On Wed, Nov 6, 2013 at 1:04 PM, Paul Mackerras <paulus@xxxxxxxxx> wrote: > On Tue, Nov 05, 2013 at 03:42:43PM +0800, Liu Ping Fan wrote: >> Since kvmppc_hv_find_lock_hpte() is called from both virtmode and >> realmode, so it can trigger the deadlock. > > Good catch, we should have preemption disabled while ever we have a > HPTE locked. > >> @@ -474,8 +474,10 @@ static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, >> } >> >> /* Find the HPTE in the hash table */ >> + preempt_disable(); >> index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v, >> HPTE_V_VALID | HPTE_V_ABSENT); >> + preempt_enable(); > > Which means we need to add the preempt_enable after unlocking the > HPTE, not here. > Yes. Sorry, but I am not sure about whether we can call preempt_disable/enable() in realmode. I think since thread_info is allocated with linear address, so we can use preempt_disable/enable() inside kvmppc_hv_find_lock_hpte(), right? Thanks and regards, Pingfan > Regards, > Paul. -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
