#include "libxl_internal.h"
#include "libxl_arch.h"
#include "libxl_libfdt_compat.h"
#include "libxl_arm.h"

#include <xc_dom.h>
#include <stdbool.h>
#include <libfdt.h>
#include <assert.h>

/**
 * IRQ line type.
 * DT_IRQ_TYPE_NONE            - default, unspecified type
 * DT_IRQ_TYPE_EDGE_RISING     - rising edge triggered
 * DT_IRQ_TYPE_EDGE_FALLING    - falling edge triggered
 * DT_IRQ_TYPE_EDGE_BOTH       - rising and falling edge triggered
 * DT_IRQ_TYPE_LEVEL_HIGH      - high level triggered
 * DT_IRQ_TYPE_LEVEL_LOW       - low level triggered
 */
#define DT_IRQ_TYPE_NONE           0x00000000
#define DT_IRQ_TYPE_EDGE_RISING    0x00000001
#define DT_IRQ_TYPE_EDGE_FALLING   0x00000002
#define DT_IRQ_TYPE_EDGE_BOTH                           \
    (DT_IRQ_TYPE_EDGE_FALLING | DT_IRQ_TYPE_EDGE_RISING)
#define DT_IRQ_TYPE_LEVEL_HIGH     0x00000004
#define DT_IRQ_TYPE_LEVEL_LOW      0x00000008

static const char *gicv_to_string(uint8_t gic_version)
{
    switch (gic_version) {
    case XEN_DOMCTL_CONFIG_GIC_V2:
        return "V2";
    case XEN_DOMCTL_CONFIG_GIC_V3:
        return "V3";
    default:
        return "unknown";
    }
}

int libxl__arch_domain_prepare_config(libxl__gc *gc,
                                      libxl_domain_config *d_config,
                                      xc_domain_configuration_t *xc_config)
{
    uint32_t nr_spis = 0;
    unsigned int i;
    uint32_t vuart_irq;
    bool vuart_enabled = false;

    /*
     * If pl011 vuart is enabled then increment the nr_spis to allow allocation
     * of SPI VIRQ for pl011.
     */
    if (d_config->b_info.arch_arm.vuart == LIBXL_VUART_TYPE_SBSA_UART) {
        nr_spis += (GUEST_VPL011_SPI - 32) + 1;
        vuart_irq = GUEST_VPL011_SPI;
        vuart_enabled = true;
    }

    for (i = 0; i < d_config->b_info.num_irqs; i++) {
        uint32_t irq = d_config->b_info.irqs[i];
        uint32_t spi;

        /*
         * This check ensures the if user has requested pass-through of a certain irq
         * which conflicts with vpl011 irq then it flags an error to indicate to the
         * user that the specific HW irq cannot be used as it is dedicated for vpl011.
         * 
         * TODO:
         * The vpl011 irq should be assigned such that it never conflicts with user
         * specified irqs thereby preventing its pass-through. This TODO is for
         * implementing that logic in future.
         */
        if (vuart_enabled && irq == vuart_irq) {
            LOG(ERROR, "Physical IRQ %u conflicting with pl011 SPI\n", irq);
            return ERROR_FAIL;
        }

        if (irq < 32)
            continue;

        spi = irq - 32;

        if (nr_spis <= spi)
            nr_spis = spi + 1;
    }

    LOG(DEBUG, "Configure the domain");

    xc_config->nr_spis = nr_spis;
    LOG(DEBUG, " - Allocate %u SPIs", nr_spis);

    switch (d_config->b_info.arch_arm.gic_version) {
    case LIBXL_GIC_VERSION_DEFAULT:
        xc_config->gic_version = XEN_DOMCTL_CONFIG_GIC_NATIVE;
        break;
    case LIBXL_GIC_VERSION_V2:
        xc_config->gic_version = XEN_DOMCTL_CONFIG_GIC_V2;
        break;
    case LIBXL_GIC_VERSION_V3:
        xc_config->gic_version = XEN_DOMCTL_CONFIG_GIC_V3;
        break;
    default:
        LOG(ERROR, "Unknown GIC version %d",
            d_config->b_info.arch_arm.gic_version);
        return ERROR_FAIL;
    }

    return 0;
}

int libxl__arch_domain_save_config(libxl__gc *gc,
                                   libxl_domain_config *d_config,
                                   const xc_domain_configuration_t *xc_config)
{
    switch (xc_config->gic_version) {
    case XEN_DOMCTL_CONFIG_GIC_V2:
        d_config->b_info.arch_arm.gic_version = LIBXL_GIC_VERSION_V2;
        break;
    case XEN_DOMCTL_CONFIG_GIC_V3:
        d_config->b_info.arch_arm.gic_version = LIBXL_GIC_VERSION_V3;
        break;
    default:
        LOG(ERROR, "Unexpected gic version %u", xc_config->gic_version);
        return ERROR_FAIL;
    }

    return 0;
}

int libxl__arch_domain_create(libxl__gc *gc, libxl_domain_config *d_config,
                              uint32_t domid)
{
    return 0;
}

int libxl__arch_extra_memory(libxl__gc *gc,
                             const libxl_domain_build_info *info,
                             uint64_t *out)
{
    int rc = 0;
    uint64_t size = 0;

    if (libxl_defbool_val(info->acpi)) {
        rc = libxl__get_acpi_size(gc, info, &size);
        if (rc < 0) {
            rc = ERROR_FAIL;
            goto out;
        }
    }

