Re: [PATCH v5 03/14] KVM: arm64: Pass mm_ops through the visitor context

[Gavin Shan <gshan@xxxxxxxxxx>]

On 11/8/22 5:56 AM, Oliver Upton wrote:
> As a prerequisite for getting visitors off of struct kvm_pgtable, pass
> mm_ops through the visitor context.
>
> No functional change intended.
>
> Signed-off-by: Oliver Upton <oliver.upton@xxxxxxxxx>
> ---
>   arch/arm64/include/asm/kvm_pgtable.h |  1 +
>   arch/arm64/kvm/hyp/nvhe/setup.c      |  3 +-
>   arch/arm64/kvm/hyp/pgtable.c         | 63 +++++++++++-----------------
>   3 files changed, 26 insertions(+), 41 deletions(-)

Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>

> diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
> index 14d4b68a1e92..a752793482cb 100644
> --- a/arch/arm64/include/asm/kvm_pgtable.h
> +++ b/arch/arm64/include/asm/kvm_pgtable.h
> @@ -203,6 +203,7 @@ struct kvm_pgtable_visit_ctx {
>   	kvm_pte_t				*ptep;
>   	kvm_pte_t				old;
>   	void					*arg;
> +	struct kvm_pgtable_mm_ops		*mm_ops;
>   	u64					addr;
>   	u64					end;
>   	u32					level;
> diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c
> index 6af443c9d78e..1068338d77f3 100644
> --- a/arch/arm64/kvm/hyp/nvhe/setup.c
> +++ b/arch/arm64/kvm/hyp/nvhe/setup.c
> @@ -189,7 +189,7 @@ static void hpool_put_page(void *addr)
>   static int finalize_host_mappings_walker(const struct kvm_pgtable_visit_ctx *ctx,
>   					 enum kvm_pgtable_walk_flags visit)
>   {
> -	struct kvm_pgtable_mm_ops *mm_ops = ctx->arg;
> +	struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
>   	enum kvm_pgtable_prot prot;
>   	enum pkvm_page_state state;
>   	phys_addr_t phys;
> @@ -239,7 +239,6 @@ static int finalize_host_mappings(void)
>   	struct kvm_pgtable_walker walker = {
>   		.cb	= finalize_host_mappings_walker,
>   		.flags	= KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST,
> -		.arg	= pkvm_pgtable.mm_ops,
>   	};
>   	int i, ret;
>   
> diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
> index fb3696b3a997..db25e81a9890 100644
> --- a/arch/arm64/kvm/hyp/pgtable.c
> +++ b/arch/arm64/kvm/hyp/pgtable.c
> @@ -181,9 +181,10 @@ static int kvm_pgtable_visitor_cb(struct kvm_pgtable_walk_data *data,
>   }
>   
>   static int __kvm_pgtable_walk(struct kvm_pgtable_walk_data *data,
> -			      kvm_pte_t *pgtable, u32 level);
> +			      struct kvm_pgtable_mm_ops *mm_ops, kvm_pte_t *pgtable, u32 level);
>   
>   static inline int __kvm_pgtable_visit(struct kvm_pgtable_walk_data *data,
> +				      struct kvm_pgtable_mm_ops *mm_ops,
>   				      kvm_pte_t *ptep, u32 level)
>   {
>   	enum kvm_pgtable_walk_flags flags = data->walker->flags;
> @@ -191,6 +192,7 @@ static inline int __kvm_pgtable_visit(struct kvm_pgtable_walk_data *data,
>   		.ptep	= ptep,
>   		.old	= READ_ONCE(*ptep),
>   		.arg	= data->walker->arg,
> +		.mm_ops	= mm_ops,
>   		.addr	= data->addr,
>   		.end	= data->end,
>   		.level	= level,
> @@ -218,8 +220,8 @@ static inline int __kvm_pgtable_visit(struct kvm_pgtable_walk_data *data,
>   		goto out;
>   	}
>   
> -	childp = kvm_pte_follow(ctx.old, data->pgt->mm_ops);
> -	ret = __kvm_pgtable_walk(data, childp, level + 1);
