hw/i386: Introduce the microvm machine type

microvm is a machine type inspired by Firecracker and constructed
after its machine model.

It's a minimalist machine type without PCI nor ACPI support, designed
for short-lived guests. microvm also establishes a baseline for
benchmarking and optimizing both QEMU and guest operating systems,
since it is optimized for both boot time and footprint.

Signed-off-by: Sergio Lopez <slp@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Sergio Lopez 2019-10-02 08:03:19 +02:00 committed by Paolo Bonzini
parent e00803aab4
commit 0ebf007dda
5 changed files with 655 additions and 0 deletions

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@ -28,3 +28,4 @@
CONFIG_ISAPC=y
CONFIG_I440FX=y
CONFIG_Q35=y
CONFIG_MICROVM=y

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@ -92,6 +92,16 @@ config Q35
select SMBIOS
select FW_CFG_DMA
config MICROVM
bool
imply SERIAL_ISA
select ISA_BUS
select APIC
select IOAPIC
select I8259
select MC146818RTC
select VIRTIO_MMIO
config VTD
bool

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@ -4,6 +4,7 @@ obj-y += x86.o
obj-y += pc.o
obj-$(CONFIG_I440FX) += pc_piix.o
obj-$(CONFIG_Q35) += pc_q35.o
obj-$(CONFIG_MICROVM) += microvm.o
obj-y += fw_cfg.o pc_sysfw.o
obj-y += x86-iommu.o
obj-$(CONFIG_VTD) += intel_iommu.o

572
hw/i386/microvm.c Normal file
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@ -0,0 +1,572 @@
/*
* Copyright (c) 2018 Intel Corporation
* Copyright (c) 2019 Red Hat, Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2 or later, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "qemu/error-report.h"
#include "qemu/cutils.h"
#include "qemu/units.h"
#include "qapi/error.h"
#include "qapi/visitor.h"
#include "qapi/qapi-visit-common.h"
#include "sysemu/sysemu.h"
#include "sysemu/cpus.h"
#include "sysemu/numa.h"
#include "sysemu/reset.h"
#include "hw/loader.h"
#include "hw/irq.h"
#include "hw/kvm/clock.h"
#include "hw/i386/microvm.h"
#include "hw/i386/x86.h"
#include "hw/i386/pc.h"
#include "target/i386/cpu.h"
#include "hw/timer/i8254.h"
#include "hw/timer/mc146818rtc.h"
#include "hw/char/serial.h"
#include "hw/i386/topology.h"
#include "hw/i386/e820_memory_layout.h"
#include "hw/i386/fw_cfg.h"
#include "hw/virtio/virtio-mmio.h"
#include "cpu.h"
#include "elf.h"
#include "kvm_i386.h"
#include "hw/xen/start_info.h"
#define MICROVM_BIOS_FILENAME "bios-microvm.bin"
static void microvm_set_rtc(MicrovmMachineState *mms, ISADevice *s)
{
X86MachineState *x86ms = X86_MACHINE(mms);
int val;
val = MIN(x86ms->below_4g_mem_size / KiB, 640);
rtc_set_memory(s, 0x15, val);
rtc_set_memory(s, 0x16, val >> 8);
/* extended memory (next 64MiB) */
if (x86ms->below_4g_mem_size > 1 * MiB) {
val = (x86ms->below_4g_mem_size - 1 * MiB) / KiB;
} else {
val = 0;
}
if (val > 65535) {
val = 65535;
}
rtc_set_memory(s, 0x17, val);
