Re: [PATCH] [RFC][PATCH] kvm: kvmtrace: kvmtrace_format for supporting big_endian

[Avi Kivity <avi@qumranet.com>]

Tan, Li wrote:
> From 9d39264bdfb00a1a717074e486a948a578547c50 Mon Sep 17 00:00:00 2001
> From: Tan Li <li.tan@intel.com>
> Date: Tue, 20 May 2008 09:14:41 +0800
> Subject: [PATCH] [RFC][PATCH] kvm: kvmtrace: kvmtrace_format for
> supporting big_endian
>
> Currently kvmtrace is not portable, and prevent from copying a trace
> file from big-endian target to little-endian workstation for analysis.
>
> In the patch, kvmtrace_format reads and checks the magic number from
> trace log. if needed, then change bytes order of all fields in records
> followed.
>
>  
> +def reverse_bytes(origin, bytes_cnt):
> +	i = 0
> +	rtn = 0L
> +	while i < bytes_cnt:
> +		i = i + 1
> +	        b = origin & 0xff
> +		origin = origin >> 8
> +		rtn = (rtn << 8) + b
> +	return rtn
> +
> +def reverse_int(origin):
> +	return reverse_bytes(origin, 4)
> +
> +def reverse_qword(origin):
> +	return reverse_bytes(origin, 8)
> +
>  def sighand(x,y):
>      global interrupted
>      interrupted = 1
> @@ -100,18 +116,40 @@ D2REC  = "II"
>  D3REC  = "III"
>  D4REC  = "IIII"
>  D5REC  = "IIIII"
> +KMAGIC  = "I"
>   

The python struct module supports reading big-endian and little-endian 
data.  So you can simply switch the format strings if you have the wrong 
endianness.

-- 
error compiling committee.c: too many arguments to function