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/*
* QEMU<->ACPI BIOS PCI hotplug interface
*
* QEMU supports PCI hotplug via ACPI. This module
* implements the interface between QEMU and the ACPI BIOS.
* Interface specification - see docs/specs/acpi_pci_hotplug.txt
*
* Copyright (c) 2013, Red Hat Inc, Michael S. Tsirkin (mst@redhat.com)
* Copyright (c) 2006 Fabrice Bellard
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License version 2.1 as published by the Free Software Foundation.
*
* 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/>
*
* Contributions after 2012-01-13 are licensed under the terms of the
* GNU GPL, version 2 or (at your option) any later version.
*/
#include "qemu/osdep.h"
#include "hw/acpi/pcihp.h"
#include "hw/pci-host/i440fx.h"
#include "hw/pci/pci.h"
#include "hw/pci/pci_bridge.h"
#include "hw/pci/pci_host.h"
#include "hw/pci/pcie_port.h"
#include "hw/pci-bridge/xio3130_downstream.h"
#include "hw/i386/acpi-build.h"
#include "hw/acpi/acpi.h"
#include "hw/pci/pci_bus.h"
#include "migration/vmstate.h"
#include "qapi/error.h"
#include "qom/qom-qobject.h"
#include "trace.h"
#define ACPI_PCIHP_SIZE 0x0018
#define PCI_UP_BASE 0x0000
#define PCI_DOWN_BASE 0x0004
#define PCI_EJ_BASE 0x0008
#define PCI_RMV_BASE 0x000c
#define PCI_SEL_BASE 0x0010
#define PCI_AIDX_BASE 0x0014
typedef struct AcpiPciHpFind {
int bsel;
PCIBus *bus;
} AcpiPciHpFind;
static int acpi_pcihp_get_bsel(PCIBus *bus)
{
Error *local_err = NULL;
uint64_t bsel = object_property_get_uint(OBJECT(bus), ACPI_PCIHP_PROP_BSEL,
&local_err);
if (local_err || bsel >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
if (local_err) {
error_free(local_err);
}
return -1;
} else {
return bsel;
}
}
typedef struct {
unsigned bsel_alloc;
bool has_bridge_hotplug;
} BSELInfo;
/* Assign BSEL property only to buses that support hotplug. */
static void *acpi_set_bsel(PCIBus *bus, void *opaque)
{
BSELInfo *info = opaque;
unsigned *bus_bsel;
DeviceState *br = bus->qbus.parent;
bool is_bridge = IS_PCI_BRIDGE(br);
/* hotplugged bridges can't be described in ACPI ignore them */
if (qbus_is_hotpluggable(BUS(bus))) {
if (!is_bridge || (!br->hotplugged && info->has_bridge_hotplug)) {
bus_bsel = g_malloc(sizeof *bus_bsel);
*bus_bsel = info->bsel_alloc++;
object_property_add_uint32_ptr(OBJECT(bus), ACPI_PCIHP_PROP_BSEL,
bus_bsel, OBJ_PROP_FLAG_READ);
}
}
return info;
}
static void acpi_set_pci_info(bool has_bridge_hotplug)
{
static bool bsel_is_set;
Object *host = acpi_get_i386_pci_host();
PCIBus *bus;
BSELInfo info = { .bsel_alloc = ACPI_PCIHP_BSEL_DEFAULT,
.has_bridge_hotplug = has_bridge_hotplug };
if (bsel_is_set) {
return;
}
bsel_is_set = true;
if (!host) {
return;
}
bus = PCI_HOST_BRIDGE(host)->bus;
if (bus) {
/* Scan all PCI buses. Set property to enable acpi based hotplug. */
pci_for_each_bus_depth_first(bus, acpi_set_bsel, NULL, &info);
}
}
static void acpi_pcihp_test_hotplug_bus(PCIBus *bus, void *opaque)
{
AcpiPciHpFind *find = opaque;
if (find->bsel == acpi_pcihp_get_bsel(bus)) {
find->bus = bus;
}
}
static PCIBus *acpi_pcihp_find_hotplug_bus(AcpiPciHpState *s, int bsel)
{
AcpiPciHpFind find = { .bsel = bsel, .bus = NULL };
if (bsel < 0) {
return NULL;
}
pci_for_each_bus(s->root, acpi_pcihp_test_hotplug_bus, &find);
/* Make bsel 0 eject root bus if bsel property is not set,
* for compatibility with non acpi setups.
* TODO: really needed?
