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

When checking whether a kernel supports virtio or it is Xen-based, it is assumed that the feature has the kernel module for it; this will fail if the feature is built-in in the kernel, misrepresenting it. The solution is to check the kernel configuration (/boot/config-$kver) whether the feature is built-in, in case there is no module available. This fixes the virtio detection on Ubuntu kernels, where virtio is built in and not as module. --- v2v/linux_kernels.ml | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/v2v/linux_kernels.ml b/v2v/linux_kernels.ml index b292921..c197f78 100644 --- a/v2v/linux_kernels.ml +++ b/v2v/linux_kernels.ml @@ -53,6 +53,21 @@ let detect_kernels (g : G.guestfs) inspect family bootloader = (* What kernel/kernel-like packages are installed on the current guest? *) let installed_kernels : kernel_info list = let rex_ko = Str.regexp ".*\\.k?o\\(\\.xz\\)?$" 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 + 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