linux/arch/loongarch/kvm/vcpu.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
 */

#include <linux/kvm_host.h>
#include <linux/entry-kvm.h>
#include <asm/fpu.h>
#include <asm/loongarch.h>
#include <asm/setup.h>
#include <asm/time.h>

#define CREATE_TRACE_POINTS
#include "trace.h"

const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
	KVM_GENERIC_VCPU_STATS(),
	STATS_DESC_COUNTER(VCPU, int_exits),
	STATS_DESC_COUNTER(VCPU, idle_exits),
	STATS_DESC_COUNTER(VCPU, cpucfg_exits),
	STATS_DESC_COUNTER(VCPU, signal_exits),
};

const struct kvm_stats_header kvm_vcpu_stats_header = {
	.name_size = KVM_STATS_NAME_SIZE,
	.num_desc = ARRAY_SIZE(kvm_vcpu_stats_desc),
	.id_offset = sizeof(struct kvm_stats_header),
	.desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
	.data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
		       sizeof(kvm_vcpu_stats_desc),
};

/*
 * kvm_check_requests - check and handle pending vCPU requests
 *
 * Return: RESUME_GUEST if we should enter the guest
 *         RESUME_HOST  if we should exit to userspace
 */
static int kvm_check_requests(struct kvm_vcpu *vcpu)
{
	if (!kvm_request_pending(vcpu))
		return RESUME_GUEST;

	if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu))
		vcpu->arch.vpid = 0;  /* Drop vpid for this vCPU */

	if (kvm_dirty_ring_check_request(vcpu))
		return RESUME_HOST;

	return RESUME_GUEST;
}

/*
 * Check and handle pending signal and vCPU requests etc
 * Run with irq enabled and preempt enabled
 *
 * Return: RESUME_GUEST if we should enter the guest
 *         RESUME_HOST  if we should exit to userspace
 *         < 0 if we should exit to userspace, where the return value
 *         indicates an error
 */
static int kvm_enter_guest_check(struct kvm_vcpu *vcpu)
{
	int ret;

	/*
	 * Check conditions before entering the guest
	 */
	ret = xfer_to_guest_mode_handle_work(vcpu);
	if (ret < 0)
		return ret;

	ret = kvm_check_requests(vcpu);

	return ret;
}

/*
 * Called with irq enabled
 *
 * Return: RESUME_GUEST if we should enter the guest, and irq disabled
 *         Others if we should exit to userspace
 */
static int kvm_pre_enter_guest(struct kvm_vcpu *vcpu)
{
	int ret;

	do {
		ret = kvm_enter_guest_check(vcpu);
		if (ret != RESUME_GUEST)
			break;

		/*
		 * Handle vcpu timer, interrupts, check requests and
		 * check vmid before vcpu enter guest
		 */
		local_irq_disable();
		kvm_acquire_timer(vcpu);
		kvm_deliver_intr(vcpu);
		kvm_deliver_exception(vcpu);
		/* Make sure the vcpu mode has been written */
		smp_store_mb(vcpu->mode, IN_GUEST_MODE);
		kvm_check_vpid(vcpu);
		vcpu->arch.host_eentry = csr_read64(LOONGARCH_CSR_EENTRY);
		/* Clear KVM_LARCH_SWCSR_LATEST as CSR will change when enter guest */
		vcpu->arch.aux_inuse &= ~KVM_LARCH_SWCSR_LATEST;

		if (kvm_request_pending(vcpu) || xfer_to_guest_mode_work_pending()) {
			/* make sure the vcpu mode has been written */
			smp_store_mb(vcpu->mode, OUTSIDE_GUEST_MODE);
			local_irq_enable();
			ret = -EAGAIN;
		}
	} while (ret != RESUME_GUEST);

	return ret;
}

/*
 * Return 1 for resume guest and "<= 0" for resume host.
 */
static int kvm_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
{
	int ret = RESUME_GUEST;
	unsigned long estat = vcpu->arch.host_estat;
	u32 intr = estat & 0x1fff; /* Ignore NMI */
	u32 ecode = (estat & CSR_ESTAT_EXC) >> CSR_ESTAT_EXC_SHIFT;

	vcpu->mode = OUTSIDE_GUEST_MODE;

