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/pci/pci_host.h"
34 #include "hw/pci/pcie_port.h"
35 #include "hw/pci-bridge/xio3130_downstream.h"
36 #include "hw/i386/acpi-build.h"
37 #include "hw/acpi/acpi.h"
38 #include "hw/pci/pci_bus.h"
39 #include "migration/vmstate.h"
40 #include "qapi/error.h"
41 #include "qom/qom-qobject.h"
44 #define ACPI_PCIHP_SIZE 0x0018
45 #define PCI_UP_BASE 0x0000
46 #define PCI_DOWN_BASE 0x0004
47 #define PCI_EJ_BASE 0x0008
48 #define PCI_RMV_BASE 0x000c
49 #define PCI_SEL_BASE 0x0010
50 #define PCI_AIDX_BASE 0x0014
52 typedef struct AcpiPciHpFind
{
57 static int acpi_pcihp_get_bsel(PCIBus
*bus
)
59 Error
*local_err
= NULL
;
60 uint64_t bsel
= object_property_get_uint(OBJECT(bus
), ACPI_PCIHP_PROP_BSEL
,
63 if (local_err
|| bsel
>= ACPI_PCIHP_MAX_HOTPLUG_BUS
) {
65 error_free(local_err
);
75 bool has_bridge_hotplug
;
78 /* Assign BSEL property only to buses that support hotplug. */
79 static void *acpi_set_bsel(PCIBus
*bus
, void *opaque
)
81 BSELInfo
*info
= opaque
;
83 DeviceState
*br
= bus
->qbus
.parent
;
84 bool is_bridge
= IS_PCI_BRIDGE(br
);
86 /* hotplugged bridges can't be described in ACPI ignore them */
87 if (qbus_is_hotpluggable(BUS(bus
))) {
88 if (!is_bridge
|| (!br
->hotplugged
&& info
->has_bridge_hotplug
)) {
89 bus_bsel
= g_malloc(sizeof *bus_bsel
);
91 *bus_bsel
= info
->bsel_alloc
++;
92 object_property_add_uint32_ptr(OBJECT(bus
), ACPI_PCIHP_PROP_BSEL
,
93 bus_bsel
, OBJ_PROP_FLAG_READ
);
100 static void acpi_set_pci_info(bool has_bridge_hotplug
)
102 static bool bsel_is_set
;
103 Object
*host
= acpi_get_i386_pci_host();
105 BSELInfo info
= { .bsel_alloc
= ACPI_PCIHP_BSEL_DEFAULT
,
106 .has_bridge_hotplug
= has_bridge_hotplug
};
117 bus
= PCI_HOST_BRIDGE(host
)->bus
;
119 /* Scan all PCI buses. Set property to enable acpi based hotplug. */
120 pci_for_each_bus_depth_first(bus
, acpi_set_bsel
, NULL
, &info
);
124 static void acpi_pcihp_test_hotplug_bus(PCIBus
*bus
, void *opaque
)
126 AcpiPciHpFind
*find
= opaque
;
127 if (find
->bsel
== acpi_pcihp_get_bsel(bus
)) {
132 static PCIBus
*acpi_pcihp_find_hotplug_bus(AcpiPciHpState
*s
, int bsel
)
134 AcpiPciHpFind find
= { .bsel
= bsel
, .bus
= NULL
};
140 pci_for_each_bus(s
->root
, acpi_pcihp_test_hotplug_bus
, &find
);
142 /* Make bsel 0 eject root bus if bsel property is not set,
143 * for compatibility with non acpi setups.
144 * TODO: really needed?
146 if (!bsel
&& !find
.bus
) {
151 * Check if find.bus is actually hotpluggable. If bsel is set to
152 * NULL for example on the root bus in order to make it
153 * non-hotpluggable, find.bus will match the root bus when bsel
154 * is 0. See acpi_pcihp_test_hotplug_bus() above. Since the
155 * bus is not hotpluggable however, we should not select the bus.
156 * Instead, we should set find.bus to NULL in that case. In the check
157 * below, we generalize this case for all buses, not just the root bus.
158 * The callers of this function check for a null return value and
159 * handle them appropriately.
