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authorAlex Bennée <alex.bennee@linaro.org>2021-03-03 17:36:39 +0000
committerAlex Bennée <alex.bennee@linaro.org>2021-03-10 15:34:11 +0000
commita33ff6d2c6bd480fbab3bc9f748655a9269881eb (patch)
tree6d9648a35dd1eeaaa7820918ef4e0d7dccdbff0f /hw
parent78da6a1bca224a8c1c4b1bdf2ca8ec19c74c6fc1 (diff)
hw/core: implement a guest-loader to support static hypervisor guests
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> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20210303173642.3805-5-alex.bennee@linaro.org>
Diffstat (limited to 'hw')
-rw-r--r--hw/core/guest-loader.c145
-rw-r--r--hw/core/guest-loader.h34
-rw-r--r--hw/core/meson.build2
3 files changed, 181 insertions, 0 deletions
diff --git a/hw/core/guest-loader.c b/hw/core/guest-loader.c
new file mode 100644
index 0000000000..bde44e27b4
--- /dev/null
+++ b/hw/core/guest-loader.c
@@ -0,0 +1,145 @@
+/*
+ * 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@0x%08" PRIx64,
+ 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", &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 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, current_machine->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/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/meson.build b/hw/core/meson.build
index 032576f571..9cd72edf51 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',