diff mbox series

[v8,039/103] KVM: x86/tdp_mmu: Init role member of struct kvm_mmu_page at allocation

Message ID 0a8fa20533048189106f9d0f100acf59602bb502.1659854790.git.isaku.yamahata@intel.com (mailing list archive)
State New, archived
Headers show
Series KVM TDX basic feature support | expand

Commit Message

Isaku Yamahata Aug. 7, 2022, 10:01 p.m. UTC 
From: Isaku Yamahata <isaku.yamahata@intel.com>

Refactor tdp_mmu_alloc_sp() and tdp_mmu_init_sp and eliminate
tdp_mmu_init_child_sp().  Currently tdp_mmu_init_sp() (or
tdp_mmu_init_child_sp()) sets kvm_mmu_page.role after tdp_mmu_alloc_sp()
allocating struct kvm_mmu_page and its page table page.  This patch makes
tdp_mmu_alloc_sp() initialize kvm_mmu_page.role instead of
tdp_mmu_init_sp().

To handle private page tables, argument of is_private needs to be passed
down.  Given that already page level is passed down, it would be cumbersome
to add one more parameter about sp. Instead replace the level argument with
union kvm_mmu_page_role.  Thus the number of argument won't be increased
and more info about sp can be passed down.

For private sp, secure page table will be also allocated in addition to
struct kvm_mmu_page and page table (spt member).  The allocation functions
(tdp_mmu_alloc_sp() and __tdp_mmu_alloc_sp_for_split()) need to know if the
allocation is for the conventional page table or private page table.  Pass
union kvm_mmu_role to those functions and initialize role member of struct
kvm_mmu_page.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
 arch/x86/kvm/mmu/tdp_iter.h | 12 ++++++++++
 arch/x86/kvm/mmu/tdp_mmu.c  | 45 +++++++++++++++++--------------------
 2 files changed, 32 insertions(+), 25 deletions(-)

Comments

Yuan Yao Sept. 1, 2022, 7:12 a.m. UTC | #1 
On Sun, Aug 07, 2022 at 03:01:24PM -0700, isaku.yamahata@intel.com wrote:
> From: Isaku Yamahata <isaku.yamahata@intel.com>
>
> Refactor tdp_mmu_alloc_sp() and tdp_mmu_init_sp and eliminate
> tdp_mmu_init_child_sp().  Currently tdp_mmu_init_sp() (or
> tdp_mmu_init_child_sp()) sets kvm_mmu_page.role after tdp_mmu_alloc_sp()
> allocating struct kvm_mmu_page and its page table page.  This patch makes
> tdp_mmu_alloc_sp() initialize kvm_mmu_page.role instead of
> tdp_mmu_init_sp().
>
> To handle private page tables, argument of is_private needs to be passed
> down.  Given that already page level is passed down, it would be cumbersome
> to add one more parameter about sp. Instead replace the level argument with
> union kvm_mmu_page_role.  Thus the number of argument won't be increased
> and more info about sp can be passed down.

Please update the description, no level argument is replaced in this
patch.

