[Libguestfs] [PATCH 2/3] v2v: linux: check also kernel config for modules

[Richard W.M. Jones]

Actually I have another comment about this patch ..

On Tue, Sep 27, 2016 at 05:58:11PM +0200, Pino Toscano wrote:
> diff --git a/v2v/linux_kernels.ml b/v2v/linux_kernels.ml
> index b292921..c197f78 100644
> --- a/v2v/linux_kernels.ml
> +++ b/v2v/linux_kernels.ml
> @@ -53,6 +53,21 @@ let detect_kernels (g : G.guestfs) inspect family bootloader =
>    (* What kernel/kernel-like packages are installed on the current guest? *)
>    let installed_kernels : kernel_info list =
>      let rex_ko = Str.regexp ".*\\.k?o\\(\\.xz\\)?$" in
> +    let check_config version feature =
> +      let prefix = "^CONFIG_" ^ String.uppercase_ascii feature ^ "=" in
> +      let lines = g#grep ~extended:true prefix ("/boot/config-" ^ version) in

This could fail if the config file doesn't exist or has an
unexpected name.

I don't think we should fail in that case.

I think what we should do is put the config file name in the
Linux_kernels.kernel_info struct, eg:

  ki_config_file : string option;

where None would be "not found".

The check_config function can then short-circuit when ki_config_file == None.

Rich.

> +      let lines = Array.to_list lines in
> +      match lines with
> +      | [] -> false
> +      | line :: _ ->
> +        let kind = snd (String.split "=" line) in
> +        (match kind with
> +        | "m" (* Theoretically this should not be needed, since the module
> +               * would be found. *)
> +        | "y" -> true
> +        | _ -> false
> +        )
> +    in
>      let rex_ko_extract = Str.regexp ".*/\\([^/]+\\)\\.k?o\\(\\.xz\\)?$" in
>      let rex_initrd =
>        if family = `Debian_family then
> @@ -156,7 +171,10 @@ let detect_kernels (g : G.guestfs) inspect family bootloader =
>               ) modules in
>               assert (List.length modules > 0);
>  
> -             let supports_virtio = List.mem "virtio_net" modules in
> +             let kernel_supports what kconf =
> +               List.mem what modules || check_config version kconf in
> +
> +             let supports_virtio = kernel_supports "virtio_net" "VIRTIO_NET" in
>               let is_xen_kernel = List.mem "xennet" modules in
>  
>               (* If the package name is like "kernel-debug", then it's
> -- 
> 2.7.4
> 
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