On Wed, Oct 21, 2020 at 10:09 AM Alex Bennée alex.bennee@linaro.org wrote:
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:
guest as in Hypervisor guest and QEMU guest is a little confusing, but I can't think of a better name
$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
This seems fine to me.
Do you mind writing some documentation though? The generic-loader documentation should be a good place to start.
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) {
The ( bracket should be on the previous line right?
Alistair
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', -- 2.20.1