> +	childp = kvm_pte_follow(ctx.old, mm_ops);
> +	ret = __kvm_pgtable_walk(data, mm_ops, childp, level + 1);
>   	if (ret)
>   		goto out;
>   
> @@ -231,7 +233,7 @@ static inline int __kvm_pgtable_visit(struct kvm_pgtable_walk_data *data,
>   }
>   
>   static int __kvm_pgtable_walk(struct kvm_pgtable_walk_data *data,
> -			      kvm_pte_t *pgtable, u32 level)
> +			      struct kvm_pgtable_mm_ops *mm_ops, kvm_pte_t *pgtable, u32 level)
>   {
>   	u32 idx;
>   	int ret = 0;
> @@ -245,7 +247,7 @@ static int __kvm_pgtable_walk(struct kvm_pgtable_walk_data *data,
>   		if (data->addr >= data->end)
>   			break;
>   
> -		ret = __kvm_pgtable_visit(data, ptep, level);
> +		ret = __kvm_pgtable_visit(data, mm_ops, ptep, level);
>   		if (ret)
>   			break;
>   	}
> @@ -269,7 +271,7 @@ static int _kvm_pgtable_walk(struct kvm_pgtable_walk_data *data)
>   	for (idx = kvm_pgd_page_idx(data); data->addr < data->end; ++idx) {
>   		kvm_pte_t *ptep = &pgt->pgd[idx * PTRS_PER_PTE];
>   
> -		ret = __kvm_pgtable_walk(data, ptep, pgt->start_level);
> +		ret = __kvm_pgtable_walk(data, pgt->mm_ops, ptep, pgt->start_level);
>   		if (ret)
>   			break;
>   	}
> @@ -332,7 +334,6 @@ int kvm_pgtable_get_leaf(struct kvm_pgtable *pgt, u64 addr,
>   struct hyp_map_data {
>   	u64				phys;
>   	kvm_pte_t			attr;
> -	struct kvm_pgtable_mm_ops	*mm_ops;
>   };
>   
>   static int hyp_set_prot_attr(enum kvm_pgtable_prot prot, kvm_pte_t *ptep)
> @@ -400,7 +401,7 @@ static bool hyp_map_walker_try_leaf(const struct kvm_pgtable_visit_ctx *ctx,
>   	if (ctx->old == new)
>   		return true;
>   	if (!kvm_pte_valid(ctx->old))
> -		data->mm_ops->get_page(ctx->ptep);
> +		ctx->mm_ops->get_page(ctx->ptep);
>   	else if (WARN_ON((ctx->old ^ new) & ~KVM_PTE_LEAF_ATTR_HI_SW))
>   		return false;
>   
> @@ -413,7 +414,7 @@ static int hyp_map_walker(const struct kvm_pgtable_visit_ctx *ctx,
>   {
>   	kvm_pte_t *childp;
>   	struct hyp_map_data *data = ctx->arg;
> -	struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops;
> +	struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
>   
>   	if (hyp_map_walker_try_leaf(ctx, data))
>   		return 0;
> @@ -436,7 +437,6 @@ int kvm_pgtable_hyp_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys,
>   	int ret;
>   	struct hyp_map_data map_data = {
>   		.phys	= ALIGN_DOWN(phys, PAGE_SIZE),
> -		.mm_ops	= pgt->mm_ops,
>   	};
>   	struct kvm_pgtable_walker walker = {
>   		.cb	= hyp_map_walker,
> @@ -454,18 +454,13 @@ int kvm_pgtable_hyp_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys,
>   	return ret;
>   }
>   
> -struct hyp_unmap_data {
> -	u64				unmapped;
> -	struct kvm_pgtable_mm_ops	*mm_ops;
> -};
> -
>   static int hyp_unmap_walker(const struct kvm_pgtable_visit_ctx *ctx,
>   			    enum kvm_pgtable_walk_flags visit)
>   {
>   	kvm_pte_t *childp = NULL;
>   	u64 granule = kvm_granule_size(ctx->level);
> -	struct hyp_unmap_data *data = ctx->arg;
> -	struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops;
> +	u64 *unmapped = ctx->arg;
> +	struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
>   
