Messages in this thread | | | From | Paolo Bonzini <> | Subject | Re: [PATCH] KVM: arm: memcg awareness | Date | Wed, 17 Mar 2021 11:40:23 +0100 |
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On 17/03/21 10:10, Marc Zyngier wrote: >> @@ -366,7 +366,7 @@ static int hyp_map_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, >> if (WARN_ON(level == KVM_PGTABLE_MAX_LEVELS - 1)) >> return -EINVAL; >> >> - childp = (kvm_pte_t *)get_zeroed_page(GFP_KERNEL); >> + childp = (kvm_pte_t *)get_zeroed_page(GFP_KERNEL_ACCOUNT); > No, this is wrong. > > You cannot account the hypervisor page tables to the guest because we > don't ever unmap them, and that we can't distinguish two data > structures from two different VMs occupying the same page.
If you never unmap them, there should at least be a shrinker to get rid of unused pages in the event of memory pressure.
Paolo
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