rtc_set_memory(s, 0x18, val >> 8);
rtc_set_memory(s, 0x30, val);
rtc_set_memory(s, 0x31, val >> 8);
/* memory between 16MiB and 4GiB */
if (x86ms->below_4g_mem_size > 16 * MiB) {
val = (x86ms->below_4g_mem_size - 16 * MiB) / (64 * KiB);
} else {
val = 0;
}
if (val > 65535) {
val = 65535;
}
rtc_set_memory(s, 0x34, val);
rtc_set_memory(s, 0x35, val >> 8);
/* memory above 4GiB */
val = x86ms->above_4g_mem_size / 65536;
rtc_set_memory(s, 0x5b, val);
rtc_set_memory(s, 0x5c, val >> 8);
rtc_set_memory(s, 0x5d, val >> 16);
}
static void microvm_gsi_handler(void *opaque, int n, int level)
{
GSIState *s = opaque;
qemu_set_irq(s->ioapic_irq[n], level);
}
static void microvm_devices_init(MicrovmMachineState *mms)
{
X86MachineState *x86ms = X86_MACHINE(mms);
ISABus *isa_bus;
ISADevice *rtc_state;
GSIState *gsi_state;
int i;
/* Core components */
gsi_state = g_malloc0(sizeof(*gsi_state));
if (mms->pic == ON_OFF_AUTO_ON || mms->pic == ON_OFF_AUTO_AUTO) {
x86ms->gsi = qemu_allocate_irqs(gsi_handler, gsi_state, GSI_NUM_PINS);
} else {
x86ms->gsi = qemu_allocate_irqs(microvm_gsi_handler,
gsi_state, GSI_NUM_PINS);
}
isa_bus = isa_bus_new(NULL, get_system_memory(), get_system_io(),
&error_abort);
isa_bus_irqs(isa_bus, x86ms->gsi);
ioapic_init_gsi(gsi_state, "machine");
kvmclock_create();
for (i = 0; i < VIRTIO_NUM_TRANSPORTS; i++) {
sysbus_create_simple("virtio-mmio",
VIRTIO_MMIO_BASE + i * 512,
x86ms->gsi[VIRTIO_IRQ_BASE + i]);
}
/* Optional and legacy devices */
if (mms->pic == ON_OFF_AUTO_ON || mms->pic == ON_OFF_AUTO_AUTO) {
qemu_irq *i8259;
i8259 = i8259_init(isa_bus, pc_allocate_cpu_irq());
for (i = 0; i < ISA_NUM_IRQS; i++) {
gsi_state->i8259_irq[i] = i8259[i];
}
g_free(i8259);
}
if (mms->pit == ON_OFF_AUTO_ON || mms->pit == ON_OFF_AUTO_AUTO) {
if (kvm_pit_in_kernel()) {
kvm_pit_init(isa_bus, 0x40);
} else {
i8254_pit_init(isa_bus, 0x40, 0, NULL);
}
}
if (mms->rtc == ON_OFF_AUTO_ON ||
(mms->rtc == ON_OFF_AUTO_AUTO && !kvm_enabled())) {
rtc_state = mc146818_rtc_init(isa_bus, 2000, NULL);
microvm_set_rtc(mms, rtc_state);
}
if (mms->isa_serial) {
serial_hds_isa_init(isa_bus, 0, 1);
}
if (bios_name == NULL) {
bios_name = MICROVM_BIOS_FILENAME;
}
x86_bios_rom_init(get_system_memory(), true);
}
static void microvm_memory_init(MicrovmMachineState *mms)
{
MachineState *machine = MACHINE(mms);
X86MachineState *x86ms = X86_MACHINE(mms);
MemoryRegion *ram, *ram_below_4g, *ram_above_4g;
MemoryRegion *system_memory = get_system_memory();
FWCfgState *fw_cfg;
ram_addr_t lowmem;
int i;
/*
* Check whether RAM fits below 4G (leaving 1/2 GByte for IO memory
* and 256 Mbytes for PCI Express Enhanced Configuration Access Mapping
* also known as MMCFG).
* If it doesn't, we need to split it in chunks below and above 4G.
* In any case, try to make sure that guest addresses aligned at
* 1G boundaries get mapped to host addresses aligned at 1G boundaries.
