/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2011 NetApp, Inc.
 * All rights reserved.
 *
 * 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 NETAPP, INC ``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 NETAPP, INC 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/param.h>
#ifndef WITHOUT_CAPSICUM
#include <sys/capsicum.h>
#endif
#include <sys/types.h>
#include <sys/mman.h>
#include <sys/pciio.h>
#include <sys/ioctl.h>
#include <sys/stat.h>

#include <dev/io/iodev.h>
#include <dev/pci/pcireg.h>
#include <dev/vmm/vmm_mem.h>

#include <vm/vm.h>

#include <machine/iodev.h>
#include <machine/vm.h>

#ifndef WITHOUT_CAPSICUM
#include <capsicum_helpers.h>
#endif
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <sysexits.h>
#include <unistd.h>

#include <machine/vmm.h>

#include "debug.h"
#include "mem.h"
#include "pci_passthru.h"

#ifndef _PATH_DEVPCI
#define _PATH_DEVPCI    "/dev/pci"
#endif

#define LEGACY_SUPPORT  1

#define MSIX_TABLE_COUNT(ctrl) (((ctrl) & PCIM_MSIXCTRL_TABLE_SIZE) + 1)
#define MSIX_CAPLEN 12

#define PASSTHRU_MMIO_MAX 3

static int pcifd = -1;

SET_DECLARE(passthru_dev_set, struct passthru_dev);

struct passthru_bar_handler {
        TAILQ_ENTRY(passthru_bar_handler) chain;
        uint64_t off;
        uint64_t size;
        passthru_read_handler read;
        passthru_write_handler write;
};

struct passthru_softc {
        struct pci_devinst *psc_pi;
        /* ROM is handled like a BAR */
        struct pcibar psc_bar[PCI_BARMAX_WITH_ROM + 1];
        struct {
                int             capoff;
                int             msgctrl;
                int             emulated;
        } psc_msi;
        struct {
                int             capoff;
        } psc_msix;
        struct pcisel psc_sel;

        struct passthru_mmio_mapping psc_mmio_map[PASSTHRU_MMIO_MAX];
        cfgread_handler psc_pcir_rhandler[PCI_REGMAX + 1];
        cfgwrite_handler psc_pcir_whandler[PCI_REGMAX + 1];

        TAILQ_HEAD(,
            passthru_bar_handler) psc_bar_handler[PCI_BARMAX_WITH_ROM + 1];
};

static int
msi_caplen(int msgctrl)
{
        int len;

        len = 10;               /* minimum length of msi capability */

        if (msgctrl & PCIM_MSICTRL_64BIT)
                len += 4;

#if 0
        /*
         * Ignore the 'mask' and 'pending' bits in the MSI capability.
         * We'll let the guest manipulate them directly.
         */
        if (msgctrl & PCIM_MSICTRL_VECTOR)
                len += 10;
#endif

        return (len);
}

static int
pcifd_open(void)
{
        int fd;

        fd = open(_PATH_DEVPCI, O_RDWR, 0);
        if (fd < 0) {
                warn("failed to open %s", _PATH_DEVPCI);
                return (-1);
        }
        return (fd);
}

static int
pcifd_init(void)
{
        pcifd = pcifd_open();
        if (pcifd < 0)
                return (1);

#ifndef WITHOUT_CAPSICUM
        cap_rights_t pcifd_rights;
        cap_rights_init(&pcifd_rights, CAP_IOCTL, CAP_READ, CAP_WRITE);
        if (caph_rights_limit(pcifd, &pcifd_rights) == -1)
                errx(EX_OSERR, "Unable to apply rights for sandbox");

        const cap_ioctl_t pcifd_ioctls[] = { PCIOCREAD, PCIOCWRITE, PCIOCGETBAR,
                PCIOCBARIO, PCIOCBARMMAP, PCIOCGETCONF };
        if (caph_ioctls_limit(pcifd, pcifd_ioctls, nitems(pcifd_ioctls)) == -1)
                errx(EX_OSERR, "Unable to apply rights for sandbox");
#endif

        return (0);
}

static uint32_t
host_read_config(int fd, const struct pcisel *sel, long reg, int width)
{
        struct pci_io pi;

        bzero(&pi, sizeof(pi));
        pi.pi_sel = *sel;
        pi.pi_reg = reg;
        pi.pi_width = width;

        if (ioctl(fd, PCIOCREAD, &pi) < 0)
                return (0);                     /* XXX */
        else
                return (pi.pi_data);
}

static uint32_t
passthru_read_config(const struct pcisel *sel, long reg, int width)
{
        return (host_read_config(pcifd, sel, reg, width));
}

uint32_t
pci_host_read_config(const struct pcisel *sel, long reg, int width)
{
        uint32_t ret;
        int fd;

        fd = pcifd_open();
        if (fd < 0)
                return (0);
        ret = host_read_config(fd, sel, reg, width);
        (void)close(fd);
        return (ret);
}

static void
host_write_config(int fd, const struct pcisel *sel, long reg, int width,
    uint32_t data)
{
        struct pci_io pi;

        bzero(&pi, sizeof(pi));
        pi.pi_sel = *sel;
        pi.pi_reg = reg;
        pi.pi_width = width;
        pi.pi_data = data;

        (void)ioctl(fd, PCIOCWRITE, &pi);               /* XXX */
}

static void
passthru_write_config(const struct pcisel *sel, long reg, int width,
    uint32_t data)
{
        host_write_config(pcifd, sel, reg, width, data);
}

void
pci_host_write_config(const struct pcisel *sel, long reg, int width,
    uint32_t data)
{
        int fd;

        fd = pcifd_open();
        if (fd < 0)
                return;
        host_write_config(fd, sel, reg, width, data);
        (void)close(fd);
}

#ifdef LEGACY_SUPPORT
static int
passthru_add_msicap(struct pci_devinst *pi, int msgnum, int nextptr)
{
        int capoff;
        struct msicap msicap;
        u_char *capdata;

        pci_populate_msicap(&msicap, msgnum, nextptr);