	/* Set a default exit reason */
	run->exit_reason = KVM_EXIT_UNKNOWN;

	guest_timing_exit_irqoff();
	guest_state_exit_irqoff();
	local_irq_enable();

	trace_kvm_exit(vcpu, ecode);
	if (ecode) {
		ret = kvm_handle_fault(vcpu, ecode);
	} else {
		WARN(!intr, "vm exiting with suspicious irq\n");
		++vcpu->stat.int_exits;
	}

	if (ret == RESUME_GUEST)
		ret = kvm_pre_enter_guest(vcpu);

	if (ret != RESUME_GUEST) {
		local_irq_disable();
		return ret;
	}

	guest_timing_enter_irqoff();
	guest_state_enter_irqoff();
	trace_kvm_reenter(vcpu);

	return RESUME_GUEST;
}

int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
{
	return !!(vcpu->arch.irq_pending) &&
		vcpu->arch.mp_state.mp_state == KVM_MP_STATE_RUNNABLE;
}

int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
{
	return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
}

bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu)
{
	return false;
}

vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
{
	return VM_FAULT_SIGBUS;
}

int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
				  struct kvm_translation *tr)
{
	return -EINVAL;
}

int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
{
	int ret;

	/* Protect from TOD sync and vcpu_load/put() */
	preempt_disable();
	ret = kvm_pending_timer(vcpu) ||
		kvm_read_hw_gcsr(LOONGARCH_CSR_ESTAT) & (1 << INT_TI);
	preempt_enable();

	return ret;
}

int kvm_arch_vcpu_dump_regs(struct kvm_vcpu *vcpu)
{
	int i;

	kvm_debug("vCPU Register Dump:\n");
	kvm_debug("\tPC = 0x%08lx\n", vcpu->arch.pc);
	kvm_debug("\tExceptions: %08lx\n", vcpu->arch.irq_pending);

	for (i = 0; i < 32; i += 4) {
		kvm_debug("\tGPR%02d: %08lx %08lx %08lx %08lx\n", i,
		       vcpu->arch.gprs[i], vcpu->arch.gprs[i + 1],
		       vcpu->arch.gprs[i + 2], vcpu->arch.gprs[i + 3]);
	}

	kvm_debug("\tCRMD: 0x%08lx, ESTAT: 0x%08lx\n",
		  kvm_read_hw_gcsr(LOONGARCH_CSR_CRMD),
		  kvm_read_hw_gcsr(LOONGARCH_CSR_ESTAT));

	kvm_debug("\tERA: 0x%08lx\n", kvm_read_hw_gcsr(LOONGARCH_CSR_ERA));

	return 0;
}

int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
				struct kvm_mp_state *mp_state)
{
	*mp_state = vcpu->arch.mp_state;

	return 0;
}

int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
				struct kvm_mp_state *mp_state)
{
	int ret = 0;

	switch (mp_state->mp_state) {
	case KVM_MP_STATE_RUNNABLE:
		vcpu->arch.mp_state = *mp_state;
		break;
	default:
		ret = -EINVAL;
	}

	return ret;
}

int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
					struct kvm_guest_debug *dbg)
{
	return -EINVAL;
}