    *out = LIBXL_MAXMEM_CONSTANT + DIV_ROUNDUP(size, 1024);
out:
    return rc;
}

static struct arch_info {
    const char *guest_type;
    const char *timer_compat;
    const char *cpu_compat;
} arch_info[] = {
    {"xen-3.0-armv7l",  "arm,armv7-timer", "arm,cortex-a15" },
    {"xen-3.0-aarch64", "arm,armv8-timer", "arm,armv8" },
};

/*
 * The device tree compiler (DTC) is allocating the phandle from 1 to
 * onwards. Reserve a high value for the GIC phandle.
 */
#define PHANDLE_GIC (65000)

typedef uint32_t be32;
typedef be32 gic_interrupt[3];

#define ROOT_ADDRESS_CELLS 2
#define ROOT_SIZE_CELLS 2

#define PROP_INITRD_START "linux,initrd-start"
#define PROP_INITRD_END "linux,initrd-end"

static void set_cell(be32 **cellp, int size, uint64_t val)
{
    int cells = size;

    while (size--) {
        (*cellp)[size] = cpu_to_fdt32(val);
        val >>= 32;
    }

    (*cellp) += cells;
}

static void set_interrupt(gic_interrupt interrupt, unsigned int irq,
                          unsigned int cpumask, unsigned int level)
{
    be32 *cells = interrupt;
    int is_ppi = (irq < 32);

    /* SGIs are not describe in the device tree */
    assert(irq >= 16);

    irq -= (is_ppi) ? 16: 32; /* PPIs start at 16, SPIs at 32 */

    /* See linux Documentation/devictree/bindings/arm/gic.txt */
    set_cell(&cells, 1, is_ppi); /* is a PPI? */
    set_cell(&cells, 1, irq);
    set_cell(&cells, 1, (cpumask << 8) | level);
}

static void set_range(be32 **cellp,
                      int address_cells, int size_cells,
                      uint64_t address, uint64_t size)
{
    set_cell(cellp, address_cells, address);
    set_cell(cellp, size_cells, size);
}

static int fdt_property_compat(libxl__gc *gc, void *fdt, unsigned nr_compat, ...)
{
    const char *compats[nr_compat];
    int i;
    size_t sz;
    va_list ap;
    char *compat, *p;

    va_start(ap, nr_compat);
    sz = 0;
    for (i = 0; i < nr_compat; i++) {
        const char *c = va_arg(ap, const char *);
        compats[i] = c;
        sz += strlen(compats[i]) + 1;
    }
    va_end(ap);

    p = compat = libxl__zalloc(gc, sz);
    for (i = 0; i < nr_compat; i++) {
        strcpy(p, compats[i]);
        p += strlen(compats[i]) + 1;
    }

    return fdt_property(fdt, "compatible", compat, sz);
}

static int fdt_property_interrupts(libxl__gc *gc, void *fdt,
                                   gic_interrupt *intr,
                                   unsigned num_irq)
{
    int res;

    res = fdt_property(fdt, "interrupts", intr, sizeof (intr[0]) * num_irq);
    if (res) return res;

    res = fdt_property_cell(fdt, "interrupt-parent", PHANDLE_GIC);
    if (res) return res;

    return 0;
}

static int fdt_property_regs(libxl__gc *gc, void *fdt,
                             unsigned addr_cells,
                             unsigned size_cells,
                             unsigned num_regs, ...)
{
    uint32_t regs[num_regs*(addr_cells+size_cells)];
    be32 *cells = &regs[0];
    int i;
    va_list ap;
    uint64_t base, size;

    va_start(ap, num_regs);
    for (i = 0 ; i < num_regs; i++) {
        base = addr_cells ? va_arg(ap, uint64_t) : 0;
        size = size_cells ? va_arg(ap, uint64_t) : 0;
        set_range(&cells, addr_cells, size_cells, base, size);
    }
    va_end(ap);

    return fdt_property(fdt, "reg", regs, sizeof(regs));
}

static int make_root_properties(libxl__gc *gc,
                                const libxl_version_info *vers,
                                void *fdt)
{
    int res;

    res = fdt_property_string(fdt, "model", GCSPRINTF("XENVM-%d.%d",
                                                      vers->xen_version_major,
                                                      vers->xen_version_minor));
    if (res) return res;

