From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:40588) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SlhfW-0005up-UY for qemu-devel@nongnu.org; Mon, 02 Jul 2012 10:32:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SlhfQ-0004JA-IB for qemu-devel@nongnu.org; Mon, 02 Jul 2012 10:32:02 -0400 Received: from thoth.sbs.de ([192.35.17.2]:28127) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SlhfQ-0004IB-8O for qemu-devel@nongnu.org; Mon, 02 Jul 2012 10:31:56 -0400 Message-ID: <4FF1B0D8.50704@siemens.com> Date: Mon, 02 Jul 2012 16:31:52 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <0de594d38ac7479645bb71547665ebf64418c9ce.1341232709.git.jan.kiszka@siemens.com> <1341239177.1207.392.camel@bling.home> In-Reply-To: <1341239177.1207.392.camel@bling.home> Content-Type: text/plain; charset=UTF-8 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: Alex Williamson Cc: qemu-devel , "Michael S. Tsirkin" 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);. > 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