On Wed, Feb 15, 2023 at 05:40:36PM +0000, Ricardo Koller wrote:
> Make it clearer that the "free_removed" functions refer to tables that
> have never been part of the paging structure: they are "unlinked".
the page table passed to ->free_removed_table() was definitely part of a
paging structure before. Maybe:
A subsequent change to KVM will add support for building page tables
that are not part of an active paging structure. The existing
'removed_table' terminology is quite clunky when applied in this
context.
Normalize on referring to tables outside of an active paging structure
as 'unlinked'. No functional change intended.
> No functional change intended.
>
> Signed-off-by: Ricardo Koller <ricarkol@xxxxxxxxxx>
besides the changelog nit:
Reviewed-by: Oliver Upton <oliver.upton@xxxxxxxxx>
--
Thanks,
Oliver
> ---
> arch/arm64/include/asm/kvm_pgtable.h | 8 ++++----
> arch/arm64/kvm/hyp/nvhe/mem_protect.c | 6 +++---
> arch/arm64/kvm/hyp/pgtable.c | 6 +++---
> arch/arm64/kvm/mmu.c | 10 +++++-----
> 4 files changed, 15 insertions(+), 15 deletions(-)
>
> diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
> index 3339192a97a9..7c45082e6c23 100644
> --- a/arch/arm64/include/asm/kvm_pgtable.h
> +++ b/arch/arm64/include/asm/kvm_pgtable.h
> @@ -99,7 +99,7 @@ static inline bool kvm_level_supports_block_mapping(u32 level)
> * allocation is physically contiguous.
> * @free_pages_exact: Free an exact number of memory pages previously
> * allocated by zalloc_pages_exact.
> - * @free_removed_table: Free a removed paging structure by unlinking and
> + * @free_unlinked_table: Free an unlinked paging structure by unlinking and
> * dropping references.
> * @get_page: Increment the refcount on a page.
> * @put_page: Decrement the refcount on a page. When the
> @@ -119,7 +119,7 @@ struct kvm_pgtable_mm_ops {
> void* (*zalloc_page)(void *arg);
> void* (*zalloc_pages_exact)(size_t size);
> void (*free_pages_exact)(void *addr, size_t size);
> - void (*free_removed_table)(void *addr, u32 level);
> + void (*free_unlinked_table)(void *addr, u32 level);
> void (*get_page)(void *addr);
> void (*put_page)(void *addr);
> int (*page_count)(void *addr);
> @@ -450,7 +450,7 @@ 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.
> + * kvm_pgtable_stage2_free_unlinked() - Free un unlinked 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.
> @@ -458,7 +458,7 @@ void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt);
> * 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);
> +void kvm_pgtable_stage2_free_unlinked(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.
> diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
> index 552653fa18be..b030170d803b 100644
> --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
> +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
> @@ -91,9 +91,9 @@ static void host_s2_put_page(void *addr)
> hyp_put_page(&host_s2_pool, addr);
> }
>
> -static void host_s2_free_removed_table(void *addr, u32 level)
> +static void host_s2_free_unlinked_table(void *addr, u32 level)
> {
> - kvm_pgtable_stage2_free_removed(&host_mmu.mm_ops, addr, level);
> + kvm_pgtable_stage2_free_unlinked(&host_mmu.mm_ops, addr, level);
> }
>
> static int prepare_s2_pool(void *pgt_pool_base)
> @@ -110,7 +110,7 @@ static int prepare_s2_pool(void *pgt_pool_base)
> host_mmu.mm_ops = (struct kvm_pgtable_mm_ops) {
> .zalloc_pages_exact = host_s2_zalloc_pages_exact,
> .zalloc_page = host_s2_zalloc_page,
> - .free_removed_table = host_s2_free_removed_table,
> + .free_unlinked_table = host_s2_free_unlinked_table,
> .phys_to_virt = hyp_phys_to_virt,
> .virt_to_phys = hyp_virt_to_phys,
> .page_count = hyp_page_count,
> diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
> index e093e222daf3..0a5ef9288371 100644
> --- a/arch/arm64/kvm/hyp/pgtable.c
> +++ b/arch/arm64/kvm/hyp/pgtable.c
> @@ -841,7 +841,7 @@ static int stage2_map_walk_table_pre(const struct kvm_pgtable_visit_ctx *ctx,
> if (ret)
> return ret;
>
> - mm_ops->free_removed_table(childp, ctx->level);
> + mm_ops->free_unlinked_table(childp, ctx->level);
> return 0;
> }
>
> @@ -886,7 +886,7 @@ static int stage2_map_walk_leaf(const struct kvm_pgtable_visit_ctx *ctx,
> * The TABLE_PRE callback runs for table entries on the way down, looking
> * for table entries which we could conceivably replace with a block entry
> * for this mapping. If it finds one it replaces the entry and calls
> - * kvm_pgtable_mm_ops::free_removed_table() to tear down the detached table.
