qemu/hw/pci/pcie_port.c
Igor Mammedov ceefa0b746 pci: fix 'hotplugglable' property behavior
Currently the property may flip its state
during VM bring up or just doesn't work as
the name implies.

In particular with PCIE root port that has
'hotplug={on|off}' property, and when it's
turned off, one would expect
  'hotpluggable' == false
for any devices attached to it.
Which is not the case since qbus_is_hotpluggable()
used by the property just checks for presence
of any hotplug_handler set on bus.

The problem is that name BusState::hotplug_handler
from its inception is misnomer, as it handles
not only hotplug but also in many cases coldplug
as well (i.e. generic wiring interface), and
it's fine to have hotplug_handler set on bus
while it doesn't support hotplug (ex. pcie-slot
with hotplug=off).

Another case of root port flipping 'hotpluggable'
state when ACPI PCI hotplug is enabled in this
case root port with 'hotplug=off' starts as
hotpluggable and then later on, pcihp
hotplug_handler clears hotplug_handler
explicitly after checking root port's 'hotplug'
property.

So root-port hotpluggablity check sort of works
if pcihp is enabled but is broken if pcihp is
disabled.

One way to deal with the issue is to ask
hotplug_handler if bus it controls is hotpluggable
or not. To do that add is_hotpluggable_bus()
hook to HotplugHandler interface and use it in
'hotpluggable' property + teach pcie-slot to
actually look into 'hotplug' property state
before deciding if bus is hotpluggable.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20230302161543.286002-13-imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-03-07 12:38:59 -05:00

