Hypervisors, especially type-1 ones, need the firmware/bootcode to put their initial guest somewhere in memory and pass the information to it via platform data. The guest-loader is modelled after the generic loader for exactly this sort of purpose:
$QEMU $ARGS -kernel ~/xen.git/xen/xen \ -append "dom0_mem=1G,max:1G loglvl=all guest_loglvl=all" \ -device guest-loader,addr=0x42000000,kernel=Image,bootargs="root=/dev/sda2 ro console=hvc0 earlyprintk=xen" \ -device guest-loader,addr=0x47000000,initrd=rootfs.cpio
Signed-off-by: Alex Bennée alex.bennee@linaro.org Message-Id: 20201021170842.25762-5-alex.bennee@linaro.org Signed-off-by: Alex Bennée alex.bennee@linaro.org --- hw/core/guest-loader.h | 34 ++++++++++ hw/core/guest-loader.c | 140 +++++++++++++++++++++++++++++++++++++++++ hw/core/meson.build | 2 + 3 files changed, 176 insertions(+) create mode 100644 hw/core/guest-loader.h create mode 100644 hw/core/guest-loader.c
diff --git a/hw/core/guest-loader.h b/hw/core/guest-loader.h new file mode 100644 index 0000000000..07f4b4884b --- /dev/null +++ b/hw/core/guest-loader.h @@ -0,0 +1,34 @@ +/* + * Guest Loader + * + * Copyright (C) 2020 Linaro + * Written by Alex Bennée alex.bennee@linaro.org + * (based on the generic-loader by Li Guang lig.fnst@cn.fujitsu.com) + * + * SPDX-License-Identifier: GPL-2.0-or-later + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#ifndef GUEST_LOADER_H +#define GUEST_LOADER_H + +#include "hw/qdev-core.h" +#include "qom/object.h" + +struct GuestLoaderState { + /* <private> */ + DeviceState parent_obj; + + /* <public> */ + uint64_t addr; + char *kernel; + char *args; + char *initrd; +}; + +#define TYPE_GUEST_LOADER "guest-loader" +OBJECT_DECLARE_SIMPLE_TYPE(GuestLoaderState, GUEST_LOADER) + +#endif diff --git a/hw/core/guest-loader.c b/hw/core/guest-loader.c new file mode 100644 index 0000000000..1ce39842be --- /dev/null +++ b/hw/core/guest-loader.c @@ -0,0 +1,140 @@ +/* + * Guest Loader + * + * Copyright (C) 2020 Linaro + * Written by Alex Bennée alex.bennee@linaro.org + * (based on the generic-loader by Li Guang lig.fnst@cn.fujitsu.com) + * + * SPDX-License-Identifier: GPL-2.0-or-later + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +/* + * Much like the generic-loader this is treated as a special device + * inside QEMU. However unlike the generic-loader this device is used + * to load guest images for hypervisors. As part of that process the + * hypervisor needs to have platform information passed to it by the + * lower levels of the stack (e.g. firmware/bootloader). If you boot + * the hypervisor directly you use the guest-loader to load the Dom0 + * or equivalent guest images in the right place in the same way a + * boot loader would. + * + * This is only relevant for full system emulation. + */ + +#include "qemu/osdep.h" +#include "hw/core/cpu.h" +#include "hw/sysbus.h" +#include "sysemu/dma.h" +#include "hw/loader.h" +#include "hw/qdev-properties.h" +#include "qapi/error.h" +#include "qemu/module.h" +#include "guest-loader.h" +#include "sysemu/device_tree.h" +#include "hw/boards.h" + +/* + * Insert some FDT nodes for the loaded blob. + */ +static void loader_insert_platform_data(GuestLoaderState *s, int size, Error **errp) +{ + MachineState *machine = MACHINE(qdev_get_machine()); + void *fdt = machine->fdt; + g_autofree