/*-
 * 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.
 */

/*
 * AMD64 machine dependent routines for kvm and minidumps.
 */

#include <sys/user.h>      /* MUST BE FIRST */
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/fnv_hash.h>
#include <strings.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <nlist.h>

#include <cpu/pmap.h>
#include <vm/vm.h>
#include <vm/vm_param.h>

#include <machine/elf.h>
#include <machine/cpufunc.h>
#include <machine/minidump.h>

#include <limits.h>

#include "kvm.h"
#include "kvm_private.h"

struct hpte {
        struct hpte *next;
        vm_paddr_t pa;
        int64_t off;
};

#define HPT_SIZE 1024

/* minidump must be the first item! */
struct vmstate {
        int minidump;           /* 1 = minidump mode */
        int pgtable;            /* pagetable mode */
        void *hpt_head[HPT_SIZE];
        uint64_t *bitmap;
        uint64_t *ptemap;
        uint64_t kernbase;
        uint64_t dmapbase;
        uint64_t dmapend;
        uint64_t bitmapsize;
};

static void
hpt_insert(kvm_t *kd, vm_paddr_t pa, int64_t off)
{
        struct hpte *hpte;
        uint32_t fnv = FNV1_32_INIT;

        fnv = fnv_32_buf(&pa, sizeof(pa), fnv);
        fnv &= (HPT_SIZE - 1);
        hpte = malloc(sizeof(*hpte));
        hpte->pa = pa;
        hpte->off = off;
        hpte->next = kd->vmst->hpt_head[fnv];
        kd->vmst->hpt_head[fnv] = hpte;
}

static int64_t
hpt_find(kvm_t *kd, vm_paddr_t pa)
{
        struct hpte *hpte;
        uint32_t fnv = FNV1_32_INIT;

        fnv = fnv_32_buf(&pa, sizeof(pa), fnv);
        fnv &= (HPT_SIZE - 1);
        for (hpte = kd->vmst->hpt_head[fnv]; hpte != NULL; hpte = hpte->next) {
                if (pa == hpte->pa)
                        return (hpte->off);
        }
        return (-1);
}

static int
inithash(kvm_t *kd, uint64_t *base, int len, off_t off)
{
        uint64_t idx;
        uint64_t bit, bits;
        vm_paddr_t pa;

        for (idx = 0; idx < len / sizeof(*base); idx++) {
                bits = base[idx];
                while (bits) {
                        bit = bsfq(bits);
                        bits &= ~(1ul << bit);
                        pa = (idx * sizeof(*base) * NBBY + bit) * PAGE_SIZE;
                        hpt_insert(kd, pa, off);
                        off += PAGE_SIZE;
                }
        }
        return (off);
}

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

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

static int _kvm_minidump_init_hdr1(kvm_t *kd, struct vmstate *vmst,
                        struct minidumphdr1 *hdr);
static int _kvm_minidump_init_hdr2(kvm_t *kd, struct vmstate *vmst,
                        struct minidumphdr2 *hdr);

int
_kvm_minidump_initvtop(kvm_t *kd)
{
        struct vmstate *vmst;
        int error;
        union {
                struct minidumphdr1 hdr1;
                struct minidumphdr2 hdr2;
        } u;

        vmst = _kvm_malloc(kd, sizeof(*vmst));
        if (vmst == NULL) {
                _kvm_err(kd, kd->program, "cannot allocate vm");
                return (-1);
        }
        kd->vmst = vmst;
        bzero(vmst, sizeof(*vmst));
        vmst->minidump = 1;

        if (pread(kd->pmfd, &u, sizeof(u), 0) != sizeof(u)) {
                _kvm_err(kd, kd->program, "cannot read dump header");
                return (-1);
        }
        if (strncmp(MINIDUMP1_MAGIC, u.hdr1.magic, sizeof(u.hdr1.magic)) == 0 &&
            u.hdr1.version == MINIDUMP1_VERSION) {
                error = _kvm_minidump_init_hdr1(kd, vmst, &u.hdr1);
        } else
        if (strncmp(MINIDUMP2_MAGIC, u.hdr1.magic, sizeof(u.hdr1.magic)) == 0 &&
            u.hdr2.version == MINIDUMP2_VERSION) {
                error = _kvm_minidump_init_hdr2(kd, vmst, &u.hdr2);
        } else {
                _kvm_err(kd, kd->program, "not a minidump for this platform");
                error = -1;
        }
        return error;
}

static
int
_kvm_minidump_init_hdr1(kvm_t *kd, struct vmstate *vmst,
                        struct minidumphdr1 *hdr)
{
        off_t off;

