KVM: PPC: Book3S HV P9: Move SPRG restore to restore_p9_host_os_sprs

Move the SPR update into its relevant helper function. This will
help with SPR scheduling improvements in later changes.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211123095231.1036501-19-npiggin@gmail.com

arch/powerpc/kvm/book3s_hv.c

@@ -4106,6 +4106,8 @@ static void save_p9_host_os_sprs(struct p9_host_os_sprs *host_os_sprs)
 static void restore_p9_host_os_sprs(struct kvm_vcpu *vcpu,
 				    struct p9_host_os_sprs *host_os_sprs)
 {
+	mtspr(SPRN_SPRG_VDSO_WRITE, local_paca->sprg_vdso);
+
 	mtspr(SPRN_PSPB, 0);
 	mtspr(SPRN_UAMOR, 0);
 
@@ -4306,8 +4308,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	timer_rearm_host_dec(tb);
 
-	mtspr(SPRN_SPRG_VDSO_WRITE, local_paca->sprg_vdso);
-
 	kvmppc_subcore_exit_guest();
 
 	return trap;