    res = fdt_property_compat(gc, fdt, 2,
                              GCSPRINTF("xen,xenvm-%d.%d",
                                        vers->xen_version_major,
                                        vers->xen_version_minor),
                              "xen,xenvm");
    if (res) return res;

    res = fdt_property_cell(fdt, "interrupt-parent", PHANDLE_GIC);
    if (res) return res;

    res = fdt_property_cell(fdt, "#address-cells", ROOT_ADDRESS_CELLS);
    if (res) return res;

    res = fdt_property_cell(fdt, "#size-cells", ROOT_SIZE_CELLS);
    if (res) return res;

    return 0;
}

static int make_chosen_node(libxl__gc *gc, void *fdt, bool ramdisk,
                            libxl__domain_build_state *state,
                            const libxl_domain_build_info *info)
{
    int res;

    /* See linux Documentation/devicetree/... */
    res = fdt_begin_node(fdt, "chosen");
    if (res) return res;

    if (state->pv_cmdline) {
        LOG(DEBUG, "/chosen/bootargs = %s", state->pv_cmdline);
        res = fdt_property_string(fdt, "bootargs", state->pv_cmdline);
        if (res) return res;
    }

    if (ramdisk) {
        uint64_t dummy = 0;
        LOG(DEBUG, "/chosen adding placeholder linux,initrd properties");
        res = fdt_property(fdt, PROP_INITRD_START, &dummy, sizeof(dummy));
        if (res) return res;
        res = fdt_property(fdt, PROP_INITRD_END, &dummy, sizeof(dummy));
        if (res) return res;
    }

    if (libxl_defbool_val(info->acpi)) {
        const uint64_t acpi_base = GUEST_ACPI_BASE;
        const char *name = GCSPRINTF("module@%"PRIx64, acpi_base);

        res = fdt_begin_node(fdt, name);
        if (res) return res;

        res = fdt_property_compat(gc, fdt, 2, "xen,guest-acpi",
                                  "multiboot,module");
        if (res) return res;

        res = fdt_property_regs(gc, fdt, ROOT_ADDRESS_CELLS, ROOT_SIZE_CELLS,
                                1, 0, 0);
        if (res) return res;

        res = fdt_end_node(fdt);
        if (res) return res;
    }

    res = fdt_end_node(fdt);
    if (res) return res;

    return 0;
}

static int make_cpus_node(libxl__gc *gc, void *fdt, int nr_cpus,
                          const struct arch_info *ainfo)
{
    int res, i;
    uint64_t mpidr_aff;

    res = fdt_begin_node(fdt, "cpus");
    if (res) return res;

    res = fdt_property_cell(fdt, "#address-cells", 1);
    if (res) return res;

    res = fdt_property_cell(fdt, "#size-cells", 0);
    if (res) return res;

    for (i = 0; i < nr_cpus; i++) {
        const char *name;

        mpidr_aff = libxl__compute_mpdir(i);
        name = GCSPRINTF("cpu@%"PRIx64, mpidr_aff);

        res = fdt_begin_node(fdt, name);
        if (res) return res;

        res = fdt_property_string(fdt, "device_type", "cpu");
        if (res) return res;

        res = fdt_property_compat(gc, fdt, 1, ainfo->cpu_compat);
        if (res) return res;

        res = fdt_property_string(fdt, "enable-method", "psci");
        if (res) return res;

        res = fdt_property_regs(gc, fdt, 1, 0, 1, mpidr_aff);
        if (res) return res;

        res = fdt_end_node(fdt);
        if (res) return res;
    }

    res = fdt_end_node(fdt);
    if (res) return res;

    return 0;
}

static int make_psci_node(libxl__gc *gc, void *fdt)
{
    int res;

    res = fdt_begin_node(fdt, "psci");
    if (res) return res;

    res = fdt_property_compat(gc, fdt, 2, "arm,psci-0.2","arm,psci");
    if (res) return res;

    res = fdt_property_string(fdt, "method", "hvc");
    if (res) return res;

    res = fdt_property_cell(fdt, "cpu_off", PSCI_cpu_off);
    if (res) return res;

    res = fdt_property_cell(fdt, "cpu_on", PSCI_cpu_on);
    if (res) return res;

    res = fdt_end_node(fdt);
    if (res) return res;

    return 0;
}

static int make_memory_nodes(libxl__gc *gc, void *fdt,
                             const struct xc_dom_image *dom)
{
    int res, i;
    const char *name;
    const uint64_t bankbase[] = GUEST_RAM_BANK_BASES;

    for (i = 0; i < GUEST_RAM_BANKS; i++) {
        name = GCSPRINTF("memory@%"PRIx64, bankbase[i]);