        /* Skip header and msgbuf */
        off = PAGE_SIZE + round_page(hdr->msgbufsize);

        vmst->bitmap = _kvm_malloc(kd, hdr->bitmapsize);
        if (vmst->bitmap == NULL) {
                _kvm_err(kd, kd->program,
                         "cannot allocate %jd bytes for bitmap",
                         (intmax_t)hdr->bitmapsize);
                return (-1);
        }
        if (pread(kd->pmfd, vmst->bitmap, hdr->bitmapsize, off) !=
            hdr->bitmapsize) {
                _kvm_err(kd, kd->program,
                         "cannot read %jd bytes for page bitmap",
                         (intmax_t)hdr->bitmapsize);
                return (-1);
        }
        off += round_page(vmst->bitmapsize);

        vmst->ptemap = _kvm_malloc(kd, hdr->ptesize);
        if (vmst->ptemap == NULL) {
                _kvm_err(kd, kd->program,
                         "cannot allocate %jd bytes for ptemap",
                         (intmax_t)hdr->ptesize);
                return (-1);
        }
        if (pread(kd->pmfd, vmst->ptemap, hdr->ptesize, off) !=
            hdr->ptesize) {
                _kvm_err(kd, kd->program,
                         "cannot read %jd bytes for ptemap",
                         (intmax_t)hdr->ptesize);
                return (-1);
        }
        off += hdr->ptesize;

        vmst->kernbase = hdr->kernbase;
        vmst->dmapbase = hdr->dmapbase;
        vmst->dmapend = hdr->dmapend;
        vmst->bitmapsize = hdr->bitmapsize;
        vmst->pgtable = 0;

        /* build physical address hash table for sparse pages */
        inithash(kd, vmst->bitmap, hdr->bitmapsize, off);

        return (0);
}

static
int
_kvm_minidump_init_hdr2(kvm_t *kd, struct vmstate *vmst,
                        struct minidumphdr2 *hdr)
{
        off_t off;

        /* Skip header and msgbuf */
        off = PAGE_SIZE + round_page(hdr->msgbufsize);

        vmst->bitmap = _kvm_malloc(kd, hdr->bitmapsize);
        if (vmst->bitmap == NULL) {
                _kvm_err(kd, kd->program,
                         "cannot allocate %jd bytes for bitmap",
                         (intmax_t)hdr->bitmapsize);
                return (-1);
        }
        if (pread(kd->pmfd, vmst->bitmap, hdr->bitmapsize, off) !=
            (intmax_t)hdr->bitmapsize) {
                _kvm_err(kd, kd->program,
                         "cannot read %jd bytes for page bitmap",
                         (intmax_t)hdr->bitmapsize);
                return (-1);
        }
        off += round_page(hdr->bitmapsize);

        vmst->ptemap = _kvm_malloc(kd, hdr->ptesize);
        if (vmst->ptemap == NULL) {
                _kvm_err(kd, kd->program,
                         "cannot allocate %jd bytes for ptemap",
                         (intmax_t)hdr->ptesize);
                return (-1);
        }
        if (pread(kd->pmfd, vmst->ptemap, hdr->ptesize, off) !=
            (intmax_t)hdr->ptesize) {
                _kvm_err(kd, kd->program,
                         "cannot read %jd bytes for ptemap",
                         (intmax_t)hdr->ptesize);
                return (-1);
        }
        off += hdr->ptesize;

        vmst->kernbase = hdr->kernbase;
        vmst->dmapbase = hdr->dmapbase;
        vmst->bitmapsize = hdr->bitmapsize;
        vmst->pgtable = 1;

        /* build physical address hash table for sparse pages */
        inithash(kd, vmst->bitmap, hdr->bitmapsize, off);

        return (0);
}

static int
_kvm_minidump_vatop(kvm_t *kd, u_long va, off_t *pa)
{
        struct vmstate *vm;
        u_long offset;
        pt_entry_t pte;
        u_long pteindex;
        u_long a;
        off_t ofs;

        vm = kd->vmst;
        offset = va & (PAGE_SIZE - 1);
        va -= offset;                   /* put va on page boundary */

