Update Linux to v5.10.109

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz

Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c
new file mode 100644
index 0000000..20ba513
--- /dev/null
+++ b/arch/arm64/kvm/psci.c
@@ -0,0 +1,578 @@
+// 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 (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;
+}