>
> For private sp, secure page table will be also allocated in addition to
> struct kvm_mmu_page and page table (spt member).  The allocation functions
> (tdp_mmu_alloc_sp() and __tdp_mmu_alloc_sp_for_split()) need to know if the
> allocation is for the conventional page table or private page table.  Pass
> union kvm_mmu_role to those functions and initialize role member of struct
> kvm_mmu_page.
>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> ---
>  arch/x86/kvm/mmu/tdp_iter.h | 12 ++++++++++
>  arch/x86/kvm/mmu/tdp_mmu.c  | 45 +++++++++++++++++--------------------
>  2 files changed, 32 insertions(+), 25 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu/tdp_iter.h b/arch/x86/kvm/mmu/tdp_iter.h
> index f0af385c56e0..9e56a5b1024c 100644
> --- a/arch/x86/kvm/mmu/tdp_iter.h
> +++ b/arch/x86/kvm/mmu/tdp_iter.h
> @@ -115,4 +115,16 @@ void tdp_iter_start(struct tdp_iter *iter, struct kvm_mmu_page *root,
>  void tdp_iter_next(struct tdp_iter *iter);
>  void tdp_iter_restart(struct tdp_iter *iter);
>
> +static inline union kvm_mmu_page_role tdp_iter_child_role(struct tdp_iter *iter)
> +{
> +	union kvm_mmu_page_role child_role;
> +	struct kvm_mmu_page *parent_sp;
> +
> +	parent_sp = sptep_to_sp(rcu_dereference(iter->sptep));
> +
> +	child_role = parent_sp->role;
> +	child_role.level--;
> +	return child_role;
> +}
> +
>  #endif /* __KVM_X86_MMU_TDP_ITER_H */
> diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
> index 90b468a3a1a2..ce69535754ff 100644
> --- a/arch/x86/kvm/mmu/tdp_mmu.c
> +++ b/arch/x86/kvm/mmu/tdp_mmu.c
> @@ -271,22 +271,28 @@ static struct kvm_mmu_page *tdp_mmu_next_root(struct kvm *kvm,
>  		    kvm_mmu_page_as_id(_root) != _as_id) {		\
>  		} else
>
> -static struct kvm_mmu_page *tdp_mmu_alloc_sp(struct kvm_vcpu *vcpu)
> +static struct kvm_mmu_page *tdp_mmu_alloc_sp(struct kvm_vcpu *vcpu,
> +					     union kvm_mmu_page_role role)
>  {
>  	struct kvm_mmu_page *sp;
>
>  	sp = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache);
>  	sp->spt = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_shadow_page_cache);
> +	sp->role = role;
>
>  	return sp;
>  }
>
>  static void tdp_mmu_init_sp(struct kvm_mmu_page *sp, tdp_ptep_t sptep,
> -			    gfn_t gfn, union kvm_mmu_page_role role)
> +			    gfn_t gfn)
>  {
>  	set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
>
> -	sp->role = role;
> +	/*
> +	 * role must be set before calling this function.  At least role.level
> +	 * is not 0 (PG_LEVEL_NONE).
> +	 */
> +	WARN_ON(!sp->role.word);
>  	sp->gfn = gfn;
>  	sp->ptep = sptep;
>  	sp->tdp_mmu_page = true;
> @@ -294,20 +300,6 @@ static void tdp_mmu_init_sp(struct kvm_mmu_page *sp, tdp_ptep_t sptep,
>  	trace_kvm_mmu_get_page(sp, true);
>  }
>
> -static void tdp_mmu_init_child_sp(struct kvm_mmu_page *child_sp,
> -				  struct tdp_iter *iter)
> -{
> -	struct kvm_mmu_page *parent_sp;
> -	union kvm_mmu_page_role role;
> -
> -	parent_sp = sptep_to_sp(rcu_dereference(iter->sptep));
> -
> -	role = parent_sp->role;
> -	role.level--;
> -
> -	tdp_mmu_init_sp(child_sp, iter->sptep, iter->gfn, role);
> -}
> -
>  hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu)
>  {
>  	union kvm_mmu_page_role role = vcpu->arch.mmu->root_role;
> @@ -326,8 +318,8 @@ hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu)
>  			goto out;
>  	}
>
> -	root = tdp_mmu_alloc_sp(vcpu);
> -	tdp_mmu_init_sp(root, NULL, 0, role);
> +	root = tdp_mmu_alloc_sp(vcpu, role);
> +	tdp_mmu_init_sp(root, NULL, 0);
>
>  	refcount_set(&root->tdp_mmu_root_count, 1);
>
> @@ -1154,8 +1146,8 @@ static int tdp_mmu_populate_nonleaf(
>  	WARN_ON(is_shadow_present_pte(iter->old_spte));
>  	WARN_ON(is_removed_spte(iter->old_spte));
>
> -	sp = tdp_mmu_alloc_sp(vcpu);
> -	tdp_mmu_init_child_sp(sp, iter);
> +	sp = tdp_mmu_alloc_sp(vcpu, tdp_iter_child_role(iter));
> +	tdp_mmu_init_sp(sp, iter->sptep, iter->gfn);
>
>  	ret = tdp_mmu_link_sp(vcpu->kvm, iter, sp, account_nx, true);
>  	if (ret)
> @@ -1423,7 +1415,8 @@ bool kvm_tdp_mmu_wrprot_slot(struct kvm *kvm,
>  	return spte_set;
>  }
>
> -static struct kvm_mmu_page *__tdp_mmu_alloc_sp_for_split(gfp_t gfp)
> +static struct kvm_mmu_page *__tdp_mmu_alloc_sp_for_split(
> +	gfp_t gfp, union kvm_mmu_page_role role)
>  {
>  	struct kvm_mmu_page *sp;
>
> @@ -1433,6 +1426,7 @@ static struct kvm_mmu_page *__tdp_mmu_alloc_sp_for_split(gfp_t gfp)
>  	if (!sp)
>  		return NULL;
>
> +	sp->role = role;
>  	sp->spt = (void *)__get_free_page(gfp);
>  	if (!sp->spt) {
>  		kmem_cache_free(mmu_page_header_cache, sp);
> @@ -1446,6 +1440,7 @@ static struct kvm_mmu_page *tdp_mmu_alloc_sp_for_split(struct kvm *kvm,
>  						       struct tdp_iter *iter,
>  						       bool shared)
>  {
> +	union kvm_mmu_page_role role = tdp_iter_child_role(iter);
>  	struct kvm_mmu_page *sp;
>
>  	/*
> @@ -1457,7 +1452,7 @@ static struct kvm_mmu_page *tdp_mmu_alloc_sp_for_split(struct kvm *kvm,
>  	 * If this allocation fails we drop the lock and retry with reclaim
>  	 * allowed.
>  	 */
> -	sp = __tdp_mmu_alloc_sp_for_split(GFP_NOWAIT | __GFP_ACCOUNT);
> +	sp = __tdp_mmu_alloc_sp_for_split(GFP_NOWAIT | __GFP_ACCOUNT, role);
>  	if (sp)
>  		return sp;
>
> @@ -1469,7 +1464,7 @@ static struct kvm_mmu_page *tdp_mmu_alloc_sp_for_split(struct kvm *kvm,
>  		write_unlock(&kvm->mmu_lock);
>
>  	iter->yielded = true;
> -	sp = __tdp_mmu_alloc_sp_for_split(GFP_KERNEL_ACCOUNT);
> +	sp = __tdp_mmu_alloc_sp_for_split(GFP_KERNEL_ACCOUNT, role);
>
>  	if (shared)
>  		read_lock(&kvm->mmu_lock);
> @@ -1488,7 +1483,7 @@ static int tdp_mmu_split_huge_page(struct kvm *kvm, struct tdp_iter *iter,
>  	const int level = iter->level;
>  	int ret, i;
>
> -	tdp_mmu_init_child_sp(sp, iter);
> +	tdp_mmu_init_sp(sp, iter->sptep, iter->gfn);
>
>  	/*
>  	 * No need for atomics when writing to sp->spt since the page table has
> --
> 2.25.1
>
diff mbox series

