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Diffstat (limited to 'arch/arm64/kvm/sys_regs.c')
| -rw-r--r-- | arch/arm64/kvm/sys_regs.c | 1050 |
1 files changed, 1050 insertions, 0 deletions
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c new file mode 100644 index 00000000000..94923609753 --- /dev/null +++ b/arch/arm64/kvm/sys_regs.c @@ -0,0 +1,1050 @@ +/* + * Copyright (C) 2012,2013 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + * + * Derived from arch/arm/kvm/coproc.c: + * Copyright (C) 2012 - Virtual Open Systems and Columbia University + * Authors: Rusty Russell <rusty@rustcorp.com.au> + * Christoffer Dall <c.dall@virtualopensystems.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#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> +#include <asm/kvm_coproc.h> +#include <asm/cacheflush.h> +#include <asm/cputype.h> +#include <trace/events/kvm.h> + +#include "sys_regs.h" + +/* + * All of this file is extremly similar to the ARM coproc.c, but the + * types are different. My gut feeling is that it should be pretty + * easy to merge, but that would be an ABI breakage -- again. VFP + * would also need to be abstracted. + * + * For AArch32, we only take care of what is being trapped. Anything + * that has to do with init and userspace access has to go via the + * 64bit interface. + */ + +/* 3 bits per cache level, as per CLIDR, but non-existent caches always 0 */ +static u32 cache_levels; + +/* CSSELR values; used to index KVM_REG_ARM_DEMUX_ID_CCSIDR */ +#define CSSELR_MAX 12 + +/* Which cache CCSIDR represents depends on CSSELR value. */ +static u32 get_ccsidr(u32 csselr) +{ + u32 ccsidr; + + /* Make sure noone else changes CSSELR during this! */ + local_irq_disable(); + /* Put value into CSSELR */ + asm volatile("msr csselr_el1, %x0" : : "r" (csselr)); + isb(); + /* Read result out of CCSIDR */ + asm volatile("mrs %0, ccsidr_el1" : "=r" (ccsidr)); + local_irq_enable(); + + return ccsidr; +} + +static void do_dc_cisw(u32 val) +{ + asm volatile("dc cisw, %x0" : : "r" (val)); + dsb(); +} + +static void do_dc_csw(u32 val) +{ + asm volatile("dc csw, %x0" : : "r" (val)); + dsb(); +} + +/* See note at ARM ARM B1.14.4 */ +static bool access_dcsw(struct kvm_vcpu *vcpu, + const struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + unsigned long val; + int cpu; + + if (!p->is_write) + return read_from_write_only(vcpu, p); + + cpu = get_cpu(); + + cpumask_setall(&vcpu->arch.require_dcache_flush); + cpumask_clear_cpu(cpu, &vcpu->arch.require_dcache_flush); + + /* If we were already preempted, take the long way around */ + if (cpu != vcpu->arch.last_pcpu) { + flush_cache_all(); + goto done; + } + + val = *vcpu_reg(vcpu, p->Rt); + + switch (p->CRm) { + case 6: /* Upgrade DCISW to DCCISW, as per HCR.SWIO */ + case 14: /* DCCISW */ + do_dc_cisw(val); + break; + + case 10: /* DCCSW */ + do_dc_csw(val); + break; + } + +done: + put_cpu(); + + return true; +} + +/* + * We could trap ID_DFR0 and tell the guest we don't support performance + * monitoring. Unfortunately the patch to make the kernel check ID_DFR0 was + * NAKed, so it will read the PMCR anyway. + * + * Therefore we tell the guest we have 0 counters. Unfortunately, we + * must always support PMCCNTR (the cycle counter): we just RAZ/WI for + * all PM registers, which doesn't crash the guest kernel at least. + */ +static bool pm_fake(struct kvm_vcpu *vcpu, + const struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + if (p->is_write) + return