On Thu, Jul 7, 2022 at 2:08 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote:
>
> On Tue, Jun 28, 2022, Yosry Ahmed wrote:
> > Add a helper to account pages used by KVM for page tables in memory
> > secondary pagetable stats. This function will be used by subsequent
> > patches in different archs.
> >
> > Signed-off-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
> > ---
> > include/linux/kvm_host.h | 10 ++++++++++
> > 1 file changed, 10 insertions(+)
> >
> > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> > index 3b40f8d68fbb1..032821d77e920 100644
> > --- a/include/linux/kvm_host.h
> > +++ b/include/linux/kvm_host.h
> > @@ -2241,6 +2241,16 @@ static inline void kvm_handle_signal_exit(struct kvm_vcpu *vcpu)
> > }
> > #endif /* CONFIG_KVM_XFER_TO_GUEST_WORK */
> >
> > +/*
> > + * If more than one page is being (un)accounted, @virt must be the address of
> > + * the first page of a block of pages what were allocated together (i.e
> > + * accounted together).
>
> Sorry for the belated thoughts...
>
> If you spin a v7, can you add a note to call out that mod_lruvec_page_state() is
> itself thread-safe? Caught my eye because the TDP MMU usage happens while holding
> mmu_lock for read.
>
Sure! I will send a v7 anyway to address the comments on patch 1. Thanks!
> > + */
> > +static inline void kvm_account_pgtable_pages(void *virt, int nr)
> > +{
> > + mod_lruvec_page_state(virt_to_page(virt), NR_SECONDARY_PAGETABLE, nr);
> > +}
> > +
> > /*
> > * This defines how many reserved entries we want to keep before we
> > * kick the vcpu to the userspace to avoid dirty ring full. This
> > --
> > 2.37.0.rc0.161.g10f37bed90-goog
> >