/**
 * kvm_migrate_count() - Migrate timer.
 * @vcpu:       Virtual CPU.
 *
 * Migrate hrtimer to the current CPU by cancelling and restarting it
 * if the hrtimer is active.
 *
 * Must be called when the vCPU is migrated to a different CPU, so that
 * the timer can interrupt the guest at the new CPU, and the timer irq can
 * be delivered to the vCPU.
 */
static void kvm_migrate_count(struct kvm_vcpu *vcpu)
{
	if (hrtimer_cancel(&vcpu->arch.swtimer))
		hrtimer_restart(&vcpu->arch.swtimer);
}

static int _kvm_getcsr(struct kvm_vcpu *vcpu, unsigned int id, u64 *val)
{
	unsigned long gintc;
	struct loongarch_csrs *csr = vcpu->arch.csr;

	if (get_gcsr_flag(id) & INVALID_GCSR)
		return -EINVAL;

	if (id == LOONGARCH_CSR_ESTAT) {
		/* ESTAT IP0~IP7 get from GINTC */
		gintc = kvm_read_sw_gcsr(csr, LOONGARCH_CSR_GINTC) & 0xff;
		*val = kvm_read_sw_gcsr(csr, LOONGARCH_CSR_ESTAT) | (gintc << 2);
		return 0;
	}

	/*
	 * Get software CSR state since software state is consistent
	 * with hardware for synchronous ioctl
	 */
	*val = kvm_read_sw_gcsr(csr, id);

	return 0;
}

static int _kvm_setcsr(struct kvm_vcpu *vcpu, unsigned int id, u64 val)
{
	int ret = 0, gintc;
	struct loongarch_csrs *csr = vcpu->arch.csr;

	if (get_gcsr_flag(id) & INVALID_GCSR)
		return -EINVAL;

	if (id == LOONGARCH_CSR_ESTAT) {
		/* ESTAT IP0~IP7 inject through GINTC */
		gintc = (val >> 2) & 0xff;
		kvm_set_sw_gcsr(csr, LOONGARCH_CSR_GINTC, gintc);

		gintc = val & ~(0xffUL << 2);
		kvm_set_sw_gcsr(csr, LOONGARCH_CSR_ESTAT, gintc);

		return ret;
	}

	kvm_write_sw_gcsr(csr, id, val);

	return ret;
}

static int kvm_get_one_reg(struct kvm_vcpu *vcpu,
		const struct kvm_one_reg *reg, u64 *v)
{
	int id, ret = 0;
	u64 type = reg->id & KVM_REG_LOONGARCH_MASK;

	switch (type) {
	case KVM_REG_LOONGARCH_CSR:
		id = KVM_GET_IOC_CSR_IDX(reg->id);
		ret = _kvm_getcsr(vcpu, id, v);
		break;
	case KVM_REG_LOONGARCH_CPUCFG:
		id = KVM_GET_IOC_CPUCFG_IDX(reg->id);
		if (id >= 0 && id < KVM_MAX_CPUCFG_REGS)
			*v = vcpu->arch.cpucfg[id];
		else
			ret = -EINVAL;
		break;
	case KVM_REG_LOONGARCH_KVM:
		switch (reg->id) {
		case KVM_REG_LOONGARCH_COUNTER:
			*v = drdtime() + vcpu->kvm->arch.time_offset;
			break;
		default:
			ret = -EINVAL;
			break;
		}
		break;
	default:
		ret = -EINVAL;
		break;
	}

	return ret;
}

static int kvm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
	int ret = 0;
	u64 v, size = reg->id & KVM_REG_SIZE_MASK;

	switch (size) {
	case KVM_REG_SIZE_U64:
		ret = kvm_get_one_reg(vcpu, reg, &v);
		if (ret)
			return ret;
		ret = put_user(v, (u64 __user *)(long)reg->addr);
		break;
	default:
		ret = -EINVAL;
		break;
	}

	return ret;
}

static int kvm_set_one_reg(struct kvm_vcpu *vcpu,
			const struct kvm_one_reg *reg, u64 v)
{
	int id, ret = 0;
	u64 type = reg->id & KVM_REG_LOONGARCH_MASK;

