2 * QEMU<->ACPI BIOS PCI hotplug interface
4 * QEMU supports PCI hotplug via ACPI. This module
5 * implements the interface between QEMU and the ACPI BIOS.
6 * Interface specification - see docs/specs/acpi_pci_hotplug.txt
8 * Copyright (c) 2013, Red Hat Inc, Michael S. Tsirkin (mst@redhat.com)
9 * Copyright (c) 2006 Fabrice Bellard
11 * This library is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU Lesser General Public
13 * License version 2.1 as published by the Free Software Foundation.
15 * This library is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * Lesser General Public License for more details.
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with this library; if not, see <http://www.gnu.org/licenses/>
23 * Contributions after 2012-01-13 are licensed under the terms of the
24 * GNU GPL, version 2 or (at your option) any later version.
27 #include "qemu/osdep.h"
28 #include "hw/acpi/pcihp.h"
30 #include "hw/pci-host/i440fx.h"
31 #include "hw/pci/pci.h"
32 #include "hw/pci/pci_bridge.h"
33 #include "hw/acpi/acpi.h"
34 #include "exec/address-spaces.h"
35 #include "hw/pci/pci_bus.h"
36 #include "migration/vmstate.h"
37 #include "qapi/error.h"
38 #include "qom/qom-qobject.h"
41 #define ACPI_PCIHP_ADDR 0xae00
42 #define ACPI_PCIHP_SIZE 0x0014
43 #define PCI_UP_BASE 0x0000
44 #define PCI_DOWN_BASE 0x0004
45 #define PCI_EJ_BASE 0x0008
46 #define PCI_RMV_BASE 0x000c
47 #define PCI_SEL_BASE 0x0010
49 typedef struct AcpiPciHpFind
{
54 static int acpi_pcihp_get_bsel(PCIBus
*bus
)
56 Error
*local_err
= NULL
;
57 uint64_t bsel
= object_property_get_uint(OBJECT(bus
), ACPI_PCIHP_PROP_BSEL
,
60 if (local_err
|| bsel
>= ACPI_PCIHP_MAX_HOTPLUG_BUS
) {
62 error_free(local_err
);
70 /* Assign BSEL property to all buses. In the future, this can be changed
71 * to only assign to buses that support hotplug.
73 static void *acpi_set_bsel(PCIBus
*bus
, void *opaque
)
75 unsigned *bsel_alloc
= opaque
;
78 if (qbus_is_hotpluggable(BUS(bus
))) {
79 bus_bsel
= g_malloc(sizeof *bus_bsel
);
81 *bus_bsel
= (*bsel_alloc
)++;
82 object_property_add_uint32_ptr(OBJECT(bus
), ACPI_PCIHP_PROP_BSEL
,
83 bus_bsel
, OBJ_PROP_FLAG_READ
);
89 static void acpi_set_pci_info(void)
91 static bool bsel_is_set
;
93 unsigned bsel_alloc
= ACPI_PCIHP_BSEL_DEFAULT
;
100 bus
= find_i440fx(); /* TODO: Q35 support */
102 /* Scan all PCI buses. Set property to enable acpi based hotplug. */
103 pci_for_each_bus_depth_first(bus
, acpi_set_bsel
, NULL
, &bsel_alloc
);
107 static void acpi_pcihp_disable_root_bus(void)
109 static bool root_hp_disabled
;
112 if (root_hp_disabled
) {
118 /* setting the hotplug handler to NULL makes the bus non-hotpluggable */
119 qbus_set_hotplug_handler(BUS(bus
), NULL
);
121 root_hp_disabled
= true;
125 static void acpi_pcihp_test_hotplug_bus(PCIBus
*bus
, void *opaque
)
127 AcpiPciHpFind
*find
= opaque
;
128 if (find
->bsel
== acpi_pcihp_get_bsel(bus
)) {
133 static PCIBus
*acpi_pcihp_find_hotplug_bus(AcpiPciHpState
*s
, int bsel
)
135 AcpiPciHpFind find
= { .bsel
= bsel
, .bus
= NULL
};
141 pci_for_each_bus(s
->root
, acpi_pcihp_test_hotplug_bus
, &find
);
143 /* Make bsel 0 eject root bus if bsel property is not set,
144 * for compatibility with non acpi setups.
145 * TODO: really needed?
147 if (!bsel
&& !find
.bus
) {
152 * Check if find.bus is actually hotpluggable. If bsel is set to
153 * NULL for example on the root bus in order to make it
154 * non-hotpluggable, find.bus will match the root bus when bsel
155 * is 0. See acpi_pcihp_test_hotplug_bus() above. Since the
156 * bus is not hotpluggable however, we should not select the bus.
157 * Instead, we should set find.bus to NULL in that case. In the check
158 * below, we generalize this case for all buses, not just the root bus.
159 * The callers of this function check for a null return value and
160 * handle them appropriately.