        if (va >= vm->kernbase) {
                switch (vm->pgtable) {
                case 0:
                        /*
                         * Page tables are specifically dumped (old style)
                         */
                        pteindex = (va - vm->kernbase) >> PAGE_SHIFT;
                        pte = vm->ptemap[pteindex];
                        if (((u_long)pte & X86_PG_V) == 0) {
                                _kvm_err(kd, kd->program,
                                         "_kvm_vatop: pte not valid");
                                goto invalid;
                        }
                        a = pte & PG_FRAME;
                        break;
                case 1:
                        /*
                         * Kernel page table pages are included in the
                         * sparse map.  We only dump the contents of
                         * the PDs (zero-filling any empty entries).
                         *
                         * Index of PD entry in PDP & PDP in PML4E together.
                         *
                         * First shift by 30 (1GB) - gives us an index
                         * into PD entries.  We do not PDP entries in the
                         * PML4E, so there are 512 * 512 PD entries possible.
                         */
                        pteindex = (va >> PDPSHIFT) & (512 * 512 - 1);
                        pte = vm->ptemap[pteindex];
                        if ((pte & X86_PG_V) == 0) {
                                _kvm_err(kd, kd->program,
                                         "_kvm_vatop: pd not valid");
                                goto invalid;
                        }
                        if (pte & X86_PG_PS) {          /* 1GB pages */
                                a = (pte & PG_PS_FRAME) +
                                    (va & (1024 * 1024 * 1024 - 1));
                                break;
                        }
                                                        /* PD page */
                        ofs = hpt_find(kd, pte & PG_FRAME);
                        if (ofs == -1) {
                                _kvm_err(kd, kd->program,
                                         "_kvm_vatop: no phys page for pd");
                                goto invalid;
                        }

                        /*
                         * Index of PT entry in PD
                         */
                        pteindex = (va >> PDRSHIFT) & 511;
                        if (pread(kd->pmfd, &pte, sizeof(pte),
                              ofs + pteindex * sizeof(pte)) != sizeof(pte)) {
                                _kvm_err(kd, kd->program,
                                         "_kvm_vatop: pd lookup not valid");
                                goto invalid;
                        }
                        if ((pte & X86_PG_V) == 0) {
                                _kvm_err(kd, kd->program,
                                         "_kvm_vatop: pt not valid");
                                goto invalid;
                        }
                        if (pte & X86_PG_PS) {          /* 2MB pages */
                                a = (pte & PG_PS_FRAME) +
                                    (va & (2048 * 1024 - 1));
                                break;
                        }
                        ofs = hpt_find(kd, pte & PG_FRAME);
                        if (ofs == -1) {
                                _kvm_err(kd, kd->program,
                                         "_kvm_vatop: no phys page for pt");
                                goto invalid;
                        }

                        /*
                         * Index of pte entry in PT
                         */
                        pteindex = (va >> PAGE_SHIFT) & 511;
                        if (pread(kd->pmfd, &pte, sizeof(pte),
                              ofs + pteindex * sizeof(pte)) != sizeof(pte)) {
                                _kvm_err(kd, kd->program,
                                         "_kvm_vatop: pte lookup not valid");
                                goto invalid;
                        }

                        /*
                         * Calculate end page
                         */
                        a = pte & PG_FRAME;
                        break;
                default:
                        _kvm_err(kd, kd->program,
                                 "_kvm_vatop: bad pgtable mode ");
                        goto invalid;
                }
                ofs = hpt_find(kd, a);
                if (ofs == -1) {
                        _kvm_err(kd, kd->program, "_kvm_vatop: physical address 0x%lx not in minidump", a);
                        goto invalid;
                }
                *pa = ofs + offset;
                return (PAGE_SIZE - offset);
        } else if (va >= vm->dmapbase && va < vm->dmapend) {
                a = (va - vm->dmapbase) & ~PAGE_MASK;
                ofs = hpt_find(kd, a);
                if (ofs == -1) {
                        _kvm_err(kd, kd->program, "_kvm_vatop: direct map address 0x%lx not in minidump", va);
                        goto invalid;
                }
                *pa = ofs + offset;
                return (PAGE_SIZE - offset);
        } else {
                _kvm_err(kd, kd->program, "_kvm_vatop: virtual address 0x%lx not minidumped", va);
                goto invalid;
        }

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

int
_kvm_minidump_kvatop(kvm_t *kd, u_long va, off_t *pa)
{
        if (kvm_ishost(kd)) {
                _kvm_err(kd, 0, "kvm_vatop called in live kernel!");
                return((off_t)0);
        }

        return (_kvm_minidump_vatop(kd, va, pa));
}