161 if (find
.bus
&& !qbus_is_hotpluggable(BUS(find
.bus
))) {
167 static bool acpi_pcihp_pc_no_hotplug(AcpiPciHpState
*s
, PCIDevice
*dev
)
169 DeviceClass
*dc
= DEVICE_GET_CLASS(dev
);
171 * ACPI doesn't allow hotplug of bridge devices. Don't allow
172 * hot-unplug of bridge devices unless they were added by hotplug
173 * (and so, not described by acpi).
175 * Don't allow hot-unplug of SR-IOV Virtual Functions, as they
176 * will be removed implicitly, when Physical Function is unplugged.
178 return (IS_PCI_BRIDGE(dev
) && !dev
->qdev
.hotplugged
) || !dc
->hotpluggable
||
182 static void acpi_pcihp_eject_slot(AcpiPciHpState
*s
, unsigned bsel
, unsigned slots
)
184 HotplugHandler
*hotplug_ctrl
;
185 BusChild
*kid
, *next
;
186 int slot
= ctz32(slots
);
187 PCIBus
*bus
= acpi_pcihp_find_hotplug_bus(s
, bsel
);
189 trace_acpi_pci_eject_slot(bsel
, slot
);
191 if (!bus
|| slot
> 31) {
195 /* Mark request as complete */
196 s
->acpi_pcihp_pci_status
[bsel
].down
&= ~(1U << slot
);
197 s
->acpi_pcihp_pci_status
[bsel
].up
&= ~(1U << slot
);
199 QTAILQ_FOREACH_SAFE(kid
, &bus
->qbus
.children
, sibling
, next
) {
200 DeviceState
*qdev
= kid
->child
;
201 PCIDevice
*dev
= PCI_DEVICE(qdev
);
202 if (PCI_SLOT(dev
->devfn
) == slot
) {
203 if (!acpi_pcihp_pc_no_hotplug(s
, dev
)) {
205 * partially_hotplugged is used by virtio-net failover:
206 * failover has asked the guest OS to unplug the device
207 * but we need to keep some references to the device
208 * to be able to plug it back in case of failure so
209 * we don't execute hotplug_handler_unplug().
211 if (dev
->partially_hotplugged
) {
213 * pending_deleted_event is set to true when
214 * virtio-net failover asks to unplug the device,
215 * and set to false here when the operation is done
216 * This is used by the migration loop to detect the
217 * end of the operation and really start the migration.
219 qdev
->pending_deleted_event
= false;
221 hotplug_ctrl
= qdev_get_hotplug_handler(qdev
);
222 hotplug_handler_unplug(hotplug_ctrl
, qdev
, &error_abort
);
223 object_unparent(OBJECT(qdev
));
230 static void acpi_pcihp_update_hotplug_bus(AcpiPciHpState
*s
, int bsel
)
232 BusChild
*kid
, *next
;
233 PCIBus
*bus
= acpi_pcihp_find_hotplug_bus(s
, bsel
);
235 /* Execute any pending removes during reset */
236 while (s
->acpi_pcihp_pci_status
[bsel
].down
) {
237 acpi_pcihp_eject_slot(s
, bsel
, s
->acpi_pcihp_pci_status
[bsel
].down
);
240 s
->acpi_pcihp_pci_status
[bsel
].hotplug_enable
= ~0;
245 QTAILQ_FOREACH_SAFE(kid
, &bus
->qbus
.children
, sibling
, next
) {
246 DeviceState
*qdev
= kid
->child
;
247 PCIDevice
*pdev
= PCI_DEVICE(qdev
);
248 int slot
= PCI_SLOT(pdev
->devfn
);
250 if (acpi_pcihp_pc_no_hotplug(s
, pdev
)) {
251 s
->acpi_pcihp_pci_status
[bsel
].hotplug_enable
&= ~(1U << slot
);
256 static void acpi_pcihp_update(AcpiPciHpState
*s
)
260 for (i
= 0; i
< ACPI_PCIHP_MAX_HOTPLUG_BUS
; ++i
) {
261 acpi_pcihp_update_hotplug_bus(s
, i
);
265 void acpi_pcihp_reset(AcpiPciHpState
*s
)
267 acpi_set_pci_info(s
->use_acpi_hotplug_bridge
);
268 acpi_pcihp_update(s
);
271 void acpi_pcihp_device_pre_plug_cb(HotplugHandler
*hotplug_dev
,
272 DeviceState
*dev
, Error
**errp
)
274 PCIDevice
*pdev
= PCI_DEVICE(dev
);
276 /* Only hotplugged devices need the hotplug capability. */
277 if (dev
->hotplugged
&&
278 acpi_pcihp_get_bsel(pci_get_bus(pdev
)) < 0) {
279 error_setg(errp
, "Unsupported bus. Bus doesn't have property '"
280 ACPI_PCIHP_PROP_BSEL
"' set");
285 void acpi_pcihp_device_plug_cb(HotplugHandler
*hotplug_dev
, AcpiPciHpState
*s
,
286 DeviceState
*dev
, Error
**errp
)
288 PCIDevice
*pdev
= PCI_DEVICE(dev
);
289 int slot
= PCI_SLOT(pdev
->devfn
);
294 /* Don't send event when device is enabled during qemu machine creation:
295 * it is present on boot, no hotplug event is necessary. We do send an
296 * event when the device is disabled later. */
297 if (!dev
->hotplugged
) {
299 * Overwrite the default hotplug handler with the ACPI PCI one
300 * for cold plugged bridges only.
