diff options
Diffstat (limited to 'arch/arm/kvm/coproc.c')
| -rw-r--r-- | arch/arm/kvm/coproc.c | 327 |
1 files changed, 327 insertions, 0 deletions
diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c index 722efe3b1675..95a0f5e5c1fc 100644 --- a/arch/arm/kvm/coproc.c +++ b/arch/arm/kvm/coproc.c @@ -18,6 +18,7 @@ */ #include <linux/mm.h> #include <linux/kvm_host.h> +#include <linux/uaccess.h> #include <asm/kvm_arm.h> #include <asm/kvm_host.h> #include <asm/kvm_emulate.h> @@ -347,6 +348,328 @@ int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run) return emulate_cp15(vcpu, ¶ms); } +/****************************************************************************** + * Userspace API + *****************************************************************************/ + +static bool index_to_params(u64 id, struct coproc_params *params) +{ + switch (id & KVM_REG_SIZE_MASK) { + case KVM_REG_SIZE_U32: + /* Any unused index bits means it's not valid. */ + if (id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK + | KVM_REG_ARM_COPROC_MASK + | KVM_REG_ARM_32_CRN_MASK + | KVM_REG_ARM_CRM_MASK + | KVM_REG_ARM_OPC1_MASK + | KVM_REG_ARM_32_OPC2_MASK)) + return false; + + params->is_64bit = false; + params->CRn = ((id & KVM_REG_ARM_32_CRN_MASK) + >> KVM_REG_ARM_32_CRN_SHIFT); + params->CRm = ((id & KVM_REG_ARM_CRM_MASK) + >> KVM_REG_ARM_CRM_SHIFT); + params->Op1 = ((id & KVM_REG_ARM_OPC1_MASK) + >> KVM_REG_ARM_OPC1_SHIFT); + params->Op2 = ((id & KVM_REG_ARM_32_OPC2_MASK) + >> KVM_REG_ARM_32_OPC2_SHIFT); + return true; + case KVM_REG_SIZE_U64: + /* Any unused index bits means it's not valid. */ + if (id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK + | KVM_REG_ARM_COPROC_MASK + | KVM_REG_ARM_CRM_MASK + | KVM_REG_ARM_OPC1_MASK)) + return false; + params->is_64bit = true; + params->CRm = ((id & KVM_REG_ARM_CRM_MASK) + >> KVM_REG_ARM_CRM_SHIFT); + params->Op1 = ((id & KVM_REG_ARM_OPC1_MASK) + >> KVM_REG_ARM_OPC1_SHIFT); + params->Op2 = 0; + params->CRn = 0; + return true; + default: + return false; + } +} + +/* Decode an index value, and find the cp15 coproc_reg entry. */ +static const struct coproc_reg *index_to_coproc_reg(struct kvm_vcpu *vcpu, + u64 id) +{ + size_t num; + const struct coproc_reg *table, *r; + struct coproc_params params; + + /* We only do cp15 for now. */ + if ((id & KVM_REG_ARM_COPROC_MASK) >> KVM_REG_ARM_COPROC_SHIFT != 15) + return NULL; + + if (!index_to_params(id, ¶ms)) + return NULL; + + table = get_target_table(vcpu->arch.target, &num); + r = find_reg(¶ms, table, num); + if (!r) + r = find_reg(¶ms, cp15_regs, ARRAY_SIZE(cp15_regs)); + + /* Not saved in the cp15 array? */ + if (r && !r->reg) + r = NULL; + + return r; +} + +/* + * These are the invariant cp15 registers: we let the guest see the host + * versions of these, so they're part of the guest state. + * + * A future CPU may provide a mechanism to present different values to + * the guest, or a future kvm may trap them. + */ +/* Unfortunately, there's no register-argument for mrc, so generate. */ +#define FUNCTION_FOR32(crn, crm, op1, op2, name) \ + static void get_##name(struct kvm_vcpu *v, \ + const struct coproc_reg *r) \ + { \ + u32 val; \ + \ + asm volatile("mrc p15, " __stringify(op1) \ + ", %0, c" __stringify(crn) \ + ", c" __stringify(crm) \ + ", " __stringify(op2) "\n" : "=r" (val)); \ + ((struct coproc_reg *)r)->val = val; \ + } + +FUNCTION_FOR32(0, 0, 0, 0, MIDR) +FUNCTION_FOR32(0, 0, 0, 1, CTR) +FUNCTION_FOR32(0, 0, 0, 2, TCMTR) +FUNCTION_FOR32(0, 