FreeBSD Alpha5 amd64 - Citrix Xen 6.2 problem

[Shanker Balan]

On 09-Oct-2013, at 8:06 PM, Mark Felder <feld at FreeBSD.org> wrote:

> On Wed, Oct 9, 2013, at 8:53, Roger Pau Monné wrote:
>> On 09/10/13 13:49, Mark Felder wrote:
>>> On Wed, Oct 9, 2013, at 2:46, Roger Pau Monné wrote:
>>>> On 09/10/13 08:18, Shanker Balan wrote:
>>>>> On 08-Oct-2013, at 9:19 PM, Mark Felder <feld at FreeBSD.org> wrote:
>>>>> 
>>>>>> On Tue, Oct 8, 2013, at 9:45, Josias L.G wrote:
>>>>>>> Problem with Citrix Xen 6.2 and install from ISO. The "solution" was
>>>>>>> remove cd-rom drive from virtual machine. Not possible now with xen
>>>>>>> default in GENERIC kernel.
>>>>>>> Message error: 
>>>>>>> run_interrupt_driven_hooks - still waiting after 300 seconds for
>>>>>>> xenbusb_nop_confighook_cb
>>>>>>> panic: run_interrupt_driven_config_hooks: waited too long
>>>>>>> 
>>>>>> 
>>>>>> I was going to test this soon... but you're right -- you probably can't
>>>>>> install FreeBSD 10 from ISO on Citrix XenServer because of this bug.
>>>>>> 
>>>>>> Can someone working on the xen bits test and maybe find a workaround?
>>>>> 
>>>>> The "xenbusb_nop_confighook_cb" issue is the only issue which I am aware
>>>>> of that prevents CloudStack/XenServer IaaS private clouds from offering
>>>>> FreeBSD 10 as a supported OS template. The "vbd-destroy" workaround is not
>>>>> possible as the ISO is attached to the VM instance during the installation.
>>>>> 
>>>>> A "please pretty please" request to @citrix R&D for the hopefully last fix
>>>>> to get FreeBSD 10 running on XenServer+CloudStack.
>>>>> 
>>>>> The earlier HyperV related panic on XenServer has been fixed in ALPHA5.
>>>> 
>>>> Hello,
>>>> 
>>>> I've taken a look into this and I'm afraid there's no easy way to
>>>> workaround it from FreeBSD. When Xen is detected all IDE devices are
>>>> disconnected, and there's no fine grained way to only disable IDE disks
>>>> and not cdrom devices.
>>>> 
>>>> Could you please contact your XenServer representative, and/or submit
>>>> this bug to xs-devel (xs-devel at lists.xenserver.org) mailing lists in
>>>> order to get this fixed on XenServer.
>>>> 
>>> 
>>> Citrix is aware of this as I've contacted several people there and this
>>> has been discussed both here and on the xs-devel list. There has to be
>>> something FreeBSD can do to work around this issue since Linux and
>>> NetBSD have no issues.
>> 
>> Linux and NetBSD have no issues because you probably only tried them on
>> PV mode, which doesn't exhibit this issue (also NetBSD doesn't have
>> PVHVM support, so it's quite clear it won't have this issue).
>> 
>>> As far as I'm aware the issue has been tracked
>>> down to badly behaving qemu in XenServer -- they don't use upstream qemu
>>> in XenServer (yet), and instead have their own fork. A future release is
>>> supposed to merge with upstream qemu.
>> 
>> The main problem here is that XenServer announces a PV block device on
>> xenstore (the cdrom), but then it seems like there's no backend to
>> handle it, so it hangs on the connection phase. IMHO the problem is not
>> with the device model (Qemu), but with the backend that should handle
>> this PV device.
>> 
>> Xen only allows you to either disable all IDE devices or none, so the
>> only possible solution I can think of is to not disable anything at all
>> and use the emulated devices, which will leave us with very poor
>> performance (unless I'm missing something, there's no way to only
>> disable disks but not cdroms).
>> 
>>> But the fact remains that this is a non-issue on Linux and NetBSD who
>>> handle this buggy virtual CDROM without any problems. There has to be
>>> some way we can add a quirk on our side so this device doesn't stop the
>>> entire boot process. If FreeBSD 10 is released without out-of-the-box
>>> support on the premier commercial Xen platform we'll be shooting
>>> ourselves in the foot and all of this work will be for naught. Amazon
>>> isn't the only Xen platform people use.
>> 
>> You can always use the pre-build VM images I guess (I have not tested
>> those, but I expect they should work fine under Xen).
>> 
>> ftp://ftp.nl.freebsd.org/pub/FreeBSD/snapshots/VM-IMAGES/20131007/10.0-ALPHA5/amd64/
>> 

This is way better. Having ready to import Xen images beats ISO installation
any day. Will try on my cloudstack setup later today.

Thanks.