This patch adds id_reg_info for ID_AA64PFR1_EL1 to make it writable by userspace.
Return an error if userspace tries to set MTE field of the register to a value that conflicts with KVM_CAP_ARM_MTE configuration for the guest. Signed-off-by: Reiji Watanabe <[email protected]> --- arch/arm64/include/asm/sysreg.h | 1 + arch/arm64/kvm/sys_regs.c | 51 ++++++++++++++++++++++++++------- 2 files changed, 42 insertions(+), 10 deletions(-) diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index b268082d67ed..aa0692595122 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -793,6 +793,7 @@ #define ID_AA64PFR0_ELx_32BIT_64BIT 0x2 /* id_aa64pfr1 */ +#define ID_AA64PFR1_CSV2FRAC_SHIFT 32 #define ID_AA64PFR1_MPAMFRAC_SHIFT 16 #define ID_AA64PFR1_RASFRAC_SHIFT 12 #define ID_AA64PFR1_MTE_SHIFT 8 diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 63eb207b387f..0e4423a81cb9 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -314,6 +314,20 @@ static int validate_id_aa64pfr0_el1(struct kvm_vcpu *vcpu, u64 val) return 0; } +static int validate_id_aa64pfr1_el1(struct kvm_vcpu *vcpu, u64 val) +{ + bool kvm_mte = kvm_has_mte(vcpu->kvm); + unsigned int mte; + + mte = cpuid_feature_extract_unsigned_field(val, ID_AA64PFR1_MTE_SHIFT); + + /* Check if there is a conflict with a request via KVM_ARM_VCPU_INIT. */ + if (kvm_mte ^ (mte > 0)) + return -EPERM; + + return 0; +} + static void init_id_aa64pfr0_el1_info(struct id_reg_info *id_reg) { u64 limit; @@ -341,6 +355,14 @@ static void init_id_aa64pfr0_el1_info(struct id_reg_info *id_reg) id_reg->vcpu_limit_val = limit; } +static void init_id_aa64pfr1_el1_info(struct id_reg_info *id_reg) +{ + id_reg->sys_val = read_sanitised_ftr_reg(id_reg->sys_reg); + id_reg->vcpu_limit_val = (system_supports_mte() ? + id_reg->sys_val : + (id_reg->sys_val & ~ARM64_FEATURE_MASK(ID_AA64PFR1_MTE))); +} + static u64 get_reset_id_aa64pfr0_el1(struct kvm_vcpu *vcpu, struct id_reg_info *idr) { @@ -349,6 +371,14 @@ static u64 get_reset_id_aa64pfr0_el1(struct kvm_vcpu *vcpu, (idr->vcpu_limit_val & ~(ARM64_FEATURE_MASK(ID_AA64PFR0_SVE))); } +static u64 get_reset_id_aa64pfr1_el1(struct kvm_vcpu *vcpu, + struct id_reg_info *idr) +{ + return kvm_has_mte(vcpu->kvm) ? + idr->vcpu_limit_val : + (idr->vcpu_limit_val & ~(ARM64_FEATURE_MASK(ID_AA64PFR1_MTE))); +} + static struct id_reg_info id_aa64pfr0_el1_info = { .sys_reg = SYS_ID_AA64PFR0_EL1, .init = init_id_aa64pfr0_el1_info, @@ -356,6 +386,16 @@ static struct id_reg_info id_aa64pfr0_el1_info = { .get_reset_val = get_reset_id_aa64pfr0_el1, }; +static struct id_reg_info id_aa64pfr1_el1_info = { + .sys_reg = SYS_ID_AA64PFR1_EL1, + .ignore_mask = ARM64_FEATURE_MASK(ID_AA64PFR1_RASFRAC) | + ARM64_FEATURE_MASK(ID_AA64PFR1_MPAMFRAC) | + ARM64_FEATURE_MASK(ID_AA64PFR1_CSV2FRAC), + .init = init_id_aa64pfr1_el1_info, + .validate = validate_id_aa64pfr1_el1, + .get_reset_val = get_reset_id_aa64pfr1_el1, +}; + /* * An ID register that needs special handling to control the value for the * guest must have its own id_reg_info in id_reg_info_table. @@ -366,6 +406,7 @@ static struct id_reg_info id_aa64pfr0_el1_info = { #define GET_ID_REG_INFO(id) (id_reg_info_table[IDREG_IDX(id)]) static struct id_reg_info *id_reg_info_table[KVM_ARM_ID_REG_MAX_NUM] = { [IDREG_IDX(SYS_ID_AA64PFR0_EL1)] = &id_aa64pfr0_el1_info, + [IDREG_IDX(SYS_ID_AA64PFR1_EL1)] = &id_aa64pfr1_el1_info, }; static int validate_id_reg(struct kvm_vcpu *vcpu, @@ -1202,16 +1243,6 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu, u64 val = raz ? 0 : __vcpu_sys_reg(vcpu, IDREG_SYS_IDX(id)); switch (id) { - case SYS_ID_AA64PFR1_EL1: - val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_MTE); - if (kvm_has_mte(vcpu->kvm)) { - u64 pfr, mte; - - pfr = read_sanitised_ftr_reg(SYS_ID_AA64PFR1_EL1); - mte = cpuid_feature_extract_unsigned_field(pfr, ID_AA64PFR1_MTE_SHIFT); - val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR1_MTE), mte); - } - break; case SYS_ID_AA64ISAR1_EL1: if (!vcpu_has_ptrauth(vcpu)) val &= ~(ARM64_FEATURE_MASK(ID_AA64ISAR1_APA) | -- 2.33.0.882.g93a45727a2-goog _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
