diff options
| author | Paul Mackerras <paulus@samba.org> | 2014-04-02 18:26:37 +1100 |
|---|---|---|
| committer | Eli Qiao <taget@linux.vnet.ibm.com> | 2014-04-02 15:49:28 +0800 |
| commit | b5942ea1135c22174455ac433304db1d32c2d75d (patch) | |
| tree | c5fa9516006cfa8d2ae906488e80a575e92cb55c | |
| parent | c6c8b0afa84e0aa6cdfd88c8bcf10549e4b4d848 (diff) | |
| download | powerkvm-b5942ea1135c22174455ac433304db1d32c2d75d.tar.gz | |
KVM: PPC: Book3S HV: Fix check for running inside guest in global_invalidates()
The global_invalidates() function contains a check that is intended
to tell whether we are currently executing in the context of a hypercall
issued by the guest. The reason is that the optimization of using a
local TLB invalidate instruction is only valid in that context. The
check was testing local_paca->kvm_hstate.kvm_vcore, which gets set
when entering the guest but no longer gets cleared when exiting the
guest. To fix this, we use the kvm_vcpu field instead, which does
get cleared when exiting the guest, by the kvmppc_release_hwthread()
calls inside kvmppc_run_core().
The effect of having the check wrong was that when kvmppc_do_h_remove()
got called from htab_write() on the destination machine during a
migration, it cleared the current cpu's bit in kvm->arch.need_tlb_flush.
This meant that when the guest started running in the destination VM,
it may miss out on doing a complete TLB flush, and therefore may end
up using stale TLB entries from a previous guest that used the same
LPID value.
This should make migration more reliable.
Signed-off-by: Paul Mackerras <paulus@samba.org>
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_rm_mmu.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c index 0357cc3b1cfb0f..b97bdbc00ad3b1 100644 --- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c +++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c @@ -42,13 +42,14 @@ static int global_invalidates(struct kvm *kvm, unsigned long flags) /* * If there is only one vcore, and it's currently running, + * as indicated by local_paca->kvm_hstate.kvm_vcpu being set, * we can use tlbiel as long as we mark all other physical * cores as potentially having stale TLB entries for this lpid. * If we're not using MMU notifiers, we never take pages away * from the guest, so we can use tlbiel if requested. * Otherwise, don't use tlbiel. */ - if (kvm->arch.online_vcores == 1 && local_paca->kvm_hstate.kvm_vcore) + if (kvm->arch.online_vcores == 1 && local_paca->kvm_hstate.kvm_vcpu) global = 0; else if (kvm->arch.using_mmu_notifiers) global = 1; |