From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:50493) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SlhwF-0003Ko-Ke for qemu-devel@nongnu.org; Mon, 02 Jul 2012 10:49:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SlhwD-00033k-JT for qemu-devel@nongnu.org; Mon, 02 Jul 2012 10:49:19 -0400 Received: from mx1.redhat.com ([209.132.183.28]:5918) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SlhwD-00033O-At for qemu-devel@nongnu.org; Mon, 02 Jul 2012 10:49:17 -0400 Message-ID: <1341240554.1207.407.camel@bling.home> From: Alex Williamson Date: Mon, 02 Jul 2012 08:49:14 -0600 In-Reply-To: <4FF1B0D8.50704@siemens.com> References: <0de594d38ac7479645bb71547665ebf64418c9ce.1341232709.git.jan.kiszka@siemens.com> <1341239177.1207.392.camel@bling.home> <4FF1B0D8.50704@siemens.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2 2/2] pci: Add INTx routing notifier List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: qemu-devel , "Michael S. Tsirkin" On Mon, 2012-07-02 at 16:31 +0200, Jan Kiszka wrote: > 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 > >> --- > >> 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);. Duh... sorry, too early yet for me ;) This is fine. Acked-by: Alex Williamson > > 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? Yes, I imagine the lock protects getting called in that gap. Thanks, Alex