arch.kvmclock_sync_work,

					KVMCLOCK_SYNC_PERIOD);

}



static bool msr_mtrr_valid(unsigned msr)

{

	switch (msr) {
@@ -6736,6 +6750,7 @@ int kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) 
{

	int r;

	struct msr_data msr;

	struct kvm *kvm = vcpu->kvm;



	r = vcpu_load(vcpu);

	if (r)
@@ -6746,6 +6761,9 @@ int kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) 
	kvm_write_tsc(vcpu, &msr);

	vcpu_put(vcpu);



	schedule_delayed_work(&kvm->arch.kvmclock_sync_work,

					KVMCLOCK_SYNC_PERIOD);



	return r;

}
@@ -7039,6 +7057,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) 
	pvclock_update_vm_gtod_copy(kvm);



	INIT_DELAYED_WORK(&kvm->arch.kvmclock_update_work, kvmclock_update_fn);

	INIT_DELAYED_WORK(&kvm->arch.kvmclock_sync_work, kvmclock_sync_fn);



	return 0;

}
@@ -7077,6 +7096,7 @@ static void kvm_free_vcpus(struct kvm *kvm) 


void kvm_arch_sync_events(struct kvm *kvm)

{

	cancel_delayed_work_sync(&kvm->arch.kvmclock_sync_work);

	cancel_delayed_work_sync(&kvm->arch.kvmclock_update_work);

	kvm_free_all_assigned_devices(kvm);

	kvm_free_pit(kvm);

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