diff mbox

[v2,3/6] KVM: MMU: make return value of mmio page fault handler more readable

Message ID 1364810209-25954-4-git-send-email-xiaoguangrong@linux.vnet.ibm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Xiao Guangrong April 1, 2013, 9:56 a.m. UTC 
Define some meaningful names instead of raw code

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
---
 arch/x86/kvm/mmu.c |   15 +++++----------
 arch/x86/kvm/mmu.h |   14 ++++++++++++++
 arch/x86/kvm/vmx.c |    4 ++--
 3 files changed, 21 insertions(+), 12 deletions(-)

Comments

Gleb Natapov April 24, 2013, 1:34 p.m. UTC | #1 
On Mon, Apr 01, 2013 at 05:56:46PM +0800, Xiao Guangrong wrote:
> Define some meaningful names instead of raw code
> 
> Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
> ---
>  arch/x86/kvm/mmu.c |   15 +++++----------
>  arch/x86/kvm/mmu.h |   14 ++++++++++++++
>  arch/x86/kvm/vmx.c |    4 ++--
>  3 files changed, 21 insertions(+), 12 deletions(-)
> 
> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
> index be4f733..31c5586 100644
> --- a/arch/x86/kvm/mmu.c
> +++ b/arch/x86/kvm/mmu.c
> @@ -3182,17 +3182,12 @@ static u64 walk_shadow_page_get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr)
>  	return spte;
>  }
>  
> -/*
> - * If it is a real mmio page fault, return 1 and emulat the instruction
> - * directly, return 0 to let CPU fault again on the address, -1 is
> - * returned if bug is detected.
> - */
>  int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct)
>  {
>  	u64 spte;
>  
>  	if (quickly_check_mmio_pf(vcpu, addr, direct))
> -		return 1;
> +		return RET_MMIO_PF_EMU;
>  
>  	spte = walk_shadow_page_get_mmio_spte(vcpu, addr);
>  
> @@ -3205,7 +3200,7 @@ int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct)
>  
>  		trace_handle_mmio_page_fault(addr, gfn, access);
>  		vcpu_cache_mmio_info(vcpu, addr, gfn, access);
> -		return 1;
> +		return RET_MMIO_PF_EMU;
>  	}
>  
>  	/*
> @@ -3213,13 +3208,13 @@ int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct)
>  	 * it's a BUG if the gfn is not a mmio page.
>  	 */
>  	if (direct && !check_direct_spte_mmio_pf(spte))
> -		return -1;
> +		return RET_MMIO_PF_BUG;
>  
>  	/*
>  	 * If the page table is zapped by other cpus, let CPU fault again on
>  	 * the address.
>  	 */
> -	return 0;
> +	return RET_MMIO_PF_RETRY;
>  }
>  EXPORT_SYMBOL_GPL(handle_mmio_page_fault_common);
>  
> @@ -3229,7 +3224,7 @@ static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr,
>  	int ret;
>  
>  	ret = handle_mmio_page_fault_common(vcpu, addr, direct);
> -	WARN_ON(ret < 0);
> +	WARN_ON(ret == RET_MMIO_PF_BUG);
>  	return ret;
>  }
>  
> diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
> index 2adcbc2..6b4ba1e 100644
> --- a/arch/x86/kvm/mmu.h
> +++ b/arch/x86/kvm/mmu.h
> @@ -52,6 +52,20 @@
>  
>  int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu *vcpu, u64 addr, u64 sptes[4]);
>  void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask);
> +
> +/*
> + * Return values of handle_mmio_page_fault_common:
> + * RET_MMIO_PF_EMU: it is a real mmio page fault, emulate the instruction
> + *		    directly.
> + * RET_MMIO_PF_RETRY: let CPU fault again on the address.
> + * RET_MMIO_PF_BUG: bug is detected.
> + */
> +enum {
> +	RET_MMIO_PF_EMU = 1,
Make it RET_MMIO_PF_EMULATE please.

