[PATCH v2 0/3] Fix io accessors for KVM

[Ilias Apalodimas]

Hi Jerome,

On Wed, 18 Jun 2025 at 14:03, Jerome Forissier
<jerome.forissier at linaro.org> wrote:
>
>
>
> On 6/18/25 08:58, Ilias Apalodimas wrote:
> > Instructions that lead ito an exception in the hypervisor can't modify two
> > CPU registers at once for the ARM ISA.
> >
> > These instructions cannot be emulated by KVM as they do not produce
> > syndrome information data that KVM can use to infer the destination
> > register, the faulting address, whether it was a load or store, or
> > if it's a 32 or 64 bit general-purpose register.
> > As a result an external abort is injected from QEMU, via ext_dabt_pending.
> >
> > Patch #1 prepares some function for the modified macros
> > Patch #2 modifies the macros
> > Patch #3 enables the functionality for armv7/8 QEMU
>
> Again, IMHO this is more complex than necessary because you're combining
> the KVM fix with some code refactoring. Patch #1 can be dropped altogether
> and patch #2 can be simplified (from "2 files changed, 123 insertions(+),
> 39 deletions(-)" to "2 files changed, 97 insertions(+)". Unless I missed
> something? Please see [1]. Of course it also passes the LVM test ;)

No you aren't. I just kept it as is because Tom said he was fine and
makes the final code easier to read, rather than having 2 macros doing
the same thing.

Thanks
/Ilias
>
> [1] https://source.denx.de/u-boot/custodians/u-boot-net/-/pipelines/26751.
>
> --
> Jerome
>
> >
> > Changes since v1:
> > - Split the function modification in its own patch
> > - Don't limit the changes to v8 only
> >
> > Ilias Apalodimas (3):
> >   nxp: Prepare macros for KVM changes
> >   arm: io.h: Fix io accessors for KVM
> >   qemu: arm: Enable virtualizable IO accesors
> >
> >  arch/arm/Kconfig             |  12 +++
> >  arch/arm/include/asm/io.h    | 152 ++++++++++++++++++++++++++---------
> >  configs/qemu_arm64_defconfig |   1 +
> >  configs/qemu_arm_defconfig   |   1 +
> >  drivers/spi/fsl_dspi.c       |   6 +-
> >  include/fsl_ifc.h            |  24 +++---
> >  6 files changed, 142 insertions(+), 54 deletions(-)
> >
> > --
> > 2.43.0
> >