Re: [Qemu-devel] The first function called after migration for a block device

[Paolo Bonzini]

Il 27/06/2014 21:41, Xiongzi Ge ha scritto:
> When I studied the code, I found in migration.c,
> bdrv_clear_incoming_migration_all();
>
> the cache of the bdrv devices will be deleted.
>
> Is this the one for the functions to be called after migration?
>
> Does the bdrv device need to be reopen or load state in block.c?
>
> I would like to find this function to add my new code.

This function is not going to do anything if your code is in "raw" 
format.  In particular, it has *nothing* to do with the guest OS's 
cache.  That cache is managed by the guest OS and, as I have already 
told you multiple times, there is *nothing* that QEMU can do about it.

All you can do is use O_DIRECT in the guest.

Paolo