Count the pages used by pKVM for the guest stage-2 in memory stats under
secondary pagetable stats, similarly to what the VHE mode does.

Signed-off-by: Vincent Donnefort <vdonnefort@google.com>

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 1f55b0c7b11d..c2e022c41313 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1088,12 +1088,18 @@ void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu)
 
 static void hyp_mc_free_fn(void *addr, void *unused)
 {
+	kvm_account_pgtable_pages(addr, -1);
 	free_page((unsigned long)addr);
 }
 
 static void *hyp_mc_alloc_fn(void *unused)
 {
-	return (void *)__get_free_page(GFP_KERNEL_ACCOUNT);
+	void *addr = (void *)__get_free_page(GFP_KERNEL_ACCOUNT);
+
+	if (addr)
+		kvm_account_pgtable_pages(addr, 1);
+
+	return addr;
 }
 
 void free_hyp_memcache(struct kvm_hyp_memcache *mc)

base-commit: d082ecbc71e9e0bf49883ee4afd435a77a5101b6
-- 
2.48.1.711.g2feabab25a-goog

On Fri, Feb 28, 2025 at 12:13:55PM +0000, Vincent Donnefort wrote:
> Count the pages used by pKVM for the guest stage-2 in memory stats under
> secondary pagetable stats, similarly to what the VHE mode does.
> 
> Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
> 
> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> index 1f55b0c7b11d..c2e022c41313 100644
> --- a/arch/arm64/kvm/mmu.c
> +++ b/arch/arm64/kvm/mmu.c
> @@ -1088,12 +1088,18 @@ void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu)
>  
>  static void hyp_mc_free_fn(void *addr, void *unused)
>  {
> +	kvm_account_pgtable_pages(addr, -1);
>  	free_page((unsigned long)addr);
>  }

Don't we drain more than just stage-2 page tables into the teardown_mc
(e.g. vcpu structs)?

Thanks,
Oliver

On Mon, Mar 03, 2025 at 01:18:35PM -0800, Oliver Upton wrote:
> On Fri, Feb 28, 2025 at 12:13:55PM +0000, Vincent Donnefort wrote:
> > Count the pages used by pKVM for the guest stage-2 in memory stats under
> > secondary pagetable stats, similarly to what the VHE mode does.
> > 
> > Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
> > 
> > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> > index 1f55b0c7b11d..c2e022c41313 100644
> > --- a/arch/arm64/kvm/mmu.c
> > +++ b/arch/arm64/kvm/mmu.c
> > @@ -1088,12 +1088,18 @@ void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu)
> >  
> >  static void hyp_mc_free_fn(void *addr, void *unused)
> >  {
> > +	kvm_account_pgtable_pages(addr, -1);
> >  	free_page((unsigned long)addr);
> >  }
> 
> Don't we drain more than just stage-2 page tables into the teardown_mc
> (e.g. vcpu structs)?

Sigh, yes we do. I've left behind some changes we have in our Android branches.
Let me respin a proper version :-\ 

> 
> Thanks,
> Oliver