diff mbox series

[7/7] KVM: MIPS: clean up redundant kvm_run parameters in assembly

Message ID 20200419075106.16248-8-tianjia.zhang@linux.alibaba.com
State Superseded
Headers show
Series clean up redundant 'kvm_run' parameters | expand

Commit Message

Tianjia Zhang April 19, 2020, 7:51 a.m. UTC
In the current kvm version, 'kvm_run' has been included in the 'kvm_vcpu'
structure. Earlier than historical reasons, many kvm-related function
parameters retain the 'kvm_run' and 'kvm_vcpu' parameters at the same time.
This patch does a unified cleanup of these remaining redundant parameters.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
---
 arch/mips/include/asm/kvm_host.h |  4 ++--
 arch/mips/kvm/entry.c            | 15 +++++----------
 arch/mips/kvm/mips.c             |  3 ++-
 arch/mips/kvm/trap_emul.c        |  2 +-
 arch/mips/kvm/vz.c               |  2 +-
 5 files changed, 11 insertions(+), 15 deletions(-)

Comments

maobibo April 20, 2020, 10:32 a.m. UTC | #1
On 04/19/2020 03:51 PM, Tianjia Zhang wrote:
> In the current kvm version, 'kvm_run' has been included in the 'kvm_vcpu'
> structure. Earlier than historical reasons, many kvm-related function
> parameters retain the 'kvm_run' and 'kvm_vcpu' parameters at the same time.
> This patch does a unified cleanup of these remaining redundant parameters.
> 
> Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
> ---
>  arch/mips/include/asm/kvm_host.h |  4 ++--
>  arch/mips/kvm/entry.c            | 15 +++++----------
>  arch/mips/kvm/mips.c             |  3 ++-
>  arch/mips/kvm/trap_emul.c        |  2 +-
>  arch/mips/kvm/vz.c               |  2 +-
>  5 files changed, 11 insertions(+), 15 deletions(-)
> 
> diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
> index 971439297cea..db915c55166d 100644
> --- a/arch/mips/include/asm/kvm_host.h
> +++ b/arch/mips/include/asm/kvm_host.h
> @@ -310,7 +310,7 @@ struct kvm_mmu_memory_cache {
>  #define KVM_MIPS_GUEST_TLB_SIZE	64
>  struct kvm_vcpu_arch {
>  	void *guest_ebase;
> -	int (*vcpu_run)(struct kvm_run *run, struct kvm_vcpu *vcpu);
> +	int (*vcpu_run)(struct kvm_vcpu *vcpu);
>  
>  	/* Host registers preserved across guest mode execution */
>  	unsigned long host_stack;
> @@ -821,7 +821,7 @@ int kvm_mips_emulation_init(struct kvm_mips_callbacks **install_callbacks);
>  /* Debug: dump vcpu state */
>  int kvm_arch_vcpu_dump_regs(struct kvm_vcpu *vcpu);
>  
> -extern int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu);
> +extern int kvm_mips_handle_exit(struct kvm_vcpu *vcpu);
>  
>  /* Building of entry/exception code */
>  int kvm_mips_entry_setup(void);
> diff --git a/arch/mips/kvm/entry.c b/arch/mips/kvm/entry.c
> index 16e1c93b484f..e3f29af3b6cd 100644
> --- a/arch/mips/kvm/entry.c
> +++ b/arch/mips/kvm/entry.c
> @@ -204,7 +204,7 @@ static inline void build_set_exc_base(u32 **p, unsigned int reg)
>   * Assemble the start of the vcpu_run function to run a guest VCPU. The function
>   * conforms to the following prototype:
>   *
> - * int vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu);
> + * int vcpu_run(struct kvm_vcpu *vcpu);
>   *
>   * The exit from the guest and return to the caller is handled by the code
>   * generated by kvm_mips_build_ret_to_host().
> @@ -217,8 +217,7 @@ void *kvm_mips_build_vcpu_run(void *addr)
>  	unsigned int i;
>  
>  	/*
> -	 * A0: run
> -	 * A1: vcpu
> +	 * A0: vcpu
>  	 */
>  
>  	/* k0/k1 not being used in host kernel context */
> @@ -237,10 +236,10 @@ void *kvm_mips_build_vcpu_run(void *addr)
>  	kvm_mips_build_save_scratch(&p, V1, K1);
>  
>  	/* VCPU scratch register has pointer to vcpu */
> -	UASM_i_MTC0(&p, A1, scratch_vcpu[0], scratch_vcpu[1]);
> +	UASM_i_MTC0(&p, A0, scratch_vcpu[0], scratch_vcpu[1]);
>  
>  	/* Offset into vcpu->arch */
> -	UASM_i_ADDIU(&p, K1, A1, offsetof(struct kvm_vcpu, arch));
> +	UASM_i_ADDIU(&p, K1, A0, offsetof(struct kvm_vcpu, arch));
>  
>  	/*
>  	 * Save the host stack to VCPU, used for exception processing
> @@ -628,10 +627,7 @@ void *kvm_mips_build_exit(void *addr)
>  	/* Now that context has been saved, we can use other registers */
>  
>  	/* Restore vcpu */
> -	UASM_i_MFC0(&p, S1, scratch_vcpu[0], scratch_vcpu[1]);
> -
> -	/* Restore run (vcpu->run) */
> -	UASM_i_LW(&p, S0, offsetof(struct kvm_vcpu, run), S1);
> +	UASM_i_MFC0(&p, S0, scratch_vcpu[0], scratch_vcpu[1]);
>  
>  	/*
>  	 * Save Host level EPC, BadVaddr and Cause to VCPU, useful to process
> @@ -793,7 +789,6 @@ void *kvm_mips_build_exit(void *addr)
>  	 * with this in the kernel
>  	 */
>  	uasm_i_move(&p, A0, S0);
> -	uasm_i_move(&p, A1, S1);
>  	UASM_i_LA(&p, T9, (unsigned long)kvm_mips_handle_exit);
>  	uasm_i_jalr(&p, RA, T9);
>  	 UASM_i_ADDIU(&p, SP, SP, -CALLFRAME_SIZ);

