On 28/11/2025 10:58, Harry Ramsey wrote:
> From: Penny Zheng <[email protected]>
>
> As MPU systems only have one secure state, we have to use secure EL2
> hypervisor timer for Xen in secure EL2.
>
> In this patch, we introduce a new Kconfig option ARM_SECURE_STATE
> and a set of secure hypervisor timer registers CNTHPS_*_EL2.
> We alias CNTHP_*_EL2 to CNTHPS_*_EL2 to keep the timer code
> flow unchanged.
>
> Signed-off-by: Penny Zheng <[email protected]>
> Signed-off-by: Wei Chen <[email protected]>
> Signed-off-by: Luca Fancellu <[email protected]>
> Signed-off-by: Harry Ramsey <[email protected]>
> ---
> xen/arch/arm/Kconfig | 5 +++++
> xen/arch/arm/include/asm/arm64/sysregs.h | 12 ++++++++++++
> 2 files changed, 17 insertions(+)
>
> diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
> index cf6af68299..a5c111e08e 100644
> --- a/xen/arch/arm/Kconfig
> +++ b/xen/arch/arm/Kconfig
> @@ -91,6 +91,7 @@ config MMU
>
> config MPU
> bool "MPU" if UNSUPPORTED
> + select ARM_SECURE_STATE if ARM_64
> select STATIC_MEMORY
> help
> Memory Protection Unit (MPU). Select if you plan to run Xen on ARMv8-R
> @@ -223,6 +224,10 @@ config HARDEN_BRANCH_PREDICTOR
>
> If unsure, say Y.
>
> +config ARM_SECURE_STATE
> + bool "Xen will run in Arm Secure State"
> + default n
No need, n is a default. I don't think this should be a selectable option.
> +
> config ARM64_PTR_AUTH
> def_bool n
> depends on ARM_64
> diff --git a/xen/arch/arm/include/asm/arm64/sysregs.h
> b/xen/arch/arm/include/asm/arm64/sysregs.h
> index 7440d495e4..29caad7155 100644
> --- a/xen/arch/arm/include/asm/arm64/sysregs.h
> +++ b/xen/arch/arm/include/asm/arm64/sysregs.h
> @@ -462,6 +462,18 @@
> #define ZCR_ELx_LEN_SIZE 9
> #define ZCR_ELx_LEN_MASK 0x1ff
>
> +#ifdef CONFIG_ARM_SECURE_STATE
> +/*
> + * The Armv8-R AArch64 architecture always executes code in Secure
> + * state with EL2 as the highest Exception.
s/Exception/exception level/
> + *
> + * Hypervisor timer registers for Secure EL2.
> + */
> +#define CNTHP_TVAL_EL2 CNTHPS_TVAL_EL2
TVAL is not used in Xen, so you can drop it
> +#define CNTHP_CTL_EL2 CNTHPS_CTL_EL2
> +#define CNTHP_CVAL_EL2 CNTHPS_CVAL_EL2
EL1 will still use the NS EL1 timer (CNTP)?
> +#endif
> +
> #define REGION_TEXT_PRBAR 0x38 /* SH=11 AP=10 XN=00 */
> #define REGION_RO_PRBAR 0x3A /* SH=11 AP=10 XN=10 */
> #define REGION_DATA_PRBAR 0x32 /* SH=11 AP=00 XN=10 */
~Michal
