[05/15] KVM: MTRR: clean up mtrr default type
diff mbox

Message ID 1432983566-15773-6-git-send-email-guangrong.xiao@linux.intel.com
State New
Headers show

Commit Message

Xiao Guangrong May 30, 2015, 10:59 a.m. UTC
Use union definition to avoid the decode/code workload and drop all the
hard code

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
---
 arch/x86/include/asm/kvm_host.h | 12 ++++++++++--
 arch/x86/kvm/mtrr.c             | 19 ++++++++-----------
 2 files changed, 18 insertions(+), 13 deletions(-)

Comments

Paolo Bonzini June 1, 2015, 9:11 a.m. UTC | #1
On 30/05/2015 12:59, Xiao Guangrong wrote:
> Use union definition to avoid the decode/code workload and drop all the
> hard code
> 
> Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
> ---
>  arch/x86/include/asm/kvm_host.h | 12 ++++++++++--
>  arch/x86/kvm/mtrr.c             | 19 ++++++++-----------
>  2 files changed, 18 insertions(+), 13 deletions(-)
> 
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 2c3c52d..95ce2ff 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -347,8 +347,16 @@ enum {
>  struct kvm_mtrr {
>  	struct mtrr_var_range var_ranges[KVM_NR_VAR_MTRR];
>  	mtrr_type fixed_ranges[KVM_NR_FIXED_MTRR_REGION];
> -	unsigned char enabled;
> -	mtrr_type def_type;
> +
> +	union {
> +		u64 deftype;
> +		struct {
> +			unsigned def_type:8;
> +			unsigned reserved:2;
> +			unsigned fixed_mtrr_enabled:1;
> +			unsigned mtrr_enabled:1;
> +		};
> +	};
>  };
>  
>  struct kvm_vcpu_arch {
> diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c
> index 562341b..6de49dd 100644
> --- a/arch/x86/kvm/mtrr.c
> +++ b/arch/x86/kvm/mtrr.c
> @@ -105,7 +105,6 @@ EXPORT_SYMBOL_GPL(kvm_mtrr_valid);
>  static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr)
>  {
>  	struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state;
> -	unsigned char mtrr_enabled = mtrr_state->enabled;
>  	gfn_t start, end, mask;
>  	int index;
>  	bool is_fixed = true;
> @@ -114,7 +113,7 @@ static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr)
>  	      !kvm_arch_has_noncoherent_dma(vcpu->kvm))
>  		return;
>  
> -	if (!(mtrr_enabled & 0x2) && msr != MSR_MTRRdefType)
> +	if (!mtrr_state->mtrr_enabled && msr != MSR_MTRRdefType)

I know Linus doesn't like bitfields too much.  Can you change these to
inline functions, and only leave an "u64 deftype" in the struct?