Patch

diff --git a/arch/x86/kvm/mmu/tdp_iter.h b/arch/x86/kvm/mmu/tdp_iter.h
index f0af385c56e0..9e56a5b1024c 100644
--- a/arch/x86/kvm/mmu/tdp_iter.h
+++ b/arch/x86/kvm/mmu/tdp_iter.h
@@ -115,4 +115,16 @@  void tdp_iter_start(struct tdp_iter *iter, struct kvm_mmu_page *root,
 void tdp_iter_next(struct tdp_iter *iter);
 void tdp_iter_restart(struct tdp_iter *iter);
 
+static inline union kvm_mmu_page_role tdp_iter_child_role(struct tdp_iter *iter)
+{
+	union kvm_mmu_page_role child_role;
+	struct kvm_mmu_page *parent_sp;
+
+	parent_sp = sptep_to_sp(rcu_dereference(iter->sptep));
+
+	child_role = parent_sp->role;
+	child_role.level--;
+	return child_role;
+}
+
 #endif /* __KVM_X86_MMU_TDP_ITER_H */
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 90b468a3a1a2..ce69535754ff 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -271,22 +271,28 @@  static struct kvm_mmu_page *tdp_mmu_next_root(struct kvm *kvm,
 		    kvm_mmu_page_as_id(_root) != _as_id) {		\
 		} else
 
-static struct kvm_mmu_page *tdp_mmu_alloc_sp(struct kvm_vcpu *vcpu)
+static struct kvm_mmu_page *tdp_mmu_alloc_sp(struct kvm_vcpu *vcpu,
+					     union kvm_mmu_page_role role)
 {
 	struct kvm_mmu_page *sp;
 
 	sp = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache);
 	sp->spt = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_shadow_page_cache);
+	sp->role = role;
 
 	return sp;
 }
 
 static void tdp_mmu_init_sp(struct kvm_mmu_page *sp, tdp_ptep_t sptep,
-			    gfn_t gfn, union kvm_mmu_page_role role)
+			    gfn_t gfn)
 {
 	set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
 
-	sp->role = role;
+	/*
+	 * role must be set before calling this function.  At least role.level
+	 * is not 0 (PG_LEVEL_NONE).
+	 */
+	WARN_ON(!sp->role.word);
 	sp->gfn = gfn;
 	sp->ptep = sptep;
 	sp->tdp_mmu_page = true;
@@ -294,20 +300,6 @@  static void tdp_mmu_init_sp(struct kvm_mmu_page *sp, tdp_ptep_t sptep,
 	trace_kvm_mmu_get_page(sp, true);
 }
 
