Re: [kvm-unit-tests PATCH v3 00/10] arm64: EL2 support

[Joey Gouly <joey.gouly@arm.com>]

On Thu, Nov 27, 2025 at 11:04:43AM +0100, Eric Auger wrote:
> Hi Joey,
> 
> On 9/25/25 4:19 PM, Joey Gouly wrote:
> > Hi all,
> >
> > This series is for adding support to running the kvm-unit-tests at EL2. These
> > have been tested with Linux 6.17-rc6 KVM nested virt.
> >
> > This latest round I also tested using the run_tests.sh script with QEMU TCG,
> > running at EL2.
> >
> > The goal is to later extend and add new tests for Nested Virtualisation,
> > however they should also work with bare metal as well.
> >
> > Changes since v2[1]:
> > 	- Move the sctlr setup in EFI to a function.
> > 	- Decided to not re-use el2_setup.h from Linux, looked more
> > 	  complicated to use than needed for KUT.
> > 	- Add EL2 env variable for testing, open to feedback for that.
> > 	  This was untested with kvmtool as my testing setup only has
> > 	  busybox ash currently, and the run_tests.sh script needs bash.
> >
> > Issues (that I think are fine to investigate/fix later):
> > 	- Some of the debug tests fail with QEMU at EL2 and kvmtool.
> > 	- The gic ipi test times out with QEMU at EL2, but works with kvmtool.
> 
> Have you noticed any failure with migration tests. On my end, as soon as
> I set EL2=1 migration tests do fail.

Yes migration also fails here, forgot to mention that.

Seems like migration completes, but then something bad happens on the first
interrupt. I will investigate a bit now and see if it's an easy fix.

Thanks,
Joey

> 
> Eric
> >
> > Thanks,
> > Joey
> >
> > [1] https://lore.kernel.org/kvmarm/20250529135557.2439500-1-joey.gouly@arm.com/
> >
> > Alexandru Elisei (2):
> >   arm64: micro-bench: use smc when at EL2
> >   arm64: selftest: update test for running at EL2
> >
> > Joey Gouly (8):
> >   arm64: drop to EL1 if booted at EL2
> >   arm64: efi: initialise SCTLR_ELx fully
> >   arm64: efi: initialise the EL
> >   arm64: timer: use hypervisor timers when at EL2
> >   arm64: micro-bench: fix timer IRQ
> >   arm64: pmu: count EL2 cycles
> >   arm64: run at EL2 if supported
> >   arm64: add EL2 environment variable
> >
> >  arm/cstart64.S             | 56 ++++++++++++++++++++++++++++++++++++--
> >  arm/efi/crt0-efi-aarch64.S |  5 ++++
> >  arm/micro-bench.c          | 26 ++++++++++++++++--
> >  arm/pmu.c                  | 13 ++++++---
> >  arm/run                    |  7 +++++
> >  arm/selftest.c             | 18 ++++++++----
> >  arm/timer.c                | 10 +++++--
> >  lib/acpi.h                 |  2 ++
> >  lib/arm/asm/setup.h        |  8 ++++++
> >  lib/arm/asm/timer.h        | 11 ++++++++
> >  lib/arm/setup.c            |  4 +++
> >  lib/arm/timer.c            | 19 +++++++++++--
> >  lib/arm64/asm/sysreg.h     | 19 +++++++++++++
> >  lib/arm64/processor.c      | 12 ++++++++
> >  14 files changed, 191 insertions(+), 19 deletions(-)
> >
>