ignore_write(vcpu, p); + else + return read_zero(vcpu, p); +} + +static void reset_amair_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) +{ + u64 amair; + + asm volatile("mrs %0, amair_el1\n" : "=r" (amair)); + vcpu_sys_reg(vcpu, AMAIR_EL1) = amair; +} + +static void reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) +{ + /* + * Simply map the vcpu_id into the Aff0 field of the MPIDR. + */ + vcpu_sys_reg(vcpu, MPIDR_EL1) = (1UL << 31) | (vcpu->vcpu_id & 0xff); +} + +/* + * Architected system registers. + * Important: Must be sorted ascending by Op0, Op1, CRn, CRm, Op2 + */ +static const struct sys_reg_desc sys_reg_descs[] = { + /* DC ISW */ + { Op0(0b01), Op1(0b000), CRn(0b0111), CRm(0b0110), Op2(0b010), + access_dcsw }, + /* DC CSW */ + { Op0(0b01), Op1(0b000), CRn(0b0111), CRm(0b1010), Op2(0b010), + access_dcsw }, + /* DC CISW */ + { Op0(0b01), Op1(0b000), CRn(0b0111), CRm(0b1110), Op2(0b010), + access_dcsw }, + + /* TEECR32_EL1 */ + { Op0(0b10), Op1(0b010), CRn(0b0000), CRm(0b0000), Op2(0b000), + NULL, reset_val, TEECR32_EL1, 0 }, + /* TEEHBR32_EL1 */ + { Op0(0b10), Op1(0b010), CRn(0b0001), CRm(0b0000), Op2(0b000), + NULL, reset_val, TEEHBR32_EL1, 0 }, + /* DBGVCR32_EL2 */ + { Op0(0b10), Op1(0b100), CRn(0b0000), CRm(0b0111), Op2(0b000), + NULL, reset_val, DBGVCR32_EL2, 0 }, + + /* MPIDR_EL1 */ + { Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0000), Op2(0b101), + NULL, reset_mpidr, MPIDR_EL1 }, + /* SCTLR_EL1 */ + { Op0(0b11), Op1(0b000), CRn(0b0001), CRm(0b0000), Op2(0b000), + NULL, reset_val, SCTLR_EL1, 0x00C50078 }, + /* CPACR_EL1 */ + { Op0(0b11), Op1(0b000), CRn(0b0001), CRm(0b0000), Op2(0b010), + NULL, reset_val, CPACR_EL1, 0 }, + /* TTBR0_EL1 */ + { Op0(0b11), Op1(0b000), CRn(0b0010), CRm(0b0000), Op2(0b000), + NULL, reset_unknown, TTBR0_EL1 }, + /* TTBR1_EL1 */ + { Op0(0b11), Op1(0b000), CRn(0b0010), CRm(0b0000), Op2(0b001), + NULL, reset_unknown, TTBR1_EL1 }, + /* TCR_EL1 */ + { Op0(0b11), Op1(0b000), CRn(0b0010), CRm(0b0000), Op2(0b010), + NULL, reset_val, TCR_EL1, 0 }, + + /* AFSR0_EL1 */ + { Op0(0b11), Op1(0b000), CRn(0b0101), CRm(0b0001), Op2(0b000), + NULL, reset_unknown, AFSR0_EL1 }, + /* AFSR1_EL1 */ + { Op0(0b11), Op1(0b000), CRn(0b0101), CRm(0b0001), Op2(0b001), + NULL, reset_unknown, AFSR1_EL1 }, + /* ESR_EL1 */ + { Op0(0b11), Op1(0b000), CRn(0b0101), CRm(0b0010), Op2(0b000), + NULL, reset_unknown, ESR_EL1 }, + /* FAR_EL1 */ + { Op0(0b11), Op1(0b000), CRn(0b0110), CRm(0b0000), Op2(0b000), + NULL, reset_unknown, FAR_EL1 }, + + /* PMINTENSET_EL1 */ + { Op0(0b11), Op1(0b000), CRn(0b1001), CRm(0b1110), Op2(0b001), + pm_fake }, + /* PMINTENCLR_EL1 */ + { Op0(0b11), Op1(0b000), CRn(0b1001), CRm(0b1110), Op2(0b010), + pm_fake }, + + /* MAIR_EL1 */ + { Op0(0b11), Op1(0b000), CRn(0b1010), CRm(0b0010), Op2(0b000), + NULL, reset_unknown, MAIR_EL1 }, + /* AMAIR_EL1 */ + { Op0(0b11), Op1(0b000), CRn(0b1010), CRm(0b0011), Op2(0b000), + NULL, reset_amair_el1, AMAIR_EL1 }, + + /* VBAR_EL1 */ + { Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b0000), Op2(0b000), + NULL, reset_val, VBAR_EL1, 0 }, + /* CONTEXTIDR_EL1 */ + { Op0(0b11), Op1(0b000), CRn(0b1101), CRm(0b0000), Op2(0b001), + NULL, reset_val, CONTEXTIDR_EL1, 0 }, + /* TPIDR_EL1 */ + { Op0(0b11), Op1(0b000), CRn(0b1101), CRm(0b0000), Op2(0b100), + NULL, reset_unknown, TPIDR_EL1 }, + + /* CNTKCTL_EL1 */ + { Op0(0b11), Op1(0b000), CRn(0b1110), CRm(0b0001), Op2(0b000), + NULL, reset_val, CNTKCTL_EL1, 0}, + + /* CSSELR_EL1 */ + { Op0(0b11), Op1(0b010), CRn(0b0000), CRm(0b0000), Op2(0b000), + NULL, reset_unknown, CSSELR_EL1 }, + + /* PMCR_EL0 */ + { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b000), + pm_fake }, + /* PMCNTENSET_EL0 */ + { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b001), + pm_fake }, + /* PMCNTENCLR_EL0 */ + { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b010), + pm_fake }, + /* PMOVSCLR_EL0 */ + { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b011), + pm_fake }, + /* PMSWINC_EL0 */ + { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b100), + pm_fake }, + /* PMSELR_EL0 */ + { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b101), + pm_fake }, + /* PMCEID0_EL0 */ + { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b110), + pm_fake }, + /* PMCEID1_EL0 */ + { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b111), + pm_fake }, + /* PMCCNTR_EL0 */ + { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1101), Op2(0b000), + pm_fake }, + /* PMXEVTYPER_EL0 */ + { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1101), Op2(0b001), + pm_fake }, + /* PMXEVCNTR_EL0 */ + { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1101), Op2(0b010), + pm_fake }, + /* PMUSERENR_EL0 */ + { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1110), Op2(0b000), + pm_fake }, + /* PMOVSSET_EL0 */ + { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1110), Op2(0b011), + pm_fake }, + + /* TPIDR_EL0 */ + { Op0(0b11), Op1(0b011), CRn(0b1101), CRm(0b0000), Op2(0b010), + NULL, reset_unknown, TPIDR_EL0 }, + /* TPIDRRO_EL0 */ + { Op0(0b11), Op1(0b011), CRn(0b1101), CRm(0b0000), Op2(0b011), + NULL, reset_unknown, TPIDRRO_EL0 }, + + /* DACR32_EL2 */ + { Op0(0b11), Op1(0b100), CRn(0b0011), CRm(0b0000), Op2(0b000), + NULL, reset_unknown, DACR32_EL2 }, + /* IFSR32_EL2 */ + { Op0(0b11), Op1(0b100), CRn(0b0101), CRm(0b0000), Op2(0b001), + NULL, reset_unknown, IFSR32_EL2 }, + /* FPEXC32_EL2 */ + { Op0(0b11), Op1(0b100), CRn(0b0101), CRm(0b0011), Op2(0b000), + NULL, reset_val, FPEXC32_EL2, 0x70 }, +}; + +/* Trapped cp15 registers */ +static const struct sys_reg_desc cp15_regs[] = { + /* + * DC{C,I,CI}SW operations: + */ + { Op1( 0), CRn( 7), CRm( 6), Op2( 2), access_dcsw }, + { Op1( 0), CRn( 7), CRm(10), Op2( 2), access_dcsw }, + { Op1( 0), CRn( 7), CRm(14), Op2( 2), access_dcsw }, + { Op1( 0), CRn( 9), CRm(12), Op2( 0), pm_fake }, + { Op1( 0), CRn( 9), CRm(12), Op2( 1), pm_fake }, + { Op1( 0), CRn( 9), CRm(12), Op2( 2), pm_fake }, + { Op1( 0), CRn( 9), CRm(12), Op2( 3), pm_fake }, + { Op1( 0), CRn( 9), CRm(12), Op2( 5), pm_fake }, + { Op1( 0), CRn( 9), CRm(12), Op2( 6), pm_fake }, + { Op1( 0), CRn( 9), CRm(12), Op2( 7), pm_fake }, + { Op1( 0), CRn( 9), CRm(13), Op2( 0), pm_fake }, + { Op1( 0), CRn( 9), CRm(13), Op2( 1), pm_fake }, + { Op1( 0), CRn( 9), CRm(13), Op2( 2), pm_fake }, + { Op1( 0), CRn( 9), CRm(14), Op2( 0), pm_fake }, + { Op1( 0), CRn( 9), CRm(14), Op2( 1), pm_fake }, + { Op1( 0), CRn( 9), CRm(14), Op2( 2), pm_fake }, +}; + +/* Target specific emulation tables */ +static struct kvm_sys_reg_target_table *target_tables[KVM_ARM_NUM_TARGETS]; + +void kvm_register_target_sys_reg_table(unsigned int target, + struct kvm_sys_reg_target_table *table) +{ + target_tables[target] = table; +} + +/* Get specific register table for this target. */ +static const struct sys_reg_desc *get_target_table(unsigned target, + bool mode_is_64, + size_t *num) +{ + struct kvm_sys_reg_target_table *table; + + table = target_tables[target]; + if (mode_is_64) { + *num = table->table64.num; + return table->table64.table; + } else { + *num = table->table32.num; + return table->table32.table; + } +} + +static const struct sys_reg_desc *find_reg(const struct sys_reg_params *params, + const struct sys_reg_desc table[], + unsigned int num) +{ + unsigned int i; + + for (i = 0; i < num; i++) { + const struct sys_reg_desc *r = &table[i]; + + if (params->Op0 != r->Op0) + continue; + if (params->Op1 != r->Op1) + continue; + if (params->CRn != r->CRn) + continue; + if (params->CRm != r->CRm) + continue; + if (params->Op2 != r->Op2) + continue; + + return r; + } + return NULL; +} + +int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu, struct kvm_run *run) +{ + kvm_inject_undefined(vcpu); + return 1; +} + +int kvm_handle_cp14_access(struct kvm_vcpu *vcpu, struct kvm_run *run) +{ + kvm_inject_undefined(vcpu); + return 1; +} + +static void emulate_cp15(struct kvm_vcpu *vcpu, + const struct sys_reg_params *params) +{ + size_t num; + const struct sys_reg_desc *table, *r; + + table = get_target_table(vcpu->arch.target, false, &num); + + /* Search target-specific then generic table. */ + r = find_reg(params, table, num); + if (!r) + r = find_reg(params, cp15_regs, ARRAY_SIZE(cp15_regs)); + + if (likely(r)) { + /* + * Not having an accessor means that we have + * configured a trap that we don't know how to + * handle. This certainly qualifies as a gross bug + * that should be fixed right away. + */ + BUG_ON(!r->access); + + if (likely(r->access(vcpu, params, r))) { + /* Skip instruction, since it was emulated */ + kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu)); + return; + } + /* If access function fails, it should complain. */ + } + + kvm_err("Unsupported guest CP15 access at: %08lx\n", *vcpu_pc(vcpu)); + print_sys_reg_instr(params); + kvm_inject_undefined(vcpu); +} + +/** + * kvm_handle_cp15_64 -- handles a mrrc/mcrr trap on a guest CP15 access + * @vcpu: The VCPU pointer + * @run: The kvm_run struct + */ +int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run) +{ + struct sys_reg_params params; + u32 hsr = kvm_vcpu_get_hsr(vcpu); + int Rt2 = (hsr >> 10) & 0xf; + + params.CRm = (hsr >> 1) & 0xf; + params.Rt = (hsr >> 5) & 0xf; + params.is_write = ((hsr & 1) == 0); + + params.Op0 = 0; + params.Op1 = (hsr >> 16) & 0xf; + params.Op2 = 0; + params.CRn = 0; + + /* + * Massive hack here. Store Rt2 in the top 32bits so we only + * have one register to deal with. As we use the same trap + * backends between AArch32 and AArch64, we get away with it. + */ + if (params.is_write) { + u64 val = *vcpu_reg(vcpu, params.Rt); + val &= 0xffffffff; + val |= *vcpu_reg(vcpu, Rt2) << 32; + *vcpu_reg(vcpu, params.Rt) = val; + } + + emulate_cp15(vcpu, ¶ms); + + /* Do the opposite hack for the read side */ + if (!params.is_write) { + u64 val = *vcpu_reg(vcpu, params.Rt); + val >>= 32; + *vcpu_reg(vcpu, Rt2) = val; + } + + return 1; +} + +/** + * kvm_handle_cp15_32 -- handles a mrc/mcr trap on a guest CP15 access + * @vcpu: The VCPU pointer + * @run: The kvm_run struct + */ +int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run) +{ + struct sys_reg_params params; + u32 hsr = kvm_vcpu_get_hsr(vcpu); + + params.CRm = (hsr >> 1) & 0xf; + params.Rt = (hsr >> 5) & 0xf; + params.is_write = ((hsr & 1) == 0); + params.CRn = (hsr >> 10) & 0xf; + params.Op0 = 0; + params.Op1 = (hsr >> 14) & 0x7; + params.Op2 = (hsr >> 17) & 0x7; + + emulate_cp15(vcpu, ¶ms); + return 1; +} + +static int emulate_sys_reg(struct kvm_vcpu *vcpu, + const struct sys_reg_params *params) +{ + size_t num; + const struct sys_reg_desc *table, *r; + + table = get_target_table(vcpu->arch.target, true, &num); + + /* Search target-specific then generic table. */ + r = find_reg(params, table, num); + if (!r) + r = find_reg(params, sys_reg_descs, ARRAY_SIZE(sys_reg_descs)); + + if (likely(r)) { + /* + * Not having an accessor means that we have + * configured a trap that we don't know how to + * handle. This certainly qualifies as a gross bug + * that should be fixed right away. + */ + BUG_ON(!r->access); + + if (likely(r->access(vcpu, params, r))) { + /* Skip instruction, since it was emulated */ + kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu)); + return 1; + } + /* If access function fails, it should complain. */ + } else { + kvm_err("Unsupported guest sys_reg access at: %lx\n", + *vcpu_pc(vcpu)); + print_sys_reg_instr(params); + } + kvm_inject_undefined(vcpu); + return 1; +} + +static void reset_sys_reg_descs(struct kvm_vcpu *vcpu, + const struct sys_reg_desc *table, size_t num) +{ + unsigned long i; + + for (i = 0; i < num; i++) + if (table[i].reset) + table[i].reset(vcpu, &table[i]); +} + +/** + * kvm_handle_sys_reg -- handles a mrs/msr trap on a guest sys_reg access + * @vcpu: The VCPU pointer + * @run: The kvm_run struct + */ +int kvm_handle_sys_reg(struct kvm_vcpu *vcpu, struct kvm_run *run) +{ + struct sys_reg_params params; + unsigned long esr = kvm_vcpu_get_hsr(vcpu); + + params.Op0 = (esr >> 20) & 3; + params.Op1 = (esr >> 14) & 0x7; + params.CRn = (esr >> 10) & 0xf; + params.CRm = (esr >> 1) & 0xf; + params.Op2 = (esr >> 17) & 0x7; + params.Rt = (esr >> 5) & 0x1f; + params.is_write = !(esr & 1); + + return emulate_sys_reg(vcpu, ¶ms); +} + +/****************************************************************************** + * Userspace API + *****************************************************************************/ + +static bool index_to_params(u64 id, struct sys_reg_params *params) +{ + switch (id & KVM_REG_SIZE_MASK) { + 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_ARM64_SYSREG_OP0_MASK + | KVM_REG_ARM64_SYSREG_OP1_MASK + | KVM_REG_ARM64_SYSREG_CRN_MASK + | KVM_REG_ARM64_SYSREG_CRM_MASK + | KVM_REG_ARM64_SYSREG_OP2_MASK)) + return false; + params->Op0 = ((id & KVM_REG_ARM64_SYSREG_OP0_MASK) + >> KVM_REG_ARM64_SYSREG_OP0_SHIFT); + params->Op1 = ((id & KVM_REG_ARM64_SYSREG_OP1_MASK) + >> KVM_REG_ARM64_SYSREG_OP1_SHIFT); + params->CRn = ((id & KVM_REG_ARM64_SYSREG_CRN_MASK) + >> KVM_REG_ARM64_SYSREG_CRN_SHIFT); + params->CRm = ((id & KVM_REG_ARM64_SYSREG_CRM_MASK) + >> KVM_REG_ARM64_SYSREG_CRM_SHIFT); + params->Op2 = ((id & KVM_REG_ARM64_SYSREG_OP2_MASK) + >> KVM_REG_ARM64_SYSREG_OP2_SHIFT); + return true; + default: + return false; + } +} + +/* Decode an index value, and find the sys_reg_desc entry. */ +static const struct sys_reg_desc *index_to_sys_reg_desc(struct kvm_vcpu *vcpu, + u64 id) +{ + size_t num; + const struct sys_reg_desc *table, *r; + struct sys_reg_params params; + + /* We only do sys_reg for now. */ + if ((id & KVM_REG_ARM_COPROC_MASK) != KVM_REG_ARM64_SYSREG) + return NULL; + + if (!index_to_params(id, ¶ms)) + return NULL; + + table = get_target_table(vcpu->arch.target, true, &num); + r = find_reg(¶ms, table, num); + if (!r) + r = find_reg(¶ms, sys_reg_descs, ARRAY_SIZE(sys_reg_descs)); + + /* Not saved in the sys_reg array? */ + if (r && !r->reg) + r = NULL; + + return r; +} + +/* + * These are the invariant sys_reg 