        LOG(DEBUG, "Creating placeholder node /%s", name);

        res = fdt_begin_node(fdt, name);
        if (res) return res;

        res = fdt_property_string(fdt, "device_type", "memory");
        if (res) return res;

        res = fdt_property_regs(gc, fdt, ROOT_ADDRESS_CELLS, ROOT_SIZE_CELLS,
                                1, 0, 0);
        if (res) return res;

        res = fdt_end_node(fdt);
        if (res) return res;
    }

    return 0;
}

static int make_gicv2_node(libxl__gc *gc, void *fdt,
                           uint64_t gicd_base, uint64_t gicd_size,
                           uint64_t gicc_base, uint64_t gicc_size)
{
    int res;
    const char *name = GCSPRINTF("interrupt-controller@%"PRIx64, gicd_base);

    res = fdt_begin_node(fdt, name);
    if (res) return res;

    res = fdt_property_compat(gc, fdt, 2,
                              "arm,cortex-a15-gic",
                              "arm,cortex-a9-gic");
    if (res) return res;


    res = fdt_property_cell(fdt, "#interrupt-cells", 3);
    if (res) return res;

    res = fdt_property_cell(fdt, "#address-cells", 0);
    if (res) return res;

    res = fdt_property(fdt, "interrupt-controller", NULL, 0);
    if (res) return res;

    res = fdt_property_regs(gc, fdt, ROOT_ADDRESS_CELLS, ROOT_SIZE_CELLS,
                            2,
                            gicd_base, gicd_size,
                            gicc_base, gicc_size);
    if (res) return res;

    res = fdt_property_cell(fdt, "linux,phandle", PHANDLE_GIC);
    if (res) return res;

    res = fdt_property_cell(fdt, "phandle", PHANDLE_GIC);
    if (res) return res;

    res = fdt_end_node(fdt);
    if (res) return res;

    return 0;
}

static int make_gicv3_node(libxl__gc *gc, void *fdt)
{
    int res;
    const uint64_t gicd_base = GUEST_GICV3_GICD_BASE;
    const uint64_t gicd_size = GUEST_GICV3_GICD_SIZE;
    const uint64_t gicr0_base = GUEST_GICV3_GICR0_BASE;
    const uint64_t gicr0_size = GUEST_GICV3_GICR0_SIZE;
    const char *name = GCSPRINTF("interrupt-controller@%"PRIx64, gicd_base);

    res = fdt_begin_node(fdt, name);
    if (res) return res;

    res = fdt_property_compat(gc, fdt, 1, "arm,gic-v3");
    if (res) return res;

    res = fdt_property_cell(fdt, "#interrupt-cells", 3);
    if (res) return res;

    res = fdt_property_cell(fdt, "#address-cells", 0);
    if (res) return res;

    res = fdt_property(fdt, "interrupt-controller", NULL, 0);
    if (res) return res;

    res = fdt_property_cell(fdt, "redistributor-stride",
                            GUEST_GICV3_RDIST_STRIDE);
    if (res) return res;

    res = fdt_property_cell(fdt, "#redistributor-regions",
                            GUEST_GICV3_RDIST_REGIONS);
    if (res) return res;

    res = fdt_property_regs(gc, fdt, ROOT_ADDRESS_CELLS, ROOT_SIZE_CELLS,
                            2,
                            gicd_base, gicd_size,
                            gicr0_base, gicr0_size);
    if (res) return res;

    res = fdt_property_cell(fdt, "linux,phandle", PHANDLE_GIC);
    if (res) return res;

    res = fdt_property_cell(fdt, "phandle", PHANDLE_GIC);
    if (res) return res;

    res = fdt_end_node(fdt);
    if (res) return res;

    return 0;
}

static int make_timer_node(libxl__gc *gc, void *fdt,
                           const struct arch_info *ainfo,
                           uint32_t frequency)
{
    int res;
    gic_interrupt ints[3];

    res = fdt_begin_node(fdt, "timer");
    if (res) return res;

    res = fdt_property_compat(gc, fdt, 1, ainfo->timer_compat);
    if (res) return res;

    set_interrupt(ints[0], GUEST_TIMER_PHYS_S_PPI, 0xf, DT_IRQ_TYPE_LEVEL_LOW);
    set_interrupt(ints[1], GUEST_TIMER_PHYS_NS_PPI, 0xf, DT_IRQ_TYPE_LEVEL_LOW);
    set_interrupt(ints[2], GUEST_TIMER_VIRT_PPI, 0xf, DT_IRQ_TYPE_LEVEL_LOW);

    res = fdt_property_interrupts(gc, fdt, ints, 3);
    if (res) return res;

    if ( frequency )
        fdt_property_u32(fdt, "clock-frequency", frequency);

    res = fdt_end_node(fdt);
    if (res) return res;

    return 0;
}

static int make_hypervisor_node(libxl__gc *gc, void *fdt,
                                const libxl_version_info *vers)
{
    int res;
    gic_interrupt intr;

