KVM: PPC: Book3S HV P9: Remove subcore HMI handling
On POWER9 and newer, rather than the complex HMI synchronisation and
subcore state, have each thread un-apply the guest TB offset before
calling into the early HMI handler.
This allows the subcore state to be avoided, including subcore enter
/ exit guest, which includes an expensive divide that shows up
slightly in profiles.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211123095231.1036501-54-npiggin@gmail.com
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 214481e..98e90bd 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4033,8 +4033,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
vcpu->arch.ceded = 0;
- kvmppc_subcore_enter_guest();
-
vcpu_vpa_increment_dispatch(vcpu);
if (kvmhv_on_pseries()) {
@@ -4087,8 +4085,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
vcpu_vpa_increment_dispatch(vcpu);
- kvmppc_subcore_exit_guest();
-
return trap;
}
@@ -6102,9 +6098,11 @@ static int kvmppc_book3s_init_hv(void)
if (r)
return r;
- r = kvm_init_subcore_bitmap();
- if (r)
- return r;
+ if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
+ r = kvm_init_subcore_bitmap();
+ if (r)
+ return r;
+ }
/*
* We need a way of accessing the XICS interrupt controller,