302 if (s
->use_acpi_hotplug_bridge
&&
303 object_dynamic_cast(OBJECT(dev
), TYPE_PCI_BRIDGE
)) {
304 PCIBus
*sec
= pci_bridge_get_sec_bus(PCI_BRIDGE(pdev
));
306 qbus_set_hotplug_handler(BUS(sec
), OBJECT(hotplug_dev
));
307 /* We don't have to overwrite any other hotplug handler yet */
308 assert(QLIST_EMPTY(&sec
->child
));
314 bus
= pci_get_bus(pdev
);
315 bridge
= pci_bridge_get_device(bus
);
316 if (object_dynamic_cast(OBJECT(bridge
), TYPE_PCIE_ROOT_PORT
) ||
317 object_dynamic_cast(OBJECT(bridge
), TYPE_XIO3130_DOWNSTREAM
)) {
318 pcie_cap_slot_enable_power(bridge
);
321 bsel
= acpi_pcihp_get_bsel(bus
);
323 s
->acpi_pcihp_pci_status
[bsel
].up
|= (1U << slot
);
324 acpi_send_event(DEVICE(hotplug_dev
), ACPI_PCI_HOTPLUG_STATUS
);
327 void acpi_pcihp_device_unplug_cb(HotplugHandler
*hotplug_dev
, AcpiPciHpState
*s
,
328 DeviceState
*dev
, Error
**errp
)
330 PCIDevice
*pdev
= PCI_DEVICE(dev
);
332 trace_acpi_pci_unplug(PCI_SLOT(pdev
->devfn
),
333 acpi_pcihp_get_bsel(pci_get_bus(pdev
)));
338 void acpi_pcihp_device_unplug_request_cb(HotplugHandler
*hotplug_dev
,
339 AcpiPciHpState
*s
, DeviceState
*dev
,
342 PCIDevice
*pdev
= PCI_DEVICE(dev
);
343 int slot
= PCI_SLOT(pdev
->devfn
);
344 int bsel
= acpi_pcihp_get_bsel(pci_get_bus(pdev
));
346 trace_acpi_pci_unplug_request(bsel
, slot
);
349 error_setg(errp
, "Unsupported bus. Bus doesn't have property '"
350 ACPI_PCIHP_PROP_BSEL
"' set");
355 * pending_deleted_event is used by virtio-net failover to detect the
356 * end of the unplug operation, the flag is set to false in
357 * acpi_pcihp_eject_slot() when the operation is completed.
359 pdev
->qdev
.pending_deleted_event
= true;
360 /* if unplug was requested before OSPM is initialized,
361 * linux kernel will clear GPE0.sts[] bits during boot, which effectively
362 * hides unplug event. And than followup qmp_device_del() calls remain
363 * blocked by above flag permanently.
364 * Unblock qmp_device_del() by setting expire limit, so user can
365 * repeat unplug request later when OSPM has been booted.