I suggest keeping asm code untouched, the change for c code is much easier to understand, however I do not see obvious advantage to remove one redundant function parameter :) 


regards
bibo,mao


> diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
> index 9710477a9827..32850470c037 100644
> --- a/arch/mips/kvm/mips.c
> +++ b/arch/mips/kvm/mips.c
> @@ -1186,8 +1186,9 @@ static void kvm_mips_set_c0_status(void)
>  /*
>   * Return value is in the form (errcode<<2 | RESUME_FLAG_HOST | RESUME_FLAG_NV)
>   */
> -int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
> +int kvm_mips_handle_exit(struct kvm_vcpu *vcpu)
>  {
> +	struct kvm_run *run = vcpu->run;
>  	u32 cause = vcpu->arch.host_cp0_cause;
>  	u32 exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
>  	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
> diff --git a/arch/mips/kvm/trap_emul.c b/arch/mips/kvm/trap_emul.c
> index d822f3aee3dc..04c864cc356a 100644
> --- a/arch/mips/kvm/trap_emul.c
> +++ b/arch/mips/kvm/trap_emul.c
> @@ -1238,7 +1238,7 @@ static int kvm_trap_emul_vcpu_run(struct kvm_vcpu *vcpu)
>  	 */
>  	kvm_mips_suspend_mm(cpu);
>  
> -	r = vcpu->arch.vcpu_run(vcpu->run, vcpu);
> +	r = vcpu->arch.vcpu_run(vcpu);
>  
>  	/* We may have migrated while handling guest exits */
>  	cpu = smp_processor_id();
> diff --git a/arch/mips/kvm/vz.c b/arch/mips/kvm/vz.c
> index 94f1d23828e3..c5878fa0636d 100644
> --- a/arch/mips/kvm/vz.c
> +++ b/arch/mips/kvm/vz.c
> @@ -3152,7 +3152,7 @@ static int kvm_vz_vcpu_run(struct kvm_vcpu *vcpu)
>  	kvm_vz_vcpu_load_tlb(vcpu, cpu);
>  	kvm_vz_vcpu_load_wired(vcpu);
>  
> -	r = vcpu->arch.vcpu_run(vcpu->run, vcpu);
> +	r = vcpu->arch.vcpu_run(vcpu);
>  
>  	kvm_vz_vcpu_save_wired(vcpu);
>  
>
Tianjia Zhang April 20, 2020, 10:42 a.m. UTC | #2
On 2020/4/20 18:32, maobibo wrote:
> 
> 
> On 04/19/2020 03:51 PM, Tianjia Zhang wrote:
>> In the current kvm version, 'kvm_run' has been included in the 'kvm_vcpu'
>> structure. Earlier than historical reasons, many kvm-related function
>> parameters retain the 'kvm_run' and 'kvm_vcpu' parameters at the same time.
>> This patch does a unified cleanup of these remaining redundant parameters.
>>
>> Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
>> ---
>>   arch/mips/include/asm/kvm_host.h |  4 ++--
>>   arch/mips/kvm/entry.c            | 15 +++++----------
>>   arch/mips/kvm/mips.c             |  3 ++-
>>   arch/mips/kvm/trap_emul.c        |  2 +-
>>   arch/mips/kvm/vz.c               |  2 +-
>>   5 files changed, 11 insertions(+), 15 deletions(-)
>>
>> diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
>> index 971439297cea..db915c55166d 100644
>> --- a/arch/mips/include/asm/kvm_host.h
>> +++ b/arch/mips/include/asm/kvm_host.h
>> @@ -310,7 +310,7 @@ struct kvm_mmu_memory_cache {
>>   #define KVM_MIPS_GUEST_TLB_SIZE	64
>>   struct kvm_vcpu_arch {
>>   	void *guest_ebase;
>> -	int (*vcpu_run)(struct kvm_run *run, struct kvm_vcpu *vcpu);
