/*
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2015 Mihai Carabas <mihai.carabas@gmail.com>
 * Copyright (c) 2024 Ruslan Bukin <br@bsdpad.com>
 *
 * This software was developed by the University of Cambridge Computer
 * Laboratory (Department of Computer Science and Technology) under Innovate
 * UK project 105694, "Digital Security by Design (DSbD) Technology Platform
 * Prototype".
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef _VMM_H_
#define _VMM_H_

#include <sys/param.h>
#include <sys/cpuset.h>
#include <vm/vm.h>
#include <vm/pmap.h>

#include "pte.h"
#include "pmap.h"

struct vcpu;

enum vm_suspend_how {
        VM_SUSPEND_NONE,
        VM_SUSPEND_RESET,
        VM_SUSPEND_POWEROFF,
        VM_SUSPEND_HALT,
        VM_SUSPEND_DESTROY,
        VM_SUSPEND_LAST
};

/*
 * Identifiers for architecturally defined registers.
 */
enum vm_reg_name {
        VM_REG_GUEST_ZERO = 0,
        VM_REG_GUEST_RA,
        VM_REG_GUEST_SP,
        VM_REG_GUEST_GP,
        VM_REG_GUEST_TP,
        VM_REG_GUEST_T0,
        VM_REG_GUEST_T1,
        VM_REG_GUEST_T2,
        VM_REG_GUEST_S0,
        VM_REG_GUEST_S1,
        VM_REG_GUEST_A0,
        VM_REG_GUEST_A1,
        VM_REG_GUEST_A2,
        VM_REG_GUEST_A3,
        VM_REG_GUEST_A4,
        VM_REG_GUEST_A5,
        VM_REG_GUEST_A6,
        VM_REG_GUEST_A7,
        VM_REG_GUEST_S2,
        VM_REG_GUEST_S3,
        VM_REG_GUEST_S4,
        VM_REG_GUEST_S5,
        VM_REG_GUEST_S6,
        VM_REG_GUEST_S7,
        VM_REG_GUEST_S8,
        VM_REG_GUEST_S9,
        VM_REG_GUEST_S10,
        VM_REG_GUEST_S11,
        VM_REG_GUEST_T3,
        VM_REG_GUEST_T4,
        VM_REG_GUEST_T5,
        VM_REG_GUEST_T6,
        VM_REG_GUEST_SEPC,
        VM_REG_LAST
};

#define VM_INTINFO_VECTOR(info) ((info) & 0xff)
#define VM_INTINFO_DEL_ERRCODE  0x800
#define VM_INTINFO_RSVD         0x7ffff000
#define VM_INTINFO_VALID        0x80000000
#define VM_INTINFO_TYPE         0x700
#define VM_INTINFO_HWINTR       (0 << 8)
#define VM_INTINFO_NMI          (2 << 8)
#define VM_INTINFO_HWEXCEPTION  (3 << 8)
#define VM_INTINFO_SWINTR       (4 << 8)

#ifdef _KERNEL
#include <machine/vmm_instruction_emul.h>

#define VMM_VCPU_MD_FIELDS                                              \
        struct vm_exit  exitinfo;                                       \
        uint64_t        nextpc;         /* (x) next instruction to execute */ \
        struct fpreg    *guestfpu       /* (a,i) guest fpu state */

#define VMM_VM_MD_FIELDS                                                \
        struct vmm_mmio_region mmio_region[VM_MAX_MMIO_REGIONS]

struct vm;
struct vm_eventinfo;
struct vm_exception;
struct vm_exit;
struct vm_run;
struct vm_object;
struct vm_guest_paging;
struct vm_aplic_descr;
struct pmap;

struct vmm_mmio_region {
        uint64_t start;
        uint64_t end;
        mem_region_read_t read;
        mem_region_write_t write;
};
#define VM_MAX_MMIO_REGIONS     4

#define DECLARE_VMMOPS_FUNC(ret_type, opname, args)             \
        ret_type vmmops_##opname args

