/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2006 Peter Wemm
 *
 * 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 THE 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 THE 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.
 */

#include <sys/cdefs.h>
/*
 * AMD64 machine dependent routines for kvm and minidumps.
 */

#include <sys/param.h>
#include <sys/endian.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <vm/vm.h>
#include <kvm.h>

#include "../../sys/amd64/include/minidump.h"

#include <limits.h>

#include "kvm_private.h"
#include "kvm_amd64.h"

#define amd64_round_page(x)     roundup2((kvaddr_t)(x), AMD64_PAGE_SIZE)
#define VM_IS_V1(vm)            (vm->hdr.version == 1)
#define VA_OFF(vm, va)          \
        (VM_IS_V1(vm) ? ((va) & (AMD64_PAGE_SIZE - 1)) : ((va) & AMD64_PAGE_MASK))

struct vmstate {
        struct minidumphdr hdr;
};

static vm_prot_t
_amd64_entry_to_prot(uint64_t entry)
{
        vm_prot_t prot = VM_PROT_READ;

        if ((entry & AMD64_PG_RW) != 0)
                prot |= VM_PROT_WRITE;
        if ((entry & AMD64_PG_NX) == 0)
                prot |= VM_PROT_EXECUTE;
        return prot;
}

/*
 * Version 2 minidumps use page directory entries, while version 1 use page
 * table entries.
 */

static amd64_pde_t
_amd64_pde_get(kvm_t *kd, u_long pdeindex)
{
        amd64_pde_t *pde = _kvm_pmap_get(kd, pdeindex, sizeof(*pde));

        return le64toh(*pde);
}

static amd64_pte_t
_amd64_pte_get(kvm_t *kd, u_long pteindex)
{
        amd64_pte_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte));

        return le64toh(*pte);
}

/* Get the first page table entry for a given page directory index. */
static amd64_pte_t *
_amd64_pde_first_pte(kvm_t *kd, u_long pdeindex)
{
        u_long *pa;

        pa = _kvm_pmap_get(kd, pdeindex, sizeof(amd64_pde_t));
        if (pa == NULL)
                return NULL;
        return _kvm_map_get(kd, *pa & AMD64_PG_FRAME, AMD64_PAGE_SIZE);
}

static int
_amd64_minidump_probe(kvm_t *kd)
{

        return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_X86_64) &&
            _kvm_is_minidump(kd));
}

static void
_amd64_minidump_freevtop(kvm_t *kd)
{
        struct vmstate *vm = kd->vmst;

        free(vm);
        kd->vmst = NULL;
}

static int
_amd64_minidump_initvtop(kvm_t *kd)
{
        struct vmstate *vmst;
        off_t off, dump_avail_off, sparse_off;

        vmst = _kvm_malloc(kd, sizeof(*vmst));
        if (vmst == NULL) {
                _kvm_err(kd, kd->program, "cannot allocate vm");
                return (-1);
        }
        kd->vmst = vmst;
        if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) !=
            sizeof(vmst->hdr)) {
                _kvm_err(kd, kd->program, "cannot read dump header");
                return (-1);
        }
        if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic, sizeof(vmst->hdr.magic)) != 0) {
                _kvm_err(kd, kd->program, "not a minidump for this platform");
                return (-1);
        }

        /*
         * NB: amd64 minidump header is binary compatible between version 1
         * and version 2; version 3 adds the dumpavailsize field
         */
        vmst->hdr.version = le32toh(vmst->hdr.version);
        if (vmst->hdr.version > MINIDUMP_VERSION || vmst->hdr.version < 1) {
                _kvm_err(kd, kd->program, "wrong minidump version. expected %d got %d",
                    MINIDUMP_VERSION, vmst->hdr.version);
                return (-1);
        }
        vmst->hdr.msgbufsize = le32toh(vmst->hdr.msgbufsize);
        vmst->hdr.bitmapsize = le32toh(vmst->hdr.bitmapsize);
        vmst->hdr.pmapsize = le32toh(vmst->hdr.pmapsize);
        vmst->hdr.kernbase = le64toh(vmst->hdr.kernbase);
        vmst->hdr.dmapbase = le64toh(vmst->hdr.dmapbase);
        vmst->hdr.dmapend = le64toh(vmst->hdr.dmapend);
        vmst->hdr.dumpavailsize = vmst->hdr.version == MINIDUMP_VERSION ?
            le32toh(vmst->hdr.dumpavailsize) : 0;

        /* Skip header and msgbuf */
        dump_avail_off = AMD64_PAGE_SIZE + amd64_round_page(vmst->hdr.msgbufsize);