>> +	int (*vcpu_run)(struct kvm_vcpu *vcpu);
>>   
>>   	/* Host registers preserved across guest mode execution */
>>   	unsigned long host_stack;
>> @@ -821,7 +821,7 @@ int kvm_mips_emulation_init(struct kvm_mips_callbacks **install_callbacks);
>>   /* Debug: dump vcpu state */
>>   int kvm_arch_vcpu_dump_regs(struct kvm_vcpu *vcpu);
>>   
>> -extern int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu);
>> +extern int kvm_mips_handle_exit(struct kvm_vcpu *vcpu);
>>   
>>   /* Building of entry/exception code */
>>   int kvm_mips_entry_setup(void);
>> diff --git a/arch/mips/kvm/entry.c b/arch/mips/kvm/entry.c
>> index 16e1c93b484f..e3f29af3b6cd 100644
>> --- a/arch/mips/kvm/entry.c
>> +++ b/arch/mips/kvm/entry.c
>> @@ -204,7 +204,7 @@ static inline void build_set_exc_base(u32 **p, unsigned int reg)
>>    * Assemble the start of the vcpu_run function to run a guest VCPU. The function
>>    * conforms to the following prototype:
>>    *
>> - * int vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu);
>> + * int vcpu_run(struct kvm_vcpu *vcpu);
>>    *
>>    * The exit from the guest and return to the caller is handled by the code
>>    * generated by kvm_mips_build_ret_to_host().
>> @@ -217,8 +217,7 @@ void *kvm_mips_build_vcpu_run(void *addr)
>>   	unsigned int i;
>>   
>>   	/*
>> -	 * A0: run
>> -	 * A1: vcpu
>> +	 * A0: vcpu
>>   	 */
>>   
>>   	/* k0/k1 not being used in host kernel context */
>> @@ -237,10 +236,10 @@ void *kvm_mips_build_vcpu_run(void *addr)
>>   	kvm_mips_build_save_scratch(&p, V1, K1);
>>   
>>   	/* VCPU scratch register has pointer to vcpu */
>> -	UASM_i_MTC0(&p, A1, scratch_vcpu[0], scratch_vcpu[1]);
>> +	UASM_i_MTC0(&p, A0, scratch_vcpu[0], scratch_vcpu[1]);
>>   
>>   	/* Offset into vcpu->arch */
>> -	UASM_i_ADDIU(&p, K1, A1, offsetof(struct kvm_vcpu, arch));
>> +	UASM_i_ADDIU(&p, K1, A0, offsetof(struct kvm_vcpu, arch));
>>   
>>   	/*
>>   	 * Save the host stack to VCPU, used for exception processing
>> @@ -628,10 +627,7 @@ void *kvm_mips_build_exit(void *addr)
>>   	/* Now that context has been saved, we can use other registers */
>>   
>>   	/* Restore vcpu */
>> -	UASM_i_MFC0(&p, S1, scratch_vcpu[0], scratch_vcpu[1]);
>> -
>> -	/* Restore run (vcpu->run) */
>> -	UASM_i_LW(&p, S0, offsetof(struct kvm_vcpu, run), S1);
>> +	UASM_i_MFC0(&p, S0, scratch_vcpu[0], scratch_vcpu[1]);
>>   
>>   	/*
>>   	 * Save Host level EPC, BadVaddr and Cause to VCPU, useful to process
>> @@ -793,7 +789,6 @@ void *kvm_mips_build_exit(void *addr)
>>   	 * with this in the kernel
>>   	 */
>>   	uasm_i_move(&p, A0, S0);
>> -	uasm_i_move(&p, A1, S1);
>>   	UASM_i_LA(&p, T9, (unsigned long)kvm_mips_handle_exit);
>>   	uasm_i_jalr(&p, RA, T9);
>>   	 UASM_i_ADDIU(&p, SP, SP, -CALLFRAME_SIZ);
> 
> I suggest keeping asm code untouched, the change for c code is much easier to understand, however I do not see obvious advantage to remove one redundant function parameter :)
> 
> 
> regards
> bibo,mao
> 

