1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2017 - Columbia University and Linaro Ltd. 4 * Author: Jintack Lim <jintack.lim@linaro.org> 5 */ 6 7 #include <linux/kvm.h> 8 #include <linux/kvm_host.h> 9 10 #include <asm/kvm_emulate.h> 11 #include <asm/kvm_nested.h> 12 #include <asm/sysreg.h> 13 14 #include "sys_regs.h" 15 16 /* Protection against the sysreg repainting madness... */ 17 #define NV_FTR(r, f) ID_AA64##r##_EL1_##f 18 19 /* 20 * Our emulated CPU doesn't support all the possible features. For the 21 * sake of simplicity (and probably mental sanity), wipe out a number 22 * of feature bits we don't intend to support for the time being. 23 * This list should get updated as new features get added to the NV 24 * support, and new extension to the architecture. 25 */ 26 void access_nested_id_reg(struct kvm_vcpu *v, struct sys_reg_params *p, 27 const struct sys_reg_desc *r) 28 { 29 u32 id = reg_to_encoding(r); 30 u64 val, tmp; 31 32 val = p->regval; 33 34 switch (id) { 35 case SYS_ID_AA64ISAR0_EL1: 36 /* Support everything but TME, O.S. and Range TLBIs */ 37 val &= ~(NV_FTR(ISAR0, TLB) | 38 NV_FTR(ISAR0, TME)); 39 break; 40 41 case SYS_ID_AA64ISAR1_EL1: 42 /* Support everything but PtrAuth and Spec Invalidation */ 43 val &= ~(GENMASK_ULL(63, 56) | 44 NV_FTR(ISAR1, SPECRES) | 45 NV_FTR(ISAR1, GPI) | 46 NV_FTR(ISAR1, GPA) | 47 NV_FTR(ISAR1, API) | 48 NV_FTR(ISAR1, APA)); 49 break; 50 51 case SYS_ID_AA64PFR0_EL1: 52 /* No AMU, MPAM, S-EL2, RAS or SVE */ 53 val &= ~(GENMASK_ULL(55, 52) | 54 NV_FTR(PFR0, AMU) | 55 NV_FTR(PFR0, MPAM) | 56 NV_FTR(PFR0, SEL2) | 57 NV_FTR(PFR0, RAS) | 58 NV_FTR(PFR0, SVE) | 59 NV_FTR(PFR0, EL3) | 60 NV_FTR(PFR0, EL2) | 61 NV_FTR(PFR0, EL1)); 62 /* 64bit EL1/EL2/EL3 only */ 63 val |= FIELD_PREP(NV_FTR(PFR0, EL1), 0b0001); 64 val |= FIELD_PREP(NV_FTR(PFR0, EL2), 0b0001); 65 val |= FIELD_PREP(NV_FTR(PFR0, EL3), 0b0001); 66 break; 67 68 case SYS_ID_AA64PFR1_EL1: 69 /* Only support SSBS */ 70 val &= NV_FTR(PFR1, SSBS); 71 break; 72 73 case SYS_ID_AA64MMFR0_EL1: 74 /* Hide ECV, FGT, ExS, Secure Memory */ 75 val &= ~(GENMASK_ULL(63, 43) | 76 NV_FTR(MMFR0, TGRAN4_2) | 77 NV_FTR(MMFR0, TGRAN16_2) | 78 NV_FTR(MMFR0, TGRAN64_2) | 79 NV_FTR(MMFR0, SNSMEM)); 80 81 /* Disallow unsupported S2 page sizes */ 82 switch (PAGE_SIZE) { 83 case SZ_64K: 84 val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN16_2), 0b0001); 85 fallthrough; 86 case SZ_16K: 87 val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN4_2), 0b0001); 88 fallthrough; 89 case SZ_4K: 90 /* Support everything */ 91 break; 92 } 93 /* 94 * Since we can't support a guest S2 page size smaller than 95 * the host's own page size (due to KVM only populating its 96 * own S2 using the kernel's page size), advertise the 97 * limitation using FEAT_GTG. 98 */ 99 switch (PAGE_SIZE) { 100 case SZ_4K: 101 val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN4_2), 0b0010); 102 fallthrough; 103 case SZ_16K: 104 val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN16_2), 0b0010); 105 fallthrough; 106 case SZ_64K: 107 val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN64_2), 0b0010); 108 break; 109 } 110 /* Cap PARange to 48bits */ 111 tmp = FIELD_GET(NV_FTR(MMFR0, PARANGE), val); 112 if (tmp > 0b0101) { 113 val &= ~NV_FTR(MMFR0, PARANGE); 114 val |= FIELD_PREP(NV_FTR(MMFR0, PARANGE), 0b0101); 115 } 116 break; 117 118 case SYS_ID_AA64MMFR1_EL1: 119 val &= (NV_FTR(MMFR1, PAN) | 120 NV_FTR(MMFR1, LO) | 121 NV_FTR(MMFR1, HPDS) | 122 NV_FTR(MMFR1, VH) | 123 NV_FTR(MMFR1, VMIDBits)); 124 break; 125 126 case SYS_ID_AA64MMFR2_EL1: 127 val &= ~(NV_FTR(MMFR2, EVT) | 128 NV_FTR(MMFR2, BBM) | 129 NV_FTR(MMFR2, TTL) | 130 GENMASK_ULL(47, 44) | 131 NV_FTR(MMFR2, ST) | 132 NV_FTR(MMFR2, CCIDX) | 133 NV_FTR(MMFR2, VARange)); 134 135 /* Force TTL support */ 136 val |= FIELD_PREP(NV_FTR(MMFR2, TTL), 0b0001); 137 break; 138 139 case SYS_ID_AA64DFR0_EL1: 140 /* Only limited support for PMU, Debug, BPs and WPs */ 141 val &= (NV_FTR(DFR0, PMUVer) | 142 NV_FTR(DFR0, WRPs) | 143 NV_FTR(DFR0, BRPs) | 144 NV_FTR(DFR0, DebugVer)); 145 146 /* Cap Debug to ARMv8.1 */ 147 tmp = FIELD_GET(NV_FTR(DFR0, DebugVer), val); 148 if (tmp > 0b0111) { 149 val &= ~NV_FTR(DFR0, DebugVer); 150 val |= FIELD_PREP(NV_FTR(DFR0, DebugVer), 0b0111); 151 } 152 break; 153 154 default: 155 /* Unknown register, just wipe it clean */ 156 val = 0; 157 break; 158 } 159 160 p->regval = val; 161 } 162