162 if (find
.bus
&& !qbus_is_hotpluggable(BUS(find
.bus
))) {
168 static bool acpi_pcihp_pc_no_hotplug(AcpiPciHpState
*s
, PCIDevice
*dev
)
170 PCIDeviceClass
*pc
= PCI_DEVICE_GET_CLASS(dev
);
171 DeviceClass
*dc
= DEVICE_GET_CLASS(dev
);
173 * ACPI doesn't allow hotplug of bridge devices. Don't allow
174 * hot-unplug of bridge devices unless they were added by hotplug
175 * (and so, not described by acpi).
177 return (pc
->is_bridge
&& !dev
->qdev
.hotplugged
) || !dc
->hotpluggable
;
180 static void acpi_pcihp_eject_slot(AcpiPciHpState
*s
, unsigned bsel
, unsigned slots
)
182 HotplugHandler
*hotplug_ctrl
;
183 BusChild
*kid
, *next
;
184 int slot
= ctz32(slots
);
185 PCIBus
*bus
= acpi_pcihp_find_hotplug_bus(s
, bsel
);
187 trace_acpi_pci_eject_slot(bsel
, slot
);
189 if (!bus
|| slot
> 31) {
193 /* Mark request as complete */
194 s
->acpi_pcihp_pci_status
[bsel
].down
&= ~(1U << slot
);
195 s
->acpi_pcihp_pci_status
[bsel
].up
&= ~(1U << slot
);
197 QTAILQ_FOREACH_SAFE(kid
, &bus
->qbus
.children
, sibling
, next
) {
198 DeviceState
*qdev
= kid
->child
;
199 PCIDevice
*dev
= PCI_DEVICE(qdev
);
200 if (PCI_SLOT(dev
->devfn
) == slot
) {
201 if (!acpi_pcihp_pc_no_hotplug(s
, dev
)) {
202 hotplug_ctrl
= qdev_get_hotplug_handler(qdev
);
203 hotplug_handler_unplug(hotplug_ctrl
, qdev
, &error_abort
);
204 object_unparent(OBJECT(qdev
));
210 static void acpi_pcihp_update_hotplug_bus(AcpiPciHpState
*s
, int bsel
)
212 BusChild
*kid
, *next
;
213 PCIBus
*bus
= acpi_pcihp_find_hotplug_bus(s
, bsel
);
215 /* Execute any pending removes during reset */
216 while (s
->acpi_pcihp_pci_status
[bsel
].down
) {
217 acpi_pcihp_eject_slot(s
, bsel
, s
->acpi_pcihp_pci_status
[bsel
].down
);
220 s
->acpi_pcihp_pci_status
[bsel
].hotplug_enable
= ~0;
225 QTAILQ_FOREACH_SAFE(kid
, &bus
->qbus
.children
, sibling
, next
) {
226 DeviceState
*qdev
= kid
->child
;
227 PCIDevice
*pdev
= PCI_DEVICE(qdev
);
228 int slot
= PCI_SLOT(pdev
->devfn
);
230 if (acpi_pcihp_pc_no_hotplug(s
, pdev
)) {
231 s
->acpi_pcihp_pci_status
[bsel
].hotplug_enable
&= ~(1U << slot
);
236 static void acpi_pcihp_update(AcpiPciHpState
*s
)
240 for (i
= 0; i
< ACPI_PCIHP_MAX_HOTPLUG_BUS
; ++i
) {
241 acpi_pcihp_update_hotplug_bus(s
, i
);
245 void acpi_pcihp_reset(AcpiPciHpState
*s
, bool acpihp_root_off
)
247 if (acpihp_root_off
) {
248 acpi_pcihp_disable_root_bus();
251 acpi_pcihp_update(s
);
254 void acpi_pcihp_device_pre_plug_cb(HotplugHandler
*hotplug_dev
,
255 DeviceState
*dev
, Error
**errp
)
257 /* Only hotplugged devices need the hotplug capability. */
258 if (dev
->hotplugged
&&
259 acpi_pcihp_get_bsel(pci_get_bus(PCI_DEVICE(dev
))) < 0) {
260 error_setg(errp
, "Unsupported bus. Bus doesn't have property '"
261 ACPI_PCIHP_PROP_BSEL
"' set");
266 void acpi_pcihp_device_plug_cb(HotplugHandler
*hotplug_dev
, AcpiPciHpState
*s
,
267 DeviceState
*dev
, Error
**errp
)
269 PCIDevice
*pdev
= PCI_DEVICE(dev
);
270 int slot
= PCI_SLOT(pdev
->devfn
);
273 /* Don't send event when device is enabled during qemu machine creation:
274 * it is present on boot, no hotplug event is necessary. We do send an
275 * event when the device is disabled later. */
276 if (!dev
->hotplugged
) {
278 * Overwrite the default hotplug handler with the ACPI PCI one
279 * for cold plugged bridges only.
