On Thu, 2012-05-17 at 15:19 +0800, Anonymous wrote: > Alex, > > On Sat, May 12, 2012 at 6:55 AM, Alex Williamson > <alex.williamson@xxxxxxxxxx> wrote: > > Integrating IOMMU groups more closely into the driver core allows > > us to more easily work around DMA quirks. The Ricoh multifunction > > controller is a favorite example of devices that are currently > > incompatible with IOMMU isolation as all the functions use the > > requestor ID of function 0 for DMA. Passing this device into > > pci_dma_quirk returns the PCI device to use for DMA. The IOMMU > > driver can then construct an IOMMU group including both devices. > > > > Please give some thought to the Marvell SATA controller quirk as well. > > Instead of multiple visible functions using the same requester ID of > function 0, the Marvell device only makes function 0 visible, but uses > the requestor ID of function 1 as well during DMA. > > See https://bugzilla.redhat.com/show_bug.cgi?id=757166 Wow. That one isn't quite as easy to deal with since there's no existing device in the kernel to point to. This comment might be on the right track: https://bugzilla.kernel.org/show_bug.cgi?id=42679#c11 Perhaps David Woodhouse can comment on support for phantom functions. If we had infrastructure for that it might be easy for the quirk to update the pci_dev struct, inserting a new phantom function. Otherwise we'd need to create a new device in the kernel for it. Thanks, Alex -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
