diff mbox series

[v2,10/26] KVM: x86/mmu: Use common code to free kvm_mmu_page structs

Message ID 20220311002528.2230172-11-dmatlack@google.com
State Changes Requested
Headers show
Series Extend Eager Page Splitting to the shadow MMU | expand

Commit Message

David Matlack March 11, 2022, 12:25 a.m. UTC 
Use a common function to free kvm_mmu_page structs in the TDP MMU and
the shadow MMU. This reduces the amount of duplicate code and is needed
in subsequent commits that allocate and free kvm_mmu_pages for eager
page splitting.

No functional change intended.

Signed-off-by: David Matlack <dmatlack@google.com>
---
 arch/x86/kvm/mmu/mmu.c          | 8 ++++----
 arch/x86/kvm/mmu/mmu_internal.h | 2 ++
 arch/x86/kvm/mmu/tdp_mmu.c      | 3 +--
 3 files changed, 7 insertions(+), 6 deletions(-)

Comments

Peter Xu March 15, 2022, 10:22 a.m. UTC | #1 
On Fri, Mar 11, 2022 at 12:25:12AM +0000, David Matlack wrote:
>  static void tdp_mmu_free_sp(struct kvm_mmu_page *sp)
>  {
> -	free_page((unsigned long)sp->spt);
> -	kmem_cache_free(mmu_page_header_cache, sp);
> +	kvm_mmu_free_shadow_page(sp);
>  }

Perhaps tdp_mmu_free_sp() can be dropped altogether with this?

Reviewed-by: Peter Xu <peterx@redhat.com>
David Matlack March 22, 2022, 10:33 p.m. UTC | #2 
On Tue, Mar 15, 2022 at 3:23 AM Peter Xu <peterx@redhat.com> wrote:
>
> On Fri, Mar 11, 2022 at 12:25:12AM +0000, David Matlack wrote:
> >  static void tdp_mmu_free_sp(struct kvm_mmu_page *sp)
> >  {
> > -     free_page((unsigned long)sp->spt);
> > -     kmem_cache_free(mmu_page_header_cache, sp);
> > +     kvm_mmu_free_shadow_page(sp);
> >  }
>
> Perhaps tdp_mmu_free_sp() can be dropped altogether with this?

It certainly can but I prefer to keep it for 2 reasons:
 - Smaller diff.
 - It mirrors tdp_mmu_alloc_sp(), which I prefer to keep as well but
I'll explain that in the next patch.

>
> Reviewed-by: Peter Xu <peterx@redhat.com>
>
> --
> Peter Xu
>
diff mbox series

Patch

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index c12d5016f6dc..2dcafbef5ffc 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1669,11 +1669,8 @@  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_mmu_free_shadow_page(struct kvm_mmu_page *sp)
+void kvm_mmu_free_shadow_page(struct kvm_mmu_page *sp)
 {
-	MMU_WARN_ON(!is_empty_shadow_page(sp->spt));
-	hlist_del(&sp->hash_link);
-	list_del(&sp->link);
 	free_page((unsigned long)sp->spt);
 	if (!sp->role.direct)
 		free_page((unsigned long)sp->gfns);
@@ -2521,6 +2518,9 @@  static void kvm_mmu_commit_zap_page(struct kvm *kvm,
 
 	list_for_each_entry_safe(sp, nsp, invalid_list, link) {
 		WARN_ON(!sp->role.invalid || sp->root_count);
+		MMU_WARN_ON(!is_empty_shadow_page(sp->spt));
+		hlist_del(&sp->hash_link);
+		list_del(&sp->link);
 		kvm_mmu_free_shadow_page(sp);
 	}
 }
diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index a0648e7ddd33..5f91e4d07a95 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -173,4 +173,6 @@  void unaccount_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp);
 
 struct kvm_mmu_page *kvm_mmu_alloc_direct_sp_for_split(bool locked);
 
+void kvm_mmu_free_shadow_page(struct kvm_mmu_page *sp);
+
 #endif /* __KVM_X86_MMU_INTERNAL_H */
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 1a43f908d508..184874a82a1b 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -64,8 +64,7 @@  void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm)
 
 static void tdp_mmu_free_sp(struct kvm_mmu_page *sp)
 {
-	free_page((unsigned long)sp->spt);
-	kmem_cache_free(mmu_page_header_cache, sp);
+	kvm_mmu_free_shadow_page(sp);
 }
 
 /*