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. + */ + +#define FUNCTION_INVARIANT(reg) \ + static void get_##reg(struct kvm_vcpu *v, \ + const struct sys_reg_desc *r) \ + { \ + u64 val; \ + \ + asm volatile("mrs %0, " __stringify(reg) "\n" \ + : "=r" (val)); \ + ((struct sys_reg_desc *)r)->val = val; \ + } + +FUNCTION_INVARIANT(midr_el1) +FUNCTION_INVARIANT(ctr_el0) +FUNCTION_INVARIANT(revidr_el1) +FUNCTION_INVARIANT(id_pfr0_el1) +FUNCTION_INVARIANT(id_pfr1_el1) +FUNCTION_INVARIANT(id_dfr0_el1) +FUNCTION_INVARIANT(id_afr0_el1) +FUNCTION_INVARIANT(id_mmfr0_el1) +FUNCTION_INVARIANT(id_mmfr1_el1) +FUNCTION_INVARIANT(id_mmfr2_el1) +FUNCTION_INVARIANT(id_mmfr3_el1) +FUNCTION_INVARIANT(id_isar0_el1) +FUNCTION_INVARIANT(id_isar1_el1) +FUNCTION_INVARIANT(id_isar2_el1) +FUNCTION_INVARIANT(id_isar3_el1) +FUNCTION_INVARIANT(id_isar4_el1) +FUNCTION_INVARIANT(id_isar5_el1) +FUNCTION_INVARIANT(clidr_el1) +FUNCTION_INVARIANT(aidr_el1) + +/* ->val is filled in by kvm_sys_reg_table_init() */ +static struct sys_reg_desc invariant_sys_regs[] = { + { Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0000), Op2(0b000), + NULL, get_midr_el1 }, + { Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0000), Op2(0b110), + NULL, get_revidr_el1 }, + { Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b000), + NULL, get_id_pfr0_el1 }, + { Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b001), + NULL, get_id_pfr1_el1 }, + { Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b010), + NULL, get_id_dfr0_el1 }, + { Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b011), + NULL, get_id_afr0_el1 }, + { Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b100), + NULL, get_id_mmfr0_el1 }, + { Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b101), + NULL, get_id_mmfr1_el1 }, + { Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b110), + NULL, get_id_mmfr2_el1 }, + { Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b111), + NULL, get_id_mmfr3_el1 }, + { Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0010), Op2(0b000), + NULL, get_id_isar0_el1 }, + { Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0010), Op2(0b001), + NULL, get_id_isar1_el1 }, + { Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0010), Op2(0b010), + NULL, get_id_isar2_el1 }, + { Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0010), Op2(0b011), + NULL, get_id_isar3_el1 }, + { Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0010), Op2(0b100), + NULL, get_id_isar4_el1 }, + { Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0010), Op2(0b101), + NULL, get_id_isar5_el1 }, + { Op0(0b11), Op1(0b001), CRn(0b0000), CRm(0b0000), Op2(0b001), + NULL, get_clidr_el1 }, + { Op0(0b11), Op1(0b001), CRn(0b0000), CRm(0b0000), Op2(0b111), + NULL, get_aidr_el1 }, + { Op0(0b11), Op1(0b011), CRn(0b0000), CRm(0b0000), Op2(0b001), + NULL, get_ctr_el0 }, +}; + +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_sys_reg(u64 id, void __user *uaddr) +{ + struct sys_reg_params params; + const struct sys_reg_desc *r; + + if (!index_to_params(id, ¶ms)) + return -ENOENT; + + r = find_reg(¶ms, invariant_sys_regs, ARRAY_SIZE(invariant_sys_regs)); + if (!r) + return -ENOENT; + + return reg_to_user(uaddr, &r->val, id); +} + +static int set_invariant_sys_reg(u64 id, void __user *uaddr) +{ + struct sys_reg_params params; + const struct sys_reg_desc *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_sys_regs, ARRAY_SIZE(invariant_sys_regs)); + 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; +} + +static bool is_valid_cache(u32 val) +{ + u32 level, ctype; + + if (val >= CSSELR_MAX) + return -ENOENT; + + /* Bottom bit is Instruction or Data bit. Next 3 bits are level. */ + level = (val >> 1); + ctype = (cache_levels >> (level * 3)) & 7; + + switch (ctype) { + case 0: /* No cache */ + return false; + case 1: /* Instruction cache only */ + return (val & 1); + case 2: /* Data cache only */ + case 4: /* Unified cache */ + return !