367 pdev
->qdev
.pending_deleted_expires_ms
=
368 qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL
); /* 1 msec */
370 s
->acpi_pcihp_pci_status
[bsel
].down
|= (1U << slot
);
371 acpi_send_event(DEVICE(hotplug_dev
), ACPI_PCI_HOTPLUG_STATUS
);
374 bool acpi_pcihp_is_hotpluggbale_bus(AcpiPciHpState
*s
, BusState
*bus
)
376 Object
*o
= OBJECT(bus
->parent
);
378 if (s
->use_acpi_hotplug_bridge
&&
379 object_dynamic_cast(o
, TYPE_PCI_BRIDGE
)) {
380 if (object_dynamic_cast(o
, TYPE_PCIE_SLOT
) && !PCIE_SLOT(o
)->hotplug
) {
386 if (s
->use_acpi_root_pci_hotplug
) {
392 static uint64_t pci_read(void *opaque
, hwaddr addr
, unsigned int size
)
394 AcpiPciHpState
*s
= opaque
;
396 int bsel
= s
->hotplug_select
;
398 if (bsel
< 0 || bsel
>= ACPI_PCIHP_MAX_HOTPLUG_BUS
) {
404 val
= s
->acpi_pcihp_pci_status
[bsel
].up
;
405 if (s
->use_acpi_hotplug_bridge
) {
406 s
->acpi_pcihp_pci_status
[bsel
].up
= 0;
408 trace_acpi_pci_up_read(val
);
411 val
= s
->acpi_pcihp_pci_status
[bsel
].down
;
412 trace_acpi_pci_down_read(val
);
415 trace_acpi_pci_features_read(val
);
418 val
= s
->acpi_pcihp_pci_status
[bsel
].hotplug_enable
;
419 trace_acpi_pci_rmv_read(val
);
422 val
= s
->hotplug_select
;
423 trace_acpi_pci_sel_read(val
);
428 trace_acpi_pci_acpi_index_read(val
);
437 static void pci_write(void *opaque
, hwaddr addr
, uint64_t data
,
442 BusChild
*kid
, *next
;
443 AcpiPciHpState
*s
= opaque
;
449 * fetch acpi-index for specified slot so that follow up read from
450 * PCI_AIDX_BASE can return it to guest
454 if (s
->hotplug_select
>= ACPI_PCIHP_MAX_HOTPLUG_BUS
) {
458 bus
= acpi_pcihp_find_hotplug_bus(s
, s
->hotplug_select
);
462 QTAILQ_FOREACH_SAFE(kid
, &bus
->qbus
.children
, sibling
, next
) {
463 Object
*o
= OBJECT(kid
->child
);
464 PCIDevice
*dev
= PCI_DEVICE(o
);
465 if (PCI_SLOT(dev
->devfn
) == slot
) {
466 s
->acpi_index
= object_property_get_uint(o
, "acpi-index", NULL
);
470 trace_acpi_pci_acpi_index_write(s
->hotplug_select
, slot
, s
->acpi_index
);
473 if (s
->hotplug_select
>= ACPI_PCIHP_MAX_HOTPLUG_BUS
) {
476 acpi_pcihp_eject_slot(s
, s
->hotplug_select
, data
);
477 trace_acpi_pci_ej_write(addr
, data
);
480 s
->hotplug_select
= s
->use_acpi_hotplug_bridge
? data
:
481 ACPI_PCIHP_BSEL_DEFAULT
;
482 trace_acpi_pci_sel_write(addr
, data
);
488 static const MemoryRegionOps acpi_pcihp_io_ops
= {
491 .endianness
= DEVICE_LITTLE_ENDIAN
,
493 .min_access_size
= 4,
494 .max_access_size
= 4,
498 void acpi_pcihp_init(Object
*owner
, AcpiPciHpState
*s
, PCIBus
*root_bus
,
499 MemoryRegion
*address_space_io
,
502 s
->io_len
= ACPI_PCIHP_SIZE
;
503 s
->io_base
= io_base
;
507 memory_region_init_io(&s
->io
, owner
, &acpi_pcihp_io_ops
, s
,
508 "acpi-pci-hotplug", s
->io_len
);
509 memory_region_add_subregion(address_space_io
, s
->io_base
, &s
->io
);
511 object_property_add_uint16_ptr(owner
, ACPI_PCIHP_IO_BASE_PROP
, &s
->io_base
,
513 object_property_add_uint16_ptr(owner
, ACPI_PCIHP_IO_LEN_PROP
, &s
->io_len
,
517 const VMStateDescription vmstate_acpi_pcihp_pci_status
= {
518 .name
= "acpi_pcihp_pci_status",
520 .minimum_version_id
= 1,
521 .fields
= (VMStateField
[]) {
522 VMSTATE_UINT32(up
, AcpiPciHpPciStatus
),
523 VMSTATE_UINT32(down
, AcpiPciHpPciStatus
),
524 VMSTATE_END_OF_LIST()