    /* See linux Documentation/devicetree/bindings/arm/xen.txt */
    res = fdt_begin_node(fdt, "hypervisor");
    if (res) return res;

    res = fdt_property_compat(gc, fdt, 2,
                              GCSPRINTF("xen,xen-%d.%d",
                                        vers->xen_version_major,
                                        vers->xen_version_minor),
                              "xen,xen");
    if (res) return res;

    /* reg 0 is grant table space */
    res = fdt_property_regs(gc, fdt, ROOT_ADDRESS_CELLS, ROOT_SIZE_CELLS,
                            1,GUEST_GNTTAB_BASE, GUEST_GNTTAB_SIZE);
    if (res) return res;

    /*
     * interrupts is evtchn upcall:
     *  - Active-low level-sensitive
     *  - All cpus
     */
    set_interrupt(intr, GUEST_EVTCHN_PPI, 0xf, DT_IRQ_TYPE_LEVEL_LOW);

    res = fdt_property_interrupts(gc, fdt, &intr, 1);
    if (res) return res;

    res = fdt_end_node(fdt);
    if (res) return res;

    return 0;
}

static int make_vpl011_uart_node(libxl__gc *gc, void *fdt,
                                 const struct arch_info *ainfo,
                                 struct xc_dom_image *dom)
{
    int res;
    gic_interrupt intr;

    res = fdt_begin_node(fdt, "sbsa-pl011");
    if (res) return res;

    res = fdt_property_compat(gc, fdt, 1, "arm,sbsa-uart");
    if (res) return res;

    res = fdt_property_regs(gc, fdt, ROOT_ADDRESS_CELLS, ROOT_SIZE_CELLS,
                            1,
                            GUEST_PL011_BASE, GUEST_PL011_SIZE);
    if (res) return res;

    set_interrupt(intr, GUEST_VPL011_SPI, 0xf, DT_IRQ_TYPE_LEVEL_HIGH);

    res = fdt_property_interrupts(gc, fdt, &intr, 1);
    if (res) return res;

    /* Use a default baud rate of 115200. */
    fdt_property_u32(fdt, "current-speed", 115200);

    res = fdt_end_node(fdt);
    if (res) return res;

    return 0;
}

static const struct arch_info *get_arch_info(libxl__gc *gc,
                                             const struct xc_dom_image *dom)
{
    int i;

    for (i=0; i < ARRAY_SIZE(arch_info); i++) {
        const struct arch_info *info = &arch_info[i];
        if (!strcmp(dom->guest_type, info->guest_type))
            return info;
    }
    LOG(ERROR, "Unable to find arch FDT info for %s", dom->guest_type);
    return NULL;
}

static void debug_dump_fdt(libxl__gc *gc, void *fdt)
{
    int fd = -1, rc, r;

    const char *dtb = getenv("LIBXL_DEBUG_DUMP_DTB");

    if (!dtb) goto out;

    fd = open(dtb, O_CREAT|O_TRUNC|O_WRONLY, 0666);
    if (fd < 0) {
        LOGE(DEBUG, "cannot open %s for LIBXL_DEBUG_DUMP_DTB", dtb);
        goto out;
    }

    rc = libxl_write_exactly(CTX, fd, fdt, fdt_totalsize(fdt), dtb, "dtb");
    if (rc < 0) goto out;

out:
    if (fd >= 0) {
        r = close(fd);
        if (r < 0) LOGE(DEBUG, "failed to close DTB debug dump output");
    }
}

#ifdef ENABLE_PARTIAL_DEVICE_TREE

static int check_partial_fdt(libxl__gc *gc, void *fdt, size_t size)
{
    int r;

    if (fdt_magic(fdt) != FDT_MAGIC) {
        LOG(ERROR, "Partial FDT is not a valid Flat Device Tree");
        return ERROR_FAIL;
    }

    r = fdt_check_header(fdt);
    if (r) {
        LOG(ERROR, "Failed to check the partial FDT (%d)", r);
        return ERROR_FAIL;
    }

    if (fdt_totalsize(fdt) > size) {
        LOG(ERROR, "Partial FDT totalsize is too big");
        return ERROR_FAIL;
    }

    return 0;
}

static int copy_properties(libxl__gc *gc, void *fdt, void *pfdt,
                           int nodeoff)
{
    int propoff, nameoff, r;
    const struct fdt_property *prop;

    for (propoff = fdt_first_property_offset(pfdt, nodeoff);
         propoff >= 0;
         propoff = fdt_next_property_offset(pfdt, propoff)) {

        if (!(prop = fdt_get_property_by_offset(pfdt, propoff, NULL))) {
            return -FDT_ERR_INTERNAL;
        }

        nameoff = fdt32_to_cpu(prop->nameoff);
        r = fdt_property(fdt, fdt_string(pfdt, nameoff),
                         prop->data, fdt32_to_cpu(prop->len));
        if (r) return r;
    }

