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Add an init callback for every ID register to setup kvm_sys_val. All per VCPU sanitizations are still handled on the fly during ID register read and write from userspace. An arm64_ftr_bits array is used to indicate writable feature fields. Refactor writings for ID_AA64PFR0_EL1.[CSV2|CSV3], ID_AA64DFR0_EL1.PMUVer and ID_DFR0_ELF.PerfMon based on utilities introduced by ID register descriptor. No functional change intended. Co-developed-by: Reiji Watanabe Signed-off-by: Reiji Watanabe Signed-off-by: Jing Zhang --- arch/arm64/include/asm/cpufeature.h | 25 +++ arch/arm64/include/asm/kvm_host.h | 2 +- arch/arm64/kernel/cpufeature.c | 26 +-- arch/arm64/kvm/arm.c | 2 +- arch/arm64/kvm/id_regs.c | 337 +++++++++++++++++++--------- arch/arm64/kvm/sys_regs.c | 3 +- arch/arm64/kvm/sys_regs.h | 2 +- 7 files changed, 257 insertions(+), 140 deletions(-) diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index fc2c739f48f1..493ec530eefc 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -64,6 +64,30 @@ struct arm64_ftr_bits { s64 safe_val; /* safe value for FTR_EXACT features */ }; +#define __ARM64_FTR_BITS(SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \ + { \ + .sign = SIGNED, \ + .visible = VISIBLE, \ + .strict = STRICT, \ + .type = TYPE, \ + .shift = SHIFT, \ + .width = WIDTH, \ + .safe_val = SAFE_VAL, \ + } + +/* Define a feature with unsigned values */ +#define ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \ + __ARM64_FTR_BITS(FTR_UNSIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) + +/* Define a feature with a signed value */ +#define S_ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \ + __ARM64_FTR_BITS(FTR_SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) + +#define ARM64_FTR_END \ + { \ + .width = 0, \ + } + /* * Describe the early feature override to the core override code: * @@ -911,6 +935,7 @@ static inline unsigned int get_vmid_bits(u64 mmfr1) return 8; } +s64 arm64_ftr_safe_value(const struct arm64_ftr_bits *ftrp, s64 new, s64 cur); struct arm64_ftr_reg *get_arm64_ftr_reg(u32 sys_id); extern struct arm64_ftr_override id_aa64mmfr1_override; diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index effb61a9a855..4795f81b31b4 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -1015,7 +1015,7 @@ int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu, long kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm, struct kvm_arm_copy_mte_tags *copy_tags); -void kvm_arm_set_default_id_regs(struct kvm *kvm); +void kvm_arm_init_id_regs(struct kvm *kvm); /* Guest/host FPSIMD coordination helpers */ int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu); diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 23bd2a926b74..e18848ee4b98 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -139,30 +139,6 @@ void dump_cpu_features(void) pr_emerg("0x%*pb\n", ARM64_NCAPS, &cpu_hwcaps); } -#define __ARM64_FTR_BITS(SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \ - { \ - .sign = SIGNED, \ - .visible = VISIBLE, \ - .strict = STRICT, \ - .type = TYPE, \ - .shift = SHIFT, \ - .width = WIDTH, \ - .safe_val = SAFE_VAL, \ - } - -/* Define a feature with unsigned values */ -#define ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \ - __ARM64_FTR_BITS(FTR_UNSIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) - -/* Define a feature with a signed value */ -#define S_ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \ - __ARM64_FTR_BITS(FTR_SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) - -#define ARM64_FTR_END \ - { \ - .width = 0, \ - } - static void cpu_enable_cnp(struct