Paolo

>  		return;
>  
>  	switch (msr) {
> @@ -153,7 +152,7 @@ static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr)
>  		end = ((start & mask) | ~mask) + 1;
>  	}
>  
> -	if (is_fixed && !(mtrr_enabled & 0x1))
> +	if (is_fixed && !mtrr_state->fixed_mtrr_enabled)
>  		return;
>  
>  	kvm_zap_gfn_range(vcpu->kvm, gpa_to_gfn(start), gpa_to_gfn(end));
> @@ -166,10 +165,9 @@ int kvm_mtrr_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data)
>  	if (!kvm_mtrr_valid(vcpu, msr, data))
>  		return 1;
>  
> -	if (msr == MSR_MTRRdefType) {
> -		vcpu->arch.mtrr_state.def_type = data;
> -		vcpu->arch.mtrr_state.enabled = (data & 0xc00) >> 10;
> -	} else if (msr == MSR_MTRRfix64K_00000)
> +	if (msr == MSR_MTRRdefType)
> +		vcpu->arch.mtrr_state.deftype = data;
> +	else if (msr == MSR_MTRRfix64K_00000)
>  		p[0] = data;
>  	else if (msr == MSR_MTRRfix16K_80000 || msr == MSR_MTRRfix16K_A0000)
>  		p[1 + msr - MSR_MTRRfix16K_80000] = data;
> @@ -216,8 +214,7 @@ int kvm_mtrr_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
>  		return 1;
>  
>  	if (msr == MSR_MTRRdefType)
> -		*pdata = vcpu->arch.mtrr_state.def_type +
> -			 (vcpu->arch.mtrr_state.enabled << 10);
> +		*pdata = vcpu->arch.mtrr_state.deftype;
>  	else if (msr == MSR_MTRRfix64K_00000)
>  		*pdata = p[0];
>  	else if (msr == MSR_MTRRfix16K_80000 || msr == MSR_MTRRfix16K_A0000)
> @@ -256,14 +253,14 @@ static int get_mtrr_type(struct kvm_mtrr *mtrr_state,
>  	int i, num_var_ranges = KVM_NR_VAR_MTRR;
>  
>  	/* MTRR is completely disabled, use UC for all of physical memory. */
> -	if (!(mtrr_state->enabled & 0x2))
> +	if (!mtrr_state->mtrr_enabled)
>  		return MTRR_TYPE_UNCACHABLE;
>  
>  	/* Make end inclusive end, instead of exclusive */
>  	end--;
>  
>  	/* Look in fixed ranges. Just return the type as per start */
> -	if ((mtrr_state->enabled & 0x1) && (start < 0x100000)) {
> +	if (mtrr_state->fixed_mtrr_enabled && (start < 0x100000)) {
>  		int idx;
>  
>  		if (start < 0x80000) {
> 
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Xiao Guangrong June 3, 2015, 1:55 a.m. UTC | #2
Thanks for your review, Paolo!


On 06/01/2015 05:11 PM, Paolo Bonzini wrote:

>>   struct kvm_vcpu_arch {
>> diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c
>> index 562341b..6de49dd 100644
>> --- a/arch/x86/kvm/mtrr.c
>> +++ b/arch/x86/kvm/mtrr.c
>> @@ -105,7 +105,6 @@ EXPORT_SYMBOL_GPL(kvm_mtrr_valid);
>>   static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr)
>>   {
>>   	struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state;
>> -	unsigned char mtrr_enabled = mtrr_state->enabled;
>>   	gfn_t start, end, mask;
>>   	int index;
>>   	bool is_fixed = true;
>> @@ -114,7 +113,7 @@ static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr)
>>   	      !kvm_arch_has_noncoherent_dma(vcpu->kvm))
>>   		return;
>>
>> -	if (!(mtrr_enabled & 0x2) && msr != MSR_MTRRdefType)
>> +	if (!mtrr_state->mtrr_enabled && msr != MSR_MTRRdefType)
>
> I know Linus doesn't like bitfields too much.  Can you change these to
> inline functions, and only leave an "u64 deftype" in the struct?
>

Sure. I will introduce mtrr_is_enabled() and fixed_mtrr_is_enabled() instead
of these bitfields.

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David Matlack June 9, 2015, 12:35 a.m. UTC | #3
On Sat, May 30, 2015 at 3:59 AM, Xiao Guangrong
<guangrong.xiao@linux.intel.com> wrote:
> Use union definition to avoid the decode/code workload and drop all the
> hard code

Thank you for doing this cleanup. The new code is much clearer!