This is acceptable, asm code is an independent patch, is to provide 
convenience for this operation.

> 
>> diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
>> index 9710477a9827..32850470c037 100644
>> --- a/arch/mips/kvm/mips.c
>> +++ b/arch/mips/kvm/mips.c
>> @@ -1186,8 +1186,9 @@ static void kvm_mips_set_c0_status(void)
>>   /*
>>    * Return value is in the form (errcode<<2 | RESUME_FLAG_HOST | RESUME_FLAG_NV)
>>    */
>> -int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
>> +int kvm_mips_handle_exit(struct kvm_vcpu *vcpu)
>>   {
>> +	struct kvm_run *run = vcpu->run;
>>   	u32 cause = vcpu->arch.host_cp0_cause;
>>   	u32 exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
>>   	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
>> diff --git a/arch/mips/kvm/trap_emul.c b/arch/mips/kvm/trap_emul.c
>> index d822f3aee3dc..04c864cc356a 100644
>> --- a/arch/mips/kvm/trap_emul.c
>> +++ b/arch/mips/kvm/trap_emul.c
>> @@ -1238,7 +1238,7 @@ static int kvm_trap_emul_vcpu_run(struct kvm_vcpu *vcpu)
>>   	 */
>>   	kvm_mips_suspend_mm(cpu);
>>   
>> -	r = vcpu->arch.vcpu_run(vcpu->run, vcpu);
>> +	r = vcpu->arch.vcpu_run(vcpu);
>>   
>>   	/* We may have migrated while handling guest exits */
>>   	cpu = smp_processor_id();
>> diff --git a/arch/mips/kvm/vz.c b/arch/mips/kvm/vz.c
>> index 94f1d23828e3..c5878fa0636d 100644
>> --- a/arch/mips/kvm/vz.c
>> +++ b/arch/mips/kvm/vz.c
>> @@ -3152,7 +3152,7 @@ static int kvm_vz_vcpu_run(struct kvm_vcpu *vcpu)
>>   	kvm_vz_vcpu_load_tlb(vcpu, cpu);
>>   	kvm_vz_vcpu_load_wired(vcpu);
>>   
>> -	r = vcpu->arch.vcpu_run(vcpu->run, vcpu);
>> +	r = vcpu->arch.vcpu_run(vcpu);
>>   
>>   	kvm_vz_vcpu_save_wired(vcpu);
>>   
>>
diff mbox series

Patch

diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
index 971439297cea..db915c55166d 100644
--- a/arch/mips/include/asm/kvm_host.h
+++ b/arch/mips/include/asm/kvm_host.h
@@ -310,7 +310,7 @@  struct kvm_mmu_memory_cache {
 #define KVM_MIPS_GUEST_TLB_SIZE	64
 struct kvm_vcpu_arch {
 	void *guest_ebase;
-	int (*vcpu_run)(struct kvm_run *run, struct kvm_vcpu *vcpu);
+	int (*vcpu_run)(struct kvm_vcpu *vcpu);
 
 	/* Host registers preserved across guest mode execution */
 	unsigned long host_stack;
@@ -821,7 +821,7 @@  int kvm_mips_emulation_init(struct kvm_mips_callbacks **install_callbacks);
 /* Debug: dump vcpu state */
 int kvm_arch_vcpu_dump_regs(struct kvm_vcpu *vcpu);
 
-extern int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu);
+extern int kvm_mips_handle_exit(struct kvm_vcpu *vcpu);
 
