Re: [Qemu-devel] [PATCH v2 04/10] migration: detect compression and decompression errors

[Xiao Guangrong <guangrong.xiao@gmail.com>]

On 03/28/2018 05:59 PM, Peter Xu wrote:
> On Tue, Mar 27, 2018 at 05:10:37PM +0800, guangrong.xiao@gmail.com wrote:
> 
> [...]
> 
>> -static int compress_threads_load_setup(void)
>> +static int compress_threads_load_setup(QEMUFile *f)
>>   {
>>       int i, thread_count;
>>   
>> @@ -2665,6 +2685,7 @@ static int compress_threads_load_setup(void)
>>           }
>>           decomp_param[i].stream.opaque = &decomp_param[i];
>>   
>> +        decomp_param[i].file = f;
> 
> On the source side the error will be set via:
> 
>          qemu_file_set_error(migrate_get_current()->to_dst_file, blen);
> 
> Maybe we can do similar things using migrate_incoming_get_current() to
> avoid caching the QEMUFile multiple times?
> 

I have considered it, however, it can not work as the @file used by ram
loader is not the file got from migrate_incoming_get_current() under some
cases.

For example, in colo_process_incoming_thread(), the file passed to
qemu_loadvm_state() is a internal buffer and it is not easy to switch it
to incoming file.