(val & 1); + case 3: /* Separate instruction and data caches */ + return true; + default: /* Reserved: we can't know instruction or data. */ + return false; + } +} + +static int demux_c15_get(u64 id, void __user *uaddr) +{ + u32 val; + u32 __user *uval = uaddr; + + /* Fail if we have unknown bits set. */ + if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK + | ((1 << KVM_REG_ARM_COPROC_SHIFT)-1))) + return -ENOENT; + + switch (id & KVM_REG_ARM_DEMUX_ID_MASK) { + case KVM_REG_ARM_DEMUX_ID_CCSIDR: + if (KVM_REG_SIZE(id) != 4) + return -ENOENT; + val = (id & KVM_REG_ARM_DEMUX_VAL_MASK) + >> KVM_REG_ARM_DEMUX_VAL_SHIFT; + if (!is_valid_cache(val)) + return -ENOENT; + + return put_user(get_ccsidr(val), uval); + default: + return -ENOENT; + } +} + +static int demux_c15_set(u64 id, void __user *uaddr) +{ + u32 val, newval; + u32 __user *uval = uaddr; + + /* Fail if we have unknown bits set. */ + if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK + | ((1 << KVM_REG_ARM_COPROC_SHIFT)-1))) + return -ENOENT; + + switch (id & KVM_REG_ARM_DEMUX_ID_MASK) { + case KVM_REG_ARM_DEMUX_ID_CCSIDR: + if (KVM_REG_SIZE(id) != 4) + return -ENOENT; + val = (id & KVM_REG_ARM_DEMUX_VAL_MASK) + >> KVM_REG_ARM_DEMUX_VAL_SHIFT; + if (!is_valid_cache(val)) + return -ENOENT; + + if (get_user(newval, uval)) + return -EFAULT; + + /* This is also invariant: you can't change it. */ + if (newval != get_ccsidr(val)) + return -EINVAL; + return 0; + default: + return -ENOENT; + } +} + +int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) +{ + const struct sys_reg_desc *r; + void __user *uaddr = (void __user *)(unsigned long)reg->addr; + + if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX) + return demux_c15_get(reg->id, uaddr); + + if (KVM_REG_SIZE(reg->id) != sizeof(__u64)) + return -ENOENT; + + r = index_to_sys_reg_desc(vcpu, reg->id); + if (!r) + return get_invariant_sys_reg(reg->id, uaddr); + + return reg_to_user(uaddr, &vcpu_sys_reg(vcpu, r->reg), reg->id); +} + +int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) +{ + const struct sys_reg_desc *r; + void __user *uaddr = (void __user *)(unsigned long)reg->addr; + + if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX) + return demux_c15_set(reg->id, uaddr); + + if (KVM_REG_SIZE(reg->id) != sizeof(__u64)) + return -ENOENT; + + r = index_to_sys_reg_desc(vcpu, reg->id); + if (!r) + return set_invariant_sys_reg(reg->id, uaddr); + + return reg_from_user(&vcpu_sys_reg(vcpu, r->reg), uaddr, reg->id); +} + +static unsigned int num_demux_regs(void) +{ + unsigned int i, count = 0; + + for (i = 0; i < CSSELR_MAX; i++) + if (is_valid_cache(i)) + count++; + + return count; +} + +static int write_demux_regids(u64 __user *uindices) +{ + u64 val = KVM_REG_ARM | KVM_REG_SIZE_U32 | KVM_REG_ARM_DEMUX; + unsigned int i; + + val |= KVM_REG_ARM_DEMUX_ID_CCSIDR; + for (i = 0; i < CSSELR_MAX; i++) { + if (!is_valid_cache(i)) + continue; + if (put_user(val | i, uindices)) + return -EFAULT; + uindices++; + } + return 0; +} + +static u64 sys_reg_to_index(const struct sys_reg_desc *reg) +{ + return (KVM_REG_ARM64 | KVM_REG_SIZE_U64 | + KVM_REG_ARM64_SYSREG | + (reg->Op0 << KVM_REG_ARM64_SYSREG_OP0_SHIFT) | + (reg->Op1 << KVM_REG_ARM64_SYSREG_OP1_SHIFT) | + (reg->CRn << KVM_REG_ARM64_SYSREG_CRN_SHIFT) | + (reg->CRm << KVM_REG_ARM64_SYSREG_CRM_SHIFT) | + (reg->Op2 << KVM_REG_ARM64_SYSREG_OP2_SHIFT)); +} + +static bool copy_reg_to_user(const struct sys_reg_desc *reg, u64 __user **uind) +{ + if (!