0, 0, 3, TLBTR) +FUNCTION_FOR32(0, 0, 0, 6, REVIDR) +FUNCTION_FOR32(0, 1, 0, 0, ID_PFR0) +FUNCTION_FOR32(0, 1, 0, 1, ID_PFR1) +FUNCTION_FOR32(0, 1, 0, 2, ID_DFR0) +FUNCTION_FOR32(0, 1, 0, 3, ID_AFR0) +FUNCTION_FOR32(0, 1, 0, 4, ID_MMFR0) +FUNCTION_FOR32(0, 1, 0, 5, ID_MMFR1) +FUNCTION_FOR32(0, 1, 0, 6, ID_MMFR2) +FUNCTION_FOR32(0, 1, 0, 7, ID_MMFR3) +FUNCTION_FOR32(0, 2, 0, 0, ID_ISAR0) +FUNCTION_FOR32(0, 2, 0, 1, ID_ISAR1) +FUNCTION_FOR32(0, 2, 0, 2, ID_ISAR2) +FUNCTION_FOR32(0, 2, 0, 3, ID_ISAR3) +FUNCTION_FOR32(0, 2, 0, 4, ID_ISAR4) +FUNCTION_FOR32(0, 2, 0, 5, ID_ISAR5) +FUNCTION_FOR32(0, 0, 1, 1, CLIDR) +FUNCTION_FOR32(0, 0, 1, 7, AIDR) + +/* ->val is filled in by kvm_invariant_coproc_table_init() */ +static struct coproc_reg invariant_cp15[] = { + { CRn( 0), CRm( 0), Op1( 0), Op2( 0), is32, NULL, get_MIDR }, + { CRn( 0), CRm( 0), Op1( 0), Op2( 1), is32, NULL, get_CTR }, + { CRn( 0), CRm( 0), Op1( 0), Op2( 2), is32, NULL, get_TCMTR }, + { CRn( 0), CRm( 0), Op1( 0), Op2( 3), is32, NULL, get_TLBTR }, + { CRn( 0), CRm( 0), Op1( 0), Op2( 6), is32, NULL, get_REVIDR }, + + { CRn( 0), CRm( 1), Op1( 0), Op2( 0), is32, NULL, get_ID_PFR0 }, + { CRn( 0), CRm( 1), Op1( 0), Op2( 1), is32, NULL, get_ID_PFR1 }, + { CRn( 0), CRm( 1), Op1( 0), Op2( 2), is32, NULL, get_ID_DFR0 }, + { CRn( 0), CRm( 1), Op1( 0), Op2( 3), is32, NULL, get_ID_AFR0 }, + { CRn( 0), CRm( 1), Op1( 0), Op2( 4), is32, NULL, get_ID_MMFR0 }, + { CRn( 0), CRm( 1), Op1( 0), Op2( 5), is32, NULL, get_ID_MMFR1 }, + { CRn( 0), CRm( 1), Op1( 0), Op2( 6), is32, NULL, get_ID_MMFR2 }, + { CRn( 0), CRm( 1), Op1( 0), Op2( 7), is32, NULL, get_ID_MMFR3 }, + + { CRn( 0), CRm( 2), Op1( 0), Op2( 0), is32, NULL, get_ID_ISAR0 }, + { CRn( 0), CRm( 2), Op1( 0), Op2( 1), is32, NULL, get_ID_ISAR1 }, + { CRn( 0), CRm( 2), Op1( 0), Op2( 2), is32, NULL, get_ID_ISAR2 }, + { CRn( 0), CRm( 2), Op1( 0), Op2( 3), is32, NULL, get_ID_ISAR3 }, + { CRn( 0), CRm( 2), Op1( 0), Op2( 4), is32, NULL, get_ID_ISAR4 }, + { CRn( 0), CRm( 2), Op1( 0), Op2( 5), is32, NULL, get_ID_ISAR5 }, + + { CRn( 0), CRm( 0), Op1( 1), Op2( 1), is32, NULL, get_CLIDR }, + { CRn( 0), CRm( 0), Op1( 1), Op2( 7), is32, NULL, get_AIDR }, +}; + +static int reg_from_user(void *val, const void __user *uaddr, u64 id) +{ + /* This Just Works because we are little endian. */ + if (copy_from_user(val, uaddr, KVM_REG_SIZE(id)) != 0) + return -EFAULT; + return 0; +} + +static int reg_to_user(void __user *uaddr, const void *val, u64 id) +{ + /* This Just Works because we are little endian. */ + if (copy_to_user(uaddr, val, KVM_REG_SIZE(id)) != 0) + return -EFAULT; + return 0; +} + +static int get_invariant_cp15(u64 id, void __user *uaddr) +{ + struct coproc_params params; + const struct coproc_reg *r; + + if (!index_to_params(id, ¶ms)) + return -ENOENT; + + r = find_reg(¶ms, invariant_cp15, ARRAY_SIZE(invariant_cp15)); + if (!r) + return -ENOENT; + + return reg_to_user(uaddr, &r->val, id); +} + +static int set_invariant_cp15(u64 id, void __user *uaddr) +{ + struct coproc_params params; + const struct coproc_reg *r; + int err; + u64 val = 0; /* Make sure high bits are 0 for 32-bit regs */ + + if (!index_to_params(id, ¶ms)) + return -ENOENT; + r = find_reg(¶ms, invariant_cp15, ARRAY_SIZE(invariant_cp15)); + if (!r) + return -ENOENT; + + err = reg_from_user(&val, uaddr, id); + if (err) + return err; + + /* This is what we mean by invariant: you can't change it. */ + if (r->val != val) + return -EINVAL; + + return 0; +} + +int