No, I was under the impression that since they were in the IOMMU group that they must be attached together. I will try it without (not sure if the driver for some reason requires both to be present on the guest system; I'm not particularly savvy with PCI bus programming).
On Wed, Feb 24, 2016 at 5:12 PM Alex Williamson <alex.william...@redhat.com> wrote: > On Wed, 24 Feb 2016 20:04:08 +0000 > Nicholas Andre <n...@axfp.org> wrote: > > > I am attempting to attach PCIe devices in passthrough to my KVM domain. I > > have two devices in one IOMMU group (#28): > > > > 03:00.0 PCI bridge: Texas Instruments XIO2001 PCI Express-to-PCI Bridge > > 04:00.0 Multimedia audio controller: Texas Instruments TMS320C6414 > > TMS320C6415 TMS320C6416 > > > > and lspci -n values: > > > > 03:00.0 0604: 104c:8240 > > 04:00.0 0401: 104c:a106 > > > > Both of which are attached to my KVM domain with managed configuration. > > > > I am running Ubuntu 14.04. I have: > > > > - Installed KVM, set up domains, ensured KVM