From 8e94e1252cc054bb31fd3e9a15235cd831970ec1 Mon Sep 17 00:00:00 2001 From: Oliver Upton Date: Mon, 7 Nov 2022 21:56:35 +0000 Subject: KVM: arm64: Add a helper to tear down unlinked stage-2 subtrees A subsequent change to KVM will move the tear down of an unlinked stage-2 subtree out of the critical path of the break-before-make sequence. Introduce a new helper for tearing down unlinked stage-2 subtrees. Leverage the existing stage-2 free walkers to do so, with a deep call into __kvm_pgtable_walk() as the subtree is no longer reachable from the root. Signed-off-by: Oliver Upton Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20221107215644.1895162-6-oliver.upton@linux.dev --- arch/arm64/include/asm/kvm_pgtable.h | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'arch/arm64/include/asm') diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index a752793482cb..93b1feeaebab 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -333,6 +333,17 @@ int __kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_s2_mmu *mmu, */ void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt); +/** + * kvm_pgtable_stage2_free_removed() - Free a removed stage-2 paging structure. + * @mm_ops: Memory management callbacks. + * @pgtable: Unlinked stage-2 paging structure to be freed. + * @level: Level of the stage-2 paging structure to be freed. + * + * The page-table is assumed to be unreachable by any hardware walkers prior to + * freeing and therefore no TLB invalidation is performed. + */ +void kvm_pgtable_stage2_free_removed(struct kvm_pgtable_mm_ops *mm_ops, void *pgtable, u32 level); + /** * kvm_pgtable_stage2_map() - Install a mapping in a guest stage-2 page-table. * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*(). -- cgit v1.2.3