char *node = g_strdup_printf("/chosen/module@%#08lx", s->addr); + uint64_t reg_attr[2] = {cpu_to_be64(s->addr), cpu_to_be64(size)}; + + if (!fdt) { + error_setg(errp, "Cannot modify FDT fields if the machine has none"); + return; + } + + qemu_fdt_add_subnode(fdt, node); + qemu_fdt_setprop(fdt, node, "reg", ®_attr, sizeof(reg_attr)); + + if (s->kernel) { + const char *compat[2] = { "multiboot,module", "multiboot,kernel" }; + if (qemu_fdt_setprop_string_array + (fdt, node, "compatible", (char **) &compat, ARRAY_SIZE(compat)) < 0) { + error_setg(errp, "couldn't set %s/compatible", node); + return; + } + if (s->args) { + if (qemu_fdt_setprop_string(fdt, node, "bootargs", s->args) < 0) { + error_setg(errp, "couldn't set %s/bootargs", node); + } + } + } else if (s->initrd) { + const char * compat[2] = { "multiboot,module", "multiboot,ramdisk" }; + if (qemu_fdt_setprop_string_array + (fdt, node, "compatible", (char **) &compat, ARRAY_SIZE(compat)) < 0) { + error_setg(errp, "couldn't set %s/compatible", node); + return; + } + } +} + +static void guest_loader_realize(DeviceState *dev, Error **errp) +{ + GuestLoaderState *s = GUEST_LOADER(dev); + char *file = s->kernel ? s->kernel : s->initrd; + int size = 0; + + /* Perform some error checking on the user's options */ + if (s->kernel && s->initrd) { + error_setg(errp, "Cannot specify a kernel and initrd in the same stanza"); + return; + } else if (!s->kernel && !s->initrd) { + error_setg(errp, "Need to specify a kernel or initrd image"); + return; + } else if (!s->addr) { + error_setg(errp, "Need to specify the address of guest blob"); + return; + } else if (s->args && !s->kernel) { + error_setg(errp, "Boot args only relevant to kernel blobs"); + } + + /* Default to the maximum size being the machine's ram size */ + size = load_image_targphys_as(file, s->addr, ram_size, NULL); + if (size < 0) { + error_setg(errp, "Cannot load specified image %s", file); + return; + } + + /* Now the image is loaded we need to update the platform data */ + loader_insert_platform_data(s, size, errp); +} + +static Property guest_loader_props[] = { + DEFINE_PROP_UINT64("addr", GuestLoaderState, addr, 0), + DEFINE_PROP_STRING("kernel", GuestLoaderState, kernel), + DEFINE_PROP_STRING("bootargs", GuestLoaderState, args), + DEFINE_PROP_STRING("initrd", GuestLoaderState, initrd), + DEFINE_PROP_END_OF_LIST(), +}; + +static void guest_loader_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->realize = guest_loader_realize; + device_class_set_props(dc, guest_loader_props); + dc->desc = "Guest Loader"; + set_bit(DEVICE_CATEGORY_MISC, dc->categories); +} + +static TypeInfo guest_loader_info = { + .name = TYPE_GUEST_LOADER, + .parent = TYPE_DEVICE, + .instance_size = sizeof(GuestLoaderState), + .class_init = guest_loader_class_init, +}; + +static void guest_loader_register_type(void) +{ + type_register_static(&guest_loader_info); +} + +type_init(guest_loader_register_type) diff --git a/hw/core/meson.build b/hw/core/meson.build index 4a744f3b5e..27a69fc578 100644 --- a/hw/core/meson.build +++ b/hw/core/meson.build @@ -37,6 +37,8 @@ softmmu_ss.add(files( 'clock-vmstate.c', ))
+softmmu_ss.add(when: 'CONFIG_TCG', if_true: files('guest-loader.c')) + specific_ss.add(when: 'CONFIG_SOFTMMU', if_true: files( 'machine-qmp-cmds.c', 'numa.c',