[PATCH 2/3] powerpc/kvm: fix rare but potential deadlock scene
paulus at samba.org
Wed Nov 6 16:04:18 EST 2013
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
> @@ -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.
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