LXR qemu/hw/core/guest-loader.c

   1/*
   2 * Guest Loader
   3 *
   4 * Copyright (C) 2020 Linaro
   5 * Written by Alex Bennée <alex.bennee@linaro.org>
   6 * (based on the generic-loader by Li Guang <lig.fnst@cn.fujitsu.com>)
   7 *
   8 * SPDX-License-Identifier: GPL-2.0-or-later
   9 *
  10 * This work is licensed under the terms of the GNU GPL, version 2 or later.
  11 * See the COPYING file in the top-level directory.
  12 */
  13
  14/*
  15 * Much like the generic-loader this is treated as a special device
  16 * inside QEMU. However unlike the generic-loader this device is used
  17 * to load guest images for hypervisors. As part of that process the
  18 * hypervisor needs to have platform information passed to it by the
  19 * lower levels of the stack (e.g. firmware/bootloader). If you boot
  20 * the hypervisor directly you use the guest-loader to load the Dom0
  21 * or equivalent guest images in the right place in the same way a
  22 * boot loader would.
  23 *
  24 * This is only relevant for full system emulation.
  25 */
  26
  27#include "qemu/osdep.h"
  28#include "hw/core/cpu.h"
  29#include "hw/sysbus.h"
  30#include "sysemu/dma.h"
  31#include "hw/loader.h"
  32#include "hw/qdev-properties.h"
  33#include "qapi/error.h"
  34#include "qemu/module.h"
  35#include "guest-loader.h"
  36#include "sysemu/device_tree.h"
  37#include "hw/boards.h"
  38
  39/*
  40 * Insert some FDT nodes for the loaded blob.
  41 */
  42static void loader_insert_platform_data(GuestLoaderState *s, int size,
  43                                        Error **errp)
  44{
  45    MachineState *machine = MACHINE(qdev_get_machine());
  46    void *fdt = machine->fdt;
  47    g_autofree char *node = g_strdup_printf("/chosen/module@0x%08" PRIx64,
  48                                            s->addr);
  49    uint64_t reg_attr[2] = {cpu_to_be64(s->addr), cpu_to_be64(size)};
  50
  51    if (!fdt) {
  52        error_setg(errp, "Cannot modify FDT fields if the machine has none");
  53        return;
  54    }
  55
  56    qemu_fdt_add_subnode(fdt, node);
  57    qemu_fdt_setprop(fdt, node, "reg", &reg_attr, sizeof(reg_attr));
  58
  59    if (s->kernel) {
  60        const char *compat[2] = { "multiboot,module", "multiboot,kernel" };
  61        if (qemu_fdt_setprop_string_array(fdt, node, "compatible",
  62                                          (char **) &compat,
  63                                          ARRAY_SIZE(compat)) < 0) {
  64            error_setg(errp, "couldn't set %s/compatible", node);
  65            return;
  66        }
  67        if (s->args) {
  68            if (qemu_fdt_setprop_string(fdt, node, "bootargs", s->args) < 0) {
  69                error_setg(errp, "couldn't set %s/bootargs", node);
  70            }
  71        }
  72    } else if (s->initrd) {
  73        const char *compat[2] = { "multiboot,module", "multiboot,ramdisk" };
  74        if (qemu_fdt_setprop_string_array(fdt, node, "compatible",
  75                                          (char **) &compat,
  76                                          ARRAY_SIZE(compat)) < 0) {
  77            error_setg(errp, "couldn't set %s/compatible", node);
  78            return;
  79        }
  80    }
  81}
  82
  83static void guest_loader_realize(DeviceState *dev, Error **errp)
  84{
  85    GuestLoaderState *s = GUEST_LOADER(dev);
  86    char *file = s->kernel ? s->kernel : s->initrd;
  87    int size = 0;
  88
  89    /* Perform some error checking on the user's options */
  90    if (s->kernel && s->initrd) {
  91        error_setg(errp, "Cannot specify a kernel and initrd in same stanza");
  92        return;
  93    } else if (!s->kernel && !s->initrd)  {
  94        error_setg(errp, "Need to specify a kernel or initrd image");
  95        return;
  96    } else if (!s->addr) {
  97        error_setg(errp, "Need to specify the address of guest blob");
  98        return;
  99    } else if (s->args && !s->kernel) {
 100        error_setg(errp, "Boot args only relevant to kernel blobs");
 101    }
 102
 103    /* Default to the maximum size being the machine's ram size */
 104    size = load_image_targphys_as(file, s->addr, current_machine->ram_size,
 105                                  NULL);
 106    if (size < 0) {
 107        error_setg(errp, "Cannot load specified image %s", file);
 108        return;
 109    }
 110
 111    /* Now the image is loaded we need to update the platform data */
 112    loader_insert_platform_data(s, size, errp);
 113}
 114
 115static Property guest_loader_props[] = {
 116    DEFINE_PROP_UINT64("addr", GuestLoaderState, addr, 0),
 117    DEFINE_PROP_STRING("kernel", GuestLoaderState, kernel),
 118    DEFINE_PROP_STRING("bootargs", GuestLoaderState, args),
 119    DEFINE_PROP_STRING("initrd", GuestLoaderState, initrd),
 120    DEFINE_PROP_END_OF_LIST(),
 121};
 122
 123static void guest_loader_class_init(ObjectClass *klass, void *data)
 124{
 125    DeviceClass *dc = DEVICE_CLASS(klass);
 126
 127    dc->realize = guest_loader_realize;
 128    device_class_set_props(dc, guest_loader_props);
 129    dc->desc = "Guest Loader";
 130    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 131}
 132
 133static TypeInfo guest_loader_info = {
 134    .name = TYPE_GUEST_LOADER,
 135    .parent = TYPE_DEVICE,
 136    .instance_size = sizeof(GuestLoaderState),
 137    .class_init = guest_loader_class_init,
 138};
 139
 140static void guest_loader_register_type(void)
 141{
 142    type_register_static(&guest_loader_info);
 143}
 144
 145type_init(guest_loader_register_type)
 146