*/
if (machine->ram_size >= 0xb0000000) {
lowmem = 0x80000000;
} else {
lowmem = 0xb0000000;
}
/*
* Handle the machine opt max-ram-below-4g. It is basically doing
* min(qemu limit, user limit).
*/
if (!x86ms->max_ram_below_4g) {
x86ms->max_ram_below_4g = 4 * GiB;
}
if (lowmem > x86ms->max_ram_below_4g) {
lowmem = x86ms->max_ram_below_4g;
if (machine->ram_size - lowmem > lowmem &&
lowmem & (1 * GiB - 1)) {
warn_report("There is possibly poor performance as the ram size "
" (0x%" PRIx64 ") is more then twice the size of"
" max-ram-below-4g (%"PRIu64") and"
" max-ram-below-4g is not a multiple of 1G.",
(uint64_t)machine->ram_size, x86ms->max_ram_below_4g);
}
}
if (machine->ram_size > lowmem) {
x86ms->above_4g_mem_size = machine->ram_size - lowmem;
x86ms->below_4g_mem_size = lowmem;
} else {
x86ms->above_4g_mem_size = 0;
x86ms->below_4g_mem_size = machine->ram_size;
}
ram = g_malloc(sizeof(*ram));
memory_region_allocate_system_memory(ram, NULL, "microvm.ram",
machine->ram_size);
ram_below_4g = g_malloc(sizeof(*ram_below_4g));
memory_region_init_alias(ram_below_4g, NULL, "ram-below-4g", ram,
0, x86ms->below_4g_mem_size);
memory_region_add_subregion(system_memory, 0, ram_below_4g);
e820_add_entry(0, x86ms->below_4g_mem_size, E820_RAM);
if (x86ms->above_4g_mem_size > 0) {
ram_above_4g = g_malloc(sizeof(*ram_above_4g));
memory_region_init_alias(ram_above_4g, NULL, "ram-above-4g", ram,
x86ms->below_4g_mem_size,
x86ms->above_4g_mem_size);
memory_region_add_subregion(system_memory, 0x100000000ULL,
ram_above_4g);
e820_add_entry(0x100000000ULL, x86ms->above_4g_mem_size, E820_RAM);
}
fw_cfg = fw_cfg_init_io_dma(FW_CFG_IO_BASE, FW_CFG_IO_BASE + 4,
&address_space_memory);
fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, machine->smp.cpus);
fw_cfg_add_i16(fw_cfg, FW_CFG_MAX_CPUS, machine->smp.max_cpus);
fw_cfg_add_i64(fw_cfg, FW_CFG_RAM_SIZE, (uint64_t)machine->ram_size);
fw_cfg_add_i32(fw_cfg, FW_CFG_IRQ0_OVERRIDE, kvm_allows_irq0_override());
fw_cfg_add_bytes(fw_cfg, FW_CFG_E820_TABLE,
&e820_reserve, sizeof(e820_reserve));
fw_cfg_add_file(fw_cfg, "etc/e820", e820_table,
sizeof(struct e820_entry) * e820_get_num_entries());
rom_set_fw(fw_cfg);
if (machine->kernel_filename != NULL) {
x86_load_linux(x86ms, fw_cfg, 0, true, true);
}
if (mms->option_roms) {
for (i = 0; i < nb_option_roms; i++) {
rom_add_option(option_rom[i].name, option_rom[i].bootindex);
}
}
x86ms->fw_cfg = fw_cfg;
x86ms->ioapic_as = &address_space_memory;
}
static gchar *microvm_get_mmio_cmdline(gchar *name)
{
gchar *cmdline;
gchar *separator;
long int index;
int ret;
separator = g_strrstr(name, ".");
if (!separator) {
return NULL;
}
if (qemu_strtol(separator + 1, NULL, 10, &index) != 0) {
return NULL;
}
cmdline = g_malloc0(VIRTIO_CMDLINE_MAXLEN);
ret = g_snprintf(cmdline, VIRTIO_CMDLINE_MAXLEN,
" virtio_mmio.device=512@0x%lx:%ld",
VIRTIO_MMIO_BASE + index * 512,
VIRTIO_IRQ_BASE + index);
if (ret < 0 || ret >= VIRTIO_CMDLINE_MAXLEN) {
g_free(cmdline);
return NULL;
}
return cmdline;
}
static void microvm_fix_kernel_cmdline(MachineState *machine)
{
X86MachineState *x86ms = X86_MACHINE(machine);
BusState *bus;
BusChild *kid;
char *cmdline;
/*
* Find MMIO transports with attached devices, and add them to the kernel
* command line.