        /*
         * XXX
         * Copy the msi capability structure in the last 16 bytes of the
         * config space. This is wrong because it could shadow something
         * useful to the device.
         */
        capoff = 256 - roundup(sizeof(msicap), 4);
        capdata = (u_char *)&msicap;
        for (size_t i = 0; i < sizeof(msicap); i++)
                pci_set_cfgdata8(pi, capoff + i, capdata[i]);

        return (capoff);
}
#endif  /* LEGACY_SUPPORT */

static int
cfginitmsi(struct passthru_softc *sc)
{
        int i, ptr, capptr, cap, sts, caplen, table_size;
        uint32_t u32;
        struct pcisel sel;
        struct pci_devinst *pi;
        struct msixcap msixcap;
        char *msixcap_ptr;

        pi = sc->psc_pi;
        sel = sc->psc_sel;

        /*
         * Parse the capabilities and cache the location of the MSI
         * and MSI-X capabilities.
         */
        sts = passthru_read_config(&sel, PCIR_STATUS, 2);
        if (sts & PCIM_STATUS_CAPPRESENT) {
                ptr = passthru_read_config(&sel, PCIR_CAP_PTR, 1);
                while (ptr != 0 && ptr != 0xff) {
                        cap = passthru_read_config(&sel, ptr + PCICAP_ID, 1);
                        if (cap == PCIY_MSI) {
                                /*
                                 * Copy the MSI capability into the config
                                 * space of the emulated pci device
                                 */
                                sc->psc_msi.capoff = ptr;
                                sc->psc_msi.msgctrl =
                                    passthru_read_config(&sel, ptr + 2, 2);
                                sc->psc_msi.emulated = 0;
                                caplen = msi_caplen(sc->psc_msi.msgctrl);
                                capptr = ptr;
                                while (caplen > 0) {
                                        u32 = passthru_read_config(&sel, capptr,
                                            4);
                                        pci_set_cfgdata32(pi, capptr, u32);
                                        caplen -= 4;
                                        capptr += 4;
                                }
                        } else if (cap == PCIY_MSIX) {
                                /*
                                 * Copy the MSI-X capability
                                 */
                                sc->psc_msix.capoff = ptr;
                                caplen = 12;
                                msixcap_ptr = (char *)&msixcap;
                                capptr = ptr;
                                while (caplen > 0) {
                                        u32 = passthru_read_config(&sel, capptr,
                                            4);
                                        memcpy(msixcap_ptr, &u32, 4);
                                        pci_set_cfgdata32(pi, capptr, u32);
                                        caplen -= 4;
                                        capptr += 4;
                                        msixcap_ptr += 4;
                                }
                        }
                        ptr = passthru_read_config(&sel, ptr + PCICAP_NEXTPTR,
                            1);
                }
        }

        if (sc->psc_msix.capoff != 0) {
                pi->pi_msix.pba_bar =
                    msixcap.pba_info & PCIM_MSIX_BIR_MASK;
                pi->pi_msix.pba_offset =
                    msixcap.pba_info & ~PCIM_MSIX_BIR_MASK;
                pi->pi_msix.table_bar =
                    msixcap.table_info & PCIM_MSIX_BIR_MASK;
                pi->pi_msix.table_offset =
                    msixcap.table_info & ~PCIM_MSIX_BIR_MASK;
                pi->pi_msix.table_count = MSIX_TABLE_COUNT(msixcap.msgctrl);
                pi->pi_msix.pba_size = PBA_SIZE(pi->pi_msix.table_count);

                /* Allocate the emulated MSI-X table array */
                table_size = pi->pi_msix.table_count * MSIX_TABLE_ENTRY_SIZE;
                pi->pi_msix.table = calloc(1, table_size);

                /* Mask all table entries */
                for (i = 0; i < pi->pi_msix.table_count; i++) {
                        pi->pi_msix.table[i].vector_control |=
                                                PCIM_MSIX_VCTRL_MASK;
                }
        }

#ifdef LEGACY_SUPPORT
        /*
         * If the passthrough device does not support MSI then craft a
         * MSI capability for it. We link the new MSI capability at the
         * head of the list of capabilities.
         */
        if ((sts & PCIM_STATUS_CAPPRESENT) != 0 && sc->psc_msi.capoff == 0) {
                int origptr, msiptr;
                origptr = passthru_read_config(&sel, PCIR_CAP_PTR, 1);
                msiptr = passthru_add_msicap(pi, 1, origptr);
                sc->psc_msi.capoff = msiptr;
                sc->psc_msi.msgctrl = pci_get_cfgdata16(pi, msiptr + 2);
                sc->psc_msi.emulated = 1;
                pci_set_cfgdata8(pi, PCIR_CAP_PTR, msiptr);
        }
#endif

        /* Make sure one of the capabilities is present */
        if (sc->psc_msi.capoff == 0 && sc->psc_msix.capoff == 0)
                return (-1);
        else
                return (0);
}

static uint64_t
msix_table_read(struct passthru_softc *sc, uint64_t offset, int size)
{
        struct pci_devinst *pi;
        struct msix_table_entry *entry;
        uint8_t *src8;
        uint16_t *src16;
        uint32_t *src32;
        uint64_t *src64;
        uint64_t data;
        size_t entry_offset;
        uint32_t table_offset;
        int index, table_count;

        pi = sc->psc_pi;

