KVM: nVMX: make emulated nested preemption timer pinned

Commit 61abdbe ("kvm: x86: make lapic hrtimer pinned") pins the emulated
lapic timer. This patch does the same for the emulated nested preemption
timer to avoid vmexit an unrelated vCPU and the latency of kicking IPI to
another vCPU.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx.c

@@ -7013,7 +7013,7 @@ static int handle_vmon(struct kvm_vcpu *vcpu)
 	vmx->nested.vmcs02_num = 0;
 
 	hrtimer_init(&vmx->nested.preemption_timer, CLOCK_MONOTONIC,
-		     HRTIMER_MODE_REL);
+		     HRTIMER_MODE_REL_PINNED);
 	vmx->nested.preemption_timer.function = vmx_preemption_timer_fn;
 
 	vmx->nested.vmxon = true;