[PATCH v2 12/17] arm64: Allow ID_AA64MMFR1_EL1.VH to be overridden from the command line
From: Marc Zyngier <maz@kernel.org>
Date: 2021-01-04 14:21:44
Also in:
kvmarm
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
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 out boot code doesn't look at the cpufeature, but only at the HW registers. Signed-off-by: Marc Zyngier <maz@kernel.org> --- arch/arm64/include/asm/cpufeature.h | 3 +++ arch/arm64/kernel/cpufeature.c | 6 +++++- arch/arm64/kernel/idreg-override.c | 12 ++++++++++++ 3 files changed, 20 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 465d2cb63bfc..ef9487dfadca 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h@@ -813,6 +813,9 @@ static inline unsigned int get_vmid_bits(u64 mmfr1) return 8; } +extern u64 id_aa64mmfr1_val; +extern u64 id_aa64mmfr1_mask; + 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 2dbfc0096b0d..623a74090c9e 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c@@ -555,6 +555,9 @@ static const struct arm64_ftr_bits ftr_raz[] = { #define ARM64_FTR_REG(id, table) ARM64_FTR_REG_OVERRIDE(id, table, NULL, NULL) +u64 id_aa64mmfr1_val; +u64 id_aa64mmfr1_mask; + static const struct __ftr_reg_entry { u32 sys_id; struct arm64_ftr_reg *reg;
@@ -602,7 +605,8 @@ 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_val, &id_aa64mmfr1_mask), 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 392f93b67103..75d9845f489b 100644
--- a/arch/arm64/kernel/idreg-override.c
+++ b/arch/arm64/kernel/idreg-override.c@@ -10,6 +10,7 @@ #include <linux/libfdt.h> #include <asm/cacheflush.h> +#include <asm/cpufeature.h> #include <asm/setup.h> struct reg_desc {
@@ -22,7 +23,18 @@ struct reg_desc { } fields[]; }; +static const struct reg_desc mmfr1 __initdata = { + .name = "id_aa64mmfr1", + .val = &id_aa64mmfr1_val, + .mask = &id_aa64mmfr1_mask, + .fields = { + { "vh", ID_AA64MMFR1_VHE_SHIFT }, + {} + }, +}; + static const struct reg_desc * const regs[] __initdata = { + &mmfr1, }; static int __init find_field(const char *cmdline, const struct reg_desc *reg,
--
2.29.2
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