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Date:   Tue, 28 Jun 2022 22:09:36 +0000
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Subject: [PATCH v6 2/4] KVM: mmu: add a helper to account memory used by KVM MMU.
From:   Yosry Ahmed <yosryahmed@google.com>
To:     Tejun Heo <tj@kernel.org>, Johannes Weiner <hannes@cmpxchg.org>,
        Zefan Li <lizefan.x@bytedance.com>,
        Marc Zyngier <maz@kernel.org>,
        James Morse <james.morse@arm.com>,
        Alexandru Elisei <alexandru.elisei@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Sean Christopherson <seanjc@google.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Joerg Roedel <joro@8bytes.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Michal Hocko <mhocko@kernel.org>,
        Roman Gushchin <roman.gushchin@linux.dev>,
        Shakeel Butt <shakeelb@google.com>,
        Oliver Upton <oupton@google.com>
Cc:     Huang@google.com, Shaoqin <shaoqin.huang@intel.com>,
        cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu,
        kvm@vger.kernel.org, linux-mm@kvack.org,
        Yosry Ahmed <yosryahmed@google.com>
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Precedence: bulk

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@google.com>
---
 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).
+ */
+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