diff mbox series

[v1,RESEND,6/9] x86/kvm/mmu: make space for source data caching in struct kvm_mmu

Message ID 20180918160906.9241-7-vkuznets@redhat.com (mailing list archive)
State New, archived
Headers show
Series x86/kvm/nVMX: optimize MMU switch between L1 and L2 | expand

Commit Message

Vitaly Kuznetsov Sept. 18, 2018, 4:09 p.m. UTC 
In preparation to MMU reconfiguration avoidance we need a space to
cache source data. As this partially intersects with kvm_mmu_page_role,
create 64bit sized union kvm_mmu_role holding both base_role and
extended data. No functional change.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 arch/x86/include/asm/kvm_host.h | 14 +++++++++++++-
 arch/x86/kvm/mmu.c              | 19 ++++++++++++-------
 arch/x86/kvm/vmx.c              |  2 +-
 3 files changed, 26 insertions(+), 9 deletions(-)

Comments

Sean Christopherson Sept. 19, 2018, 3:30 p.m. UTC | #1 
On Tue, 2018-09-18 at 18:09 +0200, Vitaly Kuznetsov wrote:
> In preparation to MMU reconfiguration avoidance we need a space to
> cache source data. As this partially intersects with kvm_mmu_page_role,
> create 64bit sized union kvm_mmu_role holding both base_role and
> extended data. No functional change.
> 
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---
>  arch/x86/include/asm/kvm_host.h | 14 +++++++++++++-
>  arch/x86/kvm/mmu.c              | 19 ++++++++++++-------
>  arch/x86/kvm/vmx.c              |  2 +-
>  3 files changed, 26 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 527aaf45eba6..6ca7d28d57e9 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -273,6 +273,18 @@ union kvm_mmu_page_role {
>  	};
>  };
>  
> +union kvm_mmu_scache {

What about "kvm_mmu_extended_role" and a variable name of "ext"?
scache might be interpreted as "shadow cache", whereas I think you
intend "source cache".  And it isn't immediately clear (to me) what
"source" refers to.

> +	unsigned int word;
> +};
> +
> +	unsigned long as_u64;
> +	struct {
> +		union kvm_mmu_page_role base_role;

Would it make sense to shorten this to simply "base"?  The usage
looks like it's always deferenced in the context of kvm_mmu_role,
i.e. the "role" part appears to be redundant.  And if scache were
renamed we'd end up with e.g. mmu_role.base and mmu_role.ext.

