KVM: PPC: Book3S HV: Context tracking exit guest context before enabling irqs

Interrupts that occur in kernel mode expect that context tracking
is set to kernel. Enabling local irqs before context tracking
switches from guest to host means interrupts can come in and trigger
warnings about wrong context, and possibly worse.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210130130852.2952424-3-npiggin@gmail.com

arch/powerpc/kvm/book3s_hv.c

@@ -3407,8 +3407,9 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 
 	kvmppc_set_host_core(pcpu);
 
+	guest_exit_irqoff();
+
 	local_irq_enable();
-	guest_exit();
 
 	/* Let secondaries go back to the offline loop */
 	for (i = 0; i < controlled_threads; ++i) {
@@ -4217,8 +4218,9 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	kvmppc_set_host_core(pcpu);
 
+	guest_exit_irqoff();
+
 	local_irq_enable();
-	guest_exit();
 
 	cpumask_clear_cpu(pcpu, &kvm->arch.cpu_in_guest);