        table_offset = pi->pi_msix.table_offset;
        table_count = pi->pi_msix.table_count;
        if (offset < table_offset ||
            offset >= table_offset + table_count * MSIX_TABLE_ENTRY_SIZE) {
                switch (size) {
                case 1:
                        src8 = (uint8_t *)(pi->pi_msix.mapped_addr + offset);
                        data = *src8;
                        break;
                case 2:
                        src16 = (uint16_t *)(pi->pi_msix.mapped_addr + offset);
                        data = *src16;
                        break;
                case 4:
                        src32 = (uint32_t *)(pi->pi_msix.mapped_addr + offset);
                        data = *src32;
                        break;
                case 8:
                        src64 = (uint64_t *)(pi->pi_msix.mapped_addr + offset);
                        data = *src64;
                        break;
                default:
                        return (-1);
                }
                return (data);
        }

        offset -= table_offset;
        index = offset / MSIX_TABLE_ENTRY_SIZE;
        assert(index < table_count);

        entry = &pi->pi_msix.table[index];
        entry_offset = offset % MSIX_TABLE_ENTRY_SIZE;

        switch (size) {
        case 1:
                src8 = (uint8_t *)((uint8_t *)entry + entry_offset);
                data = *src8;
                break;
        case 2:
                src16 = (uint16_t *)((uint8_t *)entry + entry_offset);
                data = *src16;
                break;
        case 4:
                src32 = (uint32_t *)((uint8_t *)entry + entry_offset);
                data = *src32;
                break;
        case 8:
                src64 = (uint64_t *)((uint8_t *)entry + entry_offset);
                data = *src64;
                break;
        default:
                return (-1);
        }

        return (data);
}

static void
msix_table_write(struct passthru_softc *sc, uint64_t offset, int size,
    uint64_t data)
{
        struct pci_devinst *pi;
        struct msix_table_entry *entry;
        uint8_t *dest8;
        uint16_t *dest16;
        uint32_t *dest32;
        uint64_t *dest64;
        size_t entry_offset;
        uint32_t table_offset, vector_control;
        int index, table_count;

        pi = sc->psc_pi;

        table_offset = pi->pi_msix.table_offset;
        table_count = pi->pi_msix.table_count;
        if (offset < table_offset ||
            offset >= table_offset + table_count * MSIX_TABLE_ENTRY_SIZE) {
                switch (size) {
                case 1:
                        dest8 = (uint8_t *)(pi->pi_msix.mapped_addr + offset);
                        *dest8 = data;
                        break;
                case 2:
                        dest16 = (uint16_t *)(pi->pi_msix.mapped_addr + offset);
                        *dest16 = data;
                        break;
                case 4:
                        dest32 = (uint32_t *)(pi->pi_msix.mapped_addr + offset);
                        *dest32 = data;
                        break;
                case 8:
                        dest64 = (uint64_t *)(pi->pi_msix.mapped_addr + offset);
                        *dest64 = data;
                        break;
                }
                return;
        }

        offset -= table_offset;
        index = offset / MSIX_TABLE_ENTRY_SIZE;
        assert(index < table_count);

        entry = &pi->pi_msix.table[index];
        entry_offset = offset % MSIX_TABLE_ENTRY_SIZE;

        /* Only 4 byte naturally-aligned writes are supported */
        assert(size == 4);
        assert(entry_offset % 4 == 0);

        vector_control = entry->vector_control;
        dest32 = (uint32_t *)((uint8_t *)entry + entry_offset);
        *dest32 = data;
        /* If MSI-X hasn't been enabled, do nothing */
        if (pi->pi_msix.enabled) {
                /* If the entry is masked, don't set it up */
                if ((entry->vector_control & PCIM_MSIX_VCTRL_MASK) == 0 ||
                    (vector_control & PCIM_MSIX_VCTRL_MASK) == 0) {
                        (void)vm_setup_pptdev_msix(sc->psc_pi->pi_vmctx,
                            sc->psc_sel.pc_bus, sc->psc_sel.pc_dev,
                            sc->psc_sel.pc_func, index, entry->addr,
                            entry->msg_data, entry->vector_control);
                }
        }
}

static int
init_msix_table(struct passthru_softc *sc)
{
        struct pci_devinst *pi = sc->psc_pi;
        struct pci_bar_mmap pbm;
        int b, s, f;
        uint32_t table_size, table_offset;

        assert(pci_msix_table_bar(pi) >= 0 && pci_msix_pba_bar(pi) >= 0);

        b = sc->psc_sel.pc_bus;
        s = sc->psc_sel.pc_dev;
        f = sc->psc_sel.pc_func;

        /*
         * Map the region of the BAR containing the MSI-X table.  This is
         * necessary for two reasons:
         * 1. The PBA may reside in the first or last page containing the MSI-X
         *    table.
         * 2. While PCI devices are not supposed to use the page(s) containing
         *    the MSI-X table for other purposes, some do in practice.
         */
        memset(&pbm, 0, sizeof(pbm));
        pbm.pbm_sel = sc->psc_sel;
        pbm.pbm_flags = PCIIO_BAR_MMAP_RW;
        pbm.pbm_reg = PCIR_BAR(pi->pi_msix.table_bar);
        pbm.pbm_memattr = VM_MEMATTR_DEVICE;

        if (ioctl(pcifd, PCIOCBARMMAP, &pbm) != 0) {
                warn("Failed to map MSI-X table BAR on %d/%d/%d", b, s, f);
                return (-1);
        }
        assert(pbm.pbm_bar_off == 0);
        pi->pi_msix.mapped_addr = (uint8_t *)(uintptr_t)pbm.pbm_map_base;
        pi->pi_msix.mapped_size = pbm.pbm_map_length;

        table_offset = rounddown2(pi->pi_msix.table_offset, 4096);

        table_size = pi->pi_msix.table_offset - table_offset;
        table_size += pi->pi_msix.table_count * MSIX_TABLE_ENTRY_SIZE;
        table_size = roundup2(table_size, 4096);

