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From:   Vipin Sharma <vipinsh@google.com>
Date:   Mon, 5 Dec 2022 15:40:19 -0800
Message-ID: <CAHVum0cf_AeJ8rZGcWdne=QV6f_+09b=7kJb3xd-9eNiZr75Qg@mail.gmail.com>
Subject: Re: [Patch v2 2/2] KVM: x86/mmu: Allocate page table pages on NUMA
 node of underlying pages
To:     Ben Gardon <bgardon@google.com>
Cc:     dmatlack@google.com, seanjc@google.com, pbonzini@redhat.com,
        kvm@vger.kernel.org, linux-kernel@vger.kernel.org
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On Mon, Dec 5, 2022 at 10:17 AM Ben Gardon <bgardon@google.com> wrote:
>
> On Thu, Dec 1, 2022 at 11:57 AM Vipin Sharma <vipinsh@google.com> wrote:
> > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> > index 1782c4555d94..4d59c9d48277 100644
> > --- a/virt/kvm/kvm_main.c
> > +++ b/virt/kvm/kvm_main.c
> > @@ -384,6 +384,11 @@ static void kvm_flush_shadow_all(struct kvm *kvm)
> >         kvm_arch_guest_memory_reclaimed(kvm);
> >  }
> >
> > +void * __weak kvm_arch_mmu_get_free_page(int nid, gfp_t gfp_flags)
> > +{
> > +               return (void *)__get_free_page(gfp_flags);
> > +}
> > +
>
> Rather than making this __weak, you could use #ifdef CONFIG_NUMA to
> just put all the code in the arch-neutral function.
>

I am not sure how it will work. Here, I am trying to keep this feature
only for x86. This function will be used for all architecture except
in x86 where we have different implementation in arch/x86/mmu/mmu.c
So, even if CONFIG_NUMA is defined, we want to keep the same
definition on other architectures.


> >  #ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE
> >  static inline void *mmu_memory_cache_alloc_obj(struct kvm_mmu_memory_cache *mc,
> >                                                gfp_t gfp_flags)
> > @@ -393,7 +398,7 @@ static inline void *mmu_memory_cache_alloc_obj(struct kvm_mmu_memory_cache *mc,
> >         if (mc->kmem_cache)
> >                 return kmem_cache_alloc(mc->kmem_cache, gfp_flags);
> >         else
> > -               return (void *)__get_free_page(gfp_flags);
> > +               return kvm_arch_mmu_get_free_page(mc->node, gfp_flags);
> >  }
> >
> >  int __kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int capacity, int min)
> > --
> > 2.39.0.rc0.267.gcb52ba06e7-goog
> >