path: root/arch/riscv/kvm/vcpu.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2019 Western Digital Corporation or its affiliates.
 *
 * Authors:
 *     Anup Patel <anup.patel@wdc.com>
 */

#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/kdebug.h>
#include <linux/module.h>
#include <linux/percpu.h>
#include <linux/vmalloc.h>
#include <linux/sched/signal.h>
#include <linux/fs.h>
#include <linux/kvm_host.h>
#include <asm/cacheflush.h>
#include <asm/kvm_mmu.h>
#include <asm/kvm_nacl.h>
#include <asm/kvm_vcpu_vector.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, ecall_exit_stat),
	STATS_DESC_COUNTER(VCPU, wfi_exit_stat),
	STATS_DESC_COUNTER(VCPU, wrs_exit_stat),
	STATS_DESC_COUNTER(VCPU, mmio_exit_user),
	STATS_DESC_COUNTER(VCPU, mmio_exit_kernel),
	STATS_DESC_COUNTER(VCPU, csr_exit_user),
	STATS_DESC_COUNTER(VCPU, csr_exit_kernel),
	STATS_DESC_COUNTER(VCPU, signal_exits),
	STATS_DESC_COUNTER(VCPU, exits),
	STATS_DESC_COUNTER(VCPU, instr_illegal_exits),
	STATS_DESC_COUNTER(VCPU, load_misaligned_exits),
	STATS_DESC_COUNTER(VCPU, store_misaligned_exits),
	STATS_DESC_COUNTER(VCPU, load_access_exits),
	STATS_DESC_COUNTER(VCPU, store_access_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),
};

static void kvm_riscv_vcpu_context_reset(struct kvm_vcpu *vcpu,
					 bool kvm_sbi_reset)
{
	struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
	struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;
	void *vector_datap = cntx->vector.datap;

	memset(cntx, 0, sizeof(*cntx));
	memset(csr, 0, sizeof(*csr));
	memset(&vcpu->arch.smstateen_csr, 0, sizeof(vcpu->arch.smstateen_csr));

	/* Restore datap as it's not a part of the guest context. */
	cntx->vector.datap = vector_datap;

	if (kvm_sbi_reset)
		kvm_riscv_vcpu_sbi_load_reset_state(vcpu);

	/* Setup reset state of shadow SSTATUS and HSTATUS CSRs */
	cntx->sstatus = SR_SPP | SR_SPIE;

	cntx->hstatus |= HSTATUS_VTW;
	cntx->hstatus |= HSTATUS_SPVP;
	cntx->hstatus |= HSTATUS_SPV;
}

static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu, bool kvm_sbi_reset)
{
	bool loaded;

	/**
	 * The preemption should be disabled here because it races with
	 * kvm_sched_out/kvm_sched_in(called from preempt notifiers) which
	 * also calls vcpu_load/put.
	 */
	get_cpu();
	loaded = (vcpu->cpu != -1);
	if (loaded)
		kvm_arch_vcpu_put(vcpu);

	vcpu->arch.last_exit_cpu = -1;

	kvm_riscv_vcpu_context_reset(vcpu, kvm_sbi_reset);

	kvm_riscv_vcpu_fp_reset(vcpu);

	kvm_riscv_vcpu_vector_reset(vcpu);

	kvm_riscv_vcpu_timer_reset(vcpu);

	kvm_riscv_vcpu_aia_reset(vcpu);

	bitmap_zero(vcpu->arch.irqs_pending, KVM_RISCV_VCPU_NR_IRQS);
	bitmap_zero(vcpu->arch.irqs_pending_mask, KVM_RISCV_VCPU_NR_IRQS);

	kvm_riscv_vcpu_pmu_reset(vcpu);

	vcpu->arch.hfence_head = 0;
	vcpu->arch.hfence_tail = 0;
	memset(vcpu->arch.hfence_queue, 0, sizeof(vcpu->arch.hfence_queue));

	kvm_riscv_vcpu_sbi_reset(vcpu);

	/* Reset the guest CSRs for hotplug usecase */
	if (loaded)
		kvm_arch_vcpu_load(vcpu, smp_processor_id());
	put_cpu();
}

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

int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
{
	int rc;

	spin_lock_init(&vcpu->arch.mp_state_lock);

	/* Mark this VCPU never ran */
	vcpu->arch.ran_atleast_once = false;

	vcpu->arch.cfg.hedeleg = KVM_HEDELEG_DEFAULT;
	vcpu->arch.mmu_page_cache.gfp_zero = __GFP_ZERO;
	bitmap_zero(vcpu->arch.isa, RISCV_ISA_EXT_MAX);

	/* Setup ISA features available to VCPU */
	kvm_riscv_vcpu_setup_isa(vcpu);

	/* Setup vendor, arch, and implementation details */
	vcpu->arch.mvendorid