From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kaushik Bhandankar Subject: Pending Disk io requests during live migration Date: Thu, 04 Oct 2007 00:10:50 -0400 Message-ID: <470467CA.4090808@cc.gatech.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org 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