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 gint
g_cmp_uint32(gconstpointer a
, gconstpointer b
, gpointer user_data
)
62 static GSequence
*pci_acpi_index_list(void)
64 static GSequence
*used_acpi_index_list
;
66 if (!used_acpi_index_list
) {
67 used_acpi_index_list
= g_sequence_new(NULL
);
69 return used_acpi_index_list
;
72 static int acpi_pcihp_get_bsel(PCIBus
*bus
)
74 Error
*local_err
= NULL
;
75 uint64_t bsel
= object_property_get_uint(OBJECT(bus
), ACPI_PCIHP_PROP_BSEL
,
78 if (local_err
|| bsel
>= ACPI_PCIHP_MAX_HOTPLUG_BUS
) {
80 error_free(local_err
);
90 bool has_bridge_hotplug
;
93 /* Assign BSEL property only to buses that support hotplug. */
94 static void *acpi_set_bsel(PCIBus
*bus
, void *opaque
)
96 BSELInfo
*info
= opaque
;
98 DeviceState
*br
= bus
->qbus
.parent
;
99 bool is_bridge
= IS_PCI_BRIDGE(br
);
101 /* hotplugged bridges can't be described in ACPI ignore them */
102 if (qbus_is_hotpluggable(BUS(bus
))) {
103 if (!is_bridge
|| (!br
->hotplugged
&& info
->has_bridge_hotplug
)) {
104 bus_bsel
= g_malloc(sizeof *bus_bsel
);
106 *bus_bsel
= info
->bsel_alloc
++;
107 object_property_add_uint32_ptr(OBJECT(bus
), ACPI_PCIHP_PROP_BSEL
,
108 bus_bsel
, OBJ_PROP_FLAG_READ
);
115 static void acpi_set_pci_info(bool has_bridge_hotplug
)
117 static bool bsel_is_set
;
118 Object
*host
= acpi_get_i386_pci_host();
120 BSELInfo info
= { .bsel_alloc
= ACPI_PCIHP_BSEL_DEFAULT
,
121 .has_bridge_hotplug
= has_bridge_hotplug
};
132 bus
= PCI_HOST_BRIDGE(host
)->bus
;
134 /* Scan all PCI buses. Set property to enable acpi based hotplug. */
135 pci_for_each_bus_depth_first(bus
, acpi_set_bsel
, NULL
, &info
);
139 static void acpi_pcihp_disable_root_bus(void)
141 Object
*host
= acpi_get_i386_pci_host();
144 bus
= PCI_HOST_BRIDGE(host
)->bus
;
145 if (bus
&& qbus_is_hotpluggable(BUS(bus
))) {
146 /* setting the hotplug handler to NULL makes the bus non-hotpluggable */
147 qbus_set_hotplug_handler(BUS(bus
), NULL
);
153 static void acpi_pcihp_test_hotplug_bus(PCIBus
*bus
, void *opaque
)
155 AcpiPciHpFind
*find
= opaque
;
156 if (find
->bsel
== acpi_pcihp_get_bsel(bus
)) {
161 static PCIBus
*acpi_pcihp_find_hotplug_bus(AcpiPciHpState
*s
, int bsel
)
163 AcpiPciHpFind find
= { .bsel
= bsel
, .bus
= NULL
};
169 pci_for_each_bus(s
->root
, acpi_pcihp_test_hotplug_bus
, &find
);
171 /* Make bsel 0 eject root bus if bsel property is not set,
172 * for compatibility with non acpi setups.
173 * TODO: really needed?
175 if (!bsel
&& !find
.bus
) {
180 * Check if find.bus is actually hotpluggable. If bsel is set to
181 * NULL for example on the root bus in order to make it
182 * non-hotpluggable, find.bus will match the root bus when bsel
183 * is 0. See acpi_pcihp_test_hotplug_bus() above. Since the
184 * bus is not hotpluggable however, we should not select the bus.
185 * Instead, we should set find.bus to NULL in that case. In the check
186 * below, we generalize this case for all buses, not just the root bus.
187 * The callers of this function check for a null return value and
188 * handle them appropriately.
190 if (find
.bus
&& !qbus_is_hotpluggable(BUS(find
.bus
))) {
196 static bool acpi_pcihp_pc_no_hotplug(AcpiPciHpState
*s
, PCIDevice
*dev
)
198 DeviceClass
*dc
= DEVICE_GET_CLASS(dev
);
200 * ACPI doesn't allow hotplug of bridge devices. Don't allow
201 * hot-unplug of bridge devices unless they were added by hotplug
202 * (and so, not described by acpi).
