[PATCH v2 3/3] KVM: arm64: Don't pass host_debug_state to BRBE world-switch routines

[Fuad Tabba]

On Fri, 27 Feb 2026 at 21:22, Will Deacon <will at kernel.org> wrote:
>
> Now that the SPE and BRBE nVHE world-switch routines operate on the
> host_debug_state directly, tweak the BRBE code to do the same for
> consistency.
>
> This is purely cosmetic.
>
> Cc: Marc Zyngier <maz at kernel.org>
> Cc: Oliver Upton <oupton at kernel.org>
> Cc: James Clark <james.clark at linaro.org>
> Cc: Leo Yan <leo.yan at arm.com>
> Cc: Suzuki K Poulose <suzuki.poulose at arm.com>
> Cc: Fuad Tabba <tabba at google.com>
> Cc: Alexandru Elisei <alexandru.elisei at arm.com>
> Signed-off-by: Will Deacon <will at kernel.org>

Tested-by: Fuad Tabba <tabba at google.com>
Reviewed-by: Fuad Tabba <tabba at google.com>

Cheers,
/fuad

> ---
>  arch/arm64/kvm/hyp/nvhe/debug-sr.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm64/kvm/hyp/nvhe/debug-sr.c b/arch/arm64/kvm/hyp/nvhe/debug-sr.c
> index 75158a9cd06a..06ae122a7761 100644
> --- a/arch/arm64/kvm/hyp/nvhe/debug-sr.c
> +++ b/arch/arm64/kvm/hyp/nvhe/debug-sr.c
> @@ -158,9 +158,9 @@ static void __trace_switch_to_host(void)
>                           *host_data_ptr(host_debug_state.trfcr_el1));
>  }
>
> -static void __debug_save_brbe(u64 *brbcr_el1)
> +static void __debug_save_brbe(void)
>  {
> -       *brbcr_el1 = 0;
> +       u64 *brbcr_el1 = host_data_ptr(host_debug_state.brbcr_el1);
>
>         /* Check if the BRBE is enabled */
>         if (!(read_sysreg_el1(SYS_BRBCR) & (BRBCR_ELx_E0BRE | BRBCR_ELx_ExBRE)))
> @@ -175,8 +175,10 @@ static void __debug_save_brbe(u64 *brbcr_el1)
>         write_sysreg_el1(0, SYS_BRBCR);
>  }
>
> -static void __debug_restore_brbe(u64 brbcr_el1)
> +static void __debug_restore_brbe(void)
>  {
> +       u64 brbcr_el1 = *host_data_ptr(host_debug_state.brbcr_el1);
> +
>         if (!brbcr_el1)
>                 return;
>
> @@ -192,7 +194,7 @@ void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu)
>
>         /* Disable BRBE branch records */
>         if (host_data_test_flag(HAS_BRBE))
> -               __debug_save_brbe(host_data_ptr(host_debug_state.brbcr_el1));
> +               __debug_save_brbe();
>
>         if (__trace_needs_switch())
>                 __trace_switch_to_guest();
> @@ -208,7 +210,7 @@ void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu)
>         if (host_data_test_flag(HAS_SPE))
>                 __debug_restore_spe();
>         if (host_data_test_flag(HAS_BRBE))
> -               __debug_restore_brbe(*host_data_ptr(host_debug_state.brbcr_el1));
> +               __debug_restore_brbe();
>         if (__trace_needs_switch())
>                 __trace_switch_to_host();
>  }
> --
> 2.53.0.473.g4a7958ca14-goog
>