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-rw-r--r--arch/arm64/kvm/psci.c580
1 files changed, 580 insertions, 0 deletions
diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c
new file mode 100644
index 000000000..32bb26be8
--- /dev/null
+++ b/arch/arm64/kvm/psci.c
@@ -0,0 +1,580 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2012 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/preempt.h>
+#include <linux/kvm_host.h>
+#include <linux/uaccess.h>
+#include <linux/wait.h>
+
+#include <asm/cputype.h>
+#include <asm/kvm_emulate.h>
+
+#include <kvm/arm_psci.h>
+#include <kvm/arm_hypercalls.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);
+ kvm_clear_request(KVM_REQ_UNHALT, vcpu);
+
+ return PSCI_RET_SUCCESS;
+}
+
+static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu)
+{
+ vcpu->arch.power_off = true;
+ kvm_make_request(KVM_REQ_SLEEP, vcpu);
+ kvm_vcpu_kick(vcpu);
+}
+
+static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
+{
+ struct vcpu_reset_state *reset_state;
+ struct kvm *kvm = source_vcpu->kvm;
+ struct kvm_vcpu *vcpu = NULL;
+ unsigned long cpu_id;
+
+ cpu_id = smccc_get_arg1(source_vcpu) & 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.power_off) {
+ if (kvm_psci_version(source_vcpu, kvm) != KVM_ARM_PSCI_0_1)
+ return PSCI_RET_ALREADY_ON;
+ else
+ return PSCI_RET_INVALID_PARAMS;
+ }
+
+ reset_state = &vcpu->arch.reset_state;
+
+ reset_state->pc = smccc_get_arg2(source_vcpu);
+
+ /* Propagate caller endianness */
+ reset_state->be = kvm_vcpu_is_be(source_vcpu);
+
+ /*
+ * NOTE: We always update r0 (or x0) because for PSCI v0.1
+ * the general purpose registers are undefined upon CPU_ON.
+ */
+ reset_state->r0 = smccc_get_arg3(source_vcpu);
+
+ WRITE_ONCE(reset_state->reset, true);
+ kvm_make_request(KVM_REQ_VCPU_RESET, vcpu);
+
+ /*
+ * Make sure the reset request is observed if the change to
+ * power_state is observed.
+ */
+ smp_wmb();
+
+ vcpu->arch.power_off = false;
+ kvm_vcpu_wake_up(vcpu);
+
+ return PSCI_RET_SUCCESS;
+}
+
+static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu)
+{
+ int i, matching_cpus = 0;
+ 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 = smccc_get_arg1(vcpu);
+ lowest_affinity_level = smccc_get_arg2(vcpu);
+
+ /* 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) {
+ matching_cpus++;
+ if (!tmp->arch.power_off)
+ return PSCI_0_2_AFFINITY_LEVEL_ON;
+ }
+ }
+
+ if (!matching_cpus)
+ return PSCI_RET_INVALID_PARAMS;
+
+ 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.power_off = true;
+ kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_SLEEP);
+
+ 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);
+}
+
+static void kvm_psci_narrow_to_32bit(struct kvm_vcpu *vcpu)
+{
+ int i;
+
+ /*
+ * Zero the input registers' upper 32 bits. They will be fully
+ * zeroed on exit, so we're fine changing them in place.
+ */
+ for (i = 1; i < 4; i++)
+ vcpu_set_reg(vcpu, i, lower_32_bits(vcpu_get_reg(vcpu, i)));
+}
+
+static unsigned long kvm_psci_check_allowed_function(struct kvm_vcpu *vcpu, u32 fn)
+{
+ switch(fn) {
+ case PSCI_0_2_FN64_CPU_SUSPEND:
+ case PSCI_0_2_FN64_CPU_ON:
+ case PSCI_0_2_FN64_AFFINITY_INFO:
+ /* Disallow these functions for 32bit guests */
+ if (vcpu_mode_is_32bit(vcpu))
+ return PSCI_RET_NOT_SUPPORTED;
+ break;
+ }
+
+ return 0;
+}
+
+static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
+{
+ struct kvm *kvm = vcpu->kvm;
+ u32 psci_fn = smccc_get_function(vcpu);
+ unsigned long val;
+ int ret = 1;
+
+ val = kvm_psci_check_allowed_function(vcpu, psci_fn);
+ if (val)
+ goto out;
+
+ switch (psci_fn) {
+ case PSCI_0_2_FN_PSCI_VERSION:
+ /*
+ * Bits[31:16] = Major Version = 0
+ * Bits[15:0] = Minor Version = 2
+ */
+ val = KVM_ARM_PSCI_0_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:
+ kvm_psci_narrow_to_32bit(vcpu);
+ fallthrough;
+ case PSCI_0_2_FN64_CPU_ON:
+ mutex_lock(&kvm->lock);
+ val = kvm_psci_vcpu_on(vcpu);
+ mutex_unlock(&kvm->lock);
+ break;
+ case PSCI_0_2_FN_AFFINITY_INFO:
+ kvm_psci_narrow_to_32bit(vcpu);
+ fallthrough;
+ 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 shouldn't be going back to guest VCPU after
+ * receiving SYSTEM_OFF request.