*/
if (!bsel && !find.bus) {
find.bus = s->root;
}
/*
* Check if find.bus is actually hotpluggable. If bsel is set to
* NULL for example on the root bus in order to make it
* non-hotpluggable, find.bus will match the root bus when bsel
* is 0. See acpi_pcihp_test_hotplug_bus() above. Since the
* bus is not hotpluggable however, we should not select the bus.
* Instead, we should set find.bus to NULL in that case. In the check
* below, we generalize this case for all buses, not just the root bus.
* The callers of this function check for a null return value and
* handle them appropriately.
*/
if (find.bus && !qbus_is_hotpluggable(BUS(find.bus))) {
find.bus = NULL;
}
return find.bus;
}
static bool acpi_pcihp_pc_no_hotplug(AcpiPciHpState *s, PCIDevice *dev)
{
DeviceClass *dc = DEVICE_GET_CLASS(dev);
/*
* ACPI doesn't allow hotplug of bridge devices. Don't allow
* hot-unplug of bridge devices unless they were added by hotplug
* (and so, not described by acpi).
*
* Don't allow hot-unplug of SR-IOV Virtual Functions, as they
* will be removed implicitly, when Physical Function is unplugged.
*/
return (IS_PCI_BRIDGE(dev) && !dev->qdev.hotplugged) || !dc->hotpluggable ||
pci_is_vf(dev);
}
static void acpi_pcihp_eject_slot(AcpiPciHpState *s, unsigned bsel, unsigned slots)
{
HotplugHandler *hotplug_ctrl;
BusChild *kid, *next;
int slot = ctz32(slots);
PCIBus *bus = acpi_pcihp_find_hotplug_bus(s, bsel);
trace_acpi_pci_eject_slot(bsel, slot);
if (!bus || slot > 31) {
return;
}
/* Mark request as complete */
s->acpi_pcihp_pci_status[bsel].down &= ~(1U << slot);
s->acpi_pcihp_pci_status[bsel].up &= ~(1U << slot);
QTAILQ_FOREACH_SAFE(kid, &bus->qbus.children, sibling, next) {
DeviceState *qdev = kid->child;
PCIDevice *dev = PCI_DEVICE(qdev);
if (PCI_SLOT(dev->devfn) == slot) {
if (!acpi_pcihp_pc_no_hotplug(s, dev)) {
/*
* partially_hotplugged is used by virtio-net failover:
* failover has asked the guest OS to unplug the device
* but we need to keep some references to the device
* to be able to plug it back in case of failure so
* we don't execute hotplug_handler_unplug().
*/
if (dev->partially_hotplugged) {
/*
* pending_deleted_event is set to true when
* virtio-net failover asks to unplug the device,
* and set to false here when the operation is done
* This is used by the migration loop to detect the
* end of the operation and really start the migration.
*/
qdev->pending_deleted_event = false;
} else {
hotplug_ctrl = qdev_get_hotplug_handler(qdev);
hotplug_handler_unplug(hotplug_ctrl, qdev, &error_abort);
object_unparent(OBJECT(qdev));
}
}
}
}
}
static void acpi_pcihp_update_hotplug_bus(AcpiPciHpState *s, int bsel)
{
BusChild *kid, *next;
PCIBus *bus = acpi_pcihp_find_hotplug_bus(s, bsel);
/* Execute any pending removes during reset */
while (s->acpi_pcihp_pci_status[bsel].down) {
acpi_pcihp_eject_slot(s, bsel, s->acpi_pcihp_pci_status[bsel].down);
}
s->acpi_pcihp_pci_status[bsel].hotplug_enable = ~0;
if (!bus) {
return;
}
QTAILQ_FOREACH_SAFE(kid, &bus->qbus.children, sibling, next) {
DeviceState *qdev = kid->child;
PCIDevice *pdev = PCI_DEVICE(qdev);
int slot = PCI_SLOT(pdev->devfn);
if (acpi_pcihp_pc_no_hotplug(s, pdev)) {
s->acpi_pcihp_pci_status[bsel].hotplug_enable &= ~(1U << slot);
}
}
}
static void acpi_pcihp_update(AcpiPciHpState *s)
{
int i;
for (i = 0; i < ACPI_PCIHP_MAX_HOTPLUG_BUS; ++i) {
acpi_pcihp_update_hotplug_bus(s, i);
}
}
void acpi_pcihp_reset(AcpiPciHpState *s)
{
acpi_set_pci_info(s->use_acpi_hotplug_bridge);
acpi_pcihp_update(s);
}
void acpi_pcihp_device_pre_plug_cb(HotplugHandler *hotplug_dev,
DeviceState *dev, Error **errp)
{
PCIDevice *pdev = PCI_DEVICE(dev);
/* Only hotplugged devices need the hotplug capability. */
if (dev->hotplugged &&
acpi_pcihp_get_bsel(pci_get_bus(pdev)) < 0) {
error_setg(errp, "Unsupported bus. Bus doesn't have property '"
ACPI_PCIHP_PROP_BSEL "' set");
return;
}
}
void acpi_pcihp_device_plug_cb(HotplugHandler *hotplug_dev, AcpiPciHpState *s,
DeviceState *dev, Error **errp)
{
PCIDevice *pdev = PCI_DEVICE(dev);
int slot = PCI_SLOT(pdev->devfn);
PCIDevice *bridge;
PCIBus *bus;
int bsel;
/* Don't send event when device is enabled during qemu machine creation:
* it is present on boot, no hotplug event is necessary. We do send an
* event when the device is disabled later. */
if (!dev->hotplugged) {
/*
* Overwrite the default hotplug handler with the ACPI PCI one
* for cold plugged bridges only.