    /* FDT_ERR_NOTFOUND => There is no more properties for this node */
    return (propoff != -FDT_ERR_NOTFOUND)? propoff : 0;
}

/* Copy a node from the partial device tree to the guest device tree */
static int copy_node(libxl__gc *gc, void *fdt, void *pfdt,
                     int nodeoff, int depth)
{
    int r;

    r = fdt_begin_node(fdt, fdt_get_name(pfdt, nodeoff, NULL));
    if (r) return r;

    r = copy_properties(gc, fdt, pfdt, nodeoff);
    if (r) return r;

    for (nodeoff = fdt_first_subnode(pfdt, nodeoff);
         nodeoff >= 0;
         nodeoff = fdt_next_subnode(pfdt, nodeoff)) {
        r = copy_node(gc, fdt, pfdt, nodeoff, depth + 1);
        if (r) return r;
    }

    if (nodeoff != -FDT_ERR_NOTFOUND)
        return nodeoff;

    r = fdt_end_node(fdt);
    if (r) return r;

    return 0;
}

static int copy_node_by_path(libxl__gc *gc, const char *path,
                             void *fdt, void *pfdt)
{
    int nodeoff, r;
    const char *name = strrchr(path, '/');

    if (!name)
        return -FDT_ERR_INTERNAL;

    name++;

    /*
     * The FDT function to look at a node doesn't take into account the
     * unit (i.e anything after @) when search by name. Check if the
     * name exactly matches.
     */
    nodeoff = fdt_path_offset(pfdt, path);
    if (nodeoff < 0)
        return nodeoff;

    if (strcmp(fdt_get_name(pfdt, nodeoff, NULL), name))
        return -FDT_ERR_NOTFOUND;

    r = copy_node(gc, fdt, pfdt, nodeoff, 0);
    if (r) return r;

    return 0;
}

/*
 * The partial device tree is not copied entirely. Only the relevant bits are
 * copied to the guest device tree:
 *  - /passthrough node
 *  - /aliases node
 */
static int copy_partial_fdt(libxl__gc *gc, void *fdt, void *pfdt)
{
    int r;

    r = copy_node_by_path(gc, "/passthrough", fdt, pfdt);
    if (r < 0) {
        LOG(ERROR, "Can't copy the node \"/passthrough\" from the partial FDT");
        return r;
    }

    r = copy_node_by_path(gc, "/aliases", fdt, pfdt);
    if (r < 0 && r != -FDT_ERR_NOTFOUND) {
        LOG(ERROR, "Can't copy the node \"/aliases\" from the partial FDT");
        return r;
    }

    return 0;
}

#else

static int check_partial_fdt(libxl__gc *gc, void *fdt, size_t size)
{
    LOG(ERROR, "partial device tree not supported");

    return ERROR_FAIL;
}

static int copy_partial_fdt(libxl__gc *gc, void *fdt, void *pfdt)
{
    /*
     * We should never be here when the partial device tree is not
     * supported.
     * */
    return -FDT_ERR_INTERNAL;
}

#endif /* ENABLE_PARTIAL_DEVICE_TREE */

#define FDT_MAX_SIZE (1<<20)

static int libxl__prepare_dtb(libxl__gc *gc, libxl_domain_build_info *info,
                              libxl__domain_build_state *state,
                              struct xc_dom_image *dom)
{
    void *fdt = NULL;
    void *pfdt = NULL;
    int rc, res;
    size_t fdt_size = 0;
    int pfdt_size = 0;

    const libxl_version_info *vers;
    const struct arch_info *ainfo;

    /* convenience aliases */
    xc_domain_configuration_t *xc_config = &state->config;

    vers = libxl_get_version_info(CTX);
    if (vers == NULL) return ERROR_FAIL;

    ainfo = get_arch_info(gc, dom);
    if (ainfo == NULL) return ERROR_FAIL;

    LOG(DEBUG, "constructing DTB for Xen version %d.%d guest",
        vers->xen_version_major, vers->xen_version_minor);
    LOG(DEBUG, " - vGIC version: %s", gicv_to_string(xc_config->gic_version));

    if (info->device_tree) {
        LOG(DEBUG, " - Partial device tree provided: %s", info->device_tree);

        rc = libxl_read_file_contents(CTX, info->device_tree,
                                      &pfdt, &pfdt_size);
        if (rc) {
            LOGEV(ERROR, rc, "failed to read the partial device file %s",
                  info->device_tree);
            return ERROR_FAIL;
        }
        libxl__ptr_add(gc, pfdt);