+ *
+ * If user space accidentally/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;
+ }
+
+out:
+ smccc_set_retval(vcpu, val, 0, 0, 0);
+ return ret;
+}
+
+static int kvm_psci_1_0_call(struct kvm_vcpu *vcpu)
+{
+ u32 psci_fn = smccc_get_function(vcpu);
+ u32 feature;
+ unsigned long val;
+ int ret = 1;
+
+ switch(psci_fn) {
+ case PSCI_0_2_FN_PSCI_VERSION:
+ val = KVM_ARM_PSCI_1_0;
+ break;
+ case PSCI_1_0_FN_PSCI_FEATURES:
+ feature = smccc_get_arg1(vcpu);
+ val = kvm_psci_check_allowed_function(vcpu, feature);
+ if (val)
+ break;
+
+ switch(feature) {
+ case PSCI_0_2_FN_PSCI_VERSION:
+ case PSCI_0_2_FN_CPU_SUSPEND:
+ case PSCI_0_2_FN64_CPU_SUSPEND:
+ case PSCI_0_2_FN_CPU_OFF:
+ case PSCI_0_2_FN_CPU_ON:
+ case PSCI_0_2_FN64_CPU_ON:
+ case PSCI_0_2_FN_AFFINITY_INFO:
+ case PSCI_0_2_FN64_AFFINITY_INFO:
+ case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
+ case PSCI_0_2_FN_SYSTEM_OFF:
+ case PSCI_0_2_FN_SYSTEM_RESET:
+ case PSCI_1_0_FN_PSCI_FEATURES:
+ case ARM_SMCCC_VERSION_FUNC_ID:
+ val = 0;
+ break;
+ default:
+ val = PSCI_RET_NOT_SUPPORTED;
+ break;
+ }
+ break;
+ default:
+ return kvm_psci_0_2_call(vcpu);
+ }
+
+ smccc_set_retval(vcpu, val, 0, 0, 0);
+ return ret;
+}
+
+static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
+{
+ struct kvm *kvm = vcpu->kvm;
+ u32 psci_fn = smccc_get_function(vcpu);
+ 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:
+ mutex_lock(&kvm->lock);
+ val = kvm_psci_vcpu_on(vcpu);
+ mutex_unlock(&kvm->lock);
+ break;
+ default:
+ val = PSCI_RET_NOT_SUPPORTED;
+ break;
+ }
+
+ smccc_set_retval(vcpu, val, 0, 0, 0);
+ 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, vcpu->kvm)) {
+ case KVM_ARM_PSCI_1_0:
+ return kvm_psci_1_0_call(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;
+ };
+}
+
+int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu)
+{
+ return 4; /* PSCI version and three workaround registers */
+}
+
+int kvm_arm_copy_fw_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
+{
+ if (put_user(KVM_REG_ARM_PSCI_VERSION, uindices++))
+ return -EFAULT;
+
+ if (put_user(KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1, uindices++))
+ return -EFAULT;
+
+ if (put_user(KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2, uindices++))
+ return -EFAULT;
+
+ if (put_user(KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3, uindices++))
+ return -EFAULT;
+
+ return 0;
+}
+
+#define KVM_REG_FEATURE_LEVEL_WIDTH 4
+#define KVM_REG_FEATURE_LEVEL_MASK (BIT(KVM_REG_FEATURE_LEVEL_WIDTH) - 1)
+
+/*
+ * Convert the workaround level into an easy-to-compare number, where higher
+ * values mean better protection.