> +		union kvm_mmu_scache scache;
> +	};
> +};
> +
>  struct kvm_rmap_head {
>  	unsigned long val;
>  };
> @@ -360,7 +372,7 @@ struct kvm_mmu {
>  	void (*update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
>  			   u64 *spte, const void *pte);
>  	hpa_t root_hpa;
> -	union kvm_mmu_page_role base_role;
> +	union kvm_mmu_role mmu_role;
>  	u8 root_level;
>  	u8 shadow_root_level;
>  	u8 ept_ad;
> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
> index 5f167823c50d..8d8e6fa75fa3 100644
> --- a/arch/x86/kvm/mmu.c
> +++ b/arch/x86/kvm/mmu.c
> @@ -2359,7 +2359,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
>  	int collisions = 0;
>  	LIST_HEAD(invalid_list);
>  
> -	role = vcpu->arch.mmu->base_role;
> +	role = vcpu->arch.mmu->mmu_role.base_role;
>  	role.level = level;
>  	role.direct = direct;
>  	if (role.direct)
> @@ -4407,7 +4407,8 @@ static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu,
>  void
>  reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, struct kvm_mmu *context)
>  {
> -	bool uses_nx = context->nx || context->base_role.smep_andnot_wp;
> +	bool uses_nx = context->nx ||
> +		context->mmu_role.base_role.smep_andnot_wp;
>  	struct rsvd_bits_validate *shadow_zero_check;
>  	int i;
>  
> @@ -4726,7 +4727,7 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
>  {
>  	struct kvm_mmu *context = vcpu->arch.mmu;
>  
> -	context->base_role.word = mmu_base_role_mask.word &
> +	context->mmu_role.base_role.word = mmu_base_role_mask.word &
>  				  kvm_calc_tdp_mmu_root_page_role(vcpu).word;
>  	context->page_fault = tdp_page_fault;
>  	context->sync_page = nonpaging_sync_page;
> @@ -4807,7 +4808,7 @@ void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu)
>  	else
>  		paging32_init_context(vcpu, context);
>  
> -	context->base_role.word = mmu_base_role_mask.word &
> +	context->mmu_role.base_role.word = mmu_base_role_mask.word &
>  				  kvm_calc_shadow_mmu_root_page_role(vcpu).word;
>  	reset_shadow_zero_bits_mask(vcpu, context);
>  }
> @@ -4816,7 +4817,7 @@ EXPORT_SYMBOL_GPL(kvm_init_shadow_mmu);
>  static union kvm_mmu_page_role
>  kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty)
>  {
> -	union kvm_mmu_page_role role = vcpu->arch.mmu->base_role;
> +	union kvm_mmu_page_role role = vcpu->arch.mmu->mmu_role.base_role;
>  
>  	role.level = PT64_ROOT_4LEVEL;
>  	role.direct = false;
> @@ -4846,7 +4847,8 @@ void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly,
>  	context->update_pte = ept_update_pte;
>  	context->root_level = PT64_ROOT_4LEVEL;
>  	context->direct_map = false;
> -	context->base_role.word = root_page_role.word & mmu_base_role_mask.word;
> +	context->mmu_role.base_role.word =
> +		root_page_role.word & mmu_base_role_mask.word;
>  	context->get_pdptr = kvm_pdptr_read;
>  
>  	update_permission_bitmask(vcpu, context, true);
> @@ -5161,10 +5163,13 @@ static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
>  
>  		local_flush = true;
>  		while (npte--) {
> +			unsigned int base_role =
> +				vcpu->arch.mmu->mmu_role.base_role.word;
> +
>  			entry = *spte;
>  			mmu_page_zap_pte(vcpu->kvm, sp, spte);
>  			if (gentry &&
> -			      !((sp->role.word ^ vcpu->arch.mmu->base_role.word)
> +			      !((sp->role.word ^ base_role)
>  			      & mmu_base_role_mask.word) && rmap_can_add(vcpu))
>  				mmu_pte_write_new_pte(vcpu, sp, spte, &gentry);
>  			if (need_remote_flush(entry, *spte))
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 29af40b9239f..79e0b0570dd1 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -9290,7 +9290,7 @@ static int nested_vmx_eptp_switching(struct kvm_vcpu *vcpu,
>  
>  		kvm_mmu_unload(vcpu);
>  		mmu->ept_ad = accessed_dirty;
> -		mmu->base_role.ad_disabled = !accessed_dirty;
> +		mmu->mmu_role.base_role.ad_disabled = !accessed_dirty;
>  		vmcs12->ept_pointer = address;
>  		/*
>  		 * TODO: Check what's the correct approach in case
diff mbox series

Patch

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 527aaf45eba6..6ca7d28d57e9 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -273,6 +273,18 @@  union kvm_mmu_page_role {
 	};
 };
 
+union kvm_mmu_scache {
+	unsigned int word;
+};
+
+union kvm_mmu_role {
+	unsigned long as_u64;
+	struct {
+		union kvm_mmu_page_role base_role;
+		union kvm_mmu_scache scache;
+	};
+};
+
 struct kvm_rmap_head {
 	unsigned long val;
 };
@@ -360,7 +372,7 @@  struct kvm_mmu {
 	void (*update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
 			   u64 *spte, const void *pte);
 	hpa_t root_hpa;
-	union kvm_mmu_page_role base_role;
+	union kvm_mmu_role mmu_role;
 	u8 root_level;
 	u8 shadow_root_level;
 	u8 ept_ad;
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 5f167823c50d..8d8e6fa75fa3 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2359,7 +2359,7 @@  static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
 	int collisions = 0;
 	LIST_HEAD(invalid_list);
 
