On 2012-07-02 16:26, Alex Williamson wrote:
> On Mon, 2012-07-02 at 14:38 +0200, Jan Kiszka wrote:
>> This per-device notifier shall be triggered by any interrupt router
>> along the path of a device's legacy interrupt signal on routing changes.
>> For simplicity reasons and as this is a slow path anyway, no further
>> details on the routing changes are provided. Instead, the callback is
>> expected to use pci_device_route_intx_to_irq to check the effect of the
>> change.
>>
>> Will be used by KVM PCI device assignment and VFIO.
>>
>> Signed-off-by: Jan Kiszka <jan.kis...@siemens.com>
>> ---
>> hw/pci.c | 23 +++++++++++++++++++++++
>> hw/pci.h | 7 +++++++
>> hw/piix_pci.c | 2 ++
>> 3 files changed, 32 insertions(+), 0 deletions(-)
>>
>> diff --git a/hw/pci.c b/hw/pci.c
>> index 311ba09..772141a 100644
>> --- a/hw/pci.c
>> +++ b/hw/pci.c
>> @@ -1095,6 +1095,29 @@ PCIINTxRoute pci_device_route_intx_to_irq(PCIDevice
>> *dev, int pin)
>> return bus->route_intx_to_irq(bus->irq_opaque, pin);
>> }
>>
>> +void pci_bus_fire_intx_routing_notifier(PCIBus *bus)
>> +{
>> + PCIDevice *dev;
>> + PCIBus *sec;
>> + int i;
>> +
>> + for (i = 0; i < ARRAY_SIZE(bus->devices); ++i) {
>> + dev = bus->devices[i];
>> + if (dev && dev->intx_routing_notifier) {
>> + dev->intx_routing_notifier(dev);
>> + }
>> + QLIST_FOREACH(sec, &bus->child, sibling) {
>> + pci_bus_fire_intx_routing_notifier(sec);
>> + }
>> + }
>> +}
>> +
>> +void pci_device_set_intx_routing_notifier(PCIDevice *dev,
>> + PCIINTxRoutingNotifier notifier)
>> +{
>> + dev->intx_routing_notifier = notifier;
>> +}
>> +
>
> nit, wish there was also an unset here too. If we switch to MSI mode,
> there's not much point in calling the notifier, so the driver could
> unset it.
We could add
static inline pci_device_unset_intx_routing_notifier(PCIDevice *dev)
{
dev->intx_routing_notifier = NULL;
}
- or simply do pci_device_set_intx_routing_notifier(dev, NULL);.
> Also nice to have a set in the initfn and matching unset in
> exitfn. There's potentially a race between the driver freeing data and
> the pci device going away, but I don't know if we can hit it in qemu.
Everything should be synchronized by the BQL, so far. Or not?
Jan
--
Siemens AG, Corporate Technology, CT RTC ITP SDP-DE
Corporate Competence Center Embedded Linux