>   	if (!kvm_pte_valid(ctx->old))
>   		return -EINVAL;
> @@ -486,7 +481,7 @@ static int hyp_unmap_walker(const struct kvm_pgtable_visit_ctx *ctx,
>   		kvm_clear_pte(ctx->ptep);
>   		dsb(ishst);
>   		__tlbi_level(vale2is, __TLBI_VADDR(ctx->addr, 0), ctx->level);
> -		data->unmapped += granule;
> +		*unmapped += granule;
>   	}
>   
>   	dsb(ish);
> @@ -501,12 +496,10 @@ static int hyp_unmap_walker(const struct kvm_pgtable_visit_ctx *ctx,
>   
>   u64 kvm_pgtable_hyp_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size)
>   {
> -	struct hyp_unmap_data unmap_data = {
> -		.mm_ops	= pgt->mm_ops,
> -	};
> +	u64 unmapped = 0;
>   	struct kvm_pgtable_walker walker = {
>   		.cb	= hyp_unmap_walker,
> -		.arg	= &unmap_data,
> +		.arg	= &unmapped,
>   		.flags	= KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST,
>   	};
>   
> @@ -514,7 +507,7 @@ u64 kvm_pgtable_hyp_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size)
>   		return 0;
>   
>   	kvm_pgtable_walk(pgt, addr, size, &walker);
> -	return unmap_data.unmapped;
> +	return unmapped;
>   }
>   
>   int kvm_pgtable_hyp_init(struct kvm_pgtable *pgt, u32 va_bits,
> @@ -538,7 +531,7 @@ int kvm_pgtable_hyp_init(struct kvm_pgtable *pgt, u32 va_bits,
>   static int hyp_free_walker(const struct kvm_pgtable_visit_ctx *ctx,
>   			   enum kvm_pgtable_walk_flags visit)
>   {
> -	struct kvm_pgtable_mm_ops *mm_ops = ctx->arg;
> +	struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
>   
>   	if (!kvm_pte_valid(ctx->old))
>   		return 0;
> @@ -556,7 +549,6 @@ void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt)
>   	struct kvm_pgtable_walker walker = {
>   		.cb	= hyp_free_walker,
>   		.flags	= KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST,
> -		.arg	= pgt->mm_ops,
>   	};
>   
>   	WARN_ON(kvm_pgtable_walk(pgt, 0, BIT(pgt->ia_bits), &walker));
> @@ -575,8 +567,6 @@ struct stage2_map_data {
>   	struct kvm_s2_mmu		*mmu;
>   	void				*memcache;
>   
> -	struct kvm_pgtable_mm_ops	*mm_ops;
> -
>   	/* Force mappings to page granularity */
>   	bool				force_pte;
>   };
> @@ -725,7 +715,7 @@ static int stage2_map_walker_try_leaf(const struct kvm_pgtable_visit_ctx *ctx,
>   	kvm_pte_t new;
>   	u64 granule = kvm_granule_size(ctx->level), phys = data->phys;
>   	struct kvm_pgtable *pgt = data->mmu->pgt;
> -	struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops;
> +	struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
>   
>   	if (!stage2_leaf_mapping_allowed(ctx, data))
>   		return -E2BIG;
> @@ -773,7 +763,7 @@ static int stage2_map_walk_table_pre(const struct kvm_pgtable_visit_ctx *ctx,
>   	if (!stage2_leaf_mapping_allowed(ctx, data))
>   		return 0;
>   
> -	data->childp = kvm_pte_follow(ctx->old, data->mm_ops);
> +	data->childp = kvm_pte_follow(ctx->old, ctx->mm_ops);
>   	kvm_clear_pte(ctx->ptep);
>   
>   	/*
> @@ -789,7 +779,7 @@ static int stage2_map_walk_table_pre(const struct kvm_pgtable_visit_ctx *ctx,
>   static int stage2_map_walk_leaf(const struct kvm_pgtable_visit_ctx *ctx,
>   				struct stage2_map_data *data)
>   {
> -	struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops;
