> -----Original Message----- > From: Greg KH [mailto:greg@xxxxxxxxx] > Sent: Tuesday, August 30, 2011 1:44 PM > To: KY Srinivasan > Cc: Olaf Hering; devel@xxxxxxxxxxxxxxxxxxxxxx; gregkh@xxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; virtualization@xxxxxxxxxxxxxx > Subject: Re: [PATCH 0000/0046] Staging: hv: Driver cleanup > > On Tue, Aug 30, 2011 at 05:22:54PM +0000, KY Srinivasan wrote: > > > > > > > -----Original Message----- > > > From: Olaf Hering [mailto:olaf@xxxxxxxxx] > > > Sent: Tuesday, August 30, 2011 8:49 AM > > > To: KY Srinivasan > > > Cc: gregkh@xxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > > > devel@xxxxxxxxxxxxxxxxxxxxxx; virtualization@xxxxxxxxxxxxxx > > > Subject: Re: [PATCH 0000/0046] Staging: hv: Driver cleanup > > > > > > On Sat, Aug 27, K. Y. Srinivasan wrote: > > > > > > > 2) Handle all block devices using the storvsc driver. I have modified > > > > the implementation here based on Christoph's feedback on my earlier > > > > implementation. > > > > > > The upgrade path from hv_blkvsc to hv_storvsc is difficult. > > > > > > hv_storvsc does not provide the vmbus:hv_block modalias, so mkinitrd > > > does not know what module to choose when mkinitrd is called in a > > > previous kernel (like sles11sp1). > > > > > > > > > In a guest with both SCSI and IDE controllers the IDE disks are > > > discovered first, so the SCSI drives will also change their names. > > > Thats not a problem for data partitions because they could be mounted by > > > UUID or LABEL in fstab. > > > But its difficult to adjust /boot/grub/device.map for example because > > > the old IDE drives do not provide an identifier. What is the best way > > > to make sure the rename from hd* to sd* in such config files is done > > > correctly? Is it safe to assume that all drives with a class_id of > > > 32412632-86cb-44a2-9b5c50d1417354f5 are connected to IDE ports? > > > > The class_id is invariant as we are returning the guid of the device under > class_id. > > > > So, if you see a IDE guid under class_id, you can be sure (a) it is an ide device > and (b) > > it is a device managed via the PV drivers. > > > > > > > > localhost:~ # head /sys/bus/vmbus/devices/vmbus_0_{1,2,3,10,11}/class_id > > > ==> /sys/bus/vmbus/devices/vmbus_0_1/class_id <== > > > {32412632-86cb-44a2-9b5c50d1417354f5} > > > > > > ==> /sys/bus/vmbus/devices/vmbus_0_2/class_id <== > > > {32412632-86cb-44a2-9b5c50d1417354f5} > > > > > > ==> /sys/bus/vmbus/devices/vmbus_0_3/class_id <== > > > {32412632-86cb-44a2-9b5c50d1417354f5} > > > > > > ==> /sys/bus/vmbus/devices/vmbus_0_10/class_id <== > > > {ba6163d9-04a1-4d29-b60572e2ffb1dc7f} > > > > > > ==> /sys/bus/vmbus/devices/vmbus_0_11/class_id <== > > > {ba6163d9-04a1-4d29-b60572e2ffb1dc7f} > > > > > > > > > In my test system, the IDE drives are now discovered twice, once by > > > hv_storvsc and once by libata: > > > > This is a known (old problem). The way this was handled earlier was to have the > > modprobe rules in place to setup a dependency that would force the load of > the > > hyper-v driver (blk / stor) ahead of the native driver and if the load of the PV > > driver succeeded, we would not load the native driver. In sles11 sp1, we had a > rule for > > loading blkvsc. With the merge of blkvsc and storvsc, the only change we need > to make > > is to have storvsc in the rule (instaed of blkvsc). > > Why do we need a rule at all? Shouldn't the module dependancy stuff > handle the autoloading of the drivers properly from the initrd now that > the hotplug logic is hooked up properly? > > What am I missing here? On sles11 the PV drivers are used to manage the root device. Autoloading is not the issue here; to manage the root device, we want to load the Hyper-V disk driver before the native Linux disk driver for the emulated IDE device. > > Or is the hotplug code not working correctly? Hotplug code is working as expected; the issue is taking control of the root device and preventing the same device being presented once through native drivers and once through Hyper-V drivers. Regards, K. Y > > greg k-h _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
