Apologies for the bogus subject line in the cover letter:
I accidentally put a leading ' ' into the file and then
git send-email interpreted that From line as the subject.
Intended subject line was:
[PATCH 00/10] target/arm: Forbid exception returns to unimplemented AArch32 ELs

-- PMM

On Thu, 6 Mar 2025 at 16:39, Peter Maydell <peter.maydell@linaro.org> wrote:
>
> Newer Arm CPUs need not implement AArch32 at all exception levels
> (and Armv9 forbids implementing AArch32 at any EL except EL0).
> All our current CPU models implement both AArch32 and AArch64
> at every exception levels, so we currently get away with failing
> to enforce that the guest isn't trying to do an exception return
> to AArch32 when the target EL doesn't support AArch32.
>
> This patchset adds the missing checks:
>  * SCR_EL3.RW has an effective value of 1 if EL2 is AArch64-only
>  * HCR_EL2.RW is RAO/WI if EL1 is AArch64-only
>  * return to AArch32 when no EL supports AArch32 is an illegal
>    exception return
>
> To do this it needs to start off with some cleanup. This is
> because we need to add a cpu_isar_feature() check to
> arm_el_is_aa64(), but we don't want to include cpu-features.h
> in cpu.h. arm_el_is_aa64() is really an internal part of the
> CPU implementation, so we can move it to internals.h; this
> means also moving some other functions in cpu.h that are
> defined as inline functions and which call arm_el_is_aa64().
> Removing some unused macros from linux-user allows us to
> avoid having linux-user include internals.h.
>
> (No doubt there are other functions that could be moved out
> of cpu.h, but I stuck to only the ones that I actually needed
> to move.)
>
> thanks
> -- PMM
>
> Peter Maydell (10):
>   target/arm: Move A32_BANKED_REG_{GET,SET} macros to cpregs.h
>   target/arm: Un-inline access_secure_reg()
>   linux-user/aarch64: Remove unused get/put_user macros
>   linux-user/arm: Remove unused get_put_user macros
>   target/arm: Move arm_cpu_data_is_big_endian() etc to internals.h
>   target/arm: Move arm_current_el() and arm_el_is_aa64() to internals.h
>   target/arm: SCR_EL3.RW should be treated as 1 if EL2 doesn't support
>     AArch32
>   target/arm: HCR_EL2.RW should be RAO/WI if EL1 doesn't support AArch32
>   target/arm: Add cpu local variable to exception_return helper
>   target/arm: Forbid return to AArch32 when CPU is AArch64-only
>
>  target/arm/cpregs.h           |  28 +++++++
>  target/arm/cpu.h              | 153 +---------------------------------
>  target/arm/internals.h        | 133 +++++++++++++++++++++++++++++
>  hw/intc/arm_gicv3_cpuif.c     |   1 +
>  linux-user/aarch64/cpu_loop.c |  48 -----------
>  linux-user/arm/cpu_loop.c     |  43 +---------
>  target/arm/arch_dump.c        |   1 +
>  target/arm/helper.c           |  16 +++-
>  target/arm/tcg/helper-a64.c   |  12 ++-
>  target/arm/tcg/hflags.c       |   9 ++
>  10 files changed, 202 insertions(+), 242 deletions(-)