KVM: PPC: Book3S HV P9: Juggle SPR switching around

This juggles SPR switching on the entry and exit sides to be more
symmetric, which makes the next refactoring patch possible with no
functional change.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211123095231.1036501-28-npiggin@gmail.com

arch/powerpc/kvm/book3s_hv.c

@@ -4222,7 +4222,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		msr = mfmsr(); /* TM restore can update msr */
 	}
 
-	switch_pmu_to_guest(vcpu, &host_os_sprs);
+	load_spr_state(vcpu, &host_os_sprs);
 
 	load_fp_state(&vcpu->arch.fp);
 #ifdef CONFIG_ALTIVEC
@@ -4230,7 +4230,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 #endif
 	mtspr(SPRN_VRSAVE, vcpu->arch.vrsave);
 
-	load_spr_state(vcpu, &host_os_sprs);
+	switch_pmu_to_guest(vcpu, &host_os_sprs);
 
 	if (kvmhv_on_pseries()) {
 		/*
@@ -4330,6 +4330,8 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 			vcpu->arch.slb_max = 0;
 	}
 
+	switch_pmu_to_host(vcpu, &host_os_sprs);
+
 	store_spr_state(vcpu);
 
 	store_fp_state(&vcpu->arch.fp);
@@ -4344,8 +4346,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	vcpu_vpa_increment_dispatch(vcpu);
 
-	switch_pmu_to_host(vcpu, &host_os_sprs);
-
 	timer_rearm_host_dec(*tb);
 
 	restore_p9_host_os_sprs(vcpu, &host_os_sprs);