204 * Don't allow hot-unplug of SR-IOV Virtual Functions, as they
205 * will be removed implicitly, when Physical Function is unplugged.
207 return (IS_PCI_BRIDGE(dev
) && !dev
->qdev
.hotplugged
) || !dc
->hotpluggable
||
211 static void acpi_pcihp_eject_slot(AcpiPciHpState
*s
, unsigned bsel
, unsigned slots
)
213 HotplugHandler
*hotplug_ctrl
;
214 BusChild
*kid
, *next
;
215 int slot
= ctz32(slots
);
216 PCIBus
*bus
= acpi_pcihp_find_hotplug_bus(s
, bsel
);
218 trace_acpi_pci_eject_slot(bsel
, slot
);
220 if (!bus
|| slot
> 31) {
224 /* Mark request as complete */
225 s
->acpi_pcihp_pci_status
[bsel
].down
&= ~(1U << slot
);
226 s
->acpi_pcihp_pci_status
[bsel
].up
&= ~(1U << slot
);
228 QTAILQ_FOREACH_SAFE(kid
, &bus
->qbus
.children
, sibling
, next
) {
229 DeviceState
*qdev
= kid
->child
;
230 PCIDevice
*dev
= PCI_DEVICE(qdev
);
231 if (PCI_SLOT(dev
->devfn
) == slot
) {
232 if (!acpi_pcihp_pc_no_hotplug(s
, dev
)) {
234 * partially_hotplugged is used by virtio-net failover:
235 * failover has asked the guest OS to unplug the device
236 * but we need to keep some references to the device
237 * to be able to plug it back in case of failure so
238 * we don't execute hotplug_handler_unplug().
240 if (dev
->partially_hotplugged
) {
242 * pending_deleted_event is set to true when
243 * virtio-net failover asks to unplug the device,
244 * and set to false here when the operation is done
245 * This is used by the migration loop to detect the
246 * end of the operation and really start the migration.
248 qdev
->pending_deleted_event
= false;
250 hotplug_ctrl
= qdev_get_hotplug_handler(qdev
);
251 hotplug_handler_unplug(hotplug_ctrl
, qdev
, &error_abort
);
252 object_unparent(OBJECT(qdev
));
259 static void acpi_pcihp_update_hotplug_bus(AcpiPciHpState
*s
, int bsel
)
261 BusChild
*kid
, *next
;
262 PCIBus
*bus
= acpi_pcihp_find_hotplug_bus(s
, bsel
);
264 /* Execute any pending removes during reset */
265 while (s
->acpi_pcihp_pci_status
[bsel
].down
) {
266 acpi_pcihp_eject_slot(s
, bsel
, s
->acpi_pcihp_pci_status
[bsel
].down
);
269 s
->acpi_pcihp_pci_status
[bsel
].hotplug_enable
= ~0;
274 QTAILQ_FOREACH_SAFE(kid
, &bus
->qbus
.children
, sibling
, next
) {
275 DeviceState
*qdev
= kid
->child
;
276 PCIDevice
*pdev
= PCI_DEVICE(qdev
);
277 int slot
= PCI_SLOT(pdev
->devfn
);
279 if (acpi_pcihp_pc_no_hotplug(s
, pdev
)) {
280 s
->acpi_pcihp_pci_status
[bsel
].hotplug_enable
&= ~(1U << slot
);
285 static void acpi_pcihp_update(AcpiPciHpState
*s
)
289 for (i
= 0; i
< ACPI_PCIHP_MAX_HOTPLUG_BUS
; ++i
) {
290 acpi_pcihp_update_hotplug_bus(s
, i
);
294 void acpi_pcihp_reset(AcpiPciHpState
*s
, bool acpihp_root_off
)
296 if (acpihp_root_off
) {
297 acpi_pcihp_disable_root_bus();
299 acpi_set_pci_info(!s
->legacy_piix
);
300 acpi_pcihp_update(s
);
303 #define ONBOARD_INDEX_MAX (16 * 1024 - 1)
305 void acpi_pcihp_device_pre_plug_cb(HotplugHandler
*hotplug_dev
,
306 DeviceState
*dev
, Error
**errp
)
308 PCIDevice
*pdev
= PCI_DEVICE(dev
);
310 /* Only hotplugged devices need the hotplug capability. */
311 if (dev
->hotplugged
&&
312 acpi_pcihp_get_bsel(pci_get_bus(pdev
)) < 0) {
313 error_setg(errp
, "Unsupported bus. Bus doesn't have property '"
314 ACPI_PCIHP_PROP_BSEL
"' set");
319 * capped by systemd (see: udev-builtin-net_id.c)