 /* Building of entry/exception code */
 int kvm_mips_entry_setup(void);
diff --git a/arch/mips/kvm/entry.c b/arch/mips/kvm/entry.c
index 16e1c93b484f..e3f29af3b6cd 100644
--- a/arch/mips/kvm/entry.c
+++ b/arch/mips/kvm/entry.c
@@ -204,7 +204,7 @@  static inline void build_set_exc_base(u32 **p, unsigned int reg)
  * Assemble the start of the vcpu_run function to run a guest VCPU. The function
  * conforms to the following prototype:
  *
- * int vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu);
+ * int vcpu_run(struct kvm_vcpu *vcpu);
  *
  * The exit from the guest and return to the caller is handled by the code
  * generated by kvm_mips_build_ret_to_host().
@@ -217,8 +217,7 @@  void *kvm_mips_build_vcpu_run(void *addr)
 	unsigned int i;
 
 	/*
-	 * A0: run
-	 * A1: vcpu
+	 * A0: vcpu
 	 */
 
 	/* k0/k1 not being used in host kernel context */
@@ -237,10 +236,10 @@  void *kvm_mips_build_vcpu_run(void *addr)
 	kvm_mips_build_save_scratch(&p, V1, K1);
 
 	/* VCPU scratch register has pointer to vcpu */
-	UASM_i_MTC0(&p, A1, scratch_vcpu[0], scratch_vcpu[1]);
+	UASM_i_MTC0(&p, A0, scratch_vcpu[0], scratch_vcpu[1]);
 
 	/* Offset into vcpu->arch */
-	UASM_i_ADDIU(&p, K1, A1, offsetof(struct kvm_vcpu, arch));
+	UASM_i_ADDIU(&p, K1, A0, offsetof(struct kvm_vcpu, arch));
 
 	/*
 	 * Save the host stack to VCPU, used for exception processing
@@ -628,10 +627,7 @@  void *kvm_mips_build_exit(void *addr)
 	/* Now that context has been saved, we can use other registers */
 
 	/* Restore vcpu */
-	UASM_i_MFC0(&p, S1, scratch_vcpu[0], scratch_vcpu[1]);
-
-	/* Restore run (vcpu->run) */
-	UASM_i_LW(&p, S0, offsetof(struct kvm_vcpu, run), S1);
+	UASM_i_MFC0(&p, S0, scratch_vcpu[0], scratch_vcpu[1]);
 
 	/*
 	 * Save Host level EPC, BadVaddr and Cause to VCPU, useful to process
@@ -793,7 +789,6 @@  void *kvm_mips_build_exit(void *addr)
 	 * with this in the kernel
 	 */
 	uasm_i_move(&p, A0, S0);
-	uasm_i_move(&p, A1, S1);
 	UASM_i_LA(&p, T9, (unsigned long)kvm_mips_handle_exit);
 	uasm_i_jalr(&p, RA, T9);
 	 UASM_i_ADDIU(&p, SP, SP, -CALLFRAME_SIZ);
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 9710477a9827..32850470c037 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -1186,8 +1186,9 @@  static void kvm_mips_set_c0_status(void)
 /*
  * Return value is in the form (errcode<<2 | RESUME_FLAG_HOST | RESUME_FLAG_NV)
  */
-int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
+int kvm_mips_handle_exit(struct kvm_vcpu *vcpu)
 {
+	struct kvm_run *run = vcpu->run;
 	u32 cause = vcpu->arch.host_cp0_cause;
 	u32 exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
 	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
diff --git a/arch/mips/kvm/trap_emul.c b/arch/mips/kvm/trap_emul.c
index d822f3aee3dc..04c864cc356a 100644
--- a/arch/mips/kvm/trap_emul.c
+++ b/arch/mips/kvm/trap_emul.c
@@ -1238,7 +1238,7 @@  static int kvm_trap_emul_vcpu_run(struct kvm_vcpu *vcpu)
 	 */
 	kvm_mips_suspend_mm(cpu);
 
-	r = vcpu->arch.vcpu_run(vcpu->run, vcpu);
+	r = vcpu->arch.vcpu_run(vcpu);
 
 	/* We may have migrated while handling guest exits */
 	cpu = smp_processor_id();
diff --git a/arch/mips/kvm/vz.c b/arch/mips/kvm/vz.c
index 94f1d23828e3..c5878fa0636d 100644
--- a/arch/mips/kvm/vz.c
+++ b/arch/mips/kvm/vz.c
@@ -3152,7 +3152,7 @@  static int kvm_vz_vcpu_run(struct kvm_vcpu *vcpu)
 	kvm_vz_vcpu_load_tlb(vcpu, cpu);
 	kvm_vz_vcpu_load_wired(vcpu);
 
-	r = vcpu->arch.vcpu_run(vcpu->run, vcpu);
+	r = vcpu->arch.vcpu_run(vcpu);
 
 	kvm_vz_vcpu_save_wired(vcpu);