Re: [PATCH v4 1/2] selftests: kvm: Add vm_get_fd() in kvm_util

[Krish Sadhukhan]

On 4/8/20 3:08 PM, Wainer dos Santos Moschetta wrote:
> Introduces the vm_get_fd() function in kvm_util which returns
> the VM file descriptor.
>
> Reviewed-by: Andrew Jones <drjones@xxxxxxxxxx>
> Signed-off-by: Wainer dos Santos Moschetta <wainersm@xxxxxxxxxx>
> ---
>   tools/testing/selftests/kvm/include/kvm_util.h | 1 +
>   tools/testing/selftests/kvm/lib/kvm_util.c     | 5 +++++
>   2 files changed, 6 insertions(+)
>
> diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
> index a99b875f50d2..4e122819ee24 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util.h
> @@ -254,6 +254,7 @@ bool vm_is_unrestricted_guest(struct kvm_vm *vm);
>   unsigned int vm_get_page_size(struct kvm_vm *vm);
>   unsigned int vm_get_page_shift(struct kvm_vm *vm);
>   unsigned int vm_get_max_gfn(struct kvm_vm *vm);
> +int vm_get_fd(struct kvm_vm *vm);
>   
>   unsigned int vm_calc_num_guest_pages(enum vm_guest_mode mode, size_t size);
>   unsigned int vm_num_host_pages(enum vm_guest_mode mode, unsigned int num_guest_pages);
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index 8a3523d4434f..3e36a1eb8771 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -1734,6 +1734,11 @@ unsigned int vm_get_max_gfn(struct kvm_vm *vm)
>   	return vm->max_gfn;
>   }
>   
> +int vm_get_fd(struct kvm_vm *vm)
> +{
> +        return vm->fd;
> +}
> +


I am just trying to understand why we need a separate function when the 
'vm' variable is all local within the same file. There are a number of 
places in kvm_util.c where it is used directly.

>   static unsigned int vm_calc_num_pages(unsigned int num_pages,
>   				      unsigned int page_shift,
>   				      unsigned int new_page_shift,