-	role = vcpu->arch.mmu->base_role;
+	role = vcpu->arch.mmu->mmu_role.base_role;
 	role.level = level;
 	role.direct = direct;
 	if (role.direct)
@@ -4407,7 +4407,8 @@  static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu,
 void
 reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, struct kvm_mmu *context)
 {
-	bool uses_nx = context->nx || context->base_role.smep_andnot_wp;
+	bool uses_nx = context->nx ||
+		context->mmu_role.base_role.smep_andnot_wp;
 	struct rsvd_bits_validate *shadow_zero_check;
 	int i;
 
@@ -4726,7 +4727,7 @@  static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
 {
 	struct kvm_mmu *context = vcpu->arch.mmu;
 
-	context->base_role.word = mmu_base_role_mask.word &
+	context->mmu_role.base_role.word = mmu_base_role_mask.word &
 				  kvm_calc_tdp_mmu_root_page_role(vcpu).word;
 	context->page_fault = tdp_page_fault;
 	context->sync_page = nonpaging_sync_page;
@@ -4807,7 +4808,7 @@  void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu)
 	else
 		paging32_init_context(vcpu, context);
 
-	context->base_role.word = mmu_base_role_mask.word &
+	context->mmu_role.base_role.word = mmu_base_role_mask.word &
 				  kvm_calc_shadow_mmu_root_page_role(vcpu).word;
 	reset_shadow_zero_bits_mask(vcpu, context);
 }
@@ -4816,7 +4817,7 @@  EXPORT_SYMBOL_GPL(kvm_init_shadow_mmu);
 static union kvm_mmu_page_role
 kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty)
 {
-	union kvm_mmu_page_role role = vcpu->arch.mmu->base_role;
+	union kvm_mmu_page_role role = vcpu->arch.mmu->mmu_role.base_role;
 
 	role.level = PT64_ROOT_4LEVEL;
 	role.direct = false;
@@ -4846,7 +4847,8 @@  void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly,
 	context->update_pte = ept_update_pte;
 	context->root_level = PT64_ROOT_4LEVEL;
 	context->direct_map = false;
-	context->base_role.word = root_page_role.word & mmu_base_role_mask.word;
+	context->mmu_role.base_role.word =
+		root_page_role.word & mmu_base_role_mask.word;
 	context->get_pdptr = kvm_pdptr_read;
 
 	update_permission_bitmask(vcpu, context, true);
@@ -5161,10 +5163,13 @@  static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
 
 		local_flush = true;
 		while (npte--) {
+			unsigned int base_role =
+				vcpu->arch.mmu->mmu_role.base_role.word;
+
 			entry = *spte;
 			mmu_page_zap_pte(vcpu->kvm, sp, spte);
 			if (gentry &&
-			      !((sp->role.word ^ vcpu->arch.mmu->base_role.word)
+			      !((sp->role.word ^ base_role)
 			      & mmu_base_role_mask.word) && rmap_can_add(vcpu))
 				mmu_pte_write_new_pte(vcpu, sp, spte, &gentry);
 			if (need_remote_flush(entry, *spte))
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 29af40b9239f..79e0b0570dd1 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -9290,7 +9290,7 @@  static int nested_vmx_eptp_switching(struct kvm_vcpu *vcpu,
 
 		kvm_mmu_unload(vcpu);
 		mmu->ept_ad = accessed_dirty;
-		mmu->base_role.ad_disabled = !accessed_dirty;
+		mmu->mmu_role.base_role.ad_disabled = !accessed_dirty;
 		vmcs12->ept_pointer = address;
 		/*
 		 * TODO: Check what's the correct approach in case