+ */
+static int get_kernel_wa_level(u64 regid)
+{
+ switch (regid) {
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
+ switch (arm64_get_spectre_v2_state()) {
+ case SPECTRE_VULNERABLE:
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_AVAIL;
+ case SPECTRE_MITIGATED:
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_AVAIL;
+ case SPECTRE_UNAFFECTED:
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_REQUIRED;
+ }
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_AVAIL;
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2:
+ switch (arm64_get_spectre_v4_state()) {
+ case SPECTRE_MITIGATED:
+ /*
+ * As for the hypercall discovery, we pretend we
+ * don't have any FW mitigation if SSBS is there at
+ * all times.
+ */
+ if (cpus_have_final_cap(ARM64_SSBS))
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL;
+ fallthrough;
+ case SPECTRE_UNAFFECTED:
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED;
+ case SPECTRE_VULNERABLE:
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL;
+ }
+ break;
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3:
+ switch (arm64_get_spectre_bhb_state()) {
+ case SPECTRE_VULNERABLE:
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_AVAIL;
+ case SPECTRE_MITIGATED:
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_AVAIL;
+ case SPECTRE_UNAFFECTED:
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_REQUIRED;
+ }
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_AVAIL;
+ }
+
+ return -EINVAL;
+}
+
+int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
+{
+ void __user *uaddr = (void __user *)(long)reg->addr;
+ u64 val;
+
+ switch (reg->id) {
+ case KVM_REG_ARM_PSCI_VERSION:
+ val = kvm_psci_version(vcpu, vcpu->kvm);
+ break;
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2:
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3:
+ val = get_kernel_wa_level(reg->id) & KVM_REG_FEATURE_LEVEL_MASK;
+ break;
+ default:
+ return -ENOENT;
+ }
+
+ if (copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id)))
+ return -EFAULT;
+
+ return 0;
+}
+
+int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
+{
+ void __user *uaddr = (void __user *)(long)reg->addr;
+ u64 val;
+ int wa_level;
+
+ if (KVM_REG_SIZE(reg->id) != sizeof(val))
+ return -ENOENT;
+ if (copy_from_user(&val, uaddr, KVM_REG_SIZE(reg->id)))
+ return -EFAULT;
+
+ switch (reg->id) {
+ case KVM_REG_ARM_PSCI_VERSION:
+ {
+ bool wants_02;
+
+ wants_02 = test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features);
+
+ switch (val) {
+ case KVM_ARM_PSCI_0_1:
+ if (wants_02)
+ return -EINVAL;
+ vcpu->kvm->arch.psci_version = val;
+ return 0;
+ case KVM_ARM_PSCI_0_2:
+ case KVM_ARM_PSCI_1_0:
+ if (!wants_02)
+ return -EINVAL;
+ vcpu->kvm->arch.psci_version = val;
+ return 0;
+ }
+ break;
+ }
+
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3:
+ if (val & ~KVM_REG_FEATURE_LEVEL_MASK)
+ return -EINVAL;
+
+ if (get_kernel_wa_level(reg->id) < val)
+ return -EINVAL;
+
+ return 0;
+
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2:
+ if (val & ~(KVM_REG_FEATURE_LEVEL_MASK |
+ KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED))
+ return -EINVAL;
+
+ /* The enabled bit must not be set unless the level is AVAIL. */
+ if ((val & KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED) &&
+ (val & KVM_REG_FEATURE_LEVEL_MASK) != KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL)
+ return -EINVAL;
+
+ /*
+ * Map all the possible incoming states to the only two we
+ * really want to deal with.
+ */
+ switch (val & KVM_REG_FEATURE_LEVEL_MASK) {
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL:
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_UNKNOWN:
+ wa_level = KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL;
+ break;
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL:
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED:
+ wa_level = KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /*
+ * We can deal with NOT_AVAIL on NOT_REQUIRED, but not the
+ * other way around.
+ */
+ if (get_kernel_wa_level(reg->id) < wa_level)
+ return -EINVAL;
+
+ return 0;
+ default:
+ return -ENOENT;
+ }
+
+ return -EINVAL;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-27 10:53:40 +0000