        if (check_partial_fdt(gc, pfdt, pfdt_size))
            return ERROR_FAIL;
    }

/*
 * Call "call" handling FDT_ERR_*. Will either:
 * - loop back to retry_resize
 * - set rc and goto out
 * - fall through successfully
 *
 * On FDT_ERR_NOSPACE we start again from scratch rather than
 * realloc+libfdt_open_into because "call" may have failed half way
 * through a series of steps leaving the partial tree in an
 * inconsistent state, e.g. leaving a node open.
 */
#define FDT( call ) do {                                        \
    int fdt_res = (call);                                       \
    if (fdt_res == -FDT_ERR_NOSPACE && fdt_size < FDT_MAX_SIZE) \
        goto next_resize;                                       \
    else if (fdt_res < 0) {                                     \
        LOG(ERROR, "FDT: %s failed: %d = %s",                   \
            #call, fdt_res, fdt_strerror(fdt_res));             \
        rc = ERROR_FAIL;                                        \
        goto out;                                               \
    }                                                           \
} while(0)

    for (;;) {
next_resize:
        if (fdt_size) {
            fdt_size <<= 1;
            LOG(DEBUG, "Increasing FDT size to %zd and retrying", fdt_size);
        } else {
            fdt_size = 4096;
        }

        fdt = libxl__realloc(gc, fdt, fdt_size);

        FDT( fdt_create(fdt, fdt_size) );

        FDT( fdt_finish_reservemap(fdt) );

        FDT( fdt_begin_node(fdt, "") );

        FDT( make_root_properties(gc, vers, fdt) );
        FDT( make_chosen_node(gc, fdt, !!dom->ramdisk_blob, state, info) );
        FDT( make_cpus_node(gc, fdt, info->max_vcpus, ainfo) );
        FDT( make_psci_node(gc, fdt) );

        FDT( make_memory_nodes(gc, fdt, dom) );

        switch (xc_config->gic_version) {
        case XEN_DOMCTL_CONFIG_GIC_V2:
            FDT( make_gicv2_node(gc, fdt,
                                 GUEST_GICD_BASE, GUEST_GICD_SIZE,
                                 GUEST_GICC_BASE, GUEST_GICC_SIZE) );
            break;
        case XEN_DOMCTL_CONFIG_GIC_V3:
            FDT( make_gicv3_node(gc, fdt) );
            break;
        default:
            LOG(ERROR, "Unknown GIC version %s",
                gicv_to_string(xc_config->gic_version));
            rc = ERROR_FAIL;
            goto out;
        }

        FDT( make_timer_node(gc, fdt, ainfo, xc_config->clock_frequency) );
        FDT( make_hypervisor_node(gc, fdt, vers) );

        if (info->arch_arm.vuart == LIBXL_VUART_TYPE_SBSA_UART)
            FDT( make_vpl011_uart_node(gc, fdt, ainfo, dom) );

        if (pfdt)
            FDT( copy_partial_fdt(gc, fdt, pfdt) );

        FDT( fdt_end_node(fdt) );

        FDT( fdt_finish(fdt) );
        break;
    }
#undef FDT

    LOG(DEBUG, "fdt total size %d", fdt_totalsize(fdt));

    res = xc_dom_devicetree_mem(dom, fdt, fdt_totalsize(fdt));
    if (res) {
        LOGE(ERROR, "xc_dom_devicetree_mem failed");
        rc = ERROR_FAIL;
        goto out;
    }

    rc = 0;

out:
    return rc;
}

int libxl__arch_domain_init_hw_description(libxl__gc *gc,
                                           libxl_domain_build_info *info,
                                           libxl__domain_build_state *state,
                                           struct xc_dom_image *dom)
{
    int rc;
    uint64_t val;

    assert(info->type == LIBXL_DOMAIN_TYPE_PV);

    /* Set the value of domain param HVM_PARAM_CALLBACK_IRQ. */
    val = MASK_INSR(HVM_PARAM_CALLBACK_TYPE_PPI,
                    HVM_PARAM_CALLBACK_IRQ_TYPE_MASK);
    /* Active-low level-sensitive  */
    val |= MASK_INSR(HVM_PARAM_CALLBACK_TYPE_PPI_FLAG_LOW_LEVEL,
                     HVM_PARAM_CALLBACK_TYPE_PPI_FLAG_MASK);
    val |= GUEST_EVTCHN_PPI;
    rc = xc_hvm_param_set(dom->xch, dom->guest_domid, HVM_PARAM_CALLBACK_IRQ,
                          val);
    if (rc)
        return rc;

    rc = libxl__prepare_dtb(gc, info, state, dom);
    if (rc) goto out;

    if (!libxl_defbool_val(info->acpi)) {
        LOG(DEBUG, "Generating ACPI tables is disabled by user.");
        rc = 0;
        goto out;
    }

    if (strcmp(dom->guest_type, "xen-3.0-aarch64")) {
        /* ACPI is only supported for 64-bit guest currently. */
        LOG(ERROR, "Can not enable libxl option 'acpi' for %s", dom->guest_type);
        rc = ERROR_FAIL;
        goto out;
    }