	switch (type) {
	case KVM_REG_LOONGARCH_CSR:
		id = KVM_GET_IOC_CSR_IDX(reg->id);
		ret = _kvm_setcsr(vcpu, id, v);
		break;
	case KVM_REG_LOONGARCH_CPUCFG:
		id = KVM_GET_IOC_CPUCFG_IDX(reg->id);
		if (id >= 0 && id < KVM_MAX_CPUCFG_REGS)
			vcpu->arch.cpucfg[id] = (u32)v;
		else
			ret = -EINVAL;
		break;
	case KVM_REG_LOONGARCH_KVM:
		switch (reg->id) {
		case KVM_REG_LOONGARCH_COUNTER:
			/*
			 * gftoffset is relative with board, not vcpu
			 * only set for the first time for smp system
			 */
			if (vcpu->vcpu_id == 0)
				vcpu->kvm->arch.time_offset = (signed long)(v - drdtime());
			break;
		case KVM_REG_LOONGARCH_VCPU_RESET:
			kvm_reset_timer(vcpu);
			memset(&vcpu->arch.irq_pending, 0, sizeof(vcpu->arch.irq_pending));
			memset(&vcpu->arch.irq_clear, 0, sizeof(vcpu->arch.irq_clear));
			break;
		default:
			ret = -EINVAL;
			break;
		}
		break;
	default:
		ret = -EINVAL;
		break;
	}

	return ret;
}

static int kvm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
	int ret = 0;
	u64 v, size = reg->id & KVM_REG_SIZE_MASK;

	switch (size) {
	case KVM_REG_SIZE_U64:
		ret = get_user(v, (u64 __user *)(long)reg->addr);
		if (ret)
			return ret;
		break;
	default:
		return -EINVAL;
	}

	return kvm_set_one_reg(vcpu, reg, v);
}

int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
{
	return -ENOIOCTLCMD;
}

int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
{
	return -ENOIOCTLCMD;
}

int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(vcpu->arch.gprs); i++)
		regs->gpr[i] = vcpu->arch.gprs[i];

	regs->pc = vcpu->arch.pc;

	return 0;
}

int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
{
	int i;

	for (i = 1; i < ARRAY_SIZE(vcpu->arch.gprs); i++)
		vcpu->arch.gprs[i] = regs->gpr[i];

	vcpu->arch.gprs[0] = 0; /* zero is special, and cannot be set. */
	vcpu->arch.pc = regs->pc;

	return 0;
}

static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
				     struct kvm_enable_cap *cap)
{
	/* FPU is enabled by default, will support LSX/LASX later. */
	return -EINVAL;
}

long kvm_arch_vcpu_ioctl(struct file *filp,
			 unsigned int ioctl, unsigned long arg)
{
	long r;
	void __user *argp = (void __user *)arg;
	struct kvm_vcpu *vcpu = filp->private_data;

	/*
	 * Only software CSR should be modified
	 *
	 * If any hardware CSR register is modified, vcpu_load/vcpu_put pair
	 * should be used. Since CSR registers owns by this vcpu, if switch
	 * to other vcpus, other vcpus need reload CSR registers.
	 *
	 * If software CSR is modified, bit KVM_LARCH_HWCSR_USABLE should
	 * be clear in vcpu->arch.aux_inuse, and vcpu_load will check
	 * aux_inuse flag and reload CSR registers form software.
	 */

	switch (ioctl) {
	case KVM_SET_ONE_REG:
	case KVM_GET_ONE_REG: {
		struct kvm_one_reg reg;

		r = -EFAULT;
		if (copy_from_user(&reg, argp, sizeof(reg)))
			break;
		if (ioctl == KVM_SET_ONE_REG) {
			r = kvm_set_reg(vcpu, &reg);
			vcpu->arch.aux_inuse &= ~KVM_LARCH_HWCSR_USABLE;
		} else
			r = kvm_get_reg(vcpu, &reg);
		break;
	}
	case KVM_ENABLE_CAP: {
		struct kvm_enable_cap cap;

		r = -EFAULT;
		if (copy_from_user(&cap, argp, sizeof(cap)))
			break;
		r = kvm_vcpu_ioctl_enable_cap(vcpu, &cap);
		break;
	}
	default:
		r = -ENOIOCTLCMD;
		break;
	}

	return r;
}

int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
{
	int i = 0;

