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  */
  42 static 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
  83 static 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
 115 static 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
 123 static 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
 133 static 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
 140 static void guest_loader_register_type(void)
 141 {
 142     type_register_static(&guest_loader_info);
 143 }
 144
 145 type_init(guest_loader_register_type)