From 361db0fca7affafa920f7d91bf93b9d9da44712f Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 8 Feb 2021 09:57:23 +0000 Subject: [PATCH] arm64: Allow ID_AA64MMFR1_EL1.VH to be overridden from the command line As we want to be able to disable VHE at runtime, let's match "id_aa64mmfr1.vh=" from the command line as an override. This doesn't have much effect yet as our boot code doesn't look at the cpufeature, but only at the HW registers. Signed-off-by: Marc Zyngier Acked-by: David Brazdil Acked-by: Suzuki K Poulose Reviewed-by: Catalin Marinas Link: https://lore.kernel.org/r/20210208095732.3267263-15-maz@kernel.org Signed-off-by: Will Deacon --- arch/arm64/include/asm/cpufeature.h | 2 ++ arch/arm64/kernel/cpufeature.c | 5 ++++- arch/arm64/kernel/idreg-override.c | 11 +++++++++++ 3 files changed, 17 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index b5bf7af68691..570f1b4ba3cc 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -818,6 +818,8 @@ static inline unsigned int get_vmid_bits(u64 mmfr1) return 8; } +extern struct arm64_ftr_override id_aa64mmfr1_override; + u32 get_kvm_ipa_limit(void); void dump_cpu_features(void); diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 97da9ed4b79d..faada5d8bea6 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -557,6 +557,8 @@ static const struct arm64_ftr_bits ftr_raz[] = { #define ARM64_FTR_REG(id, table) ARM64_FTR_REG_OVERRIDE(id, table, &no_override) +struct arm64_ftr_override __ro_after_init id_aa64mmfr1_override; + static const struct __ftr_reg_entry { u32 sys_id; struct arm64_ftr_reg *reg; @@ -604,7 +606,8 @@ static const struct __ftr_reg_entry { /* Op1 = 0, CRn = 0, CRm = 7 */ ARM64_FTR_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0), - ARM64_FTR_REG(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1), + ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1, + &id_aa64mmfr1_override), ARM64_FTR_REG(SYS_ID_AA64MMFR2_EL1, ftr_id_aa64mmfr2), /* Op1 = 0, CRn = 1, CRm = 2 */ diff --git a/arch/arm64/kernel/idreg-override.c b/arch/arm64/kernel/idreg-override.c index 3a347b42d07e..2da11bf60195 100644 --- a/arch/arm64/kernel/idreg-override.c +++ b/arch/arm64/kernel/idreg-override.c @@ -11,6 +11,7 @@ #include #include +#include #include #define FTR_DESC_NAME_LEN 20 @@ -25,7 +26,17 @@ struct ftr_set_desc { } fields[]; }; +static const struct ftr_set_desc mmfr1 __initconst = { + .name = "id_aa64mmfr1", + .override = &id_aa64mmfr1_override, + .fields = { + { "vh", ID_AA64MMFR1_VHE_SHIFT }, + {} + }, +}; + static const struct ftr_set_desc * const regs[] __initconst = { + &mmfr1, }; static int __init find_field(const char *cmdline, -- 2.11.0