        /* Skip dump_avail */
        off = dump_avail_off + amd64_round_page(vmst->hdr.dumpavailsize);

        sparse_off = off + amd64_round_page(vmst->hdr.bitmapsize) +
            amd64_round_page(vmst->hdr.pmapsize);
        if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
            vmst->hdr.bitmapsize, off, sparse_off, AMD64_PAGE_SIZE) == -1) {
                return (-1);
        }
        off += amd64_round_page(vmst->hdr.bitmapsize);

        if (_kvm_pmap_init(kd, vmst->hdr.pmapsize, off) == -1) {
                return (-1);
        }
        off += amd64_round_page(vmst->hdr.pmapsize);

        return (0);
}

static int
_amd64_minidump_vatop_v1(kvm_t *kd, kvaddr_t va, off_t *pa)
{
        struct vmstate *vm;
        amd64_physaddr_t offset;
        amd64_pte_t pte;
        kvaddr_t pteindex;
        amd64_physaddr_t a;
        off_t ofs;

        vm = kd->vmst;
        offset = va & AMD64_PAGE_MASK;

        if (va >= vm->hdr.kernbase) {
                pteindex = (va - vm->hdr.kernbase) >> AMD64_PAGE_SHIFT;
                if (pteindex >= vm->hdr.pmapsize / sizeof(pte))
                        goto invalid;
                pte = _amd64_pte_get(kd, pteindex);
                if ((pte & AMD64_PG_V) == 0) {
                        _kvm_err(kd, kd->program,
                            "_amd64_minidump_vatop_v1: pte not valid");
                        goto invalid;
                }
                a = pte & AMD64_PG_FRAME;
                ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE);
                if (ofs == -1) {
                        _kvm_err(kd, kd->program,
            "_amd64_minidump_vatop_v1: physical address 0x%jx not in minidump",
                            (uintmax_t)a);
                        goto invalid;
                }
                *pa = ofs + offset;
                return (AMD64_PAGE_SIZE - offset);
        } else if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) {
                a = (va - vm->hdr.dmapbase) & ~AMD64_PAGE_MASK;
                ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE);
                if (ofs == -1) {
                        _kvm_err(kd, kd->program,
    "_amd64_minidump_vatop_v1: direct map address 0x%jx not in minidump",
                            (uintmax_t)va);
                        goto invalid;
                }
                *pa = ofs + offset;
                return (AMD64_PAGE_SIZE - offset);
        } else {
                _kvm_err(kd, kd->program,
            "_amd64_minidump_vatop_v1: virtual address 0x%jx not minidumped",
                    (uintmax_t)va);
                goto invalid;
        }

invalid:
        _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
        return (0);
}

static int
_amd64_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
{
        amd64_pte_t pt[AMD64_NPTEPG];
        struct vmstate *vm;
        amd64_physaddr_t offset;
        amd64_pde_t pde;
        amd64_pte_t pte;
        kvaddr_t pteindex;
        kvaddr_t pdeindex;
        amd64_physaddr_t a;
        off_t ofs;

        vm = kd->vmst;
        offset = va & AMD64_PAGE_MASK;

        if (va >= vm->hdr.kernbase) {
                pdeindex = (va - vm->hdr.kernbase) >> AMD64_PDRSHIFT;
                if (pdeindex >= vm->hdr.pmapsize / sizeof(pde))
                        goto invalid;
                pde = _amd64_pde_get(kd, pdeindex);
                if ((pde & AMD64_PG_V) == 0) {
                        _kvm_err(kd, kd->program,
                            "_amd64_minidump_vatop: pde not valid");
                        goto invalid;
                }
                if ((pde & AMD64_PG_PS) == 0) {
                        a = pde & AMD64_PG_FRAME;
                        /* TODO: Just read the single PTE */
                        ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE);
                        if (ofs == -1) {
                                _kvm_err(kd, kd->program,
                                    "cannot find page table entry for %ju",
                                    (uintmax_t)a);
                                goto invalid;
                        }
                        if (pread(kd->pmfd, &pt, AMD64_PAGE_SIZE, ofs) !=
                            AMD64_PAGE_SIZE) {
                                _kvm_err(kd, kd->program,
                                    "cannot read page table entry for %ju",
                                    (uintmax_t)a);
                                goto invalid;
                        }
                        pteindex = (va >> AMD64_PAGE_SHIFT) &
                            (AMD64_NPTEPG - 1);
                        pte = le64toh(pt[pteindex]);
                        if ((pte & AMD64_PG_V) == 0) {
                                _kvm_err(kd, kd->program,
                                    "_amd64_minidump_vatop: pte not valid");
                                goto invalid;
                        }
                        a = pte & AMD64_PG_FRAME;
                } else {
                        a = pde & AMD64_PG_PS_FRAME;
                        a += (va & AMD64_PDRMASK) ^ offset;
                }
                ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE);
                if (ofs == -1) {
                        _kvm_err(kd, kd->program,
            "_amd64_minidump_vatop: physical address 0x%jx not in minidump",
                            (uintmax_t)a);
                        goto invalid;
                }
                *pa = ofs + offset;
                return (AMD64_PAGE_SIZE - offset);
        } else if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) {
                a = (va - vm->hdr.dmapbase) & ~AMD64_PAGE_MASK;
                ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE);
                if (ofs == -1) {
                        _kvm_err(kd, kd->program,
            "_amd64_minidump_vatop: direct map address 0x%jx not in minidump",
                            (uintmax_t)va);
                        goto invalid;
                }
                *pa = ofs + offset;
                return (AMD64_PAGE_SIZE - offset);
        } else {
                _kvm_err(kd, kd->program,
            "_amd64_minidump_vatop: virtual address 0x%jx not minidumped",
                    (uintmax_t)va);
                goto invalid;
        }

