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  */
  41 static 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
  82 static 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
 114 static 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
 122 static 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
 132 static const 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
 139 static void guest_loader_register_type(void)
 140 {
 141     type_register_static(&guest_loader_info);
 142 }
 143
 144 type_init(guest_loader_register_type)