281 if (!s
->legacy_piix
&&
282 object_dynamic_cast(OBJECT(dev
), TYPE_PCI_BRIDGE
)) {
283 PCIBus
*sec
= pci_bridge_get_sec_bus(PCI_BRIDGE(pdev
));
285 qbus_set_hotplug_handler(BUS(sec
), OBJECT(hotplug_dev
));
286 /* We don't have to overwrite any other hotplug handler yet */
287 assert(QLIST_EMPTY(&sec
->child
));
293 bsel
= acpi_pcihp_get_bsel(pci_get_bus(pdev
));
295 s
->acpi_pcihp_pci_status
[bsel
].up
|= (1U << slot
);
296 acpi_send_event(DEVICE(hotplug_dev
), ACPI_PCI_HOTPLUG_STATUS
);
299 void acpi_pcihp_device_unplug_cb(HotplugHandler
*hotplug_dev
, AcpiPciHpState
*s
,
300 DeviceState
*dev
, Error
**errp
)
302 trace_acpi_pci_unplug(PCI_SLOT(PCI_DEVICE(dev
)->devfn
),
303 acpi_pcihp_get_bsel(pci_get_bus(PCI_DEVICE(dev
))));
307 void acpi_pcihp_device_unplug_request_cb(HotplugHandler
*hotplug_dev
,
308 AcpiPciHpState
*s
, DeviceState
*dev
,
311 PCIDevice
*pdev
= PCI_DEVICE(dev
);
312 int slot
= PCI_SLOT(pdev
->devfn
);
313 int bsel
= acpi_pcihp_get_bsel(pci_get_bus(pdev
));
315 trace_acpi_pci_unplug_request(bsel
, slot
);
318 error_setg(errp
, "Unsupported bus. Bus doesn't have property '"
319 ACPI_PCIHP_PROP_BSEL
"' set");
323 s
->acpi_pcihp_pci_status
[bsel
].down
|= (1U << slot
);
324 acpi_send_event(DEVICE(hotplug_dev
), ACPI_PCI_HOTPLUG_STATUS
);
327 static uint64_t pci_read(void *opaque
, hwaddr addr
, unsigned int size
)
329 AcpiPciHpState
*s
= opaque
;
331 int bsel
= s
->hotplug_select
;
333 if (bsel
< 0 || bsel
>= ACPI_PCIHP_MAX_HOTPLUG_BUS
) {
339 val
= s
->acpi_pcihp_pci_status
[bsel
].up
;
340 if (!s
->legacy_piix
) {
341 s
->acpi_pcihp_pci_status
[bsel
].up
= 0;
343 trace_acpi_pci_up_read(val
);
346 val
= s
->acpi_pcihp_pci_status
[bsel
].down
;
347 trace_acpi_pci_down_read(val
);
350 /* No feature defined yet */
351 trace_acpi_pci_features_read(val
);
354 val
= s
->acpi_pcihp_pci_status
[bsel
].hotplug_enable
;
355 trace_acpi_pci_rmv_read(val
);
358 val
= s
->hotplug_select
;
359 trace_acpi_pci_sel_read(val
);
367 static void pci_write(void *opaque
, hwaddr addr
, uint64_t data
,
370 AcpiPciHpState
*s
= opaque
;
373 if (s
->hotplug_select
>= ACPI_PCIHP_MAX_HOTPLUG_BUS
) {
376 acpi_pcihp_eject_slot(s
, s
->hotplug_select
, data
);
377 trace_acpi_pci_ej_write(addr
, data
);
380 s
->hotplug_select
= s
->legacy_piix
? ACPI_PCIHP_BSEL_DEFAULT
: data
;
381 trace_acpi_pci_sel_write(addr
, data
);
387 static const MemoryRegionOps acpi_pcihp_io_ops
= {
390 .endianness
= DEVICE_LITTLE_ENDIAN
,
392 .min_access_size
= 4,
393 .max_access_size
= 4,
397 void acpi_pcihp_init(Object
*owner
, AcpiPciHpState
*s
, PCIBus
*root_bus
,
398 MemoryRegion
*address_space_io
, bool bridges_enabled
)
400 s
->io_len
= ACPI_PCIHP_SIZE
;
401 s
->io_base
= ACPI_PCIHP_ADDR
;
404 s
->legacy_piix
= !bridges_enabled
;
406 memory_region_init_io(&s
->io
, owner
, &acpi_pcihp_io_ops
, s
,
407 "acpi-pci-hotplug", s
->io_len
);
408 memory_region_add_subregion(address_space_io
, s
->io_base
, &s
->io
);
410 object_property_add_uint16_ptr(owner
, ACPI_PCIHP_IO_BASE_PROP
, &s
->io_base
,
412 object_property_add_uint16_ptr(owner
, ACPI_PCIHP_IO_LEN_PROP
, &s
->io_len
,
416 const VMStateDescription vmstate_acpi_pcihp_pci_status
= {
417 .name
= "acpi_pcihp_pci_status",
419 .minimum_version_id
= 1,
420 .fields
= (VMStateField
[]) {
421 VMSTATE_UINT32(up
, AcpiPciHpPciStatus
),
422 VMSTATE_UINT32(down
, AcpiPciHpPciStatus
),
423 VMSTATE_END_OF_LIST()