Re: [PATCH] powerpc/interrupt: Use early_radix_enabled() in NMI real-mode guard

["Michal Suchánek" <msuchanek@suse.de>]

Hello,

On Mon, Sep 07, 2026 at 12:30:58PM +0530, Venkat Rao Bagalkote wrote:
> radix_enabled() uses a jump label which is only valid after
> mmu_feature_keys_init() is called. Before that point, on a pSeries
> hash guest, early_check_vec5() clears MMU_FTR_TYPE_RADIX in
> cur_cpu_spec->mmu_features but the jump label has not yet been patched,
> so radix_enabled() incorrectly returns true.
> 
> Replace radix_enabled() with early_radix_enabled() which does a plain
> bitmask check against cur_cpu_spec->mmu_features and is correct at all
> times, including before jump label initialization.

Any Fixes: here?

Thanks

Michal

> 
> Add the missing #include <asm/mmu.h> since early_radix_enabled() is
> declared there.
> 
> Signed-off-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
> ---
>  arch/powerpc/include/asm/interrupt.h | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
> index 1b45a49e9bed..36a654e780f7 100644
> --- a/arch/powerpc/include/asm/interrupt.h
> +++ b/arch/powerpc/include/asm/interrupt.h
> @@ -71,6 +71,7 @@
>  
>  #include <asm/kprobes.h>
>  #include <asm/runlatch.h>
> +#include <asm/mmu.h>
>  
>  #ifdef CONFIG_PPC_IRQ_SOFT_MASK_DEBUG
>  /*
> @@ -290,7 +291,7 @@ interrupt_handler long func(struct pt_regs *regs)			\
>  		state = irqentry_nmi_enter(regs);			\
>  	} else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) &&			\
>  		   firmware_has_feature(FW_FEATURE_LPAR) &&		\
> -		   !radix_enabled()) {					\
> +		   !early_radix_enabled()) {				\
>  		/* no nmi_entry for a pseries hash guest		\
>  		 * taking a real mode exception */			\
>  	} else if (IS_ENABLED(CONFIG_KASAN)) {				\
> @@ -307,7 +308,7 @@ interrupt_handler long func(struct pt_regs *regs)			\
>  		irqentry_nmi_exit(regs, state);				\
>  	} else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) &&			\
>  		   firmware_has_feature(FW_FEATURE_LPAR) &&		\
> -		   !radix_enabled()) {					\
> +		   !early_radix_enabled()) {				\
>  		/* no nmi_exit for a pseries hash guest			\
>  		 * taking a real mode exception */			\
>  	} else if (IS_ENABLED(CONFIG_KASAN)) {				\
> -- 
> 2.45.2
> 
>