	fpu->fcc = vcpu->arch.fpu.fcc;
	fpu->fcsr = vcpu->arch.fpu.fcsr;
	for (i = 0; i < NUM_FPU_REGS; i++)
		memcpy(&fpu->fpr[i], &vcpu->arch.fpu.fpr[i], FPU_REG_WIDTH / 64);

	return 0;
}

int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
{
	int i = 0;

	vcpu->arch.fpu.fcc = fpu->fcc;
	vcpu->arch.fpu.fcsr = fpu->fcsr;
	for (i = 0; i < NUM_FPU_REGS; i++)
		memcpy(&vcpu->arch.fpu.fpr[i], &fpu->fpr[i], FPU_REG_WIDTH / 64);

	return 0;
}

/* Enable FPU and restore context */
void kvm_own_fpu(struct kvm_vcpu *vcpu)
{
	preempt_disable();

	/* Enable FPU */
	set_csr_euen(CSR_EUEN_FPEN);

	kvm_restore_fpu(&vcpu->arch.fpu);
	vcpu->arch.aux_inuse |= KVM_LARCH_FPU;
	trace_kvm_aux(vcpu, KVM_TRACE_AUX_RESTORE, KVM_TRACE_AUX_FPU);

	preempt_enable();
}

/* Save context and disable FPU */
void kvm_lose_fpu(struct kvm_vcpu *vcpu)
{
	preempt_disable();

	if (vcpu->arch.aux_inuse & KVM_LARCH_FPU) {
		kvm_save_fpu(&vcpu->arch.fpu);
		vcpu->arch.aux_inuse &= ~KVM_LARCH_FPU;
		trace_kvm_aux(vcpu, KVM_TRACE_AUX_SAVE, KVM_TRACE_AUX_FPU);

		/* Disable FPU */
		clear_csr_euen(CSR_EUEN_FPEN);
	}

	preempt_enable();
}

int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
{
	int intr = (int)irq->irq;

	if (intr > 0)
		kvm_queue_irq(vcpu, intr);
	else if (intr < 0)
		kvm_dequeue_irq(vcpu, -intr);
	else {
		kvm_err("%s: invalid interrupt ioctl %d\n", __func__, irq->irq);
		return -EINVAL;
	}

	kvm_vcpu_kick(vcpu);

	return 0;
}

long kvm_arch_vcpu_async_ioctl(struct file *filp,
			       unsigned int ioctl, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	struct kvm_vcpu *vcpu = filp->private_data;

	if (ioctl == KVM_INTERRUPT) {
		struct kvm_interrupt irq;

		if (copy_from_user(&irq, argp, sizeof(irq)))
			return -EFAULT;

		kvm_debug("[%d] %s: irq: %d\n", vcpu->vcpu_id, __func__, irq.irq);

		return kvm_vcpu_ioctl_interrupt(vcpu, &irq);
	}

	return -ENOIOCTLCMD;
}

int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
{
	return 0;
}

int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
{
	unsigned long timer_hz;
	struct loongarch_csrs *csr;

	vcpu->arch.vpid = 0;

	hrtimer_init(&vcpu->arch.swtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
	vcpu->arch.swtimer.function = kvm_swtimer_wakeup;

	vcpu->arch.handle_exit = kvm_handle_exit;
	vcpu->arch.guest_eentry = (unsigned long)kvm_loongarch_ops->exc_entry;
	vcpu->arch.csr = kzalloc(sizeof(struct loongarch_csrs), GFP_KERNEL);
	if (!vcpu->arch.csr)
		return -ENOMEM;

	/*
	 * All kvm exceptions share one exception entry, and host <-> guest
	 * switch also switch ECFG.VS field, keep host ECFG.VS info here.
	 */
	vcpu->arch.host_ecfg = (read_csr_ecfg() & CSR_ECFG_VS);

	/* Init */
	vcpu->arch.last_sched_cpu = -1;