arm64_cpu_capabilities const *cap); static bool __system_matches_cap(unsigned int n); @@ -790,7 +766,7 @@ static u64 arm64_ftr_set_value(const struct arm64_ftr_bits *ftrp, s64 reg, return reg; } -static s64 arm64_ftr_safe_value(const struct arm64_ftr_bits *ftrp, s64 new, +s64 arm64_ftr_safe_value(const struct arm64_ftr_bits *ftrp, s64 new, s64 cur) { s64 ret = 0; diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index fb2de2cb98cb..e539d9ca9d01 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -135,7 +135,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) /* The maximum number of VCPUs is limited by the host's GIC model */ kvm->max_vcpus = kvm_arm_default_max_vcpus(); - kvm_arm_set_default_id_regs(kvm); + kvm_arm_init_id_regs(kvm); kvm_arm_init_hypercalls(kvm); return 0; diff --git a/arch/arm64/kvm/id_regs.c b/arch/arm64/kvm/id_regs.c index 15d0338742b6..6d0a3b200abd 100644 --- a/arch/arm64/kvm/id_regs.c +++ b/arch/arm64/kvm/id_regs.c @@ -18,10 +18,88 @@ #include "sys_regs.h" +/* + * Number of entries in id_reg_desc's ftr_bits[] (Number of 4 bits fields + * in 64 bit register + 1 entry for a terminator entry). + */ +#define FTR_FIELDS_NUM 17 + struct id_reg_desc { const struct sys_reg_desc reg_desc; + /* + * KVM sanitised ID register value. + * It is the default value for per VM emulated ID register. + */ + u64 kvm_sys_val; + /* + * Used to validate the ID register values with arm64_check_features(). + * The last item in the array must be terminated by an item whose + * width field is zero as that is expected by arm64_check_features(). + * Only feature bits defined in this array are writable. + */ + struct arm64_ftr_bits ftr_bits[FTR_FIELDS_NUM]; + + /* + * Basically init() is used to setup the KVM sanitised value + * stored in kvm_sys_val. + */ + void (*init)(struct id_reg_desc *idr); }; +static struct id_reg_desc id_reg_descs[]; + +/** + * arm64_check_features() - Check if a feature register value constitutes + * a subset of features indicated by @limit. + * + * @ftrp: Pointer to an array of arm64_ftr_bits. It must be terminated by + * an item whose width field is zero. + * @val: The feature register value to check + * @limit: The limit value of the feature register + * + * This function will check if each feature field of @val is the "safe" value + * against @limit based on @ftrp[], each of which specifies the target field + * (shift, width), whether or not the field is for a signed value (sign), + * how the field is determined to be "safe" (type), and the safe value + * (safe_val) when type == FTR_EXACT (safe_val won't be used by this + * function when type != FTR_EXACT). Any other fields in arm64_ftr_bits + * won't be used by this function. If a field value in @val is the same + * as the one in @limit, it is always considered the safe value regardless + * of the type. For register fields that are not in @ftrp[], only the value + * in @limit is considered the safe value. + * + * Return: 0 if all the fields are safe. Otherwise, return negative errno. + */ +static int arm64_check_features(const struct arm64_ftr_bits *ftrp, u64 val, u64 limit) +{ + u64 mask = 0; + + for (; ftrp->width; ftrp++) { + s64 f_val, f_lim, safe_val; + + f_val = arm64_ftr_value(ftrp, val); + f_lim = arm64_ftr_value(ftrp, limit); + mask |= arm64_ftr_mask(ftrp); + + if (f_val == f_lim) + safe_val = f_val; + else + safe_val = arm64_ftr_safe_value(ftrp, f_val, f_lim); + + if (safe_val != f_val) + return -E2BIG; + } + + /* + * For fields that are not indicated in ftrp, values in limit are the + * safe values. + */ + if ((val & ~mask) != (limit & ~mask)) + return -E2BIG; + + return 0; +} + static u8 