220 lines
6.1 KiB
C

/*
* pcie_port.c
*
* Copyright (c) 2010 Isaku Yamahata <yamahata at valinux co jp>
* VA Linux Systems Japan K.K.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "hw/pci/pcie_port.h"
#include "hw/qdev-properties.h"
#include "qemu/module.h"
#include "hw/hotplug.h"
void pcie_port_init_reg(PCIDevice *d)
{
/* Unlike pci bridge,
66MHz and fast back to back don't apply to pci express port. */
pci_set_word(d->config + PCI_STATUS, 0);
pci_set_word(d->config + PCI_SEC_STATUS, 0);
/*
* Unlike conventional pci bridge, for some bits the spec states:
* Does not apply to PCI Express and must be hardwired to 0.
*/
pci_word_test_and_clear_mask(d->wmask + PCI_BRIDGE_CONTROL,
PCI_BRIDGE_CTL_MASTER_ABORT |
PCI_BRIDGE_CTL_FAST_BACK |
PCI_BRIDGE_CTL_DISCARD |
PCI_BRIDGE_CTL_SEC_DISCARD |
PCI_BRIDGE_CTL_DISCARD_STATUS |
PCI_BRIDGE_CTL_DISCARD_SERR);
}
/**************************************************************************
* (chassis number, pcie physical slot number) -> pcie slot conversion
*/
struct PCIEChassis {
uint8_t number;
QLIST_HEAD(, PCIESlot) slots;
QLIST_ENTRY(PCIEChassis) next;
};
static QLIST_HEAD(, PCIEChassis) chassis = QLIST_HEAD_INITIALIZER(chassis);
static struct PCIEChassis *pcie_chassis_find(uint8_t chassis_number)
{
struct PCIEChassis *c;
QLIST_FOREACH(c, &chassis, next) {
if (c->number == chassis_number) {
break;
}
}
return c;
}
void pcie_chassis_create(uint8_t chassis_number)
{
struct PCIEChassis *c;
c = pcie_chassis_find(chassis_number);
if (c) {
return;
}
c = g_malloc0(sizeof(*c));
c->number = chassis_number;
QLIST_INIT(&c->slots);
QLIST_INSERT_HEAD(&chassis, c, next);
}
static PCIESlot *pcie_chassis_find_slot_with_chassis(struct PCIEChassis *c,
uint8_t slot)
{
PCIESlot *s;
QLIST_FOREACH(s, &c->slots, next) {
if (s->slot == slot) {
break;
}
}
return s;
}
PCIESlot *pcie_chassis_find_slot(uint8_t chassis_number, uint16_t slot)
{
struct PCIEChassis *c;
c = pcie_chassis_find(chassis_number);
if (!c) {
return NULL;
}
return pcie_chassis_find_slot_with_chassis(c, slot);
}
int pcie_chassis_add_slot(struct PCIESlot *slot)
{
struct PCIEChassis *c;
c = pcie_chassis_find(slot->chassis);
if (!c) {
return -ENODEV;
}
if (pcie_chassis_find_slot_with_chassis(c, slot->slot)) {
return -EBUSY;
}
QLIST_INSERT_HEAD(&c->slots, slot, next);
return 0;
}
void pcie_chassis_del_slot(PCIESlot *s)
{
QLIST_REMOVE(s, next);
}
static Property pcie_port_props[] = {
DEFINE_PROP_UINT8("port", PCIEPort, port, 0),
DEFINE_PROP_UINT16("aer_log_max", PCIEPort,
parent_obj.parent_obj.exp.aer_log.log_max,
PCIE_AER_LOG_MAX_DEFAULT),
DEFINE_PROP_END_OF_LIST()
};
static void pcie_port_class_init(ObjectClass *oc, void *data)
{
DeviceClass *dc = DEVICE_CLASS(oc);
device_class_set_props(dc, pcie_port_props);
}
PCIDevice *pcie_find_port_by_pn(PCIBus *bus, uint8_t pn)
{
int devfn;
for (devfn = 0; devfn < ARRAY_SIZE(bus->devices); devfn++) {
PCIDevice *d = bus->devices[devfn];
PCIEPort *port;
if (!d || !pci_is_express(d) || !d->exp.exp_cap) {
continue;
}
if (!object_dynamic_cast(OBJECT(d), TYPE_PCIE_PORT)) {
continue;
}
port = PCIE_PORT(d);
if (port->port == pn) {
return d;
}
}
return NULL;
}
static bool pcie_slot_is_hotpluggbale_bus(HotplugHandler *plug_handler,
BusState *bus)
{
PCIESlot *s = PCIE_SLOT(bus->parent);
return s->hotplug;
}
static const TypeInfo pcie_port_type_info = {
.name = TYPE_PCIE_PORT,
.parent = TYPE_PCI_BRIDGE,
.instance_size = sizeof(PCIEPort),
.abstract = true,
.class_init = pcie_port_class_init,
};
static Property pcie_slot_props[] = {
DEFINE_PROP_UINT8("chassis", PCIESlot, chassis, 0),
DEFINE_PROP_UINT16("slot", PCIESlot, slot, 0),
DEFINE_PROP_BOOL("hotplug", PCIESlot, hotplug, true),
DEFINE_PROP_BOOL("x-do-not-expose-native-hotplug-cap", PCIESlot,
hide_native_hotplug_cap, false),
DEFINE_PROP_END_OF_LIST()
};
static void pcie_slot_class_init(ObjectClass *oc, void *data)
{
DeviceClass *dc = DEVICE_CLASS(oc);
HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(oc);
device_class_set_props(dc, pcie_slot_props);
hc->pre_plug = pcie_cap_slot_pre_plug_cb;
hc->plug = pcie_cap_slot_plug_cb;
hc->unplug = pcie_cap_slot_unplug_cb;
hc->unplug_request = pcie_cap_slot_unplug_request_cb;
hc->is_hotpluggable_bus = pcie_slot_is_hotpluggbale_bus;
}
static const TypeInfo pcie_slot_type_info = {
.name = TYPE_PCIE_SLOT,
.parent = TYPE_PCIE_PORT,
.instance_size = sizeof(PCIESlot),
.abstract = true,
.class_init = pcie_slot_class_init,
.interfaces = (InterfaceInfo[]) {
{ TYPE_HOTPLUG_HANDLER },
{ }
}
};
static void pcie_port_register_types(void)
{
type_register_static(&pcie_port_type_info);
type_register_static(&pcie_slot_type_info);
}
type_init(pcie_port_register_types)