LoongArch: KVM: Fix PMU pass-through issue if VM exits to host finally

commit 5add0dbbeb upstream.

In function kvm_pre_enter_guest(), it prepares to enter guest and check
whether there are pending signals or events. And it will not enter guest
if there are, PMU pass-through preparation for guest should be cancelled
and host should own PMU hardware.

Cc: stable@vger.kernel.org
Fixes: f4e40ea9f7 ("LoongArch: KVM: Add PMU support for guest")
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/loongarch/kvm/vcpu.c

@@ -294,6 +294,7 @@ static int kvm_pre_enter_guest(struct kvm_vcpu *vcpu)
 		vcpu->arch.aux_inuse &= ~KVM_LARCH_SWCSR_LATEST;
 
 		if (kvm_request_pending(vcpu) || xfer_to_guest_mode_work_pending()) {
+			kvm_lose_pmu(vcpu);
 			/* make sure the vcpu mode has been written */
 			smp_store_mb(vcpu->mode, OUTSIDE_GUEST_MODE);
 			local_irq_enable();