Commit cc706a63 authored by Quentin Perret's avatar Quentin Perret Committed by Marc Zyngier
Browse files

KVM: arm64: Avoid free_page() in page-table allocator 



Currently, the KVM page-table allocator uses a mix of put_page() and
free_page() calls depending on the context even though page-allocation
is always achieved using variants of __get_free_page().

Make the code consistent by using put_page() throughout, and reduce the
memory management API surface used by the page-table code. This will
ease factoring out page-allocation from pgtable.c, which is a
pre-requisite to creating page-tables at EL2.

Acked-by: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarQuentin Perret <qperret@google.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210319100146.1149909-6-qperret@google.com
parent 9cc77581

arch/arm64/kvm/hyp/pgtable.c

+5 −5
Original line number Diff line number Diff line
@@ -414,7 +414,7 @@ int kvm_pgtable_hyp_init(struct kvm_pgtable *pgt, u32 va_bits) 
static int hyp_free_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,

			   enum kvm_pgtable_walk_flags flag, void * const arg)

{

	free_page((unsigned long)kvm_pte_follow(*ptep));

	put_page(virt_to_page(kvm_pte_follow(*ptep)));

	return 0;

}
@@ -426,7 +426,7 @@ void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt) 
	};



	WARN_ON(kvm_pgtable_walk(pgt, 0, BIT(pgt->ia_bits), &walker));

	free_page((unsigned long)pgt->pgd);

	put_page(virt_to_page(pgt->pgd));

	pgt->pgd = NULL;

}
@@ -578,7 +578,7 @@ static int stage2_map_walk_table_post(u64 addr, u64 end, u32 level, 
	if (!data->anchor)

		return 0;



	free_page((unsigned long)kvm_pte_follow(*ptep));

	put_page(virt_to_page(kvm_pte_follow(*ptep)));

	put_page(virt_to_page(ptep));



	if (data->anchor == ptep) {
@@ -701,7 +701,7 @@ static int stage2_unmap_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, 
	}



	if (childp)

		free_page((unsigned long)childp);

		put_page(virt_to_page(childp));



	return 0;

}
@@ -898,7 +898,7 @@ static int stage2_free_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, 
	put_page(virt_to_page(ptep));



	if (kvm_pte_table(pte, level))

		free_page((unsigned long)kvm_pte_follow(pte));

		put_page(virt_to_page(kvm_pte_follow(pte)));



	return 0;

}