Re: [PATCH 1/3] KVM: VMX: Use proper types to access const arrays

[Paolo Bonzini <pbonzini@redhat.com>]

Il 26/06/2013 20:36, Mathias Krause ha scritto:
> Use a const pointer type instead of casting away the const qualifier
> from const arrays. Keep the pointer array on the stack, nonetheless.
> Making it static just increases the object size.
> 
> Signed-off-by: Mathias Krause <minipli@googlemail.com>
> ---
>  arch/x86/kvm/vmx.c |   15 +++++++--------
>  1 file changed, 7 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 260a919..7393164 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -5956,8 +5956,8 @@ static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx)
>  	unsigned long field;
>  	u64 field_value;
>  	struct vmcs *shadow_vmcs = vmx->nested.current_shadow_vmcs;
> -	unsigned long *fields = (unsigned long *)shadow_read_write_fields;
> -	int num_fields = max_shadow_read_write_fields;
> +	const unsigned long *fields = shadow_read_write_fields;
> +	const int num_fields = max_shadow_read_write_fields;
>  
>  	vmcs_load(shadow_vmcs);
>  
> @@ -5986,12 +5986,11 @@ static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx)
>  
>  static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx)
>  {
> -	unsigned long *fields[] = {
> -		(unsigned long *)shadow_read_write_fields,
> -		(unsigned long *)shadow_read_only_fields
> +	const unsigned long *fields[] = {
> +		shadow_read_write_fields,
> +		shadow_read_only_fields
>  	};
> -	int num_lists =  ARRAY_SIZE(fields);
> -	int max_fields[] = {
> +	const int max_fields[] = {
>  		max_shadow_read_write_fields,
>  		max_shadow_read_only_fields
>  	};
> @@ -6002,7 +6001,7 @@ static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx)
>  
>  	vmcs_load(shadow_vmcs);
>  
> -	for (q = 0; q < num_lists; q++) {
> +	for (q = 0; q < ARRAY_SIZE(fields); q++) {
>  		for (i = 0; i < max_fields[q]; i++) {
>  			field = fields[q][i];
>  			vmcs12_read_any(&vmx->vcpu, field, &field_value);
> 

The "const int" is not particularly useful, but doesn't hurt either.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>