*uind) + return true; + + if (put_user(sys_reg_to_index(reg), *uind)) + return false; + + (*uind)++; + return true; +} + +/* Assumed ordered tables, see kvm_sys_reg_table_init. */ +static int walk_sys_regs(struct kvm_vcpu *vcpu, u64 __user *uind) +{ + const struct sys_reg_desc *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, true, &num); + end1 = i1 + num; + i2 = sys_reg_descs; + end2 = sys_reg_descs + ARRAY_SIZE(sys_reg_descs); + + BUG_ON(i1 == end1 || i2 == end2); + + /* Walk carefully, as both tables may refer to the same register. */ + while (i1 || i2) { + int cmp = cmp_sys_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_sys_reg_descs(struct kvm_vcpu *vcpu) +{ + return ARRAY_SIZE(invariant_sys_regs) + + num_demux_regs() + + walk_sys_regs(vcpu, (u64 __user *)NULL); +} + +int kvm_arm_copy_sys_reg_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_sys_regs); i++) { + if (put_user(sys_reg_to_index(&invariant_sys_regs[i]), uindices)) + return -EFAULT; + uindices++; + } + + err = walk_sys_regs(vcpu, uindices); + if (err < 0) + return err; + uindices += err; + + return write_demux_regids(uindices); +} + +void kvm_sys_reg_table_init(void) +{ + unsigned int i; + struct sys_reg_desc clidr; + + /* Make sure tables are unique and in order. */ + for (i = 1; i < ARRAY_SIZE(sys_reg_descs); i++) + BUG_ON(cmp_sys_reg(&sys_reg_descs[i-1], &sys_reg_descs[i]) >= 0); + + /* We abuse the reset function to overwrite the table itself. */ + for (i = 0; i < ARRAY_SIZE(invariant_sys_regs); i++) + invariant_sys_regs[i].reset(NULL, &invariant_sys_regs[i]); + + /* + * CLIDR format is awkward, so clean it up. See ARM B4.1.20: + * + * If software reads the Cache Type fields from Ctype1 + * upwards, once it has seen a value of 0b000, no caches + * exist at further-out levels of the hierarchy. So, for + * example, if Ctype3 is the first Cache Type field with a + * value of 0b000, the values of Ctype4 to Ctype7 must be + * ignored. + */ + get_clidr_el1(NULL, &clidr); /* Ugly... */ + cache_levels = clidr.val; + for (i = 0; i < 7; i++) + if (((cache_levels >> (i*3)) & 7) == 0) + break; + /* Clear all higher bits. */ + cache_levels &= (1 << (i*3))-1; +} + +/** + * kvm_reset_sys_regs - sets system registers to reset value + * @vcpu: The VCPU pointer + * + * This function finds the right table above and sets the registers on the + * virtual CPU struct to their architecturally defined reset values. + */ +void kvm_reset_sys_regs(struct kvm_vcpu *vcpu) +{ + size_t num; + const struct sys_reg_desc *table; + + /* Catch someone adding a register without putting in reset entry. */ + memset(&vcpu->arch.ctxt.sys_regs, 0x42, sizeof(vcpu->arch.ctxt.sys_regs)); + + /* Generic chip reset first (so target could override). */ + reset_sys_reg_descs(vcpu, sys_reg_descs, ARRAY_SIZE(sys_reg_descs)); + + table = get_target_table(vcpu->arch.target, true, &num); + reset_sys_reg_descs(vcpu, table, num); + + for (num = 1; num < NR_SYS_REGS; num++) + if (vcpu_sys_reg(vcpu, num) == 0x4242424242424242) + panic("Didn't reset vcpu_sys_reg(%zi)", num); +} |