qemuarm64, genericarm64 and selftests (was Re: [OE-core] [PATCH v2] oeqa selftest: read qemu options from TEST_RUNQEMUPARAMS )

[Mikko Rapeli <mikko.rapeli@linaro.org>]

Hi,

On Tue, May 20, 2025 at 01:24:41PM +0000, Ross Burton wrote:
> On 20 May 2025, at 14:17, Mikko Rapeli via lists.openembedded.org <mikko.rapeli=linaro.org@lists.openembedded.org> wrote:
> > 
> > There are a few more but really, genericarm64 should IMO replace qemuarm64
> > since both run qemu and former also runs on various other boards and is
> > a good start for developing products on arm64/aarch64.
> 
> There’s quite a large conceptual gap between the two: qemuarm64 is a machine that is explicitly and specifically for booting inside a qemu, ideally with KVM.  genericarm64 has a much wider scope, assumes SystemReady firmware and real hardware.

qemuarm64 does have a bit odd kernel config, IMO, for pure KVM support.

And does the qemu-boot-with-KVM support really need a full machine config,
or could genericarm64 kernel and optimized images be sufficient?
For example include an initrd with plain KVM and rootfs storage backend
support, nothing generic.

We've used qemuarm64 and meta-arm side qemuarm64-secureboot machines
for userspace on a number of boards and setups without issues
but rolled out custom BSP, usually just kernel config and initrd.
genericarm64 easily replaces these. These then required a separate
build of the SystemReady firmware or support from board vendors
which frequently is there already.

> There’s also a case to be made for merging sbsa-ref (from meta-arm) and qemuarm64, but again I’d suggest not: sbsa-ref explicitly can’t do KVM whereas qemuarm64 can.  From a performance-of-testing-userspace perspective, this is an important distinction.

Thanks, I've been wondering what that machine was for.

Now back to the selftests and genericarm64. Does it make sense
to you to fix oe-core selftests to work on genericarm64?

If yes, how should the qemu firmware dependency to u-boot
be filled. Manually per build via local.conf or bitbake
command line to also build u-boot? Or something else?

Cheers,

-Mikko