        /*
         * Unmap any pages not containing the table, we do not need to emulate
         * accesses to them.  Avoid releasing address space to help ensure that
         * a buggy out-of-bounds access causes a crash.
         */
        if (table_offset != 0)
                if (mprotect(pi->pi_msix.mapped_addr, table_offset,
                    PROT_NONE) != 0)
                        warn("Failed to unmap MSI-X table BAR region");
        if (table_offset + table_size != pi->pi_msix.mapped_size)
                if (mprotect(
                    pi->pi_msix.mapped_addr + table_offset + table_size,
                    pi->pi_msix.mapped_size - (table_offset + table_size),
                    PROT_NONE) != 0)
                        warn("Failed to unmap MSI-X table BAR region");

        return (0);
}

static int
cfginitbar(struct passthru_softc *sc)
{
        int i, error;
        struct pci_devinst *pi;
        struct pci_bar_io bar;
        enum pcibar_type bartype;
        uint64_t base, size;

        pi = sc->psc_pi;

        /*
         * Initialize BAR registers
         */
        for (i = 0; i <= PCI_BARMAX; i++) {
                uint8_t lobits;

                bzero(&bar, sizeof(bar));
                bar.pbi_sel = sc->psc_sel;
                bar.pbi_reg = PCIR_BAR(i);

                if (ioctl(pcifd, PCIOCGETBAR, &bar) < 0)
                        continue;

                if (PCI_BAR_IO(bar.pbi_base)) {
                        bartype = PCIBAR_IO;
                        base = bar.pbi_base & PCIM_BAR_IO_BASE;
                } else {
                        switch (bar.pbi_base & PCIM_BAR_MEM_TYPE) {
                        case PCIM_BAR_MEM_64:
                                bartype = PCIBAR_MEM64;
                                break;
                        default:
                                bartype = PCIBAR_MEM32;
                                break;
                        }
                        base = bar.pbi_base & PCIM_BAR_MEM_BASE;
                }
                size = bar.pbi_length;

                if (bartype != PCIBAR_IO) {
                        if (((base | size) & PAGE_MASK) != 0) {
                                warnx("passthru device %d/%d/%d BAR %d: "
                                    "base %#lx or size %#lx not page aligned\n",
                                    sc->psc_sel.pc_bus, sc->psc_sel.pc_dev,
                                    sc->psc_sel.pc_func, i, base, size);
                                return (-1);
                        }
                }

                /* Cache information about the "real" BAR */
                sc->psc_bar[i].type = bartype;
                sc->psc_bar[i].size = size;
                sc->psc_bar[i].addr = base;
                sc->psc_bar[i].lobits = 0;

                /* Allocate the BAR in the guest I/O or MMIO space */
                error = pci_emul_alloc_bar(pi, i, bartype, size);
                if (error)
                        return (-1);

                /* Use same lobits as physical bar */
                lobits = (uint8_t)passthru_read_config(&sc->psc_sel,
                    PCIR_BAR(i), 0x01);
                if (bartype == PCIBAR_MEM32 || bartype == PCIBAR_MEM64) {
                        lobits &= ~PCIM_BAR_MEM_BASE;
                } else {
                        lobits &= ~PCIM_BAR_IO_BASE;
                }
                sc->psc_bar[i].lobits = lobits;
                pi->pi_bar[i].lobits = lobits;

                /*
                 * 64-bit BAR takes up two slots so skip the next one.
                 */
                if (bartype == PCIBAR_MEM64) {
                        i++;
                        assert(i <= PCI_BARMAX);
                        sc->psc_bar[i].type = PCIBAR_MEMHI64;
                }
        }
        return (0);
}

static int
cfginit(struct pci_devinst *pi, int bus, int slot, int func)
{
        int error;
        struct passthru_softc *sc;
        uint16_t cmd;
        uint8_t intline, intpin;

        error = 1;
        sc = pi->pi_arg;

        bzero(&sc->psc_sel, sizeof(struct pcisel));
        sc->psc_sel.pc_bus = bus;
        sc->psc_sel.pc_dev = slot;
        sc->psc_sel.pc_func = func;

        /*
         * Copy physical PCI header to virtual config space.  COMMAND,
         * INTLINE, and INTPIN shouldn't be aligned with their
         * physical value and they are already set by pci_emul_init().
         */
        cmd = pci_get_cfgdata16(pi, PCIR_COMMAND);
        intline = pci_get_cfgdata8(pi, PCIR_INTLINE);
        intpin = pci_get_cfgdata8(pi, PCIR_INTPIN);
        for (int i = 0; i <= PCIR_MAXLAT; i += 4) {
                pci_set_cfgdata32(pi, i,
                    passthru_read_config(&sc->psc_sel, i, 4));
        }
        pci_set_cfgdata16(pi, PCIR_COMMAND, cmd);
        pci_set_cfgdata8(pi, PCIR_INTLINE, intline);
        pci_set_cfgdata8(pi, PCIR_INTPIN, intpin);

        if (cfginitmsi(sc) != 0) {
                warnx("failed to initialize MSI for PCI %d/%d/%d",
                    bus, slot, func);
                goto done;
        }

        if (cfginitbar(sc) != 0) {
                warnx("failed to initialize BARs for PCI %d/%d/%d",
                    bus, slot, func);
                goto done;
        }

        if (pci_msix_table_bar(pi) >= 0) {
                error = init_msix_table(sc);
                if (error != 0) {
                        warnx(
                            "failed to initialize MSI-X table for PCI %d/%d/%d: %d",
                            bus, slot, func, error);
                        goto done;
                }
        }

        error = 0;                              /* success */
done:
        return (error);
}

struct passthru_mmio_mapping *
passthru_get_mmio(struct passthru_softc *sc, int num)
{
        assert(sc != NULL);
        assert(num < PASSTHRU_MMIO_MAX);

        return (&sc->psc_mmio_map[num]);
}

struct pcisel *
passthru_get_sel(struct passthru_softc *sc)
{
        assert(sc != NULL);

        return (&sc->psc_sel);
}

int
set_pcir_handler(struct passthru_softc *sc, int reg, int len,
    cfgread_handler rhandler, cfgwrite_handler whandler)
{
        if (reg > PCI_REGMAX || reg + len > PCI_REGMAX + 1)
                return (-1);

