Help needed with running on Xen PV

[Costin Lupu]

Hi guys,

I'm trying to run OsV on Xen as PV, but unfortunately it doesn't seem to
step over the first instruction without crashing, so I suspect it may be
something wrong with the build.

The app I'm running is native-example with the following command:
$ ./scripts/build -j16 fs=rofs image=native-example

For running I use the following command:
$ ./scripts/run.py --hypervisor xenpv --novnc

I did some debugging, but without any success.
So my questions are the following:
1. What's the status of XenPV?
2. Where can I find some pointers/documentation/etc in order to run a
simple example?

Thanks,
Costin

[Waldek Kozaczuk]

Hi,

Unfortunately, I have not tested OSv on Xen for a while now. Last time (1-2 years ago) I was able to run OSv on EC2 Xen instance.

Could you please provide more specifics regarding Ubuntu host and XEN version? 

I also wonder if you are experiencing the same issue as described here - https://github.com/cloudius-systems/osv/issues/345#issuecomment-629468453. So maybe commenting out xenplatform_pci line in arch_init_drivers:arch-setup.cc might help in your case as well. As I am pointing in that issue it would be nice to get to the bottom of it.

Waldek

[Costin Lupu]

Hi Waldek,

Thanks for your reply. I investigated this a bit more and from what I understand OSv doesn't seem to have full PV support for x86, meaning that only the PV drivers are used. Therefore OSv runs as HVM + PV drivers on Xen for x86_64. What I needed was to be able to run OSv as full PV guest on Xen, but this would require non trivial changes.

Cheers,

Costin