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 "sysemu/dma.h"
  30#include "hw/loader.h"
  31#include "hw/qdev-properties.h"
  32#include "qapi/error.h"
  33#include "qemu/module.h"
  34#include "guest-loader.h"
  35#include "sysemu/device_tree.h"
  36#include "hw/boards.h"
  37
  38/*
  39 * Insert some FDT nodes for the loaded blob.
  40 */
  41static void loader_insert_platform_data(GuestLoaderState *s, int size,
  42                                        Error **errp)
  43{
  44    MachineState *machine = MACHINE(qdev_get_machine());
  45    void *fdt = machine->fdt;
  46    g_autofree char *node = g_strdup_printf("/chosen/module@0x%08" PRIx64,
  47                                            s->addr);
  48    uint64_t reg_attr[2] = {cpu_to_be64(s->addr), cpu_to_be64(size)};
  49
  50    if (!fdt) {
  51        error_setg(errp, "Cannot modify FDT fields if the machine has none");
  52        return;
  53    }
  54
  55    qemu_fdt_add_subnode(fdt, node);
  56    qemu_fdt_setprop(fdt, node, "reg", &reg_attr, sizeof(reg_attr));
  57
  58    if (s->kernel) {
  59        const char *compat[2] = { "multiboot,module", "multiboot,kernel" };
  60        if (qemu_fdt_setprop_string_array(fdt, node, "compatible",
  61                                          (char **) &compat,
  62                                          ARRAY_SIZE(compat)) < 0) {
  63            error_setg(errp, "couldn't set %s/compatible", node);
  64            return;
  65        }
  66        if (s->args) {
  67            if (qemu_fdt_setprop_string(fdt, node, "bootargs", s->args) < 0) {
  68                error_setg(errp, "couldn't set %s/bootargs", node);
  69            }
  70        }
  71    } else if (s->initrd) {
  72        const char *compat[2] = { "multiboot,module", "multiboot,ramdisk" };
  73        if (qemu_fdt_setprop_string_array(fdt, node, "compatible",
  74                                          (char **) &compat,
  75                                          ARRAY_SIZE(compat)) < 0) {
  76            error_setg(errp, "couldn't set %s/compatible", node);
  77            return;
  78        }
  79    }
  80}
  81
  82static void guest_loader_realize(DeviceState *dev, Error **errp)
  83{
  84    GuestLoaderState *s = GUEST_LOADER(dev);
  85    char *file = s->kernel ? s->kernel : s->initrd;
  86    int size = 0;
  87
  88    /* Perform some error checking on the user's options */
  89    if (s->kernel && s->initrd) {
  90        error_setg(errp, "Cannot specify a kernel and initrd in same stanza");
  91        return;
  92    } else if (!s->kernel && !s->initrd)  {
  93        error_setg(errp, "Need to specify a kernel or initrd image");
  94        return;
  95    } else if (!s->addr) {
  96        error_setg(errp, "Need to specify the address of guest blob");
  97        return;
  98    } else if (s->args && !s->kernel) {
  99        error_setg(errp, "Boot args only relevant to kernel blobs");
 100    }
 101
 102    /* Default to the maximum size being the machine's ram size */
 103    size = load_image_targphys_as(file, s->addr, current_machine->ram_size,
 104                                  NULL);
 105    if (size < 0) {
 106        error_setg(errp, "Cannot load specified image %s", file);
 107        return;
 108    }
 109
 110    /* Now the image is loaded we need to update the platform data */
 111    loader_insert_platform_data(s, size, errp);
 112}
 113
 114static Property guest_loader_props[] = {
 115    DEFINE_PROP_UINT64("addr", GuestLoaderState, addr, 0),
 116    DEFINE_PROP_STRING("kernel", GuestLoaderState, kernel),
 117    DEFINE_PROP_STRING("bootargs", GuestLoaderState, args),
 118    DEFINE_PROP_STRING("initrd", GuestLoaderState, initrd),
 119    DEFINE_PROP_END_OF_LIST(),
 120};
 121
 122static void guest_loader_class_init(ObjectClass *klass, void *data)
 123{
 124    DeviceClass *dc = DEVICE_CLASS(klass);
 125
 126    dc->realize = guest_loader_realize;
 127    device_class_set_props(dc, guest_loader_props);
 128    dc->desc = "Guest Loader";
 129    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 130}
 131
 132static TypeInfo guest_loader_info = {
 133    .name = TYPE_GUEST_LOADER,
 134    .parent = TYPE_DEVICE,
 135    .instance_size = sizeof(GuestLoaderState),
 136    .class_init = guest_loader_class_init,
 137};
 138
 139static void guest_loader_register_type(void)
 140{
 141    type_register_static(&guest_loader_info);
 142}
 143
 144type_init(guest_loader_register_type)
 145