diff mbox series

[v5,3/4] KVM: x86/mmu: count KVM mmu usage in secondary pagetable stats.

Message ID 20220606222058.86688-4-yosryahmed@google.com (mailing list archive)
State New, archived
Headers show
Series KVM: mm: count KVM mmu usage in memory stats | expand

Commit Message

Yosry Ahmed June 6, 2022, 10:20 p.m. UTC 
Count the pages used by KVM mmu on x86 for in secondary pagetable stats.

Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
---
 arch/x86/kvm/mmu/mmu.c     | 16 ++++++++++++++--
 arch/x86/kvm/mmu/tdp_mmu.c | 12 ++++++++++++
 2 files changed, 26 insertions(+), 2 deletions(-)

Comments

Sean Christopherson June 27, 2022, 4:22 p.m. UTC | #1 
On Mon, Jun 06, 2022, Yosry Ahmed wrote:
> Count the pages used by KVM mmu on x86 for in secondary pagetable stats.

"for in" is funky.  And it's worth providing a brief explanation of what the
secondary pagetable stats actually are.  "secondary" is confusingly close to
"second level pagetables", e.g. might be misconstrued as KVM counters for the
number of stage-2 / two-dimension paging page (TDP) tables.

Code looks good, though it needs a rebased on kvm/queue.
Yosry Ahmed June 27, 2022, 4:29 p.m. UTC | #2 
On Mon, Jun 27, 2022 at 9:22 AM Sean Christopherson <seanjc@google.com> wrote:
>
> On Mon, Jun 06, 2022, Yosry Ahmed wrote:
> > Count the pages used by KVM mmu on x86 for in secondary pagetable stats.
>
> "for in" is funky.  And it's worth providing a brief explanation of what the
> secondary pagetable stats actually are.  "secondary" is confusingly close to
> "second level pagetables", e.g. might be misconstrued as KVM counters for the
> number of stage-2 / two-dimension paging page (TDP) tables.
>
> Code looks good, though it needs a rebased on kvm/queue.

Will rebase and modify the commit message accordingly, thanks!
diff mbox series

Patch

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index efe5a3dca1e09..4090d228e1756 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1652,6 +1652,18 @@  static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, long nr)
 	percpu_counter_add(&kvm_total_used_mmu_pages, nr);
 }
 
+static void kvm_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp)
+{
+	kvm_mod_used_mmu_pages(kvm, +1);
+	kvm_account_pgtable_pages((void *)sp->spt, +1);
+}
+
+static void kvm_unaccount_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp)
+{
+	kvm_mod_used_mmu_pages(kvm, -1);
+	kvm_account_pgtable_pages((void *)sp->spt, -1);
+}
+
 static void kvm_mmu_free_page(struct kvm_mmu_page *sp)
 {
 	MMU_WARN_ON(!is_empty_shadow_page(sp->spt));
@@ -1707,7 +1719,7 @@  static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, int direct
 	 */
 	sp->mmu_valid_gen = vcpu->kvm->arch.mmu_valid_gen;
 	list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
-	kvm_mod_used_mmu_pages(vcpu->kvm, +1);
+	kvm_account_mmu_page(vcpu->kvm, sp);
 	return sp;
 }
 
@@ -2336,7 +2348,7 @@  static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm,
 			list_add(&sp->link, invalid_list);
 		else
 			list_move(&sp->link, invalid_list);
-		kvm_mod_used_mmu_pages(kvm, -1);
+		kvm_unaccount_mmu_page(kvm, sp);
 	} else {
 		/*
 		 * Remove the active root from the active page list, the root
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 841feaa48be5e..0b70d1a1a3534 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -372,6 +372,16 @@  static void handle_changed_spte_dirty_log(struct kvm *kvm, int as_id, gfn_t gfn,
 	}
 }
 
+static void tdp_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp)
+{
+	kvm_account_pgtable_pages((void *)sp->spt, +1);
+}
+
+static void tdp_unaccount_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp)
+{
+	kvm_account_pgtable_pages((void *)sp->spt, -1);
+}
+
 /**
  * tdp_mmu_unlink_sp() - Remove a shadow page from the list of used pages
  *
@@ -384,6 +394,7 @@  static void handle_changed_spte_dirty_log(struct kvm *kvm, int as_id, gfn_t gfn,
 static void tdp_mmu_unlink_sp(struct kvm *kvm, struct kvm_mmu_page *sp,
 			      bool shared)
 {
+	tdp_unaccount_mmu_page(kvm, sp);
 	if (shared)
 		spin_lock(&kvm->arch.tdp_mmu_pages_lock);
 	else
@@ -1146,6 +1157,7 @@  static int tdp_mmu_link_sp(struct kvm *kvm, struct tdp_iter *iter,
 	if (account_nx)
 		account_huge_nx_page(kvm, sp);
 	spin_unlock(&kvm->arch.tdp_mmu_pages_lock);
+	tdp_account_mmu_page(kvm, sp);
 
 	return 0;
 }