Re: [PATCH v2] powernv: kvm: make _PAGE_NUMA take effect

["Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>]

Liu Ping Fan <kernelfans@gmail.com> writes:

> To make sure that on host, the pages marked with _PAGE_NUMA result in a fault
> when guest access them, we should force the checking when guest uses hypercall
> to setup hpte.
>
> Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

When we mark pte with _PAGE_NUMA we already call mmu_notifier_invalidate_range_start and
mmu_notifier_invalidate_range_end, which will mark existing guest hpte
entry as HPTE_V_ABSENT. Now we need to do that when we are inserting new
guest hpte entries. This patch does that. 

> ---
> v2:
>   It should be the reply to "[PATCH 2/4] powernv: kvm: make _PAGE_NUMA take effect"
>   And I imporve the changelog according to Aneesh's suggestion.
> ---
>  arch/powerpc/kvm/book3s_hv_rm_mmu.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
> index 9c51544..af8602d 100644
> --- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
> +++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
> @@ -232,7 +232,7 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
>  		/* Look up the Linux PTE for the backing page */
>  		pte_size = psize;
>  		pte = lookup_linux_pte(pgdir, hva, writing, &pte_size);
> -		if (pte_present(pte)) {
> +		if (pte_present(pte) && !pte_numa(pte)) {
>  			if (writing && !pte_write(pte))
>  				/* make the actual HPTE be read-only */
>  				ptel = hpte_make_readonly(ptel);
> -- 
> 1.8.1.4