320 * as it's the only known user honor it to avoid users
321 * misconfigure QEMU and then wonder why acpi-index doesn't work
323 if (pdev
->acpi_index
> ONBOARD_INDEX_MAX
) {
324 error_setg(errp
, "acpi-index should be less or equal to %u",
330 * make sure that acpi-index is unique across all present PCI devices
332 if (pdev
->acpi_index
) {
333 GSequence
*used_indexes
= pci_acpi_index_list();
335 if (g_sequence_lookup(used_indexes
, GINT_TO_POINTER(pdev
->acpi_index
),
336 g_cmp_uint32
, NULL
)) {
337 error_setg(errp
, "a PCI device with acpi-index = %" PRIu32
338 " already exist", pdev
->acpi_index
);
341 g_sequence_insert_sorted(used_indexes
,
342 GINT_TO_POINTER(pdev
->acpi_index
),
347 void acpi_pcihp_device_plug_cb(HotplugHandler
*hotplug_dev
, AcpiPciHpState
*s
,
348 DeviceState
*dev
, Error
**errp
)
350 PCIDevice
*pdev
= PCI_DEVICE(dev
);
351 int slot
= PCI_SLOT(pdev
->devfn
);
356 /* Don't send event when device is enabled during qemu machine creation:
357 * it is present on boot, no hotplug event is necessary. We do send an
358 * event when the device is disabled later. */
359 if (!dev
->hotplugged
) {
361 * Overwrite the default hotplug handler with the ACPI PCI one
362 * for cold plugged bridges only.
364 if (!s
->legacy_piix
&&
365 object_dynamic_cast(OBJECT(dev
), TYPE_PCI_BRIDGE
)) {
366 PCIBus
*sec
= pci_bridge_get_sec_bus(PCI_BRIDGE(pdev
));
368 /* Remove all hot-plug handlers if hot-plug is disabled on slot */
369 if (object_dynamic_cast(OBJECT(dev
), TYPE_PCIE_SLOT
) &&
370 !PCIE_SLOT(pdev
)->hotplug
) {
371 qbus_set_hotplug_handler(BUS(sec
), NULL
);
375 qbus_set_hotplug_handler(BUS(sec
), OBJECT(hotplug_dev
));
376 /* We don't have to overwrite any other hotplug handler yet */
377 assert(QLIST_EMPTY(&sec
->child
));
383 bus
= pci_get_bus(pdev
);
384 bridge
= pci_bridge_get_device(bus
);
385 if (object_dynamic_cast(OBJECT(bridge
), TYPE_PCIE_ROOT_PORT
) ||
386 object_dynamic_cast(OBJECT(bridge
), TYPE_XIO3130_DOWNSTREAM
)) {
387 pcie_cap_slot_enable_power(bridge
);
390 bsel
= acpi_pcihp_get_bsel(bus
);
392 s
->acpi_pcihp_pci_status
[bsel
].up
|= (1U << slot
);
393 acpi_send_event(DEVICE(hotplug_dev
), ACPI_PCI_HOTPLUG_STATUS
);
396 void acpi_pcihp_device_unplug_cb(HotplugHandler
*hotplug_dev
, AcpiPciHpState
*s
,
397 DeviceState
*dev
, Error
**errp
)
399 PCIDevice
*pdev
= PCI_DEVICE(dev
);
401 trace_acpi_pci_unplug(PCI_SLOT(pdev
->devfn
),
402 acpi_pcihp_get_bsel(pci_get_bus(pdev
)));
405 * clean up acpi-index so it could reused by another device
407 if (pdev
->acpi_index
) {
408 GSequence
*used_indexes
= pci_acpi_index_list();
410 g_sequence_remove(g_sequence_lookup(used_indexes
,
411 GINT_TO_POINTER(pdev
->acpi_index
),
412 g_cmp_uint32
, NULL
));
418 void acpi_pcihp_device_unplug_request_cb(HotplugHandler
*hotplug_dev
,
419 AcpiPciHpState
*s
, DeviceState
*dev
,
422 PCIDevice
*pdev
= PCI_DEVICE(dev
);
423 int slot
= PCI_SLOT(pdev
->devfn
);
424 int bsel
= acpi_pcihp_get_bsel(pci_get_bus(pdev
));
426 trace_acpi_pci_unplug_request(bsel
, slot
);
429 error_setg(errp
, "Unsupported bus. Bus doesn't have property '"
430 ACPI_PCIHP_PROP_BSEL
"' set");
435 * pending_deleted_event is used by virtio-net failover to detect the
436 * end of the unplug operation, the flag is set to false in
437 * acpi_pcihp_eject_slot() when the operation is completed.
