Re: UEFI support in ARM DomUs

From: Stefano Stabellini <sstabellini@kernel.org>
To: Oleksandr Andrushchenko <Oleksandr_Andrushchenko@epam.com>
Cc: Peng Fan <peng.fan@nxp.com>,
	Stefano Stabellini <sstabellini@kernel.org>,
	Julien Grall <julien@xen.org>,
	Roman Shaposhnik <roman@zededa.com>,
	Nataliya Korovkina <malus.brandywine@gmail.com>,
	Xen-devel <xen-devel@lists.xenproject.org>
Subject: Re: UEFI support in ARM DomUs
Date: Thu, 4 Jun 2020 08:31:34 -0700 (PDT)	[thread overview]
Message-ID: <alpine.DEB.2.21.2006040829390.6774@sstabellini-ThinkPad-T480s> (raw)
In-Reply-To: <c3856c1f-52bf-92fd-5226-4b09229e2127@epam.com>

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! :-)

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?