For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.

***

Subject: 
Author: klnm1908v@gmail.com

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
master

diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index 91fd3673c09a..e588a188f50a 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -126,23 +126,10 @@ static enum hrtimer_restart
xen_timer_callback(struct hrtimer *timer)
 {
 	struct kvm_vcpu *vcpu = container_of(timer, struct kvm_vcpu,
 					     arch.xen.timer);
-	struct kvm_xen_evtchn e;
-	int rc;

 	if (atomic_read(&vcpu->arch.xen.timer_pending))
 		return HRTIMER_NORESTART;

-	e.vcpu_id = vcpu->vcpu_id;
-	e.vcpu_idx = vcpu->vcpu_idx;
-	e.port = vcpu->arch.xen.timer_virq;
-	e.priority = KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL;
-
-	rc = kvm_xen_set_evtchn_fast(&e, vcpu->kvm);
-	if (rc != -EWOULDBLOCK) {
-		vcpu->arch.xen.timer_expires = 0;
-		return HRTIMER_NORESTART;
-	}
-
 	atomic_inc(&vcpu->arch.xen.timer_pending);
 	kvm_make_request(KVM_REQ_UNBLOCK, vcpu);
 	kvm_vcpu_kick(vcpu);