        for (int i = reg; i < reg + len; ++i) {
                assert(sc->psc_pcir_rhandler[i] == NULL || rhandler == NULL);
                assert(sc->psc_pcir_whandler[i] == NULL || whandler == NULL);
                sc->psc_pcir_rhandler[i] = rhandler;
                sc->psc_pcir_whandler[i] = whandler;
        }

        return (0);
}

int
passthru_set_bar_handler(struct passthru_softc *sc, int baridx, uint64_t off,
    uint64_t size, passthru_read_handler rhandler,
    passthru_write_handler whandler)
{
        struct passthru_bar_handler *handler_new;
        struct passthru_bar_handler *handler;

        assert(sc->psc_bar[baridx].type == PCIBAR_IO ||
            sc->psc_bar[baridx].type == PCIBAR_MEM32 ||
            sc->psc_bar[baridx].type == PCIBAR_MEM64);
        assert(sc->psc_bar[baridx].size >= off + size);
        assert(off < off + size);

        handler_new = malloc(sizeof(struct passthru_bar_handler));
        if (handler_new == NULL) {
                return (ENOMEM);
        }

        handler_new->off = off;
        handler_new->size = size;
        handler_new->read = rhandler;
        handler_new->write = whandler;

        TAILQ_FOREACH(handler, &sc->psc_bar_handler[baridx], chain) {
                if (handler->off < handler_new->off) {
                        assert(handler->off + handler->size < handler_new->off);
                        continue;
                }
                assert(handler->off > handler_new->off + handler_new->size);
                TAILQ_INSERT_BEFORE(handler, handler_new, chain);
                return (0);
        }

        TAILQ_INSERT_TAIL(&sc->psc_bar_handler[baridx], handler_new, chain);

        return (0);
}

static int
passthru_legacy_config(nvlist_t *nvl, const char *opts)
{
        const char *cp;
        char *tofree;
        char value[16];
        int bus, slot, func;

        if (opts == NULL)
                return (0);

        cp = strchr(opts, ',');

        if (strncmp(opts, "ppt", strlen("ppt")) == 0) {
                tofree = strndup(opts, cp - opts);
                set_config_value_node(nvl, "pptdev", tofree);
                free(tofree);
        } else if (sscanf(opts, "pci0:%d:%d:%d", &bus, &slot, &func) == 3 ||
            sscanf(opts, "pci%d:%d:%d", &bus, &slot, &func) == 3 ||
            sscanf(opts, "%d/%d/%d", &bus, &slot, &func) == 3) {
                snprintf(value, sizeof(value), "%d", bus);
                set_config_value_node(nvl, "bus", value);
                snprintf(value, sizeof(value), "%d", slot);
                set_config_value_node(nvl, "slot", value);
                snprintf(value, sizeof(value), "%d", func);
                set_config_value_node(nvl, "func", value);
        } else {
                EPRINTLN("passthru: invalid options \"%s\"", opts);
                return (-1);
        }

        if (cp == NULL) {
                return (0);
        }

        return (pci_parse_legacy_config(nvl, cp + 1));
}

static int
passthru_init_rom(struct passthru_softc *const sc, const char *const romfile)
{
        if (romfile == NULL) {
                return (0);
        }

        const int fd = open(romfile, O_RDONLY);
        if (fd < 0) {
                warnx("%s: can't open romfile \"%s\"", __func__, romfile);
                return (-1);
        }

        struct stat sbuf;
        if (fstat(fd, &sbuf) < 0) {
                warnx("%s: can't fstat romfile \"%s\"", __func__, romfile);
                close(fd);
                return (-1);
        }
        const uint64_t rom_size = sbuf.st_size;

        void *const rom_data = mmap(NULL, rom_size, PROT_READ, MAP_SHARED, fd,
            0);
        if (rom_data == MAP_FAILED) {
                warnx("%s: unable to mmap romfile \"%s\" (%d)", __func__,
                    romfile, errno);
                close(fd);
                return (-1);
        }

        void *rom_addr;
        int error = pci_emul_alloc_rom(sc->psc_pi, rom_size, &rom_addr);
        if (error) {
                warnx("%s: failed to alloc rom segment", __func__);
                munmap(rom_data, rom_size);
                close(fd);
                return (error);
        }
        memcpy(rom_addr, rom_data, rom_size);

        sc->psc_bar[PCI_ROM_IDX].type = PCIBAR_ROM;
        sc->psc_bar[PCI_ROM_IDX].addr = (uint64_t)rom_addr;
        sc->psc_bar[PCI_ROM_IDX].size = rom_size;

        munmap(rom_data, rom_size);
        close(fd);

        return (0);
}

static bool
passthru_lookup_pptdev(const char *name, int *bus, int *slot, int *func)
{
        struct pci_conf_io pc;
        struct pci_conf conf[1];
        struct pci_match_conf patterns[1];
        char *cp;

        bzero(&pc, sizeof(struct pci_conf_io));
        pc.match_buf_len = sizeof(conf);
        pc.matches = conf;

        bzero(&patterns, sizeof(patterns));