> +	RET_MMIO_PF_RETRY = 0,
> +	RET_MMIO_PF_BUG = -1
> +};
> +
>  int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct);
>  int kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *context);
>  
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 915ef56..d0f2790 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -5135,10 +5135,10 @@ static int handle_ept_misconfig(struct kvm_vcpu *vcpu)
>  	gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS);
>  
>  	ret = handle_mmio_page_fault_common(vcpu, gpa, true);
> -	if (likely(ret == 1))
> +	if (likely(ret == RET_MMIO_PF_EMU))
>  		return x86_emulate_instruction(vcpu, gpa, 0, NULL, 0) ==
>  					      EMULATE_DONE;
> -	if (unlikely(!ret))
> +	if (unlikely(ret == RET_MMIO_PF_RETRY))
>  		return 1;
>  
>  	/* It is the real ept misconfig */
> -- 
> 1.7.7.6

--
			Gleb.
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Xiao Guangrong April 25, 2013, 9:24 a.m. UTC | #2 
On 04/24/2013 09:34 PM, Gleb Natapov wrote:

>> diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
>> index 2adcbc2..6b4ba1e 100644
>> --- a/arch/x86/kvm/mmu.h
>> +++ b/arch/x86/kvm/mmu.h
>> @@ -52,6 +52,20 @@
>>  
>>  int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu *vcpu, u64 addr, u64 sptes[4]);
>>  void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask);
>> +
>> +/*
>> + * Return values of handle_mmio_page_fault_common:
>> + * RET_MMIO_PF_EMU: it is a real mmio page fault, emulate the instruction
>> + *		    directly.
>> + * RET_MMIO_PF_RETRY: let CPU fault again on the address.
>> + * RET_MMIO_PF_BUG: bug is detected.
>> + */
>> +enum {
>> +	RET_MMIO_PF_EMU = 1,
> Make it RET_MMIO_PF_EMULATE please.

Good to me, will do.

Thanks!

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diff mbox

Patch

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index be4f733..31c5586 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3182,17 +3182,12 @@  static u64 walk_shadow_page_get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr)
 	return spte;
 }
 
-/*
- * If it is a real mmio page fault, return 1 and emulat the instruction
- * directly, return 0 to let CPU fault again on the address, -1 is
- * returned if bug is detected.
- */
 int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct)
 {
 	u64 spte;
 
 	if (quickly_check_mmio_pf(vcpu, addr, direct))
-		return 1;
+		return RET_MMIO_PF_EMU;
 
 	spte = walk_shadow_page_get_mmio_spte(vcpu, addr);
 
@@ -3205,7 +3200,7 @@  int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct)
 
 		trace_handle_mmio_page_fault(addr, gfn, access);
 		vcpu_cache_mmio_info(vcpu, addr, gfn, access);
-		return 1;
+		return RET_MMIO_PF_EMU;
 	}
 
 	/*
@@ -3213,13 +3208,13 @@  int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct)
 	 * it's a BUG if the gfn is not a mmio page.
 	 */
 	if (direct && !check_direct_spte_mmio_pf(spte))
-		return -1;
+		return RET_MMIO_PF_BUG;
 
 	/*
 	 * If the page table is zapped by other cpus, let CPU fault again on
 	 * the address.
 	 */
-	return 0;
+	return RET_MMIO_PF_RETRY;
 }
 EXPORT_SYMBOL_GPL(handle_mmio_page_fault_common);
 
@@ -3229,7 +3224,7 @@  static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr,
 	int ret;
 
 	ret = handle_mmio_page_fault_common(vcpu, addr, direct);
-	WARN_ON(ret < 0);
+	WARN_ON(ret == RET_MMIO_PF_BUG);
 	return ret;
 }
 
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 2adcbc2..6b4ba1e 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -52,6 +52,20 @@ 
 
 int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu *vcpu, u64 addr, u64 sptes[4]);
 void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask);
+
+/*
+ * Return values of handle_mmio_page_fault_common:
+ * RET_MMIO_PF_EMU: it is a real mmio page fault, emulate the instruction
+ *		    directly.
+ * RET_MMIO_PF_RETRY: let CPU fault again on the address.
+ * RET_MMIO_PF_BUG: bug is detected.
+ */
+enum {
+	RET_MMIO_PF_EMU = 1,
+	RET_MMIO_PF_RETRY = 0,
+	RET_MMIO_PF_BUG = -1
+};
+
 int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct);
 int kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *context);
 
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 915ef56..d0f2790 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5135,10 +5135,10 @@  static int handle_ept_misconfig(struct kvm_vcpu *vcpu)
 	gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS);
 
 	ret = handle_mmio_page_fault_common(vcpu, gpa, true);
-	if (likely(ret == 1))
+	if (likely(ret == RET_MMIO_PF_EMU))
 		return x86_emulate_instruction(vcpu, gpa, 0, NULL, 0) ==
 					      EMULATE_DONE;
-	if (unlikely(!ret))
+	if (unlikely(ret == RET_MMIO_PF_RETRY))
 		return 1;
 
 	/* It is the real ept misconfig */