Xen project Mailing List

Not entirely clear what you're asking ...

Ok, I will try to explain myself. As far as I have been trying, my (Ubuntu's default) grub setup is configured to load via multiboot either the gz or the efi files of the xen hypervisor:

menuentry 'Ubuntu GNU/Linux, with the Xen hipervisor' ... {

...

multiboot /boot/xen-4.9-amd64.gz placeholder ${xen_rm_opts}

...

}

...

menuentry 'Ubuntu GNU/Linux, with Xen 4.9-amd64.efi y Linux 4.15.0-45-generic' ... {

...

multiboot /boot/xen-4.9-amd64.efi placeholder ${xen_rm_opts}

...

}

With both these menuentries I get a frozen system right after the grub menu. The first one gets stuck at 'Loading initial ramdisk', with the system not responding to anything and having to hold the power button. With the second one, the xen hypervisor refuses to load because of a magic number mismatch and lets me push any button to go back to the grub menu.

I believe the problem is that multiboot does not support enough parameters to load Xen, and multiboot2 should be used for that. As I can't seem to find some kind of automated way of configuring grub in Ubuntu to use multiboot2 I switched to the other way the wiki suggests to boot the hypervisor: using the EFI bootloader directly: one entry to boot Xen with the Ubuntu kernel as dom0 and another one for grub and Ubuntu without Xen:

$ efibootmgr -v

BootCurrent: 0004
Timeout: 1 seconds
BootOrder: 0004,0002,0000
Boot0000* Windows Boot Manager    VenHw(99e275e7-75a0-4b37-a2e6-c5385e6c00cb)WINDOWS.........x...B.C.D.O.B.J.E.C.T.=.{.9.d.e.a.8.6.2.c.-.5.c.d.d.-.4.e.7.0.-.a.c.c.1.-.f.3.2.b.3.4.4.d.4.7.9.5.}...\a...............
Boot0002* Xen    HD(1,GPT,097131f3-90b4-42f9-b35e-e25f7aac17e2,0x800,0x100000)/File(\EFI\XEN\XEN.EFI)
Boot0004* ubuntu    HD(1,GPT,097131f3-90b4-42f9-b35e-e25f7aac17e2,0x800,0x100000)/File(\EFI\UBUNTU\SHIMX64.EFI)

So entry 0004 is the one I am using to boot Ubuntu, while 0002 hangs with the issue I described in my first mail: blank screen, no boot information printed (I understand now it would be sent over a serial interface if I had one) and ending up in a blank screen with a white blinking cursor in the top left corner.

That's why I asked about your grub configuration to load Xen: are you using your default distro's config? Is it multiboot or multiboot2? Does it boot the gz image or the efi file?

Thank you very much for your answers.

Re: [Xen-users] EFI boot unsuccessful with Ubuntu 18.04 dom0