Re: [PATCH 2/2] KVM MMU: fix race in invlpg code

[Avi Kivity]

On 05/05/2010 03:45 PM, Xiao Guangrong wrote:
> Avi Kivity wrote:
>
>    
> > >        spin_lock(&vcpu->kvm->mmu_lock);
> > > +    index = kvm_page_table_hashfn(gfn);
> > > +    bucket =&vcpu->kvm->arch.mmu_page_hash[index];
> > > +    hlist_for_each_entry_safe(s, node, tmp, bucket, hash_link)
> > > +        if (s == sp) {
> > > +            if (s->gfn == gfn&&   s->role.word == role.word)
> > > +                live = true;
> > > +            break;
> > > +        }
> > > +
> > > +    if (!live)
> > > +        goto unlock_exit;
> > > +
> > >
> > >        
> > Did you try the root_count method?  I think it's cleaner.
> >      
> Avi, Thanks for your idea.
>
> I have considered this method, but i'm not sure when it's the good time
> to real free this page, and i think we also need a way to synchronize the
> real free path and this path. Do you have any comment for it :-(
>    

Same as mmu_free_roots():

        --sp->root_count;
        if (!sp->root_count && sp->role.invalid) {
                kvm_mmu_zap_page(vcpu->kvm, sp);
                goto unlock_exit;
        }


--
error compiling committee.c: too many arguments to function

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