[RFC PATCH v1 5/5] KVM: arm64: Adapt page-table code to new handling of coalescing tables
From: Yanan Wang <hidden>
Date: 2021-01-26 13:53:52
Also in:
kvm, kvmarm, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
With new handling of coalescing tables, we can install the block entry before unmap of the old table mappings. So make the installation in stage2_map_walk_table_pre(), and elide the installation from function stage2_map_walk_table_post(). Signed-off-by: Yanan Wang <redacted> --- arch/arm64/kvm/hyp/pgtable.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-)
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index ab1c94985ed0..fb755aac4384 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c@@ -436,6 +436,7 @@ struct stage2_map_data { kvm_pte_t attr; kvm_pte_t *anchor; + kvm_pte_t *follow; struct kvm_s2_mmu *mmu; struct kvm_mmu_memory_cache *memcache;
@@ -550,13 +551,13 @@ static int stage2_map_walk_table_pre(u64 addr, u64 end, u32 level, kvm_set_invalid_pte(ptep); /* - * Invalidate the whole stage-2, as we may have numerous leaf - * entries below us which would otherwise need invalidating - * individually. + * If there is an existing table entry and block mapping is needed here, + * then set the anchor and replace it with a block entry. The sub-level + * mappings will later be unmapped lazily. */ - kvm_call_hyp(__kvm_tlb_flush_vmid, data->mmu); data->anchor = ptep; - return 0; + data->follow = kvm_pte_follow(*ptep); + return stage2_coalesce_tables_into_block(addr, level, ptep, data); } static int stage2_map_walk_leaf(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
@@ -608,20 +609,18 @@ static int stage2_map_walk_table_post(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, struct stage2_map_data *data) { - int ret = 0; - if (!data->anchor) return 0; - free_page((unsigned long)kvm_pte_follow(*ptep)); - put_page(virt_to_page(ptep)); - - if (data->anchor == ptep) { + if (data->anchor != ptep) { + free_page((unsigned long)kvm_pte_follow(*ptep)); + put_page(virt_to_page(ptep)); + } else { + free_page((unsigned long)data->follow); data->anchor = NULL; - ret = stage2_map_walk_leaf(addr, end, level, ptep, data); } - return ret; + return 0; } /*
--
2.19.1
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