vcpu_pmuver(const struct kvm_vcpu *vcpu) { if (kvm_vcpu_has_pmu(vcpu)) @@ -33,19 +111,6 @@ static u8 vcpu_pmuver(const struct kvm_vcpu *vcpu) return 0; } -static u8 perfmon_to_pmuver(u8 perfmon) -{ - switch (perfmon) { - case ID_DFR0_EL1_PerfMon_PMUv3: - return ID_AA64DFR0_EL1_PMUVer_IMP; - case ID_DFR0_EL1_PerfMon_IMPDEF: - return ID_AA64DFR0_EL1_PMUVer_IMP_DEF; - default: - /* Anything ARMv8.1+ and NI have the same value. For now. */ - return perfmon; - } -} - static u8 pmuver_to_perfmon(u8 pmuver) { switch (pmuver) { @@ -78,7 +143,6 @@ u64 kvm_arm_read_id_reg_with_encoding(const struct kvm_vcpu *vcpu, u32 id) case SYS_ID_AA64PFR0_EL1: if (!vcpu_has_sve(vcpu)) val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_SVE); - val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_AMU); if (kvm_vgic_global_state.type == VGIC_V3) { val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_GIC); val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_GIC), 1); @@ -105,15 +169,10 @@ u64 kvm_arm_read_id_reg_with_encoding(const struct kvm_vcpu *vcpu, u32 id) val &= ~ARM64_FEATURE_MASK(ID_AA64ISAR2_EL1_WFxT); break; case SYS_ID_AA64DFR0_EL1: - /* Limit debug to ARMv8.0 */ - val &= ~ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_DebugVer); - val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_DebugVer), 6); /* Set PMUver to the required version */ val &= ~ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMUVer); val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMUVer), vcpu_pmuver(vcpu)); - /* Hide SPE from guests */ - val &= ~ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMSVer); break; case SYS_ID_DFR0_EL1: val &= ~ARM64_FEATURE_MASK(ID_DFR0_EL1_PerfMon); @@ -172,9 +231,15 @@ static int get_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, static int set_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, u64 val) { - /* This is what we mean by invariant: you can't change it. */ - if (val != read_id_reg(vcpu, rd)) - return -EINVAL; + int ret; + int id = reg_to_encoding(rd); + + ret = arm64_check_features(id_reg_descs[IDREG_IDX(id)].ftr_bits, val, + id_reg_descs[IDREG_IDX(id)].kvm_sys_val); + if (ret) + return ret; + + IDREG(vcpu->kvm, id) = val; return 0; } @@ -208,12 +273,47 @@ static unsigned int aa32_id_visibility(const struct kvm_vcpu *vcpu, return id_visibility(vcpu, r); } +static void init_id_reg(struct id_reg_desc *idr) +{ + idr->kvm_sys_val = read_sanitised_ftr_reg(reg_to_encoding(&idr->reg_desc)); +} + +static void init_id_aa64pfr0_el1(struct id_reg_desc *idr) +{ + u64 val; + u32 id = reg_to_encoding(&idr->reg_desc); + + val = read_sanitised_ftr_reg(id); + /* + * The default is to expose CSV2 == 1 if the HW isn't affected. + * Although this is a per-CPU feature, we make it global because + * asymmetric systems are just a nuisance. + * + * Userspace can override this as long as it doesn't promise + * the impossible. + */ + if (arm64_get_spectre_v2_state() == SPECTRE_UNAFFECTED) { + val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2); + val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2), 1); + } + if (arm64_get_meltdown_state() == SPECTRE_UNAFFECTED) { + val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3); + val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3), 1); + } + + val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_AMU); + + val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_GIC); + val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_GIC), 1); + + idr->kvm_sys_val = val; +} + static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, u64 val) { u8 csv2, csv3; - u64 sval = val; /* * Allow