CVSROOT: /cvs
Module name: src
Changes by: [email protected] 2026/10/09 09:42:51
Modified files:
usr.sbin/vmd : x86_vm.c
Log message:
vmd(8): add extra mmio region
this adds a no-op (reads return FFs, writes discarded) mmio region between the
end of guest RAM and 4GB. specifically recent i686 linux bootloaders/kernels do
what appear to be errant probes of high PAs in the > 0xc0000000 range, and
vmd treats all mmio accesses to unmapped regions as fatal.
this diff adds a region to cover any gap, such that accesses to those addresses
trap to vmd, which then does what real hw would do. other hypervisors do
similar things.
this allieviates the need to assign 4GB ram to these VMs which was previously
needed to work around the problem.
ok dv
