Hi Vladimir,
On Tue, 16 Mar 2021 11:25:00 +0000,
Vladimir Murzin <vladimir.murzin@xxxxxxx> wrote:
>
> Commit 78869f0f0552 ("arm64: Extract parts of el2_setup into a macro")
> reorganized el2 setup in such way that virtual cpu id registers set
> only in nVHE, yet they used (and need) to be set irrespective VHE
> support. Lack of setup causes 32-bit guest stop booting due to MIDR
> stay undefined.
Surely this affects 64bit guests as well, doesn't it? I guess the
32bit code tries to infer stuff such as the architecture revision from
MIDR and falls over, and that the 64bit Linux code has less baggage?
>
> Fixes: 78869f0f0552 ("arm64: Extract parts of el2_setup into a macro")
> Signed-off-by: Vladimir Murzin <vladimir.murzin@xxxxxxx>
> ---
>
> There is no upstream fix since issue went away due to code there has
> been reworked in 5.12: nVHE comes first, so virtual cpu id register
> are always set.
>
> Maintainers, please, Ack.
>
> arch/arm64/include/asm/el2_setup.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h
> index f988e94cdf9e..db87daca6b8c 100644
> --- a/arch/arm64/include/asm/el2_setup.h
> +++ b/arch/arm64/include/asm/el2_setup.h
> @@ -113,7 +113,7 @@
> .endm
>
> /* Virtual CPU ID registers */
> -.macro __init_el2_nvhe_idregs
> +.macro __init_el2_idregs
> mrs x0, midr_el1
> mrs x1, mpidr_el1
> msr vpidr_el2, x0
> @@ -165,6 +165,7 @@
> __init_el2_stage2
> __init_el2_gicv3
> __init_el2_hstr
> + __init_el2_idregs
>
> /*
> * When VHE is not in use, early init of EL2 needs to be done here.
> @@ -173,7 +174,6 @@
> * will be done via the _EL1 system register aliases in __cpu_setup.
> */
> .ifeqs "\mode", "nvhe"
> - __init_el2_nvhe_idregs
> __init_el2_nvhe_cptr
> __init_el2_nvhe_sve
> __init_el2_nvhe_prepare_eret
The couple of VHE systems I have around don't suffer from this issue,
but it looks like I can trigger it on the FVP model (probably because
the model is nasty enough to not have VPIDR_EL2 default to anything
sensible!).
Anyway, good catch. If you can respin it to drop the reference to
32bit guests, I'll happily ack it!
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
