hw/pcie: better hotplug/hotunplug support

The current code is broken: it does surprise removal which crashes guests.

Reimplemented the steps:
 - Hotplug triggers both 'present detect change' and
   'attention button pressed'.

 - Hotunplug starts by triggering 'attention button pressed',
   then waits for the OS to power off the device and only
   then detaches it.

Fixes CVE-2014-3471.

Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Marcel Apfelbaum 2014-06-23 17:32:49 +03:00 committed by Michael S. Tsirkin
parent f23b6bdc3c
commit 554f802da3

View File

@ -258,7 +258,8 @@ void pcie_cap_slot_hotplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTSTA,
PCI_EXP_SLTSTA_PDS);
pcie_cap_slot_event(PCI_DEVICE(hotplug_dev), PCI_EXP_HP_EV_PDC);
pcie_cap_slot_event(PCI_DEVICE(hotplug_dev),
PCI_EXP_HP_EV_PDC | PCI_EXP_HP_EV_ABP);
}
void pcie_cap_slot_hot_unplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
@ -268,10 +269,7 @@ void pcie_cap_slot_hot_unplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
pcie_cap_slot_hotplug_common(PCI_DEVICE(hotplug_dev), dev, &exp_cap, errp);
object_unparent(OBJECT(dev));
pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTSTA,
PCI_EXP_SLTSTA_PDS);
pcie_cap_slot_event(PCI_DEVICE(hotplug_dev), PCI_EXP_HP_EV_PDC);
pcie_cap_slot_push_attention_button(PCI_DEVICE(hotplug_dev));
}
/* pci express slot for pci express root/downstream port
@ -383,6 +381,11 @@ void pcie_cap_slot_reset(PCIDevice *dev)
hotplug_event_update_event_status(dev);
}
static void pcie_unplug_device(PCIBus *bus, PCIDevice *dev, void *opaque)
{
object_unparent(OBJECT(dev));
}
void pcie_cap_slot_write_config(PCIDevice *dev,
uint32_t addr, uint32_t val, int len)
{
@ -407,6 +410,22 @@ void pcie_cap_slot_write_config(PCIDevice *dev,
sltsta);
}
/*
* If the slot is polulated, power indicator is off and power
* controller is off, it is safe to detach the devices.
*/
if ((sltsta & PCI_EXP_SLTSTA_PDS) && (val & PCI_EXP_SLTCTL_PCC) &&
((val & PCI_EXP_SLTCTL_PIC_OFF) == PCI_EXP_SLTCTL_PIC_OFF)) {
PCIBus *sec_bus = pci_bridge_get_sec_bus(PCI_BRIDGE(dev));
pci_for_each_device(sec_bus, pci_bus_num(sec_bus),
pcie_unplug_device, NULL);
pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTSTA,
PCI_EXP_SLTSTA_PDS);
pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTSTA,
PCI_EXP_SLTSTA_PDC);
}
hotplug_event_notify(dev);
/*