From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42429) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V7jBj-0005Cq-DB for qemu-devel@nongnu.org; Fri, 09 Aug 2013 05:40:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1V7jBf-0006eo-2A for qemu-devel@nongnu.org; Fri, 09 Aug 2013 05:40:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:7164) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V7jBe-0006eZ-M6 for qemu-devel@nongnu.org; Fri, 09 Aug 2013 05:40:46 -0400 Message-ID: <5204B8F9.5050201@redhat.com> Date: Fri, 09 Aug 2013 11:40:09 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1376038150-14527-1-git-send-email-aik@ozlabs.ru> In-Reply-To: <1376038150-14527-1-git-send-email-aik@ozlabs.ru> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2] pci: Introduce helper to retrieve a PCI device's DMA address space List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy Cc: Anthony Liguori , "Michael S . Tsirkin" , qemu-devel@nongnu.org, David Gibson Il 09/08/2013 10:49, Alexey Kardashevskiy ha scritto: > A PCI device's DMA address space (possibly an IOMMU) is returned by a > method on the PCIBus. At the moment that only has one caller, so the > method is simply open coded. We'll need another caller for VFIO, so > this patch introduces a helper/wrapper function. > > Signed-off-by: David Gibson > [aik: added inheritance from parent if iommu is not set for the current bus] > Signed-off-by: Alexey Kardashevskiy > > --- > Changes: > v2: > * added inheritance, needed for a pci-bridge on spapr-ppc64 > * pci_iommu_as renamed to pci_device_iommu_address_space > --- > hw/pci/pci.c | 22 ++++++++++++++++------ > include/hw/pci/pci.h | 1 + > 2 files changed, 17 insertions(+), 6 deletions(-) > > diff --git a/hw/pci/pci.c b/hw/pci/pci.c > index 4c004f5..0072b54 100644 > --- a/hw/pci/pci.c > +++ b/hw/pci/pci.c > @@ -812,12 +812,7 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus, > } > > pci_dev->bus = bus; > - if (bus->iommu_fn) { > - dma_as = bus->iommu_fn(bus, bus->iommu_opaque, devfn); > - } else { > - /* FIXME: inherit memory region from bus creator */ > - dma_as = &address_space_memory; > - } > + dma_as = pci_device_iommu_address_space(pci_dev); > > memory_region_init_alias(&pci_dev->bus_master_enable_region, > OBJECT(pci_dev), "bus master", > @@ -2239,6 +2234,21 @@ static void pci_device_class_init(ObjectClass *klass, void *data) > k->props = pci_props; > } > > +AddressSpace *pci_device_iommu_address_space(PCIDevice *dev) > +{ > + PCIBus *bus = PCI_BUS(dev->bus); > + > + if (bus->iommu_fn) { > + return bus->iommu_fn(bus, bus->iommu_opaque, dev->devfn); > + } > + > + if (bus->parent_dev) { > + return pci_device_iommu_address_space(bus->parent_dev); > + } No, this would fail if bus->parent_dev is not NULL but not a PCI device either. You can use object_dynamic_cast to convert the parent_dev to PCIDevice, and if the cast succeeds you call the new function. Perhaps you could make the new function take a PCIBus instead. Accessing the PCIDevice's IOMMU address space (as opposed to the bus-master address space) doesn't make much sense, VFIO is really a special case. Putting the new API on the bus side instead looks better. (BTW, do you need to enable bus-master DMA on PCI bridges, to do DMA for devices sitting on the secondary bus?) Paolo > + return &address_space_memory; > +} > + > void pci_setup_iommu(PCIBus *bus, PCIIOMMUFunc fn, void *opaque) > { > bus->iommu_fn = fn; > diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h > index ccec2ba..2374aa9 100644 > --- a/include/hw/pci/pci.h > +++ b/include/hw/pci/pci.h > @@ -405,6 +405,7 @@ void pci_device_deassert_intx(PCIDevice *dev); > > typedef AddressSpace *(*PCIIOMMUFunc)(PCIBus *, void *, int); > > +AddressSpace *pci_device_iommu_address_space(PCIDevice *dev); > void pci_setup_iommu(PCIBus *bus, PCIIOMMUFunc fn, void *opaque); > > static inline void >