>
> Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
> ---
>  arch/x86/include/asm/kvm_host.h | 12 ++++++++++--
>  arch/x86/kvm/mtrr.c             | 19 ++++++++-----------
>  2 files changed, 18 insertions(+), 13 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 2c3c52d..95ce2ff 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -347,8 +347,16 @@ enum {
>  struct kvm_mtrr {
>         struct mtrr_var_range var_ranges[KVM_NR_VAR_MTRR];
>         mtrr_type fixed_ranges[KVM_NR_FIXED_MTRR_REGION];
> -       unsigned char enabled;
> -       mtrr_type def_type;
> +
> +       union {
> +               u64 deftype;
> +               struct {
> +                       unsigned def_type:8;
> +                       unsigned reserved:2;
> +                       unsigned fixed_mtrr_enabled:1;
> +                       unsigned mtrr_enabled:1;
> +               };
> +       };
>  };
>
>  struct kvm_vcpu_arch {
> diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c
> index 562341b..6de49dd 100644
> --- a/arch/x86/kvm/mtrr.c
> +++ b/arch/x86/kvm/mtrr.c
> @@ -105,7 +105,6 @@ EXPORT_SYMBOL_GPL(kvm_mtrr_valid);
>  static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr)
>  {
>         struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state;
> -       unsigned char mtrr_enabled = mtrr_state->enabled;
>         gfn_t start, end, mask;
>         int index;
>         bool is_fixed = true;
> @@ -114,7 +113,7 @@ static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr)
>               !kvm_arch_has_noncoherent_dma(vcpu->kvm))
>                 return;
>
> -       if (!(mtrr_enabled & 0x2) && msr != MSR_MTRRdefType)
> +       if (!mtrr_state->mtrr_enabled && msr != MSR_MTRRdefType)
>                 return;
>
>         switch (msr) {
> @@ -153,7 +152,7 @@ static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr)
>                 end = ((start & mask) | ~mask) + 1;
>         }
>
> -       if (is_fixed && !(mtrr_enabled & 0x1))
> +       if (is_fixed && !mtrr_state->fixed_mtrr_enabled)
>                 return;
>
>         kvm_zap_gfn_range(vcpu->kvm, gpa_to_gfn(start), gpa_to_gfn(end));
> @@ -166,10 +165,9 @@ int kvm_mtrr_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data)
>         if (!kvm_mtrr_valid(vcpu, msr, data))
>                 return 1;
>
> -       if (msr == MSR_MTRRdefType) {
> -               vcpu->arch.mtrr_state.def_type = data;
> -               vcpu->arch.mtrr_state.enabled = (data & 0xc00) >> 10;
> -       } else if (msr == MSR_MTRRfix64K_00000)
> +       if (msr == MSR_MTRRdefType)
> +               vcpu->arch.mtrr_state.deftype = data;
> +       else if (msr == MSR_MTRRfix64K_00000)
>                 p[0] = data;
>         else if (msr == MSR_MTRRfix16K_80000 || msr == MSR_MTRRfix16K_A0000)
>                 p[1 + msr - MSR_MTRRfix16K_80000] = data;
> @@ -216,8 +214,7 @@ int kvm_mtrr_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
>                 return 1;
>
>         if (msr == MSR_MTRRdefType)
> -               *pdata = vcpu->arch.mtrr_state.def_type +
> -                        (vcpu->arch.mtrr_state.enabled << 10);
> +               *pdata = vcpu->arch.mtrr_state.deftype;
>         else if (msr == MSR_MTRRfix64K_00000)
>                 *pdata = p[0];
>         else if (msr == MSR_MTRRfix16K_80000 || msr == MSR_MTRRfix16K_A0000)
> @@ -256,14 +253,14 @@ static int get_mtrr_type(struct kvm_mtrr *mtrr_state,
>         int i, num_var_ranges = KVM_NR_VAR_MTRR;
>
>         /* MTRR is completely disabled, use UC for all of physical memory. */
> -       if (!(mtrr_state->enabled & 0x2))
> +       if (!mtrr_state->mtrr_enabled)
>                 return MTRR_TYPE_UNCACHABLE;
>
>         /* Make end inclusive end, instead of exclusive */
>         end--;
>
>         /* Look in fixed ranges. Just return the type as per start */
> -       if ((mtrr_state->enabled & 0x1) && (start < 0x100000)) {
> +       if (mtrr_state->fixed_mtrr_enabled && (start < 0x100000)) {
>                 int idx;
>
>                 if (start < 0x80000) {
> --
> 2.1.0
>
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Patch
diff mbox