        /*
         * The pattern structure requires the unit to be split out from
         * the driver name.  Walk backwards from the end of the name to
         * find the start of the unit.
         */
        cp = strchr(name, '\0');
        assert(cp != NULL);
        while (cp != name && isdigit(cp[-1]))
                cp--;
        if (cp == name || !isdigit(*cp)) {
                EPRINTLN("Invalid passthru device name %s", name);
                return (false);
        }
        if ((size_t)(cp - name) + 1 > sizeof(patterns[0].pd_name)) {
                EPRINTLN("Passthru device name %s is too long", name);
                return (false);
        }
        memcpy(patterns[0].pd_name, name, cp - name);
        patterns[0].pd_unit = strtol(cp, &cp, 10);
        if (*cp != '\0') {
                EPRINTLN("Invalid passthru device name %s", name);
                return (false);
        }
        patterns[0].flags = PCI_GETCONF_MATCH_NAME | PCI_GETCONF_MATCH_UNIT;
        pc.num_patterns = 1;
        pc.pat_buf_len = sizeof(patterns);
        pc.patterns = patterns;

        if (ioctl(pcifd, PCIOCGETCONF, &pc) == -1) {
                EPRINTLN("ioctl(PCIOCGETCONF): %s", strerror(errno));
                return (false);
        }
        if (pc.status != PCI_GETCONF_LAST_DEVICE &&
            pc.status != PCI_GETCONF_MORE_DEVS) {
                EPRINTLN("error returned from PCIOCGETCONF ioctl");
                return (false);
        }
        if (pc.num_matches == 0) {
                EPRINTLN("Passthru device %s not found", name);
                return (false);
        }

        if (conf[0].pc_sel.pc_domain != 0) {
                EPRINTLN("Passthru device %s on unsupported domain", name);
                return (false);
        }
        *bus = conf[0].pc_sel.pc_bus;
        *slot = conf[0].pc_sel.pc_dev;
        *func = conf[0].pc_sel.pc_func;
        return (true);
}

static int
passthru_init(struct pci_devinst *pi, nvlist_t *nvl)
{
        int bus, slot, func, error, memflags;
        struct passthru_softc *sc;
        struct passthru_dev **devpp;
        struct passthru_dev *devp, *dev = NULL;
        const char *value;

        sc = NULL;
        error = 1;

        memflags = vm_get_memflags(pi->pi_vmctx);
        if (!(memflags & VM_MEM_F_WIRED)) {
                warnx("passthru requires guest memory to be wired");
                return (error);
        }

        if (pcifd < 0 && pcifd_init()) {
                return (error);
        }

#define GET_INT_CONFIG(var, name) do {                                  \
        value = get_config_value_node(nvl, name);                       \
        if (value == NULL) {                                            \
                EPRINTLN("passthru: missing required %s setting", name); \
                return (error);                                         \
        }                                                               \
        var = atoi(value);                                              \
} while (0)

        value = get_config_value_node(nvl, "pptdev");
        if (value != NULL) {
                if (!passthru_lookup_pptdev(value, &bus, &slot, &func))
                        return (error);
        } else {
                GET_INT_CONFIG(bus, "bus");
                GET_INT_CONFIG(slot, "slot");
                GET_INT_CONFIG(func, "func");
        }

        if (vm_assign_pptdev(pi->pi_vmctx, bus, slot, func) != 0) {
                if (errno == ENOENT) {
                        EPRINTLN(
                    "PCI device at %d/%d/%d is not using the ppt driver",
                            bus, slot, func);
                } else {
                        EPRINTLN("vm_assign_pptdev: %s", strerror(errno));
                }
                goto done;
        }

        sc = calloc(1, sizeof(struct passthru_softc));

        pi->pi_arg = sc;
        sc->psc_pi = pi;

        for (uint8_t i = 0; i < PCI_BARMAX_WITH_ROM + 1; ++i)
                TAILQ_INIT(&sc->psc_bar_handler[i]);

        /* initialize config space */
        if ((error = cfginit(pi, bus, slot, func)) != 0)
                goto done;

        /* initialize ROM */
        if ((error = passthru_init_rom(sc,
            get_config_value_node(nvl, "rom"))) != 0)
                goto done;

        /* Emulate most PCI header register. */
        if ((error = set_pcir_handler(sc, 0, PCIR_MAXLAT + 1,
            passthru_cfgread_emulate, passthru_cfgwrite_emulate)) != 0)
                goto done;

        /* Allow access to the physical status register. */
        if ((error = set_pcir_handler(sc, PCIR_COMMAND, 0x04, NULL, NULL)) != 0)
                goto done;

        SET_FOREACH(devpp, passthru_dev_set) {
                devp = *devpp;
                assert(devp->probe != NULL);
                if (devp->probe(pi) == 0) {
                        dev = devp;
                        break;
                }
        }

        if (dev != NULL) {
                error = dev->init(pi, nvl);
                if (error != 0)
                        goto done;
        }

        error = 0;              /* success */
done:
        if (error) {
                if (dev != NULL)
                        dev->deinit(pi);
                free(sc);
                vm_unassign_pptdev(pi->pi_vmctx, bus, slot, func);
        }
        return (error);
}

static int
msicap_access(struct passthru_softc *sc, int coff)
{
        int caplen;

        if (sc->psc_msi.capoff == 0)
                return (0);

        caplen = msi_caplen(sc->psc_msi.msgctrl);

        if (coff >= sc->psc_msi.capoff && coff < sc->psc_msi.capoff + caplen)
                return (1);
        else
                return (0);
}

static int
msixcap_access(struct passthru_softc *sc, int coff)
{
        if (sc->psc_msix.capoff == 0)
                return (0);

        return (coff >= sc->psc_msix.capoff &&
                coff < sc->psc_msix.capoff + MSIX_CAPLEN);
}

static int
passthru_cfgread_default(struct passthru_softc *sc,
    struct pci_devinst *pi __unused, int coff, int bytes, uint32_t *rv)
{
        /*
         * MSI capability is emulated.
         */
        if (msicap_access(sc, coff) || msixcap_access(sc, coff))
                return (-1);

        /*
         * Emulate the command register.  If a single read reads both the
         * command and status registers, read the status register from the
         * device's config space.
         */
        if (coff == PCIR_COMMAND) {
                uint32_t st;

                if (bytes <= 2)
                        return (-1);
                st = passthru_read_config(&sc->psc_sel, PCIR_STATUS, 2);
                *rv = (st << 16) | pci_get_cfgdata16(pi, PCIR_COMMAND);
                return (0);
        }