AA64PFR0_EL1.CSV2 to be set from userspace as long as @@ -231,16 +331,29 @@ static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu, (csv3 && arm64_get_meltdown_state() != SPECTRE_UNAFFECTED)) return -EINVAL; - /* We can only differ with CSV[23], and anything else is an error */ - val ^= read_id_reg(vcpu, rd); - val &= ~(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2) | - ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3)); - if (val) - return -EINVAL; + return set_id_reg(vcpu, rd, val); +} - IDREG_RD(vcpu->kvm, rd) = sval; +static void init_id_aa64dfr0_el1(struct id_reg_desc *idr) +{ + u64 val; + u32 id = reg_to_encoding(&idr->reg_desc); - return 0; + val = read_sanitised_ftr_reg(id); + /* Limit debug to ARMv8.0 */ + val &= ~ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_DebugVer); + val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_DebugVer), 6); + /* + * Initialise the default PMUver before there is a chance to + * create an actual PMU. + */ + val &= ~ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMUVer); + val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMUVer), + kvm_arm_pmu_get_pmuver_limit()); + /* Hide SPE from guests */ + val &= ~ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMSVer); + + idr->kvm_sys_val = val; } static int set_id_aa64dfr0_el1(struct kvm_vcpu *vcpu, @@ -268,23 +381,39 @@ static int set_id_aa64dfr0_el1(struct kvm_vcpu *vcpu, if (kvm_vcpu_has_pmu(vcpu) != valid_pmu) return -EINVAL; - /* We can only differ with PMUver, and anything else is an error */ - val ^= read_id_reg(vcpu, rd); - val &= ~ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMUVer); - if (val) - return -EINVAL; - if (valid_pmu) { - IDREG(vcpu->kvm, SYS_ID_AA64DFR0_EL1) &= ~ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMUVer); - IDREG(vcpu->kvm, SYS_ID_AA64DFR0_EL1) |= - FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMUVer), pmuver); - } else if (pmuver == ID_AA64DFR0_EL1_PMUVer_IMP_DEF) { - set_bit(KVM_ARCH_FLAG_VCPU_HAS_IMP_DEF_PMU, &vcpu->kvm->arch.flags); + return set_id_reg(vcpu, rd, val); } else { - clear_bit(KVM_ARCH_FLAG_VCPU_HAS_IMP_DEF_PMU, &vcpu->kvm->arch.flags); + /* We can only differ with PMUver, and anything else is an error */ + val ^= read_id_reg(vcpu, rd); + val &= ~ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMUVer); + if (val) + return -EINVAL; + + if (pmuver == ID_AA64DFR0_EL1_PMUVer_IMP_DEF) + set_bit(KVM_ARCH_FLAG_VCPU_HAS_IMP_DEF_PMU, &vcpu->kvm->arch.flags); + else + clear_bit(KVM_ARCH_FLAG_VCPU_HAS_IMP_DEF_PMU, &vcpu->kvm->arch.flags); + + return 0; } +} - return 0; +static void init_id_dfr0_el1(struct id_reg_desc *idr) +{ + u64 val; + u32 id = reg_to_encoding(&idr->reg_desc); + + val = read_sanitised_ftr_reg(id); + /* + * Initialise the default PMUver before there is a chance to + * create an actual PMU. + */ + val &= ~ARM64_FEATURE_MASK(ID_DFR0_EL1_PerfMon); + val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_DFR0_EL1_PerfMon), + kvm_arm_pmu_get_pmuver_limit()); + + idr->kvm_sys_val = val; } static int set_id_dfr0_el1(struct kvm_vcpu *vcpu, @@ -313,34 +442,37 @@ static int set_id_dfr0_el1(struct kvm_vcpu *vcpu, if (kvm_vcpu_has_pmu(vcpu) != valid_pmu) return -EINVAL; - /* We can only differ with PerfMon, and anything else is an error */ - val ^= read_id_reg(vcpu, rd); - val &= ~ARM64_FEATURE_MASK(ID_DFR0_EL1_PerfMon); - if (val) - return -EINVAL; - if (valid_pmu) { - IDREG(vcpu->kvm, SYS_ID_DFR0_EL1) &= ~ARM64_FEATURE_MASK(ID_DFR0_EL1_PerfMon); - IDREG(vcpu->kvm, SYS_ID_DFR0_EL1) |= - FIELD_PREP(ARM64_FEATURE_MASK(ID_DFR0_EL1_PerfMon), perfmon_to_pmuver(perfmon)); - } else if (perfmon == ID_DFR0_EL1_PerfMon_IMPDEF) { - set_bit(KVM_ARCH_FLAG_VCPU_HAS_IMP_DEF_PMU, &vcpu->kvm->arch.flags); + return set_id_reg(vcpu, rd, val); } else { - clear_bit(KVM_ARCH_FLAG_VCPU_HAS_IMP_DEF_PMU, &vcpu->kvm->arch.flags); - } + /* We can only differ with PerfMon, and anything else is an error */ + val ^= read_id_reg(vcpu, rd); + val &= ~ARM64_FEATURE_MASK(ID_DFR0_EL1_PerfMon); + if (val) + return -EINVAL; - return 0; + if (perfmon == ID_DFR0_EL1_PerfMon_IMPDEF) + set_bit(KVM_ARCH_FLAG_VCPU_HAS_IMP_DEF_PMU, &vcpu->kvm->arch.flags); + else + clear_bit(KVM_ARCH_FLAG_VCPU_HAS_IMP_DEF_PMU, &vcpu->kvm->arch.flags); + + return 0; + } } /* sys_reg_desc initialiser for known cpufeature ID registers */ +#define SYS_DESC_SANITISED(name) { \ + SYS_DESC(SYS_##name), \ + .access = access_id_reg, \ + .get_user = get_id_reg, \ + .set_user = set_id_reg, \ + .visibility = id_visibility, \ +} + #define ID_SANITISED(name) { \ - .reg_desc = { \ - SYS_DESC(SYS_##name), \ - .access = access_id_reg, \ - .get_user = get_id_reg, \ - .set_user = set_id_reg, \ - .visibility = id_visibility, \ - }, \ + .reg_desc = SYS_DESC_SANITISED(name), \ + .ftr_bits = { ARM64_FTR_END, }, \ + .init = init_id_reg, \ } /* sys_reg_desc initialiser for known cpufeature ID registers */ @@ -352,6 +484,8 @@ static int set_id_dfr0_el1(struct kvm_vcpu *vcpu, .set_user = set_id_reg, \ .visibility = aa32_id_visibility, \ }, \ + .ftr_bits = { ARM64_FTR_END, }, \ + .init = init_id_reg, \ } /* @@ -367,6 +501,7 @@ static int set_id_dfr0_el1(struct kvm_vcpu *vcpu, .set_user = set_id_reg, \ .visibility = raz_visibility \ }, \ + .ftr_bits = { ARM64_FTR_END, }, \ } /* @@ -382,9 +517,10 @@ static int set_id_dfr0_el1(struct kvm_vcpu *vcpu, .set_user = set_id_reg, \ .visibility = raz_visibility, \ }, \ + .ftr_bits = { ARM64_FTR_END, }, \ } -static const struct id_reg_desc id_reg_descs[KVM_ARM_ID_REG_NUM] = { +static struct id_reg_desc id_reg_descs[KVM_ARM_ID_REG_NUM] = { /* * ID regs: all ID_SANITISED() entries here must have corresponding * entries in arm64_ftr_regs[]. @@ -400,6 +536,11 @@ static const struct id_reg_desc id_reg_descs[KVM_ARM_ID_REG_NUM] = { .get_user = get_id_reg, .set_user = set_id_dfr0_el1, .visibility = aa32_id_visibility, }, + .ftr_bits = { + ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, + ID_DFR0_EL1_PerfMon_SHIFT, ID_DFR0_EL1_PerfMon_WIDTH, 0), + ARM64_FTR_END, }, + .init = init_id_dfr0_el1, }, ID_HIDDEN(ID_AFR0_EL1), AA32_ID_SANITISED(ID_MMFR0_EL1), @@ -434,6 +575,13 @@ static const struct id_reg_desc id_reg_descs[KVM_ARM_ID_REG_NUM] = { .access = access_id_reg, .get_user = get_id_reg, .set_user = set_id_aa64pfr0_el1, }, + .ftr_bits = { + ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, + ID_AA64PFR0_EL1_CSV2_SHIFT, ID_AA64PFR0_EL1_CSV2_WIDTH, 0), + ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, + ID_AA64PFR0_EL1_CSV3_SHIFT, ID_AA64PFR0_EL1_CSV3_WIDTH, 0), + ARM64_FTR_END, }, + .init = init_id_aa64pfr0_el1, }, ID_SANITISED(ID_AA64PFR1_EL1), ID_UNALLOCATED(4, 2), @@ -449,6 +597,11 @@ static const struct id_reg_desc id_reg_descs[KVM_ARM_ID_REG_NUM] = { .access = access_id_reg, .get_user = get_id_reg, .set_user = set_id_aa64dfr0_el1, }, + .ftr_bits = { + ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, + ID_AA64DFR0_EL1_PMUVer_SHIFT, ID_AA64DFR0_EL1_PMUVer_WIDTH, 0), + ARM64_FTR_END, }, + .init = init_id_aa64dfr0_el1, }, ID_SANITISED(ID_AA64DFR1_EL1), ID_UNALLOCATED(5, 2), @@ -561,7 +714,7 @@ int kvm_arm_set_id_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) return ret; } -bool kvm_arm_check_idreg_table(void) +bool kvm_arm_idreg_table_init(void) { unsigned int i; @@ -578,6 +731,9 @@ bool kvm_arm_check_idreg_table(void) &id_reg_descs[i - 1].reg_desc, i - 1); return false; } + + if (id_reg_descs[i].init) + id_reg_descs[i].init(&id_reg_descs[i]); } return true; @@ -602,55 +758,16 @@ int kvm_arm_walk_id_regs(struct kvm_vcpu *vcpu, u64 __user *uind) } /* - * Set the guest's ID registers that are defined in id_reg_descs[] - * with ID_SANITISED() to the host's sanitized value. + * Initialize the guest's ID registers with KVM sanitised values that were setup + * during ID register descriptors initialization. */ -void kvm_arm_set_default_id_regs(struct kvm *kvm) +void kvm_arm_init_id_regs(struct kvm *kvm) { int i; u32 id; - u64 val; for (i = 0; i < ARRAY_SIZE(id_reg_descs); i++) { id = reg_to_encoding(&id_reg_descs[i].reg_desc); - if (WARN_ON_ONCE(!is_id_reg(id))) - /* Shouldn't happen */ - continue; - - if (id_reg_descs[i].reg_desc.visibility == raz_visibility) - /* Hidden or reserved ID register */ - continue; - - val = read_sanitised_ftr_reg(id); - IDREG(kvm, id) = val; - } - /* - * The default is to expose CSV2 == 1 if the HW isn't affected. - * Although this is a per-CPU feature, we make it global because - * asymmetric systems are just a nuisance. - * - * Userspace can override this as long as it doesn't promise - * the impossible. - */ - val = IDREG(kvm, SYS_ID_AA64PFR0_EL1); - - if (arm64_get_spectre_v2_state() == SPECTRE_UNAFFECTED) { - val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2); - val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2), 1); + IDREG(kvm, id) = id_reg_descs[i].kvm_sys_val; } - if (arm64_get_meltdown_state() == SPECTRE_UNAFFECTED) { - val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3); - val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3), 1); - } - - IDREG(kvm, SYS_ID_AA64PFR0_EL1) = val; - - /* - * Initialise the default PMUver before there is a chance to - * create an actual PMU. - */ - IDREG(kvm, SYS_ID_AA64DFR0_EL1) &= ~ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMUVer); - IDREG(kvm, SYS_ID_AA64DFR0_EL1) |= - FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMUVer), - kvm_arm_pmu_get_pmuver_limit()); } diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index cdcd61ac9868..c377f4a3e3bf 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2911,14 +2911,13 @@ int __init kvm_sys_reg_table_init(void) unsigned int i; /* Make sure tables are unique and in order. */ - valid &= kvm_arm_check_idreg_table(); valid &= check_sysreg_table(sys_reg_descs, ARRAY_SIZE(sys_reg_descs), false); valid &= check_sysreg_table(cp14_regs, ARRAY_SIZE(cp14_regs), true); valid &= check_sysreg_table(cp14_64_regs, ARRAY_SIZE(cp14_64_regs), true); valid &= check_sysreg_table(cp15_regs, ARRAY_SIZE(cp15_regs), true); valid &= check_sysreg_table(cp15_64_regs, ARRAY_SIZE(cp15_64_regs), true); valid &= check_sysreg_table(invariant_sys_regs, ARRAY_SIZE(invariant_sys_regs), false); - + valid &= kvm_arm_idreg_table_init(); if (!valid) return -EINVAL; diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h index 3797d1b494a2..0b22955d233b 100644 --- a/arch/arm64/kvm/sys_regs.h +++ b/arch/arm64/kvm/sys_regs.h @@ -247,7 +247,7 @@ const struct sys_reg_desc *kvm_arm_find_id_reg(const struct sys_reg_params *para void kvm_arm_reset_id_regs(struct kvm_vcpu *vcpu); int kvm_arm_get_id_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg); int kvm_arm_set_id_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg); -bool kvm_arm_check_idreg_table(void); +bool kvm_arm_idreg_table_init(void); int kvm_arm_walk_id_regs(struct kvm_vcpu *vcpu, u64 __user *uind); u64 kvm_arm_read_id_reg_with_encoding(const struct kvm_vcpu *vcpu, u32 id);