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spapr_pci: fix multifunction hotplug

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Since 3f1e147, QEMU has adopted a convention of supporting function
hotplug by deferring hotplug events until func 0 is hotplugged.
This is likely how management tools like libvirt would expose
such support going forward.

Since sPAPR guests rely on per-func events rather than
slot-based, our protocol has been to hotplug func 0 *first* to
avoid cases where devices appear within guests without func 0
present to avoid undefined behavior.

To remain compatible with new convention, defer hotplug in a
similar manner, but then generate events in 0-first order as we
did in the past. Once func 0 present, fail any attempts to plug
additional functions (as we do with PCIe).

For unplug, defer unplug operations in a similar manner, but
generate unplug events such that function 0 is removed last in guest.

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Michael Roth 2016-03-03 15:55:36 -06:00 committed by David Gibson
parent a88dced8eb
commit 788d2599de
1 changed files with 86 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

93
hw/ppc/spapr_pci.c
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@ -1142,14 +1142,21 @@ static void spapr_phb_remove_pci_device(sPAPRDRConnector *drc,
drck->detach(drc, DEVICE(pdev), spapr_phb_remove_pci_device_cb, phb, errp);
}
static sPAPRDRConnector *spapr_phb_get_pci_func_drc(sPAPRPHBState *phb,
uint32_t busnr,
int32_t devfn)
{
return spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_PCI,
(phb->index << 16) |
(busnr << 8) |
devfn);
}
static sPAPRDRConnector *spapr_phb_get_pci_drc(sPAPRPHBState *phb,
PCIDevice *pdev)
{
uint32_t busnr = pci_bus_num(PCI_BUS(qdev_get_parent_bus(DEVICE(pdev))));
return spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_PCI,
(phb->index << 16) |
(busnr << 8) |
pdev->devfn);
return spapr_phb_get_pci_func_drc(phb, busnr, pdev->devfn);
}
static uint32_t spapr_phb_get_pci_drc_index(sPAPRPHBState *phb,
@ -1173,6 +1180,8 @@ static void spapr_phb_hot_plug_child(HotplugHandler *plug_handler,
PCIDevice *pdev = PCI_DEVICE(plugged_dev);
sPAPRDRConnector *drc = spapr_phb_get_pci_drc(phb, pdev);
Error *local_err = NULL;
PCIBus *bus = PCI_BUS(qdev_get_parent_bus(DEVICE(pdev)));
uint32_t slotnr = PCI_SLOT(pdev->devfn);
/* if DR is disabled we don't need to do anything in the case of
* hotplug or coldplug callbacks
@ -1190,13 +1199,44 @@ static void spapr_phb_hot_plug_child(HotplugHandler *plug_handler,
g_assert(drc);
/* Following the QEMU convention used for PCIe multifunction
* hotplug, we do not allow functions to be hotplugged to a
* slot that already has function 0 present
*/
if (plugged_dev->hotplugged && bus->devices[PCI_DEVFN(slotnr, 0)] &&
PCI_FUNC(pdev->devfn) != 0) {
error_setg(errp, "PCI: slot %d function 0 already ocuppied by %s,"
" additional functions can no longer be exposed to guest.",
slotnr, bus->devices[PCI_DEVFN(slotnr, 0)]->name);
return;
}
spapr_phb_add_pci_device(drc, phb, pdev, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
if (plugged_dev->hotplugged) {
spapr_hotplug_req_add_by_index(drc);
/* If this is function 0, signal hotplug for all the device functions.
* Otherwise defer sending the hotplug event.
*/
if (plugged_dev->hotplugged && PCI_FUNC(pdev->devfn) == 0) {
int i;
for (i = 0; i < 8; i++) {
sPAPRDRConnector *func_drc;
sPAPRDRConnectorClass *func_drck;
sPAPRDREntitySense state;
func_drc = spapr_phb_get_pci_func_drc(phb, pci_bus_num(bus),
PCI_DEVFN(slotnr, i));
func_drck = SPAPR_DR_CONNECTOR_GET_CLASS(func_drc);
func_drck->entity_sense(func_drc, &state);
if (state == SPAPR_DR_ENTITY_SENSE_PRESENT) {
spapr_hotplug_req_add_by_index(func_drc);
}
}
}
}
@ -1219,12 +1259,51 @@ static void spapr_phb_hot_unplug_child(HotplugHandler *plug_handler,
drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
if (!drck->release_pending(drc)) {
PCIBus *bus = PCI_BUS(qdev_get_parent_bus(DEVICE(pdev)));
uint32_t slotnr = PCI_SLOT(pdev->devfn);
sPAPRDRConnector *func_drc;
sPAPRDRConnectorClass *func_drck;
sPAPRDREntitySense state;
int i;
/* ensure any other present functions are pending unplug */
if (PCI_FUNC(pdev->devfn) == 0) {
for (i = 1; i < 8; i++) {
func_drc = spapr_phb_get_pci_func_drc(phb, pci_bus_num(bus),
PCI_DEVFN(slotnr, i));
func_drck = SPAPR_DR_CONNECTOR_GET_CLASS(func_drc);
func_drck->entity_sense(func_drc, &state);
if (state == SPAPR_DR_ENTITY_SENSE_PRESENT
&& !func_drck->release_pending(func_drc)) {
error_setg(errp,
"PCI: slot %d, function %d still present. "
"Must unplug all non-0 functions first.",
slotnr, i);
return;
}
}
}
spapr_phb_remove_pci_device(drc, phb, pdev, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
spapr_hotplug_req_remove_by_index(drc);
/* if this isn't func 0, defer unplug event. otherwise signal removal
* for all present functions
*/
if (PCI_FUNC(pdev->devfn) == 0) {
for (i = 7; i >= 0; i--) {
func_drc = spapr_phb_get_pci_func_drc(phb, pci_bus_num(bus),
PCI_DEVFN(slotnr, i));
func_drck = SPAPR_DR_CONNECTOR_GET_CLASS(func_drc);
func_drck->entity_sense(func_drc, &state);
if (state == SPAPR_DR_ENTITY_SENSE_PRESENT) {
spapr_hotplug_req_remove_by_index(func_drc);
}
}
}
}
}