On 5/14/2025 1:33 PM, Manuel Bouyer wrote: > On Wed, May 14, 2025 at 09:54:35AM -0400, Chuck Zmudzinski wrote: >> Another odd thing I saw with this system (Intel Raptor Lake i5-14500). I >> first installed NetBSD 10.1 as a Xen HVM DomU on Xen 4.19.2 distributed by >> Fedora Linux, with a Fedora 41 Linux PV Dom0 before trying to boot NetBSD PV >> Dom0 on the pkgsrc version of Xen 4.18. In that configuration, the NetBSD >> GENERIC kernel did not detect hypervisor0 at mainbus0, and instead detected >> hyperv0 at cpu0, which would only be valid if the hypervisor was Microsoft >> Hyper-V instead of Xen! It still boots, but it uses the emulated Qemu >> devices for disk and network I/O instead of the Xen PV devices. Perhaps this >> is happening because, according to the information on the NetBSD port-xen >> HOWTO wiki page, some versions of Xen distributed by Linux distros don't >> compile Xen with CONFIG_PV_LINEAR_PT, which is required for NetBSD PV >> support. But I have not checked if Xen 4.19.2 shipped by Fedora is compiled >> without CONFIG_PV_LINEAR_PT. If Fedora's Xen 4.19.2 does have >> CONFIG_PV_LINEAR_PT, though, then something strange is happening on my >> system with Xen because I presume NetBSD/Xen HVM should detect hypervisor0, >> not hyperv0, when running on Xen with the CONFIG_PV_LINEAR_PT option. > > It's not related to CONFIG_PV_LINEAR_PT, it's probably because Viridian > is enabled by defaut. You should be able to disable it on a per-guest basis. >
Ah, yes I think Viridian is a Microsoft thing and I usually have it on for Windows and Linux HVM guests. I will try turning Viridian off for the NetBSD HVM next time I try it.
