| /* |
| * Copyright (C) 2012 - ARM Ltd |
| * Author: Marc Zyngier <marc.zyngier@arm.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/preempt.h> |
| #include <linux/kvm_host.h> |
| #include <linux/wait.h> |
| |
| #include <asm/cputype.h> |
| #include <asm/kvm_emulate.h> |
| #include <asm/kvm_psci.h> |
| #include <asm/kvm_host.h> |
| |
| /* |
| * This is an implementation of the Power State Coordination Interface |
| * as described in ARM document number ARM DEN 0022A. |
| */ |
| |
| #define AFFINITY_MASK(level) ~((0x1UL << ((level) * MPIDR_LEVEL_BITS)) - 1) |
| |
| static unsigned long psci_affinity_mask(unsigned long affinity_level) |
| { |
| if (affinity_level <= 3) |
| return MPIDR_HWID_BITMASK & AFFINITY_MASK(affinity_level); |
| |
| return 0; |
| } |
| |
| static unsigned long kvm_psci_vcpu_suspend(struct kvm_vcpu *vcpu) |
| { |
| /* |
| * NOTE: For simplicity, we make VCPU suspend emulation to be |
| * same-as WFI (Wait-for-interrupt) emulation. |
| * |
| * This means for KVM the wakeup events are interrupts and |
| * this is consistent with intended use of StateID as described |
| * in section 5.4.1 of PSCI v0.2 specification (ARM DEN 0022A). |
| * |
| * Further, we also treat power-down request to be same as |
| * stand-by request as-per section 5.4.2 clause 3 of PSCI v0.2 |
| * specification (ARM DEN 0022A). This means all suspend states |
| * for KVM will preserve the register state. |
| */ |
| kvm_vcpu_block(vcpu); |
| |
| return PSCI_RET_SUCCESS; |
| } |
| |
| static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu) |
| { |
| vcpu->arch.pause = true; |
| } |
| |
| static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) |
| { |
| struct kvm *kvm = source_vcpu->kvm; |
| struct kvm_vcpu *vcpu = NULL; |
| wait_queue_head_t *wq; |
| unsigned long cpu_id; |
| unsigned long context_id; |
| phys_addr_t target_pc; |
| |
| cpu_id = *vcpu_reg(source_vcpu, 1) & MPIDR_HWID_BITMASK; |
| if (vcpu_mode_is_32bit(source_vcpu)) |
| cpu_id &= ~((u32) 0); |
| |
| vcpu = kvm_mpidr_to_vcpu(kvm, cpu_id); |
| |
| /* |
| * Make sure the caller requested a valid CPU and that the CPU is |
| * turned off. |
| */ |
| if (!vcpu) |
| return PSCI_RET_INVALID_PARAMS; |
| if (!vcpu->arch.pause) { |
| if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1) |
| return PSCI_RET_ALREADY_ON; |
| else |
| return PSCI_RET_INVALID_PARAMS; |
| } |
| |
| target_pc = *vcpu_reg(source_vcpu, 2); |
| context_id = *vcpu_reg(source_vcpu, 3); |
| |
| kvm_reset_vcpu(vcpu); |
| |
| /* Gracefully handle Thumb2 entry point */ |
| if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) { |
| target_pc &= ~((phys_addr_t) 1); |
| vcpu_set_thumb(vcpu); |
| } |
| |
| /* Propagate caller endianness */ |
| if (kvm_vcpu_is_be(source_vcpu)) |
| kvm_vcpu_set_be(vcpu); |
| |
| *vcpu_pc(vcpu) = target_pc; |
| /* |
| * NOTE: We always update r0 (or x0) because for PSCI v0.1 |
| * the general puspose registers are undefined upon CPU_ON. |
| */ |
| *vcpu_reg(vcpu, 0) = context_id; |
| vcpu->arch.pause = false; |
| smp_mb(); /* Make sure the above is visible */ |
| |
| wq = kvm_arch_vcpu_wq(vcpu); |
| wake_up_interruptible(wq); |
| |
| return PSCI_RET_SUCCESS; |
| } |
| |
| static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu) |
| { |
| int i; |
| unsigned long mpidr; |
| unsigned long target_affinity; |
| unsigned long target_affinity_mask; |
| unsigned long lowest_affinity_level; |
| struct kvm *kvm = vcpu->kvm; |
| struct kvm_vcpu *tmp; |
| |
| target_affinity = *vcpu_reg(vcpu, 1); |
| lowest_affinity_level = *vcpu_reg(vcpu, 2); |
| |
| /* Determine target affinity mask */ |
| target_affinity_mask = psci_affinity_mask(lowest_affinity_level); |
| if (!target_affinity_mask) |
| return PSCI_RET_INVALID_PARAMS; |
| |
| /* Ignore other bits of target affinity */ |
| target_affinity &= target_affinity_mask; |
| |
| /* |
| * If one or more VCPU matching target affinity are running |
| * then ON else OFF |
| */ |
| kvm_for_each_vcpu(i, tmp, kvm) { |
| mpidr = kvm_vcpu_get_mpidr_aff(tmp); |
| if (((mpidr & target_affinity_mask) == target_affinity) && |
| !tmp->arch.pause) { |
| return PSCI_0_2_AFFINITY_LEVEL_ON; |
| } |
| } |
| |
| return PSCI_0_2_AFFINITY_LEVEL_OFF; |
| } |
| |
| static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type) |
| { |
| int i; |
| struct kvm_vcpu *tmp; |
