On Tue, Feb 24, 2026 at 10:51:35AM +0000, Teddy Astie wrote: > It's currently possible to build Linux with CONFIG_PVH|CONFIG_XEN_PVHVM > and no CONFIG_XEN_PVH. That leads to inconsistent kernels that fails with > "Missing xen PVH initialization" when booting using PVH boot method or > display various errors and fail to initialize Xen PV drivers when booting > with PVH-GRUB. > > platform_pci_unplug: Xen Platform PCI: unrecognised magic value > ... > # modprobe xen-blkfront > modprobe: ERROR: could not insert 'xen_blkfront': No such device > # modprobe xen-netfront > modprobe: ERROR: could not insert 'xen_netfront': No such device > > When built without CONFIG_XEN_PVH, PVH-specific logic is disabled, hence when > booting with e.g PVH-OVMF, Linux assumes we are a HVM guest, even when we > aren't > actually one (in the "with HVM emulated devices" sense). > > As it is actually possible to boot Xen PVH without CONFIG_PVH; and that most > Xen-related logic exist within CONFIG_XEN_PVHVM; consider PVH guests support > within CONFIG_XEN_PVHVM instead of CONFIG_XEN_PVH.
So the current CONFIG_PVH selection done by CONFIG_XEN_PVH is moot? > Keep CONFIG_XEN_PVH as a shortcut to enable PVH boot, ACPI support and PVHVM. > > Signed-off-by: Teddy Astie <[email protected]> > --- > Cc: Juergen Gross <[email protected]> > Cc: Boris Ostrovsky <[email protected]> > Cc: Oleksandr Tyshchenko <[email protected]> > > A tentative patch, I'm not sure of the way of dealing with the KConfig part, > keeping CONFIG_XEN_PVH as a shortcut is interesting, but there may be other > options. > > There are widespreadly used Linux distributions that have a similar > configuration > to this one, thus exhibit this issue i.e fail to boot. Do you know the underlying cause of not enabling CONFIG_XEN_PVH? Is the default set to n on the defconfig? Or are distros specifically disabling this option on purpose? It seems like a step backwards to merge this into some bigger generic option, we always try to fine-grain as much as possible. Maybe you could introduce XEN_HVM meta option, that selects both PVHVM and PVH? Thanks, Roger.