	/*
	 * Initialize guest register state to valid architectural reset state.
	 */
	timer_hz = calc_const_freq();
	kvm_init_timer(vcpu, timer_hz);

	/* Set Initialize mode for guest */
	csr = vcpu->arch.csr;
	kvm_write_sw_gcsr(csr, LOONGARCH_CSR_CRMD, CSR_CRMD_DA);

	/* Set cpuid */
	kvm_write_sw_gcsr(csr, LOONGARCH_CSR_TMID, vcpu->vcpu_id);

	/* Start with no pending virtual guest interrupts */
	csr->csrs[LOONGARCH_CSR_GINTC] = 0;

	return 0;
}

void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
{
}

void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
{
	int cpu;
	struct kvm_context *context;

	hrtimer_cancel(&vcpu->arch.swtimer);
	kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
	kfree(vcpu->arch.csr);

	/*
	 * If the vCPU is freed and reused as another vCPU, we don't want the
	 * matching pointer wrongly hanging around in last_vcpu.
	 */
	for_each_possible_cpu(cpu) {
		context = per_cpu_ptr(vcpu->kvm->arch.vmcs, cpu);
		if (context->last_vcpu == vcpu)
			context->last_vcpu = NULL;
	}
}

static int _kvm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
	bool migrated;
	struct kvm_context *context;
	struct loongarch_csrs *csr = vcpu->arch.csr;

	/*
	 * Have we migrated to a different CPU?
	 * If so, any old guest TLB state may be stale.
	 */
	migrated = (vcpu->arch.last_sched_cpu != cpu);

	/*
	 * Was this the last vCPU to run on this CPU?
	 * If not, any old guest state from this vCPU will have been clobbered.
	 */
	context = per_cpu_ptr(vcpu->kvm->arch.vmcs, cpu);
	if (migrated || (context->last_vcpu != vcpu))
		vcpu->arch.aux_inuse &= ~KVM_LARCH_HWCSR_USABLE;
	context->last_vcpu = vcpu;

	/* Restore timer state regardless */
	kvm_restore_timer(vcpu);

	/* Control guest page CCA attribute */
	change_csr_gcfg(CSR_GCFG_MATC_MASK, CSR_GCFG_MATC_ROOT);

	/* Don't bother restoring registers multiple times unless necessary */
	if (vcpu->arch.aux_inuse & KVM_LARCH_HWCSR_USABLE)
		return 0;

	write_csr_gcntc((ulong)vcpu->kvm->arch.time_offset);

	/* Restore guest CSR registers */
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_CRMD);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_PRMD);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_EUEN);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_MISC);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_ECFG);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_ERA);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_BADV);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_BADI);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_EENTRY);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBIDX);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBEHI);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBELO0);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBELO1);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_ASID);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_PGDL);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_PGDH);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_PWCTL0);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_PWCTL1);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_STLBPGSIZE);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_RVACFG);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_CPUID);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_KS0);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_KS1);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_KS2);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_KS3);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_KS4);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_KS5);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_KS6);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_KS7);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TMID);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_CNTC);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBRENTRY);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBRBADV);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBRERA);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBRSAVE);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBRELO0);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBRELO1);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBREHI);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBRPRMD);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_DMWIN0);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_DMWIN1);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_DMWIN2);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_DMWIN3);
	kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_LLBCTL);

	/* Restore Root.GINTC from unused Guest.GINTC register */
	write_csr_gintc(csr->csrs[LOONGARCH_CSR_GINTC]);

	/*
	 * We should clear linked load bit to break interrupted atomics. This
	 * prevents a SC on the next vCPU from succeeding by matching a LL on
	 * the previous vCPU.
	 */
	if (vcpu->kvm->created_vcpus > 1)
		set_gcsr_llbctl(CSR_LLBCTL_WCLLB);

	vcpu->arch.aux_inuse |= KVM_LARCH_HWCSR_USABLE;

	return 0;
}

void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
	unsigned long flags;

	local_irq_save(flags);
	if (vcpu->arch.last_sched_cpu != cpu) {
		kvm_debug("[%d->%d]KVM vCPU[%d] switch\n",
				vcpu->arch.last_sched_cpu, cpu, vcpu->vcpu_id);
		/*
		 * Migrate the timer interrupt to the current CPU so that it
		 * always interrupts the guest and synchronously triggers a
		 * guest timer interrupt.
		 */
		kvm_migrate_count(vcpu);
	}

