RE: UEFI support in ARM DomUs

[Peng Fan <peng.fan@nxp.com>]

Hi Stefano,

> -----Original Message-----
> From: Stefano Stabellini [mailto:sstabellini@kernel.org]
> Sent: 2020年6月4日 23:32
> To: Oleksandr Andrushchenko <Oleksandr_Andrushchenko@epam.com>
> Cc: Peng Fan <peng.fan@nxp.com>; Roman Shaposhnik
> <roman@zededa.com>; Xen-devel <xen-devel@lists.xenproject.org>; Stefano
> Stabellini <sstabellini@kernel.org>; Julien Grall <julien@xen.org>; Nataliya
> Korovkina <malus.brandywine@gmail.com>
> Subject: Re: UEFI support in ARM DomUs
> 
> On Thu, 4 Jun 2020, Oleksandr Andrushchenko wrote:
> > On 6/4/20 4:57 AM, Peng Fan wrote:
> > > Grall <julien@xen.org>;
> > >> Nataliya Korovkina <malus.brandywine@gmail.com>
> > >> Subject: UEFI support in ARM DomUs
> > > We have made U-Boot run inside XEN DomU, but just only PV console
> > > part, not implement other frontend drivers currently. Would this
> > > help for your case if enable EFI in U-Boot?
> >
> > Well, we have a working PV block implementation on top of that on iMX8
> >
> > platform, mostly ported from mini-os. Currently we are finalizing the
> > work
> >
> > and cleaning up (it's going to take a week or so hopefully). Then, we
> > we'll post
> >
> > it on our public github. We are also thinking about upstreaming the
> > work, but it may
> >
> > take quite some time if the whole idea fits u-boot's view on such an
> extension at all.
> 
> Yes please to both of you! :-)

The simple console part

https://source.codeaurora.org/external/imx/uboot-imx/tree/drivers/serial/serial_xen.c?h=imx_v2020.04_5.4.24_2.1.0

We enable U-Boot in DomU is mostly for android auto dual bootloader case.

It has the issue that only have console output after mmu enabled in U-Boot stage.

Regards,
Peng.

> 
> In the meantime, while we wait for those changes to go upstream in uboot,
> could you please post a branch on github and a link on this email thread?
> 
> Maybe we should have a wikipage on wiki.xenproject.org about
> work-in-progress uboot items.
> 
> 
> 
> 
> > > Regards,
> > > Peng.
> > >
> > >> Hi!
> > >>
> > >> with a lot of help from Stefano, we're getting RPi4 support in
> > >> Project EVE pretty much on par between KVM and Xen.
> > >>
> > >> One big area that still remains is supporting UEFI boot sequence for
> DomUs.
> > >> With KVM, given the qemu virt device model this is as simple as
> > >> using either stock UEFI build for arm or even U-Boot EFI emulation
> > >> environment and passing it via -bios option.
> > >>
> > >> Obviously with Xen on ARM we don't have the device model so my
> > >> understanding is that the easiest way we can support it would be to
> > >> port UEFI's OvmfPkg/OvmfXen target to ARM (it seems to be currently
> > >> exclusively X64).
> > >>
> > >> So here's my first question: if there's anybody on this list who
> > >> had a hand in implementing OvmfPkg/OvmfXen can you please share
> > >> your thoughts on how much work that port may be (or whether it is
> > >> even feasible -- I may totally be missing something really obvious here).
> > >>
> > >> And as long as I've got your attention: two more questions:
> > >>     1.. compared to the above, would porting pvgrub to ARM be any
> > >>     easier or more difficult?
> > >>
> > >>     2. same question for teaching u-boot about PV calls.
> > >>
> > >> Thanks,
> > >> Roman.
> > >>
> > >> P.S. Oh and I guess between:
> > >>     0. OvmfPkg/OvmfXen on ARM64
> > >>     1. pvgrub on ARM64
> > >>     2. u-boot/EFI emulation with PV calls backend I didn't miss any
> > >> other obvious way of making UEFI-aware VM images to boot on Xen
> > >> ARM64 DomU, right?