DECLARE_VMMOPS_FUNC(int, modinit, (void));
DECLARE_VMMOPS_FUNC(int, modcleanup, (void));
DECLARE_VMMOPS_FUNC(void *, init, (struct vm *vm, struct pmap *pmap));
DECLARE_VMMOPS_FUNC(int, gla2gpa, (void *vcpui, struct vm_guest_paging *paging,
    uint64_t gla, int prot, uint64_t *gpa, int *is_fault));
DECLARE_VMMOPS_FUNC(int, run, (void *vcpui, register_t pc, struct pmap *pmap,
    struct vm_eventinfo *info));
DECLARE_VMMOPS_FUNC(void, cleanup, (void *vmi));
DECLARE_VMMOPS_FUNC(void *, vcpu_init, (void *vmi, struct vcpu *vcpu,
    int vcpu_id));
DECLARE_VMMOPS_FUNC(void, vcpu_cleanup, (void *vcpui));
DECLARE_VMMOPS_FUNC(int, exception, (void *vcpui, uint64_t scause));
DECLARE_VMMOPS_FUNC(int, getreg, (void *vcpui, int num, uint64_t *retval));
DECLARE_VMMOPS_FUNC(int, setreg, (void *vcpui, int num, uint64_t val));
DECLARE_VMMOPS_FUNC(int, getcap, (void *vcpui, int num, int *retval));
DECLARE_VMMOPS_FUNC(int, setcap, (void *vcpui, int num, int val));
DECLARE_VMMOPS_FUNC(struct vmspace *, vmspace_alloc, (vm_offset_t min,
    vm_offset_t max));
DECLARE_VMMOPS_FUNC(void, vmspace_free, (struct vmspace *vmspace));

int vm_get_register(struct vcpu *vcpu, int reg, uint64_t *retval);
int vm_set_register(struct vcpu *vcpu, int reg, uint64_t val);
int vm_run(struct vcpu *vcpu);
void *vm_get_cookie(struct vm *vm);
void *vcpu_get_cookie(struct vcpu *vcpu);
int vm_get_capability(struct vcpu *vcpu, int type, int *val);
int vm_set_capability(struct vcpu *vcpu, int type, int val);
int vm_inject_exception(struct vcpu *vcpu, uint64_t scause);
int vm_attach_aplic(struct vm *vm, struct vm_aplic_descr *descr);
int vm_assert_irq(struct vm *vm, uint32_t irq);
int vm_deassert_irq(struct vm *vm, uint32_t irq);
int vm_raise_msi(struct vm *vm, uint64_t msg, uint64_t addr, int bus, int slot,
    int func);
struct vm_exit *vm_exitinfo(struct vcpu *vcpu);
void vm_exit_suspended(struct vcpu *vcpu, uint64_t pc);
void vm_exit_debug(struct vcpu *vcpu, uint64_t pc);
void vm_exit_astpending(struct vcpu *vcpu, uint64_t pc);
#endif  /* _KERNEL */

#define VM_DIR_READ     0
#define VM_DIR_WRITE    1

#define VM_GP_M_MASK            0x1f
#define VM_GP_MMU_ENABLED       (1 << 5)

struct vm_guest_paging {
        int             flags;
        int             padding;
};

struct vie {
        uint8_t access_size:4, sign_extend:1, dir:1, unused:2;
        enum vm_reg_name reg;
};

struct vre {
        uint32_t inst_syndrome;
        uint8_t dir:1, unused:7;
        enum vm_reg_name reg;
};

/*
 * Identifiers for optional vmm capabilities
 */
enum vm_cap_type {
        VM_CAP_UNRESTRICTED_GUEST,
        VM_CAP_SSTC,
        VM_CAP_MAX
};

enum vm_exitcode {
        VM_EXITCODE_BOGUS,
        VM_EXITCODE_ECALL,
        VM_EXITCODE_HYP,
        VM_EXITCODE_PAGING,
        VM_EXITCODE_SUSPENDED,
        VM_EXITCODE_DEBUG,
        VM_EXITCODE_INST_EMUL,
        VM_EXITCODE_WFI,
        VM_EXITCODE_MAX
};

struct vm_exit {
        uint64_t scause;
        uint64_t sepc;
        uint64_t stval;
        uint64_t htval;
        uint64_t htinst;
        enum vm_exitcode exitcode;
        int inst_length;
        uint64_t pc;
        union {
                struct {
                        uint64_t gpa;
                } paging;

                struct {
                        uint64_t gpa;
                        struct vm_guest_paging paging;
                        struct vie vie;
                } inst_emul;

                struct {
                        uint64_t args[8];
                } ecall;

                struct {
                        enum vm_suspend_how how;
                } suspended;

                struct {
                        uint64_t scause;
                } hyp;
        } u;
};

#endif  /* _VMM_H_ */