*
* Yes, this is a hack, but one that heavily improves the UX without
* introducing any significant issues.
*/
cmdline = g_strdup(machine->kernel_cmdline);
bus = sysbus_get_default();
QTAILQ_FOREACH(kid, &bus->children, sibling) {
DeviceState *dev = kid->child;
ObjectClass *class = object_get_class(OBJECT(dev));
if (class == object_class_by_name(TYPE_VIRTIO_MMIO)) {
VirtIOMMIOProxy *mmio = VIRTIO_MMIO(OBJECT(dev));
VirtioBusState *mmio_virtio_bus = &mmio->bus;
BusState *mmio_bus = &mmio_virtio_bus->parent_obj;
if (!QTAILQ_EMPTY(&mmio_bus->children)) {
gchar *mmio_cmdline = microvm_get_mmio_cmdline(mmio_bus->name);
if (mmio_cmdline) {
char *newcmd = g_strjoin(NULL, cmdline, mmio_cmdline, NULL);
g_free(mmio_cmdline);
g_free(cmdline);
cmdline = newcmd;
}
}
}
}
fw_cfg_modify_i32(x86ms->fw_cfg, FW_CFG_CMDLINE_SIZE, strlen(cmdline) + 1);
fw_cfg_modify_string(x86ms->fw_cfg, FW_CFG_CMDLINE_DATA, cmdline);
}
static void microvm_machine_state_init(MachineState *machine)
{
MicrovmMachineState *mms = MICROVM_MACHINE(machine);
X86MachineState *x86ms = X86_MACHINE(machine);
Error *local_err = NULL;
microvm_memory_init(mms);
x86_cpus_init(x86ms, CPU_VERSION_LATEST);
if (local_err) {
error_report_err(local_err);
exit(1);
}
microvm_devices_init(mms);
}
static void microvm_machine_reset(MachineState *machine)
{
MicrovmMachineState *mms = MICROVM_MACHINE(machine);
CPUState *cs;
X86CPU *cpu;
if (machine->kernel_filename != NULL &&
mms->auto_kernel_cmdline && !mms->kernel_cmdline_fixed) {
microvm_fix_kernel_cmdline(machine);
mms->kernel_cmdline_fixed = true;
}
qemu_devices_reset();
CPU_FOREACH(cs) {
cpu = X86_CPU(cs);
if (cpu->apic_state) {
device_reset(cpu->apic_state);
}
}
}
static void microvm_machine_get_pic(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
MicrovmMachineState *mms = MICROVM_MACHINE(obj);
OnOffAuto pic = mms->pic;
visit_type_OnOffAuto(v, name, &pic, errp);
}
static void microvm_machine_set_pic(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
MicrovmMachineState *mms = MICROVM_MACHINE(obj);
visit_type_OnOffAuto(v, name, &mms->pic, errp);
}
static void microvm_machine_get_pit(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
MicrovmMachineState *mms = MICROVM_MACHINE(obj);
OnOffAuto pit = mms->pit;
visit_type_OnOffAuto(v, name, &pit, errp);
}
static void microvm_machine_set_pit(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
MicrovmMachineState *mms = MICROVM_MACHINE(obj);
visit_type_OnOffAuto(v, name, &mms->pit, errp);
}
static void microvm_machine_get_rtc(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
MicrovmMachineState *mms = MICROVM_MACHINE(obj);
OnOffAuto rtc = mms->rtc;
visit_type_OnOffAuto(v, name, &rtc, errp);
}
static void microvm_machine_set_rtc(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
MicrovmMachineState *mms = MICROVM_MACHINE(obj);
visit_type_OnOffAuto(v, name, &mms->rtc, errp);
}
static bool microvm_machine_get_isa_serial(Object *obj, Error **errp)
{
MicrovmMachineState *mms = MICROVM_MACHINE(obj);
return mms->isa_serial;
}
static void microvm_machine_set_isa_serial(Object *obj, bool value,
Error **errp)
{
MicrovmMachineState *mms = MICROVM_MACHINE(obj);
mms->isa_serial = value;
}
static bool microvm_machine_get_option_roms(Object *obj, Error **errp)
{
MicrovmMachineState *mms = MICROVM_MACHINE(obj);
return mms->option_roms;
}
static void microvm_machine_set_option_roms(Object *obj, bool value,
Error **errp)
{
MicrovmMachineState *mms = MICROVM_MACHINE(obj);
mms->option_roms = value;
}
static bool microvm_machine_get_auto_kernel_cmdline(Object *obj, Error **errp)
{
MicrovmMachineState *mms = MICROVM_MACHINE(obj);
return mms->auto_kernel_cmdline;
}
static void microvm_machine_set_auto_kernel_cmdline(Object *obj, bool value,
Error **errp)
{
MicrovmMachineState *mms = MICROVM_MACHINE(obj);
mms->auto_kernel_cmdline = value;
}
static void microvm_machine_initfn(Object *obj)
{
MicrovmMachineState *mms = MICROVM_MACHINE(obj);
/* Configuration */
mms->pic = ON_OFF_AUTO_AUTO;
mms->pit = ON_OFF_AUTO_AUTO;
mms->rtc = ON_OFF_AUTO_AUTO;
mms->isa_serial = true;
mms->option_roms = true;
mms->auto_kernel_cmdline = true;
/* State */
mms->kernel_cmdline_fixed = false;
}
static void microvm_class_init(ObjectClass *oc, void *data)
{
MachineClass *mc = MACHINE_CLASS(oc);
mc->init = microvm_machine_state_init;
mc->family = "microvm_i386";
mc->desc = "microvm (i386)";
mc->units_per_default_bus = 1;
mc->no_floppy = 1;
mc->max_cpus = 288;
mc->has_hotpluggable_cpus = false;
mc->auto_enable_numa_with_memhp = false;
mc->default_cpu_type = TARGET_DEFAULT_CPU_TYPE;
mc->nvdimm_supported = false;
/* Avoid relying too much on kernel components */
mc->default_kernel_irqchip_split = true;
/* Machine class handlers */
mc->reset = microvm_machine_reset;
object_class_property_add(oc, MICROVM_MACHINE_PIC, "OnOffAuto",
microvm_machine_get_pic,
microvm_machine_set_pic,
NULL, NULL, &error_abort);
object_class_property_set_description(oc, MICROVM_MACHINE_PIC,
"Enable i8259 PIC", &error_abort);
object_class_property_add(oc, MICROVM_MACHINE_PIT, "OnOffAuto",
microvm_machine_get_pit,
microvm_machine_set_pit,
NULL, NULL, &error_abort);
object_class_property_set_description(oc, MICROVM_MACHINE_PIT,
"Enable i8254 PIT", &error_abort);
object_class_property_add(oc, MICROVM_MACHINE_RTC, "OnOffAuto",
microvm_machine_get_rtc,
microvm_machine_set_rtc,
NULL, NULL, &error_abort);
object_class_property_set_description(oc, MICROVM_MACHINE_RTC,
"Enable MC146818 RTC", &error_abort);
object_class_property_add_bool(oc, MICROVM_MACHINE_ISA_SERIAL,
microvm_machine_get_isa_serial,
microvm_machine_set_isa_serial,
&error_abort);
object_class_property_set_description(oc, MICROVM_MACHINE_ISA_SERIAL,
"Set off to disable the instantiation an ISA serial port",
&error_abort);
object_class_property_add_bool(oc, MICROVM_MACHINE_OPTION_ROMS,
microvm_machine_get_option_roms,
microvm_machine_set_option_roms,
&error_abort);
object_class_property_set_description(oc, MICROVM_MACHINE_OPTION_ROMS,
"Set off to disable loading option ROMs", &error_abort);
object_class_property_add_bool(oc, MICROVM_MACHINE_AUTO_KERNEL_CMDLINE,
microvm_machine_get_auto_kernel_cmdline,
microvm_machine_set_auto_kernel_cmdline,
&error_abort);
object_class_property_set_description(oc,
MICROVM_MACHINE_AUTO_KERNEL_CMDLINE,
"Set off to disable adding virtio-mmio devices to the kernel cmdline",
&error_abort);
}
static const TypeInfo microvm_machine_info = {
.name = TYPE_MICROVM_MACHINE,
.parent = TYPE_X86_MACHINE,
.instance_size = sizeof(MicrovmMachineState),
.instance_init = microvm_machine_initfn,
.class_size = sizeof(MicrovmMachineClass),
.class_init = microvm_class_init,
.interfaces = (InterfaceInfo[]) {
{ }
},
};
static void microvm_machine_init(void)
{
type_register_static(&microvm_machine_info);
}
type_init(microvm_machine_init);

71
include/hw/i386/microvm.h Normal file
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/*
* Copyright (c) 2018 Intel Corporation
* Copyright (c) 2019 Red Hat, Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2 or later, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef HW_I386_MICROVM_H
#define HW_I386_MICROVM_H
#include "qemu-common.h"
#include "exec/hwaddr.h"
#include "qemu/notify.h"
#include "hw/boards.h"
#include "hw/i386/x86.h"
/* Platform virtio definitions */
#define VIRTIO_MMIO_BASE 0xc0000000
#define VIRTIO_IRQ_BASE 5
#define VIRTIO_NUM_TRANSPORTS 8
#define VIRTIO_CMDLINE_MAXLEN 64
/* Machine type options */
#define MICROVM_MACHINE_PIT "pit"
#define MICROVM_MACHINE_PIC "pic"
#define MICROVM_MACHINE_RTC "rtc"
#define MICROVM_MACHINE_ISA_SERIAL "isa-serial"
#define MICROVM_MACHINE_OPTION_ROMS "x-option-roms"
#define MICROVM_MACHINE_AUTO_KERNEL_CMDLINE "auto-kernel-cmdline"
typedef struct {
X86MachineClass parent;
HotplugHandler *(*orig_hotplug_handler)(MachineState *machine,
DeviceState *dev);
} MicrovmMachineClass;
typedef struct {
X86MachineState parent;
/* Machine type options */
OnOffAuto pic;
OnOffAuto pit;
OnOffAuto rtc;
bool isa_serial;
bool option_roms;
bool auto_kernel_cmdline;
/* Machine state */
bool kernel_cmdline_fixed;
} MicrovmMachineState;
#define TYPE_MICROVM_MACHINE MACHINE_TYPE_NAME("microvm")
#define MICROVM_MACHINE(obj) \
OBJECT_CHECK(MicrovmMachineState, (obj), TYPE_MICROVM_MACHINE)
#define MICROVM_MACHINE_GET_CLASS(obj) \
OBJECT_GET_CLASS(MicrovmMachineClass, obj, TYPE_MICROVM_MACHINE)
#define MICROVM_MACHINE_CLASS(class) \
OBJECT_CLASS_CHECK(MicrovmMachineClass, class, TYPE_MICROVM_MACHINE)
#endif