Re: [PATCH] x86: kvm: avoid unused variable warning

[David Hildenbrand]

On 20.08.2018 23:37, Arnd Bergmann wrote:
> Removing one of the two accesses of the maxphyaddr variable led to
> a harmless warning:
> 
> arch/x86/kvm/x86.c: In function 'kvm_set_mmio_spte_mask':
> arch/x86/kvm/x86.c:6563:6: error: unused variable 'maxphyaddr' [-Werror=unused-variable]
> 
> Removing the #ifdef seems to be the nicest workaround, as it
> makes the code look cleaner than adding another #ifdef.
> 
> Fixes: 28a1f3ac1d0c ("kvm: x86: Set highest physical address bits in non-present/reserved SPTEs")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
>  arch/x86/kvm/x86.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 4a74a7cf0a8b..506bd2b4b8bb 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -6576,14 +6576,12 @@ static void kvm_set_mmio_spte_mask(void)
>  	/* Set the present bit. */
>  	mask |= 1ull;
>  
> -#ifdef CONFIG_X86_64
>  	/*
>  	 * If reserved bit is not supported, clear the present bit to disable
>  	 * mmio page fault.
>  	 */
> -	if (maxphyaddr == 52)
> +	if (IS_ENABLED(CONFIG_X86_64) && maxphyaddr == 52)
>  		mask &= ~1ull;
> -#endif
>  
>  	kvm_mmu_set_mmio_spte_mask(mask, mask);
>  }
> 

Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>

-- 

Thanks,

David / dhildenb