        /* Everything else just read from the device's config space */
        *rv = passthru_read_config(&sc->psc_sel, coff, bytes);

        return (0);
}

int
passthru_cfgread_emulate(struct passthru_softc *sc __unused,
    struct pci_devinst *pi __unused, int coff __unused, int bytes __unused,
    uint32_t *rv __unused)
{
        return (-1);
}

static int
passthru_cfgread(struct pci_devinst *pi, int coff, int bytes, uint32_t *rv)
{
        struct passthru_softc *sc;

        sc = pi->pi_arg;

        if (sc->psc_pcir_rhandler[coff] != NULL)
                return (sc->psc_pcir_rhandler[coff](sc, pi, coff, bytes, rv));

        return (passthru_cfgread_default(sc, pi, coff, bytes, rv));
}

static int
passthru_cfgwrite_default(struct passthru_softc *sc, struct pci_devinst *pi,
    int coff, int bytes, uint32_t val)
{
        int error, msix_table_entries, i;
        uint16_t cmd_old;

        /*
         * MSI capability is emulated
         */
        if (msicap_access(sc, coff)) {
                pci_emul_capwrite(pi, coff, bytes, val, sc->psc_msi.capoff,
                    PCIY_MSI);
                error = vm_setup_pptdev_msi(pi->pi_vmctx, sc->psc_sel.pc_bus,
                        sc->psc_sel.pc_dev, sc->psc_sel.pc_func,
                        pi->pi_msi.addr, pi->pi_msi.msg_data,
                        pi->pi_msi.maxmsgnum);
                if (error != 0)
                        err(1, "vm_setup_pptdev_msi");
                return (0);
        }

        if (msixcap_access(sc, coff)) {
                pci_emul_capwrite(pi, coff, bytes, val, sc->psc_msix.capoff,
                    PCIY_MSIX);
                if (pi->pi_msix.enabled) {
                        msix_table_entries = pi->pi_msix.table_count;
                        for (i = 0; i < msix_table_entries; i++) {
                                error = vm_setup_pptdev_msix(pi->pi_vmctx,
                                    sc->psc_sel.pc_bus, sc->psc_sel.pc_dev,
                                    sc->psc_sel.pc_func, i,
                                    pi->pi_msix.table[i].addr,
                                    pi->pi_msix.table[i].msg_data,
                                    pi->pi_msix.table[i].vector_control);

                                if (error)
                                        err(1, "vm_setup_pptdev_msix");
                        }
                } else {
                        error = vm_disable_pptdev_msix(pi->pi_vmctx,
                            sc->psc_sel.pc_bus, sc->psc_sel.pc_dev,
                            sc->psc_sel.pc_func);
                        if (error)
                                err(1, "vm_disable_pptdev_msix");
                }
                return (0);
        }

        /*
         * The command register is emulated, but the status register
         * is passed through.
         */
        if (coff == PCIR_COMMAND) {
                if (bytes <= 2)
                        return (-1);

                /* Update the physical status register. */
                passthru_write_config(&sc->psc_sel, PCIR_STATUS, val >> 16, 2);

                /* Update the virtual command register. */
                cmd_old = pci_get_cfgdata16(pi, PCIR_COMMAND);
                pci_set_cfgdata16(pi, PCIR_COMMAND, val & 0xffff);
                pci_emul_cmd_changed(pi, cmd_old);
                return (0);
        }

        passthru_write_config(&sc->psc_sel, coff, bytes, val);

        return (0);
}

int
passthru_cfgwrite_emulate(struct passthru_softc *sc __unused,
    struct pci_devinst *pi __unused, int coff __unused, int bytes __unused,
    uint32_t val __unused)
{
        return (-1);
}

static int
passthru_cfgwrite(struct pci_devinst *pi, int coff, int bytes, uint32_t val)
{
        struct passthru_softc *sc;

        sc = pi->pi_arg;

        if (sc->psc_pcir_whandler[coff] != NULL)
                return (sc->psc_pcir_whandler[coff](sc, pi, coff, bytes, val));

        return (passthru_cfgwrite_default(sc, pi, coff, bytes, val));
}

static void
passthru_write(struct pci_devinst *pi, int baridx, uint64_t offset, int size,
    uint64_t value)
{
        struct passthru_softc *sc;
        struct passthru_bar_handler *handler;
        struct pci_bar_ioreq pio;

        sc = pi->pi_arg;

        if (baridx == pci_msix_table_bar(pi)) {
                msix_table_write(sc, offset, size, value);
        } else {
                assert(size == 1 || size == 2 || size == 4);

                TAILQ_FOREACH(handler, &sc->psc_bar_handler[baridx], chain) {
                        if (offset >= handler->off + handler->size) {
                                continue;
                        } else if (offset < handler->off) {
                                assert(offset + size < handler->off);
                                /*
                                 * The list is sorted in ascending order, so all
                                 * remaining handlers will have an even larger
                                 * offset.
                                 */
                                break;
                        }

                        assert(offset + size <= handler->off + handler->size);

                        handler->write(pi, baridx,
                            offset - handler->off, size, value);
                        return;
                }

                bzero(&pio, sizeof(pio));
                pio.pbi_sel = sc->psc_sel;
                pio.pbi_op = PCIBARIO_WRITE;
                pio.pbi_bar = baridx;
                pio.pbi_offset = (uint32_t)offset;
                pio.pbi_width = size;
                pio.pbi_value = (uint32_t)value;

                (void)ioctl(pcifd, PCIOCBARIO, &pio);
        }
}

static uint64_t
passthru_read(struct pci_devinst *pi, int baridx, uint64_t offset, int size)
{
        struct passthru_softc *sc;
        struct passthru_bar_handler *handler;
        struct pci_bar_ioreq pio;
        uint64_t val;

        sc = pi->pi_arg;

        if (baridx == pci_msix_table_bar(pi)) {
                val = msix_table_read(sc, offset, size);
        } else {
                assert(size == 1 || size == 2 || size == 4);