439 pdev
->qdev
.pending_deleted_event
= true;
440 s
->acpi_pcihp_pci_status
[bsel
].down
|= (1U << slot
);
441 acpi_send_event(DEVICE(hotplug_dev
), ACPI_PCI_HOTPLUG_STATUS
);
444 static uint64_t pci_read(void *opaque
, hwaddr addr
, unsigned int size
)
446 AcpiPciHpState
*s
= opaque
;
448 int bsel
= s
->hotplug_select
;
450 if (bsel
< 0 || bsel
>= ACPI_PCIHP_MAX_HOTPLUG_BUS
) {
456 val
= s
->acpi_pcihp_pci_status
[bsel
].up
;
457 if (!s
->legacy_piix
) {
458 s
->acpi_pcihp_pci_status
[bsel
].up
= 0;
460 trace_acpi_pci_up_read(val
);
463 val
= s
->acpi_pcihp_pci_status
[bsel
].down
;
464 trace_acpi_pci_down_read(val
);
467 trace_acpi_pci_features_read(val
);
470 val
= s
->acpi_pcihp_pci_status
[bsel
].hotplug_enable
;
471 trace_acpi_pci_rmv_read(val
);
474 val
= s
->hotplug_select
;
475 trace_acpi_pci_sel_read(val
);
480 trace_acpi_pci_acpi_index_read(val
);
489 static void pci_write(void *opaque
, hwaddr addr
, uint64_t data
,
494 BusChild
*kid
, *next
;
495 AcpiPciHpState
*s
= opaque
;
501 * fetch acpi-index for specified slot so that follow up read from
502 * PCI_AIDX_BASE can return it to guest
506 if (s
->hotplug_select
>= ACPI_PCIHP_MAX_HOTPLUG_BUS
) {
510 bus
= acpi_pcihp_find_hotplug_bus(s
, s
->hotplug_select
);
514 QTAILQ_FOREACH_SAFE(kid
, &bus
->qbus
.children
, sibling
, next
) {
515 Object
*o
= OBJECT(kid
->child
);
516 PCIDevice
*dev
= PCI_DEVICE(o
);
517 if (PCI_SLOT(dev
->devfn
) == slot
) {
518 s
->acpi_index
= object_property_get_uint(o
, "acpi-index", NULL
);
522 trace_acpi_pci_acpi_index_write(s
->hotplug_select
, slot
, s
->acpi_index
);
525 if (s
->hotplug_select
>= ACPI_PCIHP_MAX_HOTPLUG_BUS
) {
528 acpi_pcihp_eject_slot(s
, s
->hotplug_select
, data
);
529 trace_acpi_pci_ej_write(addr
, data
);
532 s
->hotplug_select
= s
->legacy_piix
? ACPI_PCIHP_BSEL_DEFAULT
: data
;
533 trace_acpi_pci_sel_write(addr
, data
);
539 static const MemoryRegionOps acpi_pcihp_io_ops
= {
542 .endianness
= DEVICE_LITTLE_ENDIAN
,
544 .min_access_size
= 4,
545 .max_access_size
= 4,
549 void acpi_pcihp_init(Object
*owner
, AcpiPciHpState
*s
, PCIBus
*root_bus
,
550 MemoryRegion
*address_space_io
, bool bridges_enabled
,
553 s
->io_len
= ACPI_PCIHP_SIZE
;
554 s
->io_base
= io_base
;
557 s
->legacy_piix
= !bridges_enabled
;
559 memory_region_init_io(&s
->io
, owner
, &acpi_pcihp_io_ops
, s
,
560 "acpi-pci-hotplug", s
->io_len
);
561 memory_region_add_subregion(address_space_io
, s
->io_base
, &s
->io
);
563 object_property_add_uint16_ptr(owner
, ACPI_PCIHP_IO_BASE_PROP
, &s
->io_base
,
565 object_property_add_uint16_ptr(owner
, ACPI_PCIHP_IO_LEN_PROP
, &s
->io_len
,
569 const VMStateDescription vmstate_acpi_pcihp_pci_status
= {
570 .name
= "acpi_pcihp_pci_status",
572 .minimum_version_id
= 1,
573 .fields
= (VMStateField
[]) {
574 VMSTATE_UINT32(up
, AcpiPciHpPciStatus
),
575 VMSTATE_UINT32(down
, AcpiPciHpPciStatus
),
576 VMSTATE_END_OF_LIST()