From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sean Christopherson Subject: Re: [PATCH v6 2/4] KVM: mmu: add a helper to account memory used by KVM MMU. Date: Thu, 7 Jul 2022 21:08:36 +0000 Message-ID: References: <20220628220938.3657876-1-yosryahmed@google.com> <20220628220938.3657876-3-yosryahmed@google.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=Z0i/FsEtEYZWQoqmAH7Voc71S2cgw06FoAKusiT8OZ4=; b=WoU0PSQ0Wj5Vhi5VAdOixoxhmqcmoNDkx6vHqBySeC9zqf2nqsQfssDemp0HQ+Ov1B x/J5MxoGXzLdJH5GEyRAbOhWT68fOGc+6rHAXDByBx1OVQfP46gGjK+Mi+BzW6aTzy1J zCmFPJ2SlEc+diWQW3EPCjFu0t4IWIGEdVT9pGCnFTtf0M7aL/JzkavojLQOy4s/UgNF NGApv5Q7B2F5jgchJKAeNIaqUXEoBZLJR5OdL0c5HU9ZNIBlR45kMkufdSbiFomJXlCl /ZAg/DkWLMF98iVndrnP9vxLYNAXMsIgTDVMZU2Ziwpk1aIQXpLAs3/2s4PDhY8kMxbt LAVQ== Content-Disposition: inline In-Reply-To: <20220628220938.3657876-3-yosryahmed-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Yosry Ahmed Cc: Tejun Heo , Johannes Weiner , Zefan Li , Marc Zyngier , James Morse , Alexandru Elisei , Suzuki K Poulose , Paolo Bonzini , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Andrew Morton , Michal Hocko , Roman Gushchin , Shakeel Butt , Oliver Upton , Huang-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, Shaoqin , cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWNGWvitb5QawA@public.gmane.org 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 > --- > 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. > + */ > +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 >