[PATCH v2 03/19] KVM: x86/xen: Initialize hrtimer in kvm_xen_init_vcpu()

[Nam Cao]

The hrtimer is initialized in the KVM_XEN_VCPU_SET_ATTR ioctl. That caused
problem in the past, because the hrtimer can be initialized multiple times,
which was fixed by commit af735db31285 ("KVM: x86/xen: Initialize Xen timer
only once"). This commit avoids initializing the timer multiple times by
checking the field 'function' of struct hrtimer to determine if it has
already been initialized.

This is not required and in the way to make the function field private.

Move the hrtimer initialization into kvm_xen_init_vcpu() so that it will
only be initialized once.

Signed-off-by: Nam Cao <namcao@xxxxxxxxxxxxx>
Acked-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
---
v2: drop kvm_xen_init_timer() and open code its content
---
 arch/x86/kvm/xen.c | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index 622fe24da910646ced4300a84ab92fce4ac8e00a..a909b817b9c0da1714169d937c1=
35474e8a9cf7d 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -263,13 +263,6 @@ static void kvm_xen_stop_timer(struct kvm_vcpu *vcpu)
 	atomic_set(&vcpu->arch.xen.timer_pending, 0);
 }
=20
-static void kvm_xen_init_timer(struct kvm_vcpu *vcpu)
-{
-	hrtimer_init(&vcpu->arch.xen.timer, CLOCK_MONOTONIC,
-		     HRTIMER_MODE_ABS_HARD);
-	vcpu->arch.xen.timer.function =3D xen_timer_callback;
-}
-
 static void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, bool atomic)
 {
 	struct kvm_vcpu_xen *vx =3D &v->arch.xen;
@@ -1070,9 +1063,6 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, stru=
ct kvm_xen_vcpu_attr *data)
 			break;
 		}
=20
-		if (!vcpu->arch.xen.timer.function)
-			kvm_xen_init_timer(vcpu);
-
 		/* Stop the timer (if it's running) before changing the vector */
 		kvm_xen_stop_timer(vcpu);
 		vcpu->arch.xen.timer_virq =3D data->u.timer.port;
@@ -2235,6 +2225,8 @@ void kvm_xen_init_vcpu(struct kvm_vcpu *vcpu)
 	vcpu->arch.xen.poll_evtchn =3D 0;
=20
 	timer_setup(&vcpu->arch.xen.poll_timer, cancel_evtchn_poll, 0);
+	hrtimer_init(&vcpu->arch.xen.timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HAR=
D);
+	vcpu->arch.xen.timer.function =3D xen_timer_callback;
=20
 	kvm_gpc_init(&vcpu->arch.xen.runstate_cache, vcpu->kvm);
 	kvm_gpc_init(&vcpu->arch.xen.runstate2_cache, vcpu->kvm);

--=20
2.45.2