Add flags to kvm_hyp_memcache and propagate the latter to the allocation
and free callbacks. This will later allow to account for memory, based
on the memcache configuration.

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

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 3a7ec98ef123..12691ae23d4c 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -86,6 +86,7 @@ struct kvm_hyp_memcache {
 	phys_addr_t head;
 	unsigned long nr_pages;
 	struct pkvm_mapping *mapping; /* only used from EL1 */
+	unsigned long flags;
 };
 
 static inline void push_hyp_memcache(struct kvm_hyp_memcache *mc,
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 1f55b0c7b11d..c01ad4430729 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1086,12 +1086,12 @@ void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu)
 	}
 }
 
-static void hyp_mc_free_fn(void *addr, void *unused)
+static void hyp_mc_free_fn(void *addr, void *mc)
 {
 	free_page((unsigned long)addr);
 }
 
-static void *hyp_mc_alloc_fn(void *unused)
+static void *hyp_mc_alloc_fn(void *mc)
 {
 	return (void *)__get_free_page(GFP_KERNEL_ACCOUNT);
 }
@@ -1102,7 +1102,7 @@ void free_hyp_memcache(struct kvm_hyp_memcache *mc)
 		return;
 
 	kfree(mc->mapping);
-	__free_hyp_memcache(mc, hyp_mc_free_fn, kvm_host_va, NULL);
+	__free_hyp_memcache(mc, hyp_mc_free_fn, kvm_host_va, (void *)mc);
 }
 
 int topup_hyp_memcache(struct kvm_hyp_memcache *mc, unsigned long min_pages)
@@ -1117,7 +1117,7 @@ int topup_hyp_memcache(struct kvm_hyp_memcache *mc, unsigned long min_pages)
 	}
 
 	return __topup_hyp_memcache(mc, min_pages, hyp_mc_alloc_fn,
-				    kvm_host_pa, NULL);
+				    kvm_host_pa, (void *)mc);
 }
 
 /**
-- 
2.49.0.rc0.332.g42c0ae87b1-goog

On Fri, 07 Mar 2025 11:34:09 +0000,
Vincent Donnefort <vdonnefort@google.com> wrote:
> 
> Add flags to kvm_hyp_memcache and propagate the latter to the allocation
> and free callbacks. This will later allow to account for memory, based
> on the memcache configuration.
> 
> Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
> 
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index 3a7ec98ef123..12691ae23d4c 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -86,6 +86,7 @@ struct kvm_hyp_memcache {
>  	phys_addr_t head;
>  	unsigned long nr_pages;
>  	struct pkvm_mapping *mapping; /* only used from EL1 */
> +	unsigned long flags;
>  };
>  
>  static inline void push_hyp_memcache(struct kvm_hyp_memcache *mc,
> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> index 1f55b0c7b11d..c01ad4430729 100644
> --- a/arch/arm64/kvm/mmu.c
> +++ b/arch/arm64/kvm/mmu.c
> @@ -1086,12 +1086,12 @@ void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu)
>  	}
>  }
>  
> -static void hyp_mc_free_fn(void *addr, void *unused)
> +static void hyp_mc_free_fn(void *addr, void *mc)
>  {
>  	free_page((unsigned long)addr);
>  }
>  
> -static void *hyp_mc_alloc_fn(void *unused)
> +static void *hyp_mc_alloc_fn(void *mc)
>  {
>  	return (void *)__get_free_page(GFP_KERNEL_ACCOUNT);
>  }
> @@ -1102,7 +1102,7 @@ void free_hyp_memcache(struct kvm_hyp_memcache *mc)
>  		return;
>  
>  	kfree(mc->mapping);
> -	__free_hyp_memcache(mc, hyp_mc_free_fn, kvm_host_va, NULL);
> +	__free_hyp_memcache(mc, hyp_mc_free_fn, kvm_host_va, (void *)mc);

Why the cast? It looks superfluous to me.

>  }
>  
>  int topup_hyp_memcache(struct kvm_hyp_memcache *mc, unsigned long min_pages)
> @@ -1117,7 +1117,7 @@ int topup_hyp_memcache(struct kvm_hyp_memcache *mc, unsigned long min_pages)
>  	}
>  
>  	return __topup_hyp_memcache(mc, min_pages, hyp_mc_alloc_fn,
> -				    kvm_host_pa, NULL);
> +				    kvm_host_pa, (void *)mc);

Same here.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.

[...]

> > @@ -1102,7 +1102,7 @@ void free_hyp_memcache(struct kvm_hyp_memcache *mc)
> >  		return;
> >  
> >  	kfree(mc->mapping);
> > -	__free_hyp_memcache(mc, hyp_mc_free_fn, kvm_host_va, NULL);
> > +	__free_hyp_memcache(mc, hyp_mc_free_fn, kvm_host_va, (void *)mc);
> 
> Why the cast? It looks superfluous to me.

Ha yes it is now I pass mc and not mc->flags.

> 
> >  }
> >  
> >  int topup_hyp_memcache(struct kvm_hyp_memcache *mc, unsigned long min_pages)
> > @@ -1117,7 +1117,7 @@ int topup_hyp_memcache(struct kvm_hyp_memcache *mc, unsigned long min_pages)
> >  	}
> >  
> >  	return __topup_hyp_memcache(mc, min_pages, hyp_mc_alloc_fn,
> > -				    kvm_host_pa, NULL);
> > +				    kvm_host_pa, (void *)mc);
> 
> Same here.
> 
> Thanks,
> 
> 	M.
> 
> -- 
> Without deviation from the norm, progress is not possible.