diff options
| author | Paul Mackerras <paulus@samba.org> | 2014-05-26 19:48:36 +1000 |
|---|---|---|
| committer | Alexander Graf <agraf@suse.de> | 2014-05-30 14:26:28 +0200 |
| commit | 55765483e1df8135102ae9ca77dccbca9a7a6184 (patch) | |
| tree | 476ccf436ad7c734e32e47fd1a2b9aa779a99f8a /arch/powerpc | |
| parent | e1d8a96daf641aea11c25268eab678a76215541a (diff) | |
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>
Signed-off-by: Alexander Graf <agraf@suse.de>
Diffstat (limited to 'arch/powerpc')
| -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 1d6c56ad5b60..ac840c6dfa9b 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; |