                TAILQ_FOREACH(handler, &sc->psc_bar_handler[baridx], chain) {
                        if (offset >= handler->off + handler->size) {
                                continue;
                        } else if (offset < handler->off) {
                                assert(offset + size < handler->off);
                                /*
                                 * The list is sorted in ascending order, so all
                                 * remaining handlers will have an even larger
                                 * offset.
                                 */
                                break;
                        }

                        assert(offset + size <= handler->off + handler->size);

                        return (handler->read(pi, baridx,
                            offset - handler->off, size));
                }

                bzero(&pio, sizeof(pio));
                pio.pbi_sel = sc->psc_sel;
                pio.pbi_op = PCIBARIO_READ;
                pio.pbi_bar = baridx;
                pio.pbi_offset = (uint32_t)offset;
                pio.pbi_width = size;

                (void)ioctl(pcifd, PCIOCBARIO, &pio);

                val = pio.pbi_value;
        }

        return (val);
}

static int
passthru_mmio_map(struct pci_devinst *pi, int baridx, int enabled,
    uint64_t address, uint64_t off, uint64_t size)
{
        struct passthru_softc *sc;

        sc = pi->pi_arg;
        if (!enabled) {
                if (vm_unmap_pptdev_mmio(pi->pi_vmctx, sc->psc_sel.pc_bus,
                    sc->psc_sel.pc_dev, sc->psc_sel.pc_func, address + off,
                    size) != 0) {
                        EPRINTLN("pci_passthru: unmap_pptdev_mmio failed: %s",
                            strerror(errno));
                        return (-1);
                }
        } else {
                if (vm_map_pptdev_mmio(pi->pi_vmctx, sc->psc_sel.pc_bus,
                    sc->psc_sel.pc_dev, sc->psc_sel.pc_func, address + off,
                    size, sc->psc_bar[baridx].addr + off) != 0) {
                        EPRINTLN("pci_passthru: map_pptdev_mmio failed: %s",
                            strerror(errno));
                        return (-1);
                }
        }

        return (0);
}

static void
passthru_msix_addr(struct pci_devinst *pi, int baridx, int enabled,
    uint64_t address)
{
        size_t remaining;
        uint32_t table_size, table_offset;

        table_offset = rounddown2(pi->pi_msix.table_offset, 4096);
        if (table_offset > 0) {
                (void)passthru_mmio_map(pi, baridx, enabled, address, 0,
                    table_offset);
        }
        table_size = pi->pi_msix.table_offset - table_offset;
        table_size += pi->pi_msix.table_count * MSIX_TABLE_ENTRY_SIZE;
        table_size = roundup2(table_size, 4096);
        remaining = pi->pi_bar[baridx].size - table_offset - table_size;
        if (remaining > 0) {
                (void)passthru_mmio_map(pi, baridx, enabled, address,
                    table_offset + table_size, remaining);
        }
}

static void
passthru_mmio_addr(struct pci_devinst *pi, int baridx, int enabled,
    uint64_t address)
{
        struct passthru_softc *sc;
        struct passthru_bar_handler *handler;
        uint64_t off;

        sc = pi->pi_arg;

        off = 0;

        /* The queue is sorted by offset in ascending order. */
        TAILQ_FOREACH(handler, &sc->psc_bar_handler[baridx], chain) {
                uint64_t handler_off = trunc_page(handler->off);
                uint64_t handler_end = round_page(handler->off + handler->size);

                /*
                 * When two handlers point to the same page, handler_off can be
                 * lower than off. That's fine because we have nothing to do in
                 * that case.
                 */
                if (handler_off > off) {
                        passthru_mmio_map(pi, baridx, enabled, address, off,
                            handler_off - off);
                }

                off = handler_end;
        }

        passthru_mmio_map(pi, baridx, enabled, address, off,
            sc->psc_bar[baridx].size - off);
}

static void
passthru_addr_rom(struct pci_devinst *const pi, const int idx,
    const int enabled)
{
        const uint64_t addr = pi->pi_bar[idx].addr;
        const uint64_t size = pi->pi_bar[idx].size;

        if (!enabled) {
                if (vm_munmap_memseg(pi->pi_vmctx, addr, size) != 0) {
                        errx(4, "%s: munmap_memseg @ [%016lx - %016lx] failed",
                            __func__, addr, addr + size);
                }

        } else {
                if (vm_mmap_memseg(pi->pi_vmctx, addr, VM_PCIROM,
                        pi->pi_romoffset, size, PROT_READ | PROT_EXEC) != 0) {
                        errx(4, "%s: mmap_memseg @ [%016lx - %016lx]  failed",
                            __func__, addr, addr + size);
                }
        }
}

static void
passthru_addr(struct pci_devinst *pi, int baridx, int enabled, uint64_t address)
{
        switch (pi->pi_bar[baridx].type) {
        case PCIBAR_IO:
                /* IO BARs are emulated */
                break;
        case PCIBAR_ROM:
                passthru_addr_rom(pi, baridx, enabled);
                break;
        case PCIBAR_MEM32:
        case PCIBAR_MEM64:
                if (baridx == pci_msix_table_bar(pi))
                        passthru_msix_addr(pi, baridx, enabled, address);
                else
                        passthru_mmio_addr(pi, baridx, enabled, address);
                break;
        default:
                errx(4, "%s: invalid BAR type %d", __func__,
                    pi->pi_bar[baridx].type);
        }
}

static const struct pci_devemu passthru = {
        .pe_emu         = "passthru",
        .pe_init        = passthru_init,
        .pe_legacy_config = passthru_legacy_config,
        .pe_cfgwrite    = passthru_cfgwrite,
        .pe_cfgread     = passthru_cfgread,
        .pe_barwrite    = passthru_write,
        .pe_barread     = passthru_read,
        .pe_baraddr     = passthru_addr,
};
PCI_EMUL_SET(passthru);