Libguestfs - Apr 2014 - [supermin] Be smarter about finding suitable kernel images and device trees

* Richard W.M. Jones:
> On Sat, Apr 26, 2014 at 02:27:07PM +0200, Hilko Bengen wrote:
>> ---
>>  src/kernel.ml | 43 ++++++++++++++++++++++++++++---------------
>>  1 file changed, 28 insertions(+), 15 deletions(-)
>> 
>> diff --git a/src/kernel.ml b/src/kernel.ml
>> index ed5aea3..436b1b0 100644
>> --- a/src/kernel.ml
>> +++ b/src/kernel.ml
>> @@ -23,6 +23,19 @@ open Utils
>>  open Ext2fs
>>  open Fnmatch
>>  
>> +let patt_of_cpu host_cpu >> +  let models >> +    match
host_cpu with
>> +    | "mips" | "mips64" -> [host_cpu;
"*-malta"]
>> +    | "ppc" | "powerpc" -> ["ppc";
"powerpc"]
looks like I missed powerpc64.
>> +    | "sparc" | "sparc64" ->
["sparc"; "sparc64"]
>> +    | "amd64" | "x86_64" -> ["amd64";
"x86_64"]
>> +    | _ when host_cpu.[0] = 'i' && host_cpu.[2] =
'8' && host_cpu.[3] = '6' -> ["?86"]
>> +    | _ when String.sub host_cpu 0 5 = "armv7" -> 
["armmp"]
This fails on short strings.

I have fixed those and added a fix so that device trees can be found on
Debian.

Cheers,
-Hilko

---
 src/kernel.ml | 58 ++++++++++++++++++++++++++++++++++++++--------------------
 1 file changed, 38 insertions(+), 20 deletions(-)

diff --git a/src/kernel.ml b/src/kernel.ml
index ed5aea3..7076aa5 100644
--- a/src/kernel.ml
+++ b/src/kernel.ml
@@ -23,6 +23,19 @@ open Utils
 open Ext2fs
 open Fnmatch
 
+let patt_of_cpu host_cpu +  let models +    match host_cpu with
+    | "mips" | "mips64" -> [host_cpu;
"*-malta"]
+    | "ppc" | "powerpc" -> ["ppc";
"powerpc"; "powerpc64"]
+    | "sparc" | "sparc64" -> ["sparc";
"sparc64"]
+    | "amd64" | "x86_64" -> ["amd64";
"x86_64"]
+    | _ when host_cpu.[0] = 'i' && host_cpu.[2] = '8'
&& host_cpu.[3] = '6' -> ["?86"]
+    | _ when String.length host_cpu >= 5 && String.sub host_cpu 0 5
= "armv7" ->  ["armmp"]
+    | _ -> [host_cpu]
+  in
+  List.map (fun model -> sprintf "vmlinu?-*-%s" model) models
+
 let rec build_kernel debug host_cpu dtb_wildcard copy_kernel kernel dtb    (*
Locate the kernel. *)
   let kernel_name, kernel_version @@ -59,9 +72,6 @@ and find_kernel debug
host_cpu copy_kernel kernel        let kernel_name = Filename.basename
kernel_env in
       kernel_env, kernel_name, kernel_version
     with Not_found ->
-      let is_x86 -        String.length host_cpu = 4 &&
-        host_cpu.[0] = 'i' && host_cpu.[2] = '8'
&& host_cpu.[3] = '6' in
       let is_arm          String.length host_cpu >= 3 &&
         host_cpu.[0] = 'a' && host_cpu.[1] = 'r'
&& host_cpu.[2] = 'm' in
@@ -70,18 +80,16 @@ and find_kernel debug host_cpu copy_kernel kernel        let
all_files = Array.to_list all_files in
 
       (* In original: ls -1dvr /boot/vmlinuz-*.$arch* 2>/dev/null | grep -v
xen *)
-      let patt -        if is_x86 then "vmlinuz-*.i?86*"
-        else "vmlinuz-*." ^ host_cpu ^ "*" in
-      let files = kernel_filter patt is_arm all_files in
+      let patterns = patt_of_cpu host_cpu in
+      let files = kernel_filter patterns is_arm all_files in
 
       let files          if files <> [] then files
         else
           (* In original: ls -1dvr /boot/vmlinuz-* 2>/dev/null | grep -v xen
*)
-          kernel_filter "vmlinuz-*" is_arm all_files in
+          kernel_filter ["vmlinu?-*"] is_arm all_files in
 
-      if files = [] then no_kernels ();
+      if files = [] then no_kernels host_cpu;
 
       let files = List.sort (fun a b -> compare_version b a) files in
       let kernel_name = List.hd files in
@@ -95,10 +103,13 @@ and find_kernel debug host_cpu copy_kernel kernel   
copy_or_symlink_file copy_kernel kernel_file kernel;
   kernel_name, kernel_version
 