> +	struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
>   	kvm_pte_t *childp;
>   	int ret;
>   
> @@ -831,7 +821,7 @@ static int stage2_map_walk_leaf(const struct kvm_pgtable_visit_ctx *ctx,
>   static int stage2_map_walk_table_post(const struct kvm_pgtable_visit_ctx *ctx,
>   				      struct stage2_map_data *data)
>   {
> -	struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops;
> +	struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
>   	kvm_pte_t *childp;
>   	int ret = 0;
>   
> @@ -898,7 +888,6 @@ int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size,
>   		.phys		= ALIGN_DOWN(phys, PAGE_SIZE),
>   		.mmu		= pgt->mmu,
>   		.memcache	= mc,
> -		.mm_ops		= pgt->mm_ops,
>   		.force_pte	= pgt->force_pte_cb && pgt->force_pte_cb(addr, addr + size, prot),
>   	};
>   	struct kvm_pgtable_walker walker = {
> @@ -929,7 +918,6 @@ int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, u64 addr, u64 size,
>   		.phys		= KVM_PHYS_INVALID,
>   		.mmu		= pgt->mmu,
>   		.memcache	= mc,
> -		.mm_ops		= pgt->mm_ops,
>   		.owner_id	= owner_id,
>   		.force_pte	= true,
>   	};
> @@ -953,7 +941,7 @@ static int stage2_unmap_walker(const struct kvm_pgtable_visit_ctx *ctx,
>   {
>   	struct kvm_pgtable *pgt = ctx->arg;
>   	struct kvm_s2_mmu *mmu = pgt->mmu;
> -	struct kvm_pgtable_mm_ops *mm_ops = pgt->mm_ops;
> +	struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
>   	kvm_pte_t *childp = NULL;
>   	bool need_flush = false;
>   
> @@ -1007,7 +995,6 @@ struct stage2_attr_data {
>   	kvm_pte_t			attr_clr;
>   	kvm_pte_t			pte;
>   	u32				level;
> -	struct kvm_pgtable_mm_ops	*mm_ops;
>   };
>   
>   static int stage2_attr_walker(const struct kvm_pgtable_visit_ctx *ctx,
> @@ -1015,7 +1002,7 @@ static int stage2_attr_walker(const struct kvm_pgtable_visit_ctx *ctx,
>   {
>   	kvm_pte_t pte = ctx->old;
>   	struct stage2_attr_data *data = ctx->arg;
> -	struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops;
> +	struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
>   
>   	if (!kvm_pte_valid(ctx->old))
>   		return 0;
> @@ -1055,7 +1042,6 @@ static int stage2_update_leaf_attrs(struct kvm_pgtable *pgt, u64 addr,
>   	struct stage2_attr_data data = {
>   		.attr_set	= attr_set & attr_mask,
>   		.attr_clr	= attr_clr & attr_mask,
> -		.mm_ops		= pgt->mm_ops,
>   	};
>   	struct kvm_pgtable_walker walker = {
>   		.cb		= stage2_attr_walker,
> @@ -1198,7 +1184,7 @@ int __kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_s2_mmu *mmu,
>   static int stage2_free_walker(const struct kvm_pgtable_visit_ctx *ctx,
>   			      enum kvm_pgtable_walk_flags visit)
>   {
> -	struct kvm_pgtable_mm_ops *mm_ops = ctx->arg;
> +	struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
>   
>   	if (!stage2_pte_is_counted(ctx->old))
>   		return 0;
> @@ -1218,7 +1204,6 @@ void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt)
>   		.cb	= stage2_free_walker,
>   		.flags	= KVM_PGTABLE_WALK_LEAF |
>   			  KVM_PGTABLE_WALK_TABLE_POST,
> -		.arg	= pgt->mm_ops,
>   	};
>   
>   	WARN_ON(kvm_pgtable_walk(pgt, 0, BIT(pgt->ia_bits), &walker));