*/
if (s->use_acpi_hotplug_bridge &&
object_dynamic_cast(OBJECT(dev), TYPE_PCI_BRIDGE)) {
PCIBus *sec = pci_bridge_get_sec_bus(PCI_BRIDGE(pdev));
qbus_set_hotplug_handler(BUS(sec), OBJECT(hotplug_dev));
/* We don't have to overwrite any other hotplug handler yet */
assert(QLIST_EMPTY(&sec->child));
}
return;
}
bus = pci_get_bus(pdev);
bridge = pci_bridge_get_device(bus);
if (object_dynamic_cast(OBJECT(bridge), TYPE_PCIE_ROOT_PORT) ||
object_dynamic_cast(OBJECT(bridge), TYPE_XIO3130_DOWNSTREAM)) {
pcie_cap_slot_enable_power(bridge);
}
bsel = acpi_pcihp_get_bsel(bus);
g_assert(bsel >= 0);
s->acpi_pcihp_pci_status[bsel].up |= (1U << slot);
acpi_send_event(DEVICE(hotplug_dev), ACPI_PCI_HOTPLUG_STATUS);
}
void acpi_pcihp_device_unplug_cb(HotplugHandler *hotplug_dev, AcpiPciHpState *s,
DeviceState *dev, Error **errp)
{
PCIDevice *pdev = PCI_DEVICE(dev);
trace_acpi_pci_unplug(PCI_SLOT(pdev->devfn),
acpi_pcihp_get_bsel(pci_get_bus(pdev)));
qdev_unrealize(dev);
}
void acpi_pcihp_device_unplug_request_cb(HotplugHandler *hotplug_dev,
AcpiPciHpState *s, DeviceState *dev,
Error **errp)
{
PCIDevice *pdev = PCI_DEVICE(dev);
int slot = PCI_SLOT(pdev->devfn);
int bsel = acpi_pcihp_get_bsel(pci_get_bus(pdev));
trace_acpi_pci_unplug_request(bsel, slot);
if (bsel < 0) {
error_setg(errp, "Unsupported bus. Bus doesn't have property '"
ACPI_PCIHP_PROP_BSEL "' set");
return;
}
/*
* pending_deleted_event is used by virtio-net failover to detect the
* end of the unplug operation, the flag is set to false in
* acpi_pcihp_eject_slot() when the operation is completed.
*/
pdev->qdev.pending_deleted_event = true;
/* if unplug was requested before OSPM is initialized,
* linux kernel will clear GPE0.sts[] bits during boot, which effectively
* hides unplug event. And than followup qmp_device_del() calls remain
* blocked by above flag permanently.
* Unblock qmp_device_del() by setting expire limit, so user can
* repeat unplug request later when OSPM has been booted.
