Re: Pending Disk io requests during live migration

[Kaushik Bhandankar <kaushikb@cc.gatech.edu>]

one modification:

register_savevm() in tools/ioemu/vl.c is simply used to register the 
save & load routines......... register_savevm() is called in 
tools/ioemu/hw/ide.c:pci_piix_ide_init to register pci_ide_save() and 
pci_ide_load() as the save & load routines for IDE disks.......

But I am still unsure as to where these save/load routines for IDE disks 
get invoked....

Kaushik Bhandankar wrote:
> Hello
>
> I am trying to implement functionality in fully-virtualized xen 
> wherein the responses to the pending disk I/O requests during live VM 
> migration get trasnsferred to the new VMM form the old VMM. 
> Specifically, I am looking at IDE disk (tools/ioemu/hw/ide.c)
>
> Basically, ide.c:pci_ide_save() saves the state of the IDE disk in a 
> QEMUFile and this file is sent over the network (can somebody point me 
> to the code where this happens ??)) so that the new VMM (where the VM 
> has migrated) invokes ide.c:pci_ide_load() to retrieve the IDE Disk 
> contents form the file. As of now, the pending disk I/O requests do 
> not get saved in this file so these pending disk I/O requests are not 
> available when executing pci_ide_load().
>
> I am still trying to figure out where the pending Disk I/O requests 
> get stored in the VMM so that during live VM migration, these requests 
> can be put in the QEMUFile (As mentioned above)
>
> Also, looks like tools/ioemu/vl.c:register_savevm() seems to be 
> invoking pci_ide_save()/pci_ide_load() methods but I am still looking 
> for all possible scenarios in which pci_ide_save()/pci_ide_load() gets 
> invoked.
>
> Any help in locating the code would be greatly appreciated.
>
> -Kaushik
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel