qemu/hw/mem/pc-dimm.c
Yangming e919402b9e virtio-balloon: optimize the virtio-balloon on the ARM platform
Optimize the virtio-balloon feature on the ARM platform by adding
a variable to keep track of the current hot-plugged pc-dimm size,
instead of traversing the virtual machine's memory modules to count
the current RAM size during the balloon inflation or deflation
process. This variable can be updated only when plugging or unplugging
the device, which will result in an increase of approximately 60%
efficiency of balloon process on the ARM platform.

We tested the total amount of time required for the balloon inflation process on ARM:
inflate the balloon to 64GB of a 128GB guest under stress.
Before: 102 seconds
After: 42 seconds

Signed-off-by: Qi Xi <xiqi2@huawei.com>
Signed-off-by: Ming Yang yangming73@huawei.com
Message-Id: <e13bc78f96774bfab4576814c293aa52@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
2023-04-21 04:25:52 -04:00

319 lines
9.9 KiB
C

/*
* Dimm device for Memory Hotplug
*
* Copyright ProfitBricks GmbH 2012
* Copyright (C) 2014 Red Hat Inc
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>
*/
#include "qemu/osdep.h"
#include "hw/boards.h"
#include "hw/mem/pc-dimm.h"
#include "hw/qdev-properties.h"
#include "migration/vmstate.h"
#include "hw/mem/nvdimm.h"
#include "hw/mem/memory-device.h"
#include "qapi/error.h"
#include "qapi/visitor.h"
#include "qemu/module.h"
#include "sysemu/hostmem.h"
#include "sysemu/numa.h"
#include "trace.h"
static int pc_dimm_get_free_slot(const int *hint, int max_slots, Error **errp);
static MemoryRegion *pc_dimm_get_memory_region(PCDIMMDevice *dimm, Error **errp)
{
if (!dimm->hostmem) {
error_setg(errp, "'" PC_DIMM_MEMDEV_PROP "' property must be set");
return NULL;
}
return host_memory_backend_get_memory(dimm->hostmem);
}
void pc_dimm_pre_plug(PCDIMMDevice *dimm, MachineState *machine,
const uint64_t *legacy_align, Error **errp)
{
Error *local_err = NULL;
int slot;
slot = object_property_get_int(OBJECT(dimm), PC_DIMM_SLOT_PROP,
&error_abort);
if ((slot < 0 || slot >= machine->ram_slots) &&
slot != PC_DIMM_UNASSIGNED_SLOT) {
error_setg(errp,
"invalid slot number %d, valid range is [0-%" PRIu64 "]",
slot, machine->ram_slots - 1);
return;
}
slot = pc_dimm_get_free_slot(slot == PC_DIMM_UNASSIGNED_SLOT ? NULL : &slot,
machine->ram_slots, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
object_property_set_int(OBJECT(dimm), PC_DIMM_SLOT_PROP, slot,
&error_abort);
trace_mhp_pc_dimm_assigned_slot(slot);
memory_device_pre_plug(MEMORY_DEVICE(dimm), machine, legacy_align,
errp);
}
void pc_dimm_plug(PCDIMMDevice *dimm, MachineState *machine)
{
MemoryRegion *vmstate_mr = pc_dimm_get_memory_region(dimm,
&error_abort);
memory_device_plug(MEMORY_DEVICE(dimm), machine);
vmstate_register_ram(vmstate_mr, DEVICE(dimm));
/* count only "real" DIMMs, not NVDIMMs */
if (!object_dynamic_cast(OBJECT(dimm), TYPE_NVDIMM)) {
machine->device_memory->dimm_size += memory_region_size(vmstate_mr);
}
}
void pc_dimm_unplug(PCDIMMDevice *dimm, MachineState *machine)
{
MemoryRegion *vmstate_mr = pc_dimm_get_memory_region(dimm,
&error_abort);
memory_device_unplug(MEMORY_DEVICE(dimm), machine);
vmstate_unregister_ram(vmstate_mr, DEVICE(dimm));
if (!object_dynamic_cast(OBJECT(dimm), TYPE_NVDIMM)) {
machine->device_memory->dimm_size -= memory_region_size(vmstate_mr);
}
}
static int pc_dimm_slot2bitmap(Object *obj, void *opaque)
{
unsigned long *bitmap = opaque;
if (object_dynamic_cast(obj, TYPE_PC_DIMM)) {
DeviceState *dev = DEVICE(obj);
if (dev->realized) { /* count only realized DIMMs */
PCDIMMDevice *d = PC_DIMM(obj);
set_bit(d->slot, bitmap);
}
}
object_child_foreach(obj, pc_dimm_slot2bitmap, opaque);
return 0;
}
static int pc_dimm_get_free_slot(const int *hint, int max_slots, Error **errp)
{
unsigned long *bitmap;
int slot = 0;
if (max_slots <= 0) {
error_setg(errp, "no slots where allocated, please specify "
"the 'slots' option");
return slot;
}
bitmap = bitmap_new(max_slots);
object_child_foreach(qdev_get_machine(), pc_dimm_slot2bitmap, bitmap);
/* check if requested slot is not occupied */
if (hint) {
if (*hint >= max_slots) {
error_setg(errp, "invalid slot# %d, should be less than %d",
*hint, max_slots);
} else if (!test_bit(*hint, bitmap)) {
slot = *hint;
} else {
error_setg(errp, "slot %d is busy", *hint);
}
goto out;
}
/* search for free slot */
slot = find_first_zero_bit(bitmap, max_slots);
if (slot == max_slots) {
error_setg(errp, "no free slots available");
}
out:
g_free(bitmap);
return slot;
}
static Property pc_dimm_properties[] = {
DEFINE_PROP_UINT64(PC_DIMM_ADDR_PROP, PCDIMMDevice, addr, 0),
DEFINE_PROP_UINT32(PC_DIMM_NODE_PROP, PCDIMMDevice, node, 0),
DEFINE_PROP_INT32(PC_DIMM_SLOT_PROP, PCDIMMDevice, slot,
PC_DIMM_UNASSIGNED_SLOT),
DEFINE_PROP_LINK(PC_DIMM_MEMDEV_PROP, PCDIMMDevice, hostmem,
TYPE_MEMORY_BACKEND, HostMemoryBackend *),
DEFINE_PROP_END_OF_LIST(),
};
static void pc_dimm_get_size(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
Error *local_err = NULL;
uint64_t value;
value = memory_device_get_region_size(MEMORY_DEVICE(obj), &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
visit_type_uint64(v, name, &value, errp);
}
static void pc_dimm_init(Object *obj)
{
object_property_add(obj, PC_DIMM_SIZE_PROP, "uint64", pc_dimm_get_size,
NULL, NULL, NULL);
}
static void pc_dimm_realize(DeviceState *dev, Error **errp)
{
PCDIMMDevice *dimm = PC_DIMM(dev);
PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
MachineState *ms = MACHINE(qdev_get_machine());
if (ms->numa_state) {
int nb_numa_nodes = ms->numa_state->num_nodes;
if (((nb_numa_nodes > 0) && (dimm->node >= nb_numa_nodes)) ||
(!nb_numa_nodes && dimm->node)) {
error_setg(errp, "'DIMM property " PC_DIMM_NODE_PROP " has value %"
PRIu32 "' which exceeds the number of numa nodes: %d",
dimm->node, nb_numa_nodes ? nb_numa_nodes : 1);
return;
}
} else if (dimm->node > 0) {
error_setg(errp, "machine doesn't support NUMA");
return;
}
if (!dimm->hostmem) {
error_setg(errp, "'" PC_DIMM_MEMDEV_PROP "' property is not set");
return;
} else if (host_memory_backend_is_mapped(dimm->hostmem)) {
error_setg(errp, "can't use already busy memdev: %s",
object_get_canonical_path_component(OBJECT(dimm->hostmem)));
return;
}
if (ddc->realize) {
ddc->realize(dimm, errp);
}
host_memory_backend_set_mapped(dimm->hostmem, true);
}
static void pc_dimm_unrealize(DeviceState *dev)
{
PCDIMMDevice *dimm = PC_DIMM(dev);
PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
if (ddc->unrealize) {
ddc->unrealize(dimm);
}
host_memory_backend_set_mapped(dimm->hostmem, false);
}
static uint64_t pc_dimm_md_get_addr(const MemoryDeviceState *md)
{
return object_property_get_uint(OBJECT(md), PC_DIMM_ADDR_PROP,
&error_abort);
}
static void pc_dimm_md_set_addr(MemoryDeviceState *md, uint64_t addr,
Error **errp)
{
object_property_set_uint(OBJECT(md), PC_DIMM_ADDR_PROP, addr, errp);
}
static MemoryRegion *pc_dimm_md_get_memory_region(MemoryDeviceState *md,
Error **errp)
{
return pc_dimm_get_memory_region(PC_DIMM(md), errp);
}
static void pc_dimm_md_fill_device_info(const MemoryDeviceState *md,
MemoryDeviceInfo *info)
{
PCDIMMDeviceInfo *di = g_new0(PCDIMMDeviceInfo, 1);
const DeviceClass *dc = DEVICE_GET_CLASS(md);
const PCDIMMDevice *dimm = PC_DIMM(md);
const DeviceState *dev = DEVICE(md);
if (dev->id) {
di->id = g_strdup(dev->id);
}
di->hotplugged = dev->hotplugged;
di->hotpluggable = dc->hotpluggable;
di->addr = dimm->addr;
di->slot = dimm->slot;
di->node = dimm->node;
di->size = object_property_get_uint(OBJECT(dimm), PC_DIMM_SIZE_PROP,
NULL);
di->memdev = object_get_canonical_path(OBJECT(dimm->hostmem));
if (object_dynamic_cast(OBJECT(dev), TYPE_NVDIMM)) {
info->u.nvdimm.data = di;
info->type = MEMORY_DEVICE_INFO_KIND_NVDIMM;
} else {
info->u.dimm.data = di;
info->type = MEMORY_DEVICE_INFO_KIND_DIMM;
}
}
static void pc_dimm_class_init(ObjectClass *oc, void *data)
{
DeviceClass *dc = DEVICE_CLASS(oc);
MemoryDeviceClass *mdc = MEMORY_DEVICE_CLASS(oc);
dc->realize = pc_dimm_realize;
dc->unrealize = pc_dimm_unrealize;
device_class_set_props(dc, pc_dimm_properties);
dc->desc = "DIMM memory module";
mdc->get_addr = pc_dimm_md_get_addr;
mdc->set_addr = pc_dimm_md_set_addr;
/* for a dimm plugged_size == region_size */
mdc->get_plugged_size = memory_device_get_region_size;
mdc->get_memory_region = pc_dimm_md_get_memory_region;
mdc->fill_device_info = pc_dimm_md_fill_device_info;
}
static const TypeInfo pc_dimm_info = {
.name = TYPE_PC_DIMM,
.parent = TYPE_DEVICE,
.instance_size = sizeof(PCDIMMDevice),
.instance_init = pc_dimm_init,
.class_init = pc_dimm_class_init,
.class_size = sizeof(PCDIMMDeviceClass),
.interfaces = (InterfaceInfo[]) {
{ TYPE_MEMORY_DEVICE },
{ }
},
};
static void pc_dimm_register_types(void)
{
type_register_static(&pc_dimm_info);
}
type_init(pc_dimm_register_types)