*/
pdev->qdev.pending_deleted_expires_ms =
qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL); /* 1 msec */
s->acpi_pcihp_pci_status[bsel].down |= (1U << slot);
acpi_send_event(DEVICE(hotplug_dev), ACPI_PCI_HOTPLUG_STATUS);
}
bool acpi_pcihp_is_hotpluggbale_bus(AcpiPciHpState *s, BusState *bus)
{
Object *o = OBJECT(bus->parent);
if (s->use_acpi_hotplug_bridge &&
object_dynamic_cast(o, TYPE_PCI_BRIDGE)) {
if (object_dynamic_cast(o, TYPE_PCIE_SLOT) && !PCIE_SLOT(o)->hotplug) {
return false;
}
return true;
}
if (s->use_acpi_root_pci_hotplug) {
return true;
}
return false;
}
static uint64_t pci_read(void *opaque, hwaddr addr, unsigned int size)
{
AcpiPciHpState *s = opaque;
uint32_t val = 0;
int bsel = s->hotplug_select;
if (bsel < 0 || bsel >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
return 0;
}
switch (addr) {
case PCI_UP_BASE:
val = s->acpi_pcihp_pci_status[bsel].up;
if (s->use_acpi_hotplug_bridge) {
s->acpi_pcihp_pci_status[bsel].up = 0;
}
trace_acpi_pci_up_read(val);
break;
case PCI_DOWN_BASE:
val = s->acpi_pcihp_pci_status[bsel].down;
trace_acpi_pci_down_read(val);
break;
case PCI_EJ_BASE:
trace_acpi_pci_features_read(val);
break;
case PCI_RMV_BASE:
val = s->acpi_pcihp_pci_status[bsel].hotplug_enable;
trace_acpi_pci_rmv_read(val);
break;
case PCI_SEL_BASE:
val = s->hotplug_select;
trace_acpi_pci_sel_read(val);
break;
case PCI_AIDX_BASE:
val = s->acpi_index;
s->acpi_index = 0;
trace_acpi_pci_acpi_index_read(val);
break;
default:
break;
}
return val;
}
static void pci_write(void *opaque, hwaddr addr, uint64_t data,
unsigned int size)
{
int slot;
PCIBus *bus;
BusChild *kid, *next;
AcpiPciHpState *s = opaque;
s->acpi_index = 0;
switch (addr) {
case PCI_AIDX_BASE:
/*
* fetch acpi-index for specified slot so that follow up read from
* PCI_AIDX_BASE can return it to guest
*/
slot = ctz32(data);
if (s->hotplug_select >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
break;
}
bus = acpi_pcihp_find_hotplug_bus(s, s->hotplug_select);
if (!bus) {
break;
}
QTAILQ_FOREACH_SAFE(kid, &bus->qbus.children, sibling, next) {
Object *o = OBJECT(kid->child);
PCIDevice *dev = PCI_DEVICE(o);
if (PCI_SLOT(dev->devfn) == slot) {
s->acpi_index = object_property_get_uint(o, "acpi-index", NULL);
break;
}
}
trace_acpi_pci_acpi_index_write(s->hotplug_select, slot, s->acpi_index);
break;
case PCI_EJ_BASE:
if (s->hotplug_select >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
break;
}
acpi_pcihp_eject_slot(s, s->hotplug_select, data);
trace_acpi_pci_ej_write(addr, data);
break;
case PCI_SEL_BASE:
s->hotplug_select = s->use_acpi_hotplug_bridge ? data :
ACPI_PCIHP_BSEL_DEFAULT;
trace_acpi_pci_sel_write(addr, data);
default:
break;
}
}
static const MemoryRegionOps acpi_pcihp_io_ops = {
.read = pci_read,
.write = pci_write,
.endianness = DEVICE_LITTLE_ENDIAN,
.valid = {
.min_access_size = 4,
.max_access_size = 4,
},
};
void acpi_pcihp_init(Object *owner, AcpiPciHpState *s, PCIBus *root_bus,
MemoryRegion *io, uint16_t io_base)
{
s->io_len = ACPI_PCIHP_SIZE;
s->io_base = io_base;
s->root = root_bus;
memory_region_init_io(&s->io, owner, &acpi_pcihp_io_ops, s,
"acpi-pci-hotplug", s->io_len);
memory_region_add_subregion(io, s->io_base, &s->io);
object_property_add_uint16_ptr(owner, ACPI_PCIHP_IO_BASE_PROP, &s->io_base,
OBJ_PROP_FLAG_READ);
object_property_add_uint16_ptr(owner, ACPI_PCIHP_IO_LEN_PROP, &s->io_len,
OBJ_PROP_FLAG_READ);
}
const VMStateDescription vmstate_acpi_pcihp_pci_status = {
.name = "acpi_pcihp_pci_status",
.version_id = 1,
.minimum_version_id = 1,
.fields = (const VMStateField[]) {
VMSTATE_UINT32(up, AcpiPciHpPciStatus),
VMSTATE_UINT32(down, AcpiPciHpPciStatus),
VMSTATE_END_OF_LIST()
}
};