-and kernel_filter patt is_arm all_files +and kernel_filter patterns is_arm
all_files    let files      List.filter
-      (fun filename -> fnmatch patt filename [FNM_NOESCAPE]) all_files in
+      (fun filename ->
+        List.exists
+          (fun patt -> fnmatch patt filename [FNM_NOESCAPE]) patterns
+      ) all_files in
   let files      List.filter (fun filename -> find filename "xen"
= -1) files in
   let files @@ -110,15 +121,16 @@ and kernel_filter patt is_arm all_files     
) in
   List.filter (fun filename -> has_modpath filename) files
 
-and no_kernels () +and no_kernels host_cpu    eprintf "\
-supermin: failed to find a suitable kernel.
+supermin: failed to find a suitable kernel (host_cpu=%s).
 
 I looked for kernels in /boot and modules in /lib/modules.
 
 If this is a Xen guest, and you only have Xen domU kernels
 installed, try installing a fullvirt kernel (only for
-supermin use, you shouldn't boot the Xen guest with it).\n";
+supermin use, you shouldn't boot the Xen guest with it).\n"
+    host_cpu;
   exit 1
 
 and find_dtb debug copy_kernel kernel_name wildcard dtb @@ -131,13 +143,18 @@
and find_dtb debug copy_kernel kernel_name wildcard dtb        dtb_file
     with Not_found ->
       (* Replace vmlinuz- with dtb- *)
-      if not (string_prefix "vmlinuz-" kernel_name) then
+      if not (string_prefix "vmlinuz-" kernel_name) &&
+        not (string_prefix "vmlinuz-" kernel_name) then
         no_dtb_dir kernel_name;
       let dtb_dir -        "/boot/dtb-" ^
-          String.sub kernel_name 8 (String.length kernel_name - 8) in
-      if not (dir_exists dtb_dir) then
-        no_dtb_dir kernel_name;
+        try
+          List.find dir_exists (
+            List.map (fun prefix ->
+              prefix ^ String.sub kernel_name 8 (String.length kernel_name - 8)
+            ) ["/boot/dtb-"; "/usr/lib/linux-image-"])
+        with Not_found ->
+          no_dtb_dir kernel_name; ""
+      in
 
       let all_files = Sys.readdir dtb_dir in
       let all_files = Array.to_list all_files in
@@ -200,7 +217,8 @@ and has_modpath kernel_name    | Not_found -> false
 
 and get_kernel_version kernel_name -  if string_prefix "vmlinuz-"
kernel_name then (
+  if (string_prefix "vmlinuz-" kernel_name) ||
+    (string_prefix "vmlinux-" kernel_name) then (
     let kv = String.sub kernel_name 8 (String.length kernel_name - 8) in
     if modules_dep_exists kv then kv
     else get_kernel_version_from_name kernel_name
-- 
2.0.0.rc0