kvm_arm_coproc_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) +{ + const struct coproc_reg *r; + void __user *uaddr = (void __user *)(long)reg->addr; + + r = index_to_coproc_reg(vcpu, reg->id); + if (!r) + return get_invariant_cp15(reg->id, uaddr); + + /* Note: copies two regs if size is 64 bit. */ + return reg_to_user(uaddr, &vcpu->arch.cp15[r->reg], reg->id); +} + +int kvm_arm_coproc_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) +{ + const struct coproc_reg *r; + void __user *uaddr = (void __user *)(long)reg->addr; + + r = index_to_coproc_reg(vcpu, reg->id); + if (!r) + return set_invariant_cp15(reg->id, uaddr); + + /* Note: copies two regs if size is 64 bit */ + return reg_from_user(&vcpu->arch.cp15[r->reg], uaddr, reg->id); +} + +static u64 cp15_to_index(const struct coproc_reg *reg) +{ + u64 val = KVM_REG_ARM | (15 << KVM_REG_ARM_COPROC_SHIFT); + if (reg->is_64) { + val |= KVM_REG_SIZE_U64; + val |= (reg->Op1 << KVM_REG_ARM_OPC1_SHIFT); + val |= (reg->CRm << KVM_REG_ARM_CRM_SHIFT); + } else { + val |= KVM_REG_SIZE_U32; + val |= (reg->Op1 << KVM_REG_ARM_OPC1_SHIFT); + val |= (reg->Op2 << KVM_REG_ARM_32_OPC2_SHIFT); + val |= (reg->CRm << KVM_REG_ARM_CRM_SHIFT); + val |= (reg->CRn << KVM_REG_ARM_32_CRN_SHIFT); + } + return val; +} + +static bool copy_reg_to_user(const struct coproc_reg *reg, u64 __user **uind) +{ + if (!*uind) + return true; + + if (put_user(cp15_to_index(reg), *uind)) + return false; + + (*uind)++; + return true; +} + +/* Assumed ordered tables, see kvm_coproc_table_init. */ +static int walk_cp15(struct kvm_vcpu *vcpu, u64 __user *uind) +{ + const struct coproc_reg *i1, *i2, *end1, *end2; + unsigned int total = 0; + size_t num; + + /* We check for duplicates here, to allow arch-specific overrides. */ + i1 = get_target_table(vcpu->arch.target, &num); + end1 = i1 + num; + i2 = cp15_regs; + end2 = cp15_regs + ARRAY_SIZE(cp15_regs); + + BUG_ON(i1 == end1 || i2 == end2); + + /* Walk carefully, as both tables may refer to the same register. */ + while (i1 || i2) { + int cmp = cmp_reg(i1, i2); + /* target-specific overrides generic entry. */ + if (cmp <= 0) { + /* Ignore registers we trap but don't save. */ + if (i1->reg) { + if (!copy_reg_to_user(i1, &uind)) + return -EFAULT; + total++; + } + } else { + /* Ignore registers we trap but don't save. */ + if (i2->reg) { + if (!copy_reg_to_user(i2, &uind)) + return -EFAULT; + total++; + } + } + + if (cmp <= 0 && ++i1 == end1) + i1 = NULL; + if (cmp >= 0 && ++i2 == end2) + i2 = NULL; + } + return total; +} + +unsigned long kvm_arm_num_coproc_regs(struct kvm_vcpu *vcpu) +{ + return ARRAY_SIZE(invariant_cp15) + + walk_cp15(vcpu, (u64 __user *)NULL); +} + +int kvm_arm_copy_coproc_indices(struct kvm_vcpu *vcpu, u64 __user *uindices) +{ + unsigned int i; + int err; + + /* Then give them all the invariant registers' indices. */ + for (i = 0; i < ARRAY_SIZE(invariant_cp15); i++) { + if (put_user(cp15_to_index(&invariant_cp15[i]), uindices)) + return -EFAULT; + uindices++; + } + + err = walk_cp15(vcpu, uindices); + if (err > 0) + err = 0; + return err; +} + void kvm_coproc_table_init(void) { unsigned int i; @@ -354,6 +677,10 @@ void kvm_coproc_table_init(void) /* Make sure tables are unique and in order. */ for (i = 1; i < ARRAY_SIZE(cp15_regs); i++) BUG_ON(cmp_reg(&cp15_regs[i-1], &cp15_regs[i]) >= 0); + + /* We abuse the reset function to overwrite the table itself. */ + for (i = 0; i < ARRAY_SIZE(invariant_cp15); i++) + invariant_cp15[i].reset(NULL, &invariant_cp15[i]); } /** |