| |
| /* |
| * The KVM ABI specifies that a system event exit may call KVM_RUN |
| * again and may perform shutdown/reboot at a later time that when the |
| * actual request is made. Since we are implementing PSCI and a |
| * caller of PSCI reboot and shutdown expects that the system shuts |
| * down or reboots immediately, let's make sure that VCPUs are not run |
| * after this call is handled and before the VCPUs have been |
| * re-initialized. |
| */ |
| kvm_for_each_vcpu(i, tmp, vcpu->kvm) { |
| tmp->arch.pause = true; |
| kvm_vcpu_kick(tmp); |
| } |
| |
| memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event)); |
| vcpu->run->system_event.type = type; |
| vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT; |
| } |
| |
| static void kvm_psci_system_off(struct kvm_vcpu *vcpu) |
| { |
| kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_SHUTDOWN); |
| } |
| |
| static void kvm_psci_system_reset(struct kvm_vcpu *vcpu) |
| { |
| kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET); |
| } |
| |
| int kvm_psci_version(struct kvm_vcpu *vcpu) |
| { |
| if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features)) |
| return KVM_ARM_PSCI_0_2; |
| |
| return KVM_ARM_PSCI_0_1; |
| } |
| |
| static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) |
| { |
| int ret = 1; |
| unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); |
| unsigned long val; |
| |
| switch (psci_fn) { |
| case PSCI_0_2_FN_PSCI_VERSION: |
| /* |
| * Bits[31:16] = Major Version = 0 |
| * Bits[15:0] = Minor Version = 2 |
| */ |
| val = 2; |
| break; |
| case PSCI_0_2_FN_CPU_SUSPEND: |
| case PSCI_0_2_FN64_CPU_SUSPEND: |
| val = kvm_psci_vcpu_suspend(vcpu); |
| break; |
| case PSCI_0_2_FN_CPU_OFF: |
| kvm_psci_vcpu_off(vcpu); |
| val = PSCI_RET_SUCCESS; |
| break; |
| case PSCI_0_2_FN_CPU_ON: |
| case PSCI_0_2_FN64_CPU_ON: |
| val = kvm_psci_vcpu_on(vcpu); |
| break; |
| case PSCI_0_2_FN_AFFINITY_INFO: |
| case PSCI_0_2_FN64_AFFINITY_INFO: |
| val = kvm_psci_vcpu_affinity_info(vcpu); |
| break; |
| case PSCI_0_2_FN_MIGRATE_INFO_TYPE: |
| /* |
| * Trusted OS is MP hence does not require migration |
| * or |
| * Trusted OS is not present |
| */ |
| val = PSCI_0_2_TOS_MP; |
| break; |
| case PSCI_0_2_FN_SYSTEM_OFF: |
| kvm_psci_system_off(vcpu); |
| /* |
| * We should'nt be going back to guest VCPU after |
| * receiving SYSTEM_OFF request. |
| * |
| * If user space accidently/deliberately resumes |
| * guest VCPU after SYSTEM_OFF request then guest |
| * VCPU should see internal failure from PSCI return |
| * value. To achieve this, we preload r0 (or x0) with |
| * PSCI return value INTERNAL_FAILURE. |
| */ |
| val = PSCI_RET_INTERNAL_FAILURE; |
| ret = 0; |
| break; |
| case PSCI_0_2_FN_SYSTEM_RESET: |
| kvm_psci_system_reset(vcpu); |
| /* |
| * Same reason as SYSTEM_OFF for preloading r0 (or x0) |
| * with PSCI return value INTERNAL_FAILURE. |
| */ |
| val = PSCI_RET_INTERNAL_FAILURE; |
| ret = 0; |
| break; |
| default: |
| val = PSCI_RET_NOT_SUPPORTED; |
| break; |
| } |
| |
| *vcpu_reg(vcpu, 0) = val; |
| return ret; |
| } |
| |
| static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu) |
| { |
| unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); |
| unsigned long val; |
| |
| switch (psci_fn) { |
| case KVM_PSCI_FN_CPU_OFF: |
| kvm_psci_vcpu_off(vcpu); |
| val = PSCI_RET_SUCCESS; |
| break; |
| case KVM_PSCI_FN_CPU_ON: |
| val = kvm_psci_vcpu_on(vcpu); |
| break; |
| default: |
| val = PSCI_RET_NOT_SUPPORTED; |
| break; |
| } |
| |
| *vcpu_reg(vcpu, 0) = val; |
| return 1; |
| } |
| |
| /** |
| * kvm_psci_call - handle PSCI call if r0 value is in range |
| * @vcpu: Pointer to the VCPU struct |
| * |
| * Handle PSCI calls from guests through traps from HVC instructions. |
| * The calling convention is similar to SMC calls to the secure world |
| * where the function number is placed in r0. |
| * |
| * This function returns: > 0 (success), 0 (success but exit to user |
| * space), and < 0 (errors) |
| * |
| * Errors: |
| * -EINVAL: Unrecognized PSCI function |
| */ |
| int kvm_psci_call(struct kvm_vcpu *vcpu) |
| { |
| switch (kvm_psci_version(vcpu)) { |
| case KVM_ARM_PSCI_0_2: |
| return kvm_psci_0_2_call(vcpu); |
| case KVM_ARM_PSCI_0_1: |
| return kvm_psci_0_1_call(vcpu); |
| default: |
| return -EINVAL; |
| }; |
| } |