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 2c3c52d..95ce2ff 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -347,8 +347,16 @@  enum {
 struct kvm_mtrr {
 	struct mtrr_var_range var_ranges[KVM_NR_VAR_MTRR];
 	mtrr_type fixed_ranges[KVM_NR_FIXED_MTRR_REGION];
-	unsigned char enabled;
-	mtrr_type def_type;
+
+	union {
+		u64 deftype;
+		struct {
+			unsigned def_type:8;
+			unsigned reserved:2;
+			unsigned fixed_mtrr_enabled:1;
+			unsigned mtrr_enabled:1;
+		};
+	};
 };
 
 struct kvm_vcpu_arch {
diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c
index 562341b..6de49dd 100644
--- a/arch/x86/kvm/mtrr.c
+++ b/arch/x86/kvm/mtrr.c
@@ -105,7 +105,6 @@  EXPORT_SYMBOL_GPL(kvm_mtrr_valid);
 static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr)
 {
 	struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state;
-	unsigned char mtrr_enabled = mtrr_state->enabled;
 	gfn_t start, end, mask;
 	int index;
 	bool is_fixed = true;
@@ -114,7 +113,7 @@  static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr)
 	      !kvm_arch_has_noncoherent_dma(vcpu->kvm))
 		return;
 
-	if (!(mtrr_enabled & 0x2) && msr != MSR_MTRRdefType)
+	if (!mtrr_state->mtrr_enabled && msr != MSR_MTRRdefType)
 		return;
 
 	switch (msr) {
@@ -153,7 +152,7 @@  static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr)
 		end = ((start & mask) | ~mask) + 1;
 	}
 
-	if (is_fixed && !(mtrr_enabled & 0x1))
+	if (is_fixed && !mtrr_state->fixed_mtrr_enabled)
 		return;
 
 	kvm_zap_gfn_range(vcpu->kvm, gpa_to_gfn(start), gpa_to_gfn(end));
@@ -166,10 +165,9 @@  int kvm_mtrr_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data)
 	if (!kvm_mtrr_valid(vcpu, msr, data))
 		return 1;
 
-	if (msr == MSR_MTRRdefType) {
-		vcpu->arch.mtrr_state.def_type = data;
-		vcpu->arch.mtrr_state.enabled = (data & 0xc00) >> 10;
-	} else if (msr == MSR_MTRRfix64K_00000)
+	if (msr == MSR_MTRRdefType)
+		vcpu->arch.mtrr_state.deftype = data;
+	else if (msr == MSR_MTRRfix64K_00000)
 		p[0] = data;
 	else if (msr == MSR_MTRRfix16K_80000 || msr == MSR_MTRRfix16K_A0000)
 		p[1 + msr - MSR_MTRRfix16K_80000] = data;
@@ -216,8 +214,7 @@  int kvm_mtrr_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
 		return 1;
 
 	if (msr == MSR_MTRRdefType)
-		*pdata = vcpu->arch.mtrr_state.def_type +
-			 (vcpu->arch.mtrr_state.enabled << 10);
+		*pdata = vcpu->arch.mtrr_state.deftype;
 	else if (msr == MSR_MTRRfix64K_00000)
 		*pdata = p[0];
 	else if (msr == MSR_MTRRfix16K_80000 || msr == MSR_MTRRfix16K_A0000)
@@ -256,14 +253,14 @@  static int get_mtrr_type(struct kvm_mtrr *mtrr_state,
 	int i, num_var_ranges = KVM_NR_VAR_MTRR;
 
 	/* MTRR is completely disabled, use UC for all of physical memory. */
-	if (!(mtrr_state->enabled & 0x2))
+	if (!mtrr_state->mtrr_enabled)
 		return MTRR_TYPE_UNCACHABLE;
 
 	/* Make end inclusive end, instead of exclusive */
 	end--;
 
 	/* Look in fixed ranges. Just return the type as per start */
-	if ((mtrr_state->enabled & 0x1) && (start < 0x100000)) {
+	if (mtrr_state->fixed_mtrr_enabled && (start < 0x100000)) {
 		int idx;
 
 		if (start < 0x80000) {