On Thu, 27 Mar 2025 11:12:24 +0000 (GMT), Stephen Borrill <netbsd%precedence.co.uk@localhost> said:
On Thu, 27 Mar 2025, Manuel Bouyer wrote:
[...]
So my guess is that it's failing in xen_init_hypercall_page(),
when doing:
wrmsr(descs[1], (uintptr_t)&hypercall_page - KERNBASE);
this means that when booting in this mode, the Xen interfaces are not
available to the guest.
IIRC there were two mechanisms to access Xen - one that was primarily
used with PV mode (a shared table of info/trampoline code) and a more
structured path for PVH iirc.
Again, pretty vague comments from dated memory.