	/* Restore guest state to registers */
	_kvm_vcpu_load(vcpu, cpu);
	local_irq_restore(flags);
}

static int _kvm_vcpu_put(struct kvm_vcpu *vcpu, int cpu)
{
	struct loongarch_csrs *csr = vcpu->arch.csr;

	kvm_lose_fpu(vcpu);

	/*
	 * Update CSR state from hardware if software CSR state is stale,
	 * most CSR registers are kept unchanged during process context
	 * switch except CSR registers like remaining timer tick value and
	 * injected interrupt state.
	 */
	if (vcpu->arch.aux_inuse & KVM_LARCH_SWCSR_LATEST)
		goto out;

	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_CRMD);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_PRMD);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_EUEN);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_MISC);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_ECFG);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_ERA);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_BADV);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_BADI);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_EENTRY);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBIDX);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBEHI);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBELO0);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBELO1);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_ASID);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_PGDL);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_PGDH);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_PWCTL0);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_PWCTL1);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_STLBPGSIZE);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_RVACFG);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_CPUID);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_PRCFG1);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_PRCFG2);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_PRCFG3);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_KS0);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_KS1);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_KS2);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_KS3);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_KS4);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_KS5);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_KS6);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_KS7);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TMID);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_CNTC);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_LLBCTL);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBRENTRY);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBRBADV);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBRERA);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBRSAVE);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBRELO0);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBRELO1);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBREHI);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBRPRMD);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_DMWIN0);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_DMWIN1);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_DMWIN2);
	kvm_save_hw_gcsr(csr, LOONGARCH_CSR_DMWIN3);

	vcpu->arch.aux_inuse |= KVM_LARCH_SWCSR_LATEST;

out:
	kvm_save_timer(vcpu);
	/* Save Root.GINTC into unused Guest.GINTC register */
	csr->csrs[LOONGARCH_CSR_GINTC] = read_csr_gintc();

	return 0;
}

void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
	int cpu;
	unsigned long flags;

	local_irq_save(flags);
	cpu = smp_processor_id();
	vcpu->arch.last_sched_cpu = cpu;

	/* Save guest state in registers */
	_kvm_vcpu_put(vcpu, cpu);
	local_irq_restore(flags);
}

int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
{
	int r = -EINTR;
	struct kvm_run *run = vcpu->run;

	if (vcpu->mmio_needed) {
		if (!vcpu->mmio_is_write)
			kvm_complete_mmio_read(vcpu, run);
		vcpu->mmio_needed = 0;
	}

	if (run->exit_reason == KVM_EXIT_LOONGARCH_IOCSR) {
		if (!run->iocsr_io.is_write)
			kvm_complete_iocsr_read(vcpu, run);
	}

	if (run->immediate_exit)
		return r;

	/* Clear exit_reason */
	run->exit_reason = KVM_EXIT_UNKNOWN;
	lose_fpu(1);
	vcpu_load(vcpu);
	kvm_sigset_activate(vcpu);
	r = kvm_pre_enter_guest(vcpu);
	if (r != RESUME_GUEST)
		goto out;

	guest_timing_enter_irqoff();
	guest_state_enter_irqoff();
	trace_kvm_enter(vcpu);
	r = kvm_loongarch_ops->enter_guest(run, vcpu);

	trace_kvm_out(vcpu);
	/*
	 * Guest exit is already recorded at kvm_handle_exit()
	 * return value must not be RESUME_GUEST
	 */
	local_irq_enable();
out:
	kvm_sigset_deactivate(vcpu);
	vcpu_put(vcpu);

	return r;
}