invalid:
        _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
        return (0);
}

static int
_amd64_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
{

        if (ISALIVE(kd)) {
                _kvm_err(kd, 0,
                    "_amd64_minidump_kvatop called in live kernel!");
                return (0);
        }
        if (((struct vmstate *)kd->vmst)->hdr.version == 1)
                return (_amd64_minidump_vatop_v1(kd, va, pa));
        else
                return (_amd64_minidump_vatop(kd, va, pa));
}

static int
_amd64_minidump_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *arg)
{
        struct vmstate *vm = kd->vmst;
        u_long npdes = vm->hdr.pmapsize / sizeof(amd64_pde_t);
        u_long bmindex, dva, pa, pdeindex, va;
        struct kvm_bitmap bm;
        int ret = 0;
        vm_prot_t prot;
        unsigned int pgsz = AMD64_PAGE_SIZE;

        if (vm->hdr.version < 2)
                return (0);

        if (!_kvm_bitmap_init(&bm, vm->hdr.bitmapsize, &bmindex))
                return (0);

        for (pdeindex = 0; pdeindex < npdes; pdeindex++) {
                amd64_pde_t pde = _amd64_pde_get(kd, pdeindex);
                amd64_pte_t *ptes;
                u_long i;

                va = vm->hdr.kernbase + (pdeindex << AMD64_PDRSHIFT);
                if ((pde & AMD64_PG_V) == 0)
                        continue;

                if ((pde & AMD64_PG_PS) != 0) {
                        /*
                         * Large page.  Iterate on each 4K page section
                         * within this page.  This differs from 4K pages in
                         * that every page here uses the same PDE to
                         * generate permissions.
                         */
                        pa = (pde & AMD64_PG_PS_FRAME) +
                            ((va & AMD64_PDRMASK) ^ VA_OFF(vm, va));
                        dva = vm->hdr.dmapbase + pa;
                        _kvm_bitmap_set(&bm, _kvm_pa_bit_id(kd, pa, AMD64_PAGE_SIZE));
                        if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
                            _amd64_entry_to_prot(pde), AMD64_NBPDR, pgsz)) {
                                goto out;
                        }
                        continue;
                }

                /* 4K pages: pde references another page of entries. */
                ptes = _amd64_pde_first_pte(kd, pdeindex);
                /* Ignore page directory pages that were not dumped. */
                if (ptes == NULL)
                        continue;

                for (i = 0; i < AMD64_NPTEPG; i++) {
                        amd64_pte_t pte = (u_long)ptes[i];

                        pa = pte & AMD64_PG_FRAME;
                        dva = vm->hdr.dmapbase + pa;
                        if ((pte & AMD64_PG_V) != 0) {
                                _kvm_bitmap_set(&bm,
                                    _kvm_pa_bit_id(kd, pa, AMD64_PAGE_SIZE));
                                if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
                                    _amd64_entry_to_prot(pte), pgsz, 0)) {
                                        goto out;
                                }
                        }
                        va += AMD64_PAGE_SIZE;
                }
        }

        while (_kvm_bitmap_next(&bm, &bmindex)) {
                pa = _kvm_bit_id_pa(kd, bmindex, AMD64_PAGE_SIZE);
                if (pa == _KVM_PA_INVALID)
                        break;
                dva = vm->hdr.dmapbase + pa;
                if (vm->hdr.dmapend < (dva + pgsz))
                        break;
                va = 0;
                /* amd64/pmap.c: create_pagetables(): dmap always R|W. */
                prot = VM_PROT_READ | VM_PROT_WRITE;
                if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva, prot, pgsz, 0)) {
                        goto out;
                }
        }

        ret = 1;

out:
        _kvm_bitmap_deinit(&bm);
        return (ret);
}

static struct kvm_arch kvm_amd64_minidump = {
        .ka_probe = _amd64_minidump_probe,
        .ka_initvtop = _amd64_minidump_initvtop,
        .ka_freevtop = _amd64_minidump_freevtop,
        .ka_kvatop = _amd64_minidump_kvatop,
        .ka_native = _amd64_native,
        .ka_walk_pages = _amd64_minidump_walk_pages,
};

KVM_ARCH(kvm_amd64_minidump);