-static void tdp_mmu_init_child_sp(struct kvm_mmu_page *child_sp,
-				  struct tdp_iter *iter)
-{
-	struct kvm_mmu_page *parent_sp;
-	union kvm_mmu_page_role role;
-
-	parent_sp = sptep_to_sp(rcu_dereference(iter->sptep));
-
-	role = parent_sp->role;
-	role.level--;
-
-	tdp_mmu_init_sp(child_sp, iter->sptep, iter->gfn, role);
-}
-
 hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu)
 {
 	union kvm_mmu_page_role role = vcpu->arch.mmu->root_role;
@@ -326,8 +318,8 @@  hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu)
 			goto out;
 	}
 
-	root = tdp_mmu_alloc_sp(vcpu);
-	tdp_mmu_init_sp(root, NULL, 0, role);
+	root = tdp_mmu_alloc_sp(vcpu, role);
+	tdp_mmu_init_sp(root, NULL, 0);
 
 	refcount_set(&root->tdp_mmu_root_count, 1);
 
@@ -1154,8 +1146,8 @@  static int tdp_mmu_populate_nonleaf(
 	WARN_ON(is_shadow_present_pte(iter->old_spte));
 	WARN_ON(is_removed_spte(iter->old_spte));
 
-	sp = tdp_mmu_alloc_sp(vcpu);
-	tdp_mmu_init_child_sp(sp, iter);
+	sp = tdp_mmu_alloc_sp(vcpu, tdp_iter_child_role(iter));
+	tdp_mmu_init_sp(sp, iter->sptep, iter->gfn);
 
 	ret = tdp_mmu_link_sp(vcpu->kvm, iter, sp, account_nx, true);
 	if (ret)
@@ -1423,7 +1415,8 @@  bool kvm_tdp_mmu_wrprot_slot(struct kvm *kvm,
 	return spte_set;
 }
 
-static struct kvm_mmu_page *__tdp_mmu_alloc_sp_for_split(gfp_t gfp)
+static struct kvm_mmu_page *__tdp_mmu_alloc_sp_for_split(
+	gfp_t gfp, union kvm_mmu_page_role role)
 {
 	struct kvm_mmu_page *sp;
 
@@ -1433,6 +1426,7 @@  static struct kvm_mmu_page *__tdp_mmu_alloc_sp_for_split(gfp_t gfp)
 	if (!sp)
 		return NULL;
 
+	sp->role = role;
 	sp->spt = (void *)__get_free_page(gfp);
 	if (!sp->spt) {
 		kmem_cache_free(mmu_page_header_cache, sp);
@@ -1446,6 +1440,7 @@  static struct kvm_mmu_page *tdp_mmu_alloc_sp_for_split(struct kvm *kvm,
 						       struct tdp_iter *iter,
 						       bool shared)
 {
+	union kvm_mmu_page_role role = tdp_iter_child_role(iter);
 	struct kvm_mmu_page *sp;
 
 	/*
@@ -1457,7 +1452,7 @@  static struct kvm_mmu_page *tdp_mmu_alloc_sp_for_split(struct kvm *kvm,
 	 * If this allocation fails we drop the lock and retry with reclaim
 	 * allowed.
 	 */
-	sp = __tdp_mmu_alloc_sp_for_split(GFP_NOWAIT | __GFP_ACCOUNT);
+	sp = __tdp_mmu_alloc_sp_for_split(GFP_NOWAIT | __GFP_ACCOUNT, role);
 	if (sp)
 		return sp;
 
@@ -1469,7 +1464,7 @@  static struct kvm_mmu_page *tdp_mmu_alloc_sp_for_split(struct kvm *kvm,
 		write_unlock(&kvm->mmu_lock);
 
 	iter->yielded = true;
-	sp = __tdp_mmu_alloc_sp_for_split(GFP_KERNEL_ACCOUNT);
+	sp = __tdp_mmu_alloc_sp_for_split(GFP_KERNEL_ACCOUNT, role);
 
 	if (shared)
 		read_lock(&kvm->mmu_lock);
@@ -1488,7 +1483,7 @@  static int tdp_mmu_split_huge_page(struct kvm *kvm, struct tdp_iter *iter,
 	const int level = iter->level;
 	int ret, i;
 
-	tdp_mmu_init_child_sp(sp, iter);
+	tdp_mmu_init_sp(sp, iter->sptep, iter->gfn);
 
 	/*
 	 * No need for atomics when writing to sp->spt since the page table has