On Mon, Apr 28, 2014 at 09:21:33PM +0200, Hilko Bengen
wrote:
> ---
>  src/kernel.ml | 58
++++++++++++++++++++++++++++++++++++++--------------------
>  1 file changed, 38 insertions(+), 20 deletions(-)
> 
> diff --git a/src/kernel.ml b/src/kernel.ml
> index ed5aea3..7076aa5 100644
> --- a/src/kernel.ml
> +++ b/src/kernel.ml
> @@ -23,6 +23,19 @@ open Utils
>  open Ext2fs
>  open Fnmatch
>  
> +let patt_of_cpu host_cpu > +  let models > +    match host_cpu with
> +    | "mips" | "mips64" -> [host_cpu;
"*-malta"]
> +    | "ppc" | "powerpc" -> ["ppc";
"powerpc"; "powerpc64"]
> +    | "sparc" | "sparc64" -> ["sparc";
"sparc64"]
> +    | "amd64" | "x86_64" -> ["amd64";
"x86_64"]
> +    | _ when host_cpu.[0] = 'i' && host_cpu.[2] =
'8' && host_cpu.[3] = '6' -> ["?86"]
> +    | _ when String.length host_cpu >= 5 && String.sub host_cpu
0 5 = "armv7" ->  ["armmp"]
> +    | _ -> [host_cpu]
> +  in
> +  List.map (fun model -> sprintf "vmlinu?-*-%s" model) models
> +
>  let rec build_kernel debug host_cpu dtb_wildcard copy_kernel kernel dtb
>    (* Locate the kernel. *)
>    let kernel_name, kernel_version > @@ -59,9 +72,6 @@ and find_kernel
debug host_cpu copy_kernel kernel >        let kernel_name =
Filename.basename kernel_env in
>        kernel_env, kernel_name, kernel_version
>      with Not_found ->
> -      let is_x86 > -        String.length host_cpu = 4 &&
> -        host_cpu.[0] = 'i' && host_cpu.[2] = '8'
&& host_cpu.[3] = '6' in
>        let is_arm >          String.length host_cpu >= 3 &&
>          host_cpu.[0] = 'a' && host_cpu.[1] = 'r'
&& host_cpu.[2] = 'm' in
> @@ -70,18 +80,16 @@ and find_kernel debug host_cpu copy_kernel kernel > 
let all_files = Array.to_list all_files in
>  
>        (* In original: ls -1dvr /boot/vmlinuz-*.$arch* 2>/dev/null |
grep -v xen *)
> -      let patt > -        if is_x86 then "vmlinuz-*.i?86*"
> -        else "vmlinuz-*." ^ host_cpu ^ "*" in
> -      let files = kernel_filter patt is_arm all_files in
> +      let patterns = patt_of_cpu host_cpu in
> +      let files = kernel_filter patterns is_arm all_files in
>  
>        let files >          if files <> [] then files
>          else
>            (* In original: ls -1dvr /boot/vmlinuz-* 2>/dev/null | grep
-v xen *)
> -          kernel_filter "vmlinuz-*" is_arm all_files in
> +          kernel_filter ["vmlinu?-*"] is_arm all_files in
>  
> -      if files = [] then no_kernels ();
> +      if files = [] then no_kernels host_cpu;
>  
>        let files = List.sort (fun a b -> compare_version b a) files in
>        let kernel_name = List.hd files in
> @@ -95,10 +103,13 @@ and find_kernel debug host_cpu copy_kernel kernel >
copy_or_symlink_file copy_kernel kernel_file kernel;
>    kernel_name, kernel_version
>  
> -and kernel_filter patt is_arm all_files > +and kernel_filter patterns
is_arm all_files >    let files >      List.filter
> -      (fun filename -> fnmatch patt filename [FNM_NOESCAPE]) all_files
in
> +      (fun filename ->
> +        List.exists
> +          (fun patt -> fnmatch patt filename [FNM_NOESCAPE]) patterns
> +      ) all_files in
>    let files >      List.filter (fun filename -> find filename
"xen" = -1) files in
>    let files > @@ -110,15 +121,16 @@ and kernel_filter patt is_arm
all_files >      ) in
>    List.filter (fun filename -> has_modpath filename) files
>  
> -and no_kernels () > +and no_kernels host_cpu >    eprintf "\
> -supermin: failed to find a suitable kernel.
> +supermin: failed to find a suitable kernel (host_cpu=%s).
>  
>  I looked for kernels in /boot and modules in /lib/modules.
>  
>  If this is a Xen guest, and you only have Xen domU kernels
>  installed, try installing a fullvirt kernel (only for
> -supermin use, you shouldn't boot the Xen guest with it).\n";
> +supermin use, you shouldn't boot the Xen guest with it).\n"
> +    host_cpu;
>    exit 1
>  
>  and find_dtb debug copy_kernel kernel_name wildcard dtb > @@ -131,13
+143,18 @@ and find_dtb debug copy_kernel kernel_name wildcard dtb >       
dtb_file
>      with Not_found ->
>        (* Replace vmlinuz- with dtb- *)
> -      if not (string_prefix "vmlinuz-" kernel_name) then
> +      if not (string_prefix "vmlinuz-" kernel_name) &&
> +        not (string_prefix "vmlinuz-" kernel_name) then
>          no_dtb_dir kernel_name;
>        let dtb_dir > -        "/boot/dtb-" ^
> -          String.sub kernel_name 8 (String.length kernel_name - 8) in
> -      if not (dir_exists dtb_dir) then
> -        no_dtb_dir kernel_name;
> +        try
> +          List.find dir_exists (
> +            List.map (fun prefix ->
> +              prefix ^ String.sub kernel_name 8 (String.length kernel_name
- 8)
> +            ) ["/boot/dtb-"; "/usr/lib/linux-image-"])
> +        with Not_found ->
> +          no_dtb_dir kernel_name; ""
> +      in
>  
>        let all_files = Sys.readdir dtb_dir in
>        let all_files = Array.to_list all_files in
> @@ -200,7 +217,8 @@ and has_modpath kernel_name >    | Not_found ->
false
>  
>  and get_kernel_version kernel_name > -  if string_prefix
"vmlinuz-" kernel_name then (
> +  if (string_prefix "vmlinuz-" kernel_name) ||
> +    (string_prefix "vmlinux-" kernel_name) then (
>      let kv = String.sub kernel_name 8 (String.length kernel_name - 8) in
>      if modules_dep_exists kv then kv
>      else get_kernel_version_from_name kernel_name
ACK.

Thanks,

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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