> + * kvm_pgtable_mm_ops::free_unlinked_table() to tear down the detached table.
> *
> * Otherwise, the LEAF callback performs the mapping at the existing leaves
> * instead.
> @@ -1250,7 +1250,7 @@ void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt)
> pgt->pgd = NULL;
> }
>
> -void kvm_pgtable_stage2_free_removed(struct kvm_pgtable_mm_ops *mm_ops, void *pgtable, u32 level)
> +void kvm_pgtable_stage2_free_unlinked(struct kvm_pgtable_mm_ops *mm_ops, void *pgtable, u32 level)
> {
> kvm_pteref_t ptep = (kvm_pteref_t)pgtable;
> struct kvm_pgtable_walker walker = {
> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> index a3ee3b605c9b..9bd3c2cfb476 100644
> --- a/arch/arm64/kvm/mmu.c
> +++ b/arch/arm64/kvm/mmu.c
> @@ -130,21 +130,21 @@ static void kvm_s2_free_pages_exact(void *virt, size_t size)
>
> static struct kvm_pgtable_mm_ops kvm_s2_mm_ops;
>
> -static void stage2_free_removed_table_rcu_cb(struct rcu_head *head)
> +static void stage2_free_unlinked_table_rcu_cb(struct rcu_head *head)
> {
> struct page *page = container_of(head, struct page, rcu_head);
> void *pgtable = page_to_virt(page);
> u32 level = page_private(page);
>
> - kvm_pgtable_stage2_free_removed(&kvm_s2_mm_ops, pgtable, level);
> + kvm_pgtable_stage2_free_unlinked(&kvm_s2_mm_ops, pgtable, level);
> }
>
> -static void stage2_free_removed_table(void *addr, u32 level)
> +static void stage2_free_unlinked_table(void *addr, u32 level)
> {
> struct page *page = virt_to_page(addr);
>
> set_page_private(page, (unsigned long)level);
> - call_rcu(&page->rcu_head, stage2_free_removed_table_rcu_cb);
> + call_rcu(&page->rcu_head, stage2_free_unlinked_table_rcu_cb);
> }
>
> static void kvm_host_get_page(void *addr)
> @@ -681,7 +681,7 @@ static struct kvm_pgtable_mm_ops kvm_s2_mm_ops = {
> .zalloc_page = stage2_memcache_zalloc_page,
> .zalloc_pages_exact = kvm_s2_zalloc_pages_exact,
> .free_pages_exact = kvm_s2_free_pages_exact,
> - .free_removed_table = stage2_free_removed_table,
> + .free_unlinked_table = stage2_free_unlinked_table,
> .get_page = kvm_host_get_page,
> .put_page = kvm_s2_put_page,
> .page_count = kvm_host_page_count,
> --
> 2.39.1.637.g21b0678d19-goog
>
>
--
Thanks,
Oliver
