On Thu, Apr 15, 2021 at 01:39:37PM +0100, Patrick Welche wrote: > On Thu, Apr 15, 2021 at 07:28:32AM -0400, Brad Spencer wrote: > > Manuel Bouyer <[email protected]> writes: > > > > > On Thu, Apr 15, 2021 at 09:53:50AM +0100, Patrick Welche wrote: > > >> I have tried and failed to run xen on 3 -current/amd64 systems with > > >> 3 different failure modes: > > >> > > >> 1) laptop: xen.gz Building a PV Dom0 / ELF: not an ELF binary -> > > >> panic/reboot > > >> 2) desktop: XEN3_DOM0 panics including PR port-xen/55978 > > >> 3) server: Trampoline space cannot be allocated; will try fallback -> > > >> reboot > > >> > > >> They are all working NetBSD-current/amd64 systems. > > >> > > >> My conclusion was that xen is hopelessly broken, so was quite surprised > > >> by Greg Wood's thread about the finer points of running a guest OS, given > > >> that those systems won't even start the host OS. > > >> > > >> I dug out an old desktop, and to my pleasant surprise it booted > > >> XEN3_DOM0, > > >> and I have managed to run some XEN3_DOMUs. > > >> > > >> The difference between the working/broken setups seems to be that the > > >> working one is "BIOS" booting rather than EFI booting. > > >> > > >> Among all your xen success stories, are any of you EFI booting? > > > > > > AFAIK EFI is not yet supported by Xen (maybe this is supported by 4.15, > > > I've not had a chance to try yet). I have it running on fairly recent > > > Dell servers (in BIOS mode) > > > > > > There has been fiddling with Xen and EFI for quite some time. See: > > > > https://wiki.xenproject.org/wiki/Xen_EFI > > > > for example (might be old)... this indicates that Xen 4.3 or later could > > be built as a EFI binary and probably booted from the EFI firmware > > directly or with grub2 when grub2 is a EFI binary itself. Of course > > those instructions are all Linux-centric and I don't know if you created > > a Xen kernel like this if it would boot a NetBSD DOM0 kernel. I am in > > no position to try any tests with this right now personally, but it is > > tempting as I have a EFI only laptop that I could probably replace the > > hard drive temporarily. > > Looking at > > https://xenproject.org/2021/04/08/xen-project-hypervisor-4-15/ > > (so 4.15 only just came out!) I see > > Unified boot images: It is now possible to create an image bundling > together files needed for Xen to boot into a single EFI binary; > making it now possible to boot a functional Xen system directly > from the EFI boot manager, rather than having to go through grub > multiboot. Files that can be bundled include a hypervisor, dom0 > kernel, dom0 initrd, Xen KConfig, XSM configuration, and a device > tree. > > I thought that "go through grub multiboot" was the equivalent of our > boot.cfg "multiboot /xen.gz dom0_mem=1024M", but apparently not?
It should be; but there are probably differences between BIOS and EFI, even when using multiboot (the way to access the console, or find the ACPI tables, may be different, for example) -- Manuel Bouyer <[email protected]> NetBSD: 26 ans d'experience feront toujours la difference --