    rc = libxl__prepare_acpi(gc, info, dom);

out:
    return rc;
}

static void finalise_one_node(libxl__gc *gc, void *fdt, const char *uname,
                              uint64_t base, uint64_t size)
{
    int node, res;
    const char *name = GCSPRINTF("%s@%"PRIx64, uname, base);

    node = fdt_path_offset(fdt, name);
    assert(node > 0);

    if (size == 0) {
        LOG(DEBUG, "Nopping out placeholder node %s", name);
        fdt_nop_node(fdt, node);
    } else {
        uint32_t regs[ROOT_ADDRESS_CELLS+ROOT_SIZE_CELLS];
        be32 *cells = &regs[0];

        LOG(DEBUG, "Populating placeholder node %s", name);

        set_range(&cells, ROOT_ADDRESS_CELLS, ROOT_SIZE_CELLS, base, size);

        res = fdt_setprop_inplace(fdt, node, "reg", regs, sizeof(regs));
        assert(!res);
    }
}

int libxl__arch_domain_finalise_hw_description(libxl__gc *gc,
                                               libxl_domain_build_info *info,
                                               struct xc_dom_image *dom)
{
    void *fdt = dom->devicetree_blob;
    int i;
    const uint64_t bankbase[] = GUEST_RAM_BANK_BASES;

    const struct xc_dom_seg *ramdisk = dom->ramdisk_blob ?
        &dom->ramdisk_seg : NULL;

    if (ramdisk) {
        int chosen, res;
        uint64_t val;

        /* Neither the fdt_path_offset() nor either of the
         * fdt_setprop_inplace() calls can fail. If they do then
         * make_chosen_node() (see above) has got something very
         * wrong.
         */
        chosen = fdt_path_offset(fdt, "/chosen");
        assert(chosen > 0);

        LOG(DEBUG, "/chosen updating initrd properties to cover "
            "%"PRIx64"-%"PRIx64,
            ramdisk->vstart, ramdisk->vend);

        val = cpu_to_fdt64(ramdisk->vstart);
        res = fdt_setprop_inplace(fdt, chosen, PROP_INITRD_START,
                                  &val, sizeof(val));
        assert(!res);

        val = cpu_to_fdt64(ramdisk->vend);
        res = fdt_setprop_inplace(fdt, chosen, PROP_INITRD_END,
                                  &val, sizeof(val));
        assert(!res);

    }

    for (i = 0; i < GUEST_RAM_BANKS; i++) {
        const uint64_t size = (uint64_t)dom->rambank_size[i] << XC_PAGE_SHIFT;

        finalise_one_node(gc, fdt, "/memory", bankbase[i], size);
    }

    if (dom->acpi_modules[0].data) {
        finalise_one_node(gc, fdt, "/chosen/module", GUEST_ACPI_BASE,
                          dom->acpi_modules[0].length);
    }

    debug_dump_fdt(gc, fdt);

    return 0;
}

int libxl__arch_build_dom_finish(libxl__gc *gc,
                                 libxl_domain_build_info *info,
                                 struct xc_dom_image *dom,
                                 libxl__domain_build_state *state)
{
    int rc = 0, ret;

    if (info->arch_arm.vuart != LIBXL_VUART_TYPE_SBSA_UART) {
        rc = 0;
        goto out;
    }

    ret = xc_dom_vuart_init(CTX->xch,
                            XEN_DOMCTL_VUART_TYPE_VPL011,
                            dom->guest_domid,
                            dom->console_domid,
                            dom->vuart_gfn,
                            &state->vuart_port);
    if (ret < 0) {
        rc = ERROR_FAIL;
        LOG(ERROR, "xc_dom_vuart_init failed\n");
    }

out:
    return rc;
}

int libxl__arch_vnuma_build_vmemrange(libxl__gc *gc,
                                      uint32_t domid,
                                      libxl_domain_build_info *info,
                                      libxl__domain_build_state *state)
{
    return libxl__vnuma_build_vmemrange_pv_generic(gc, domid, info, state);
}

int libxl__arch_domain_map_irq(libxl__gc *gc, uint32_t domid, int irq)
{
    return xc_domain_bind_pt_spi_irq(CTX->xch, domid, irq, irq);
}

int libxl__arch_domain_construct_memmap(libxl__gc *gc,
                                        libxl_domain_config *d_config,
                                        uint32_t domid,
                                        struct xc_dom_image *dom)
{
    return 0;
}

void libxl__arch_domain_build_info_acpi_setdefault(
                                        libxl_domain_build_info *b_info)
{
    libxl_defbool_setdefault(&b_info->acpi, false);
}

/*
 * Local variables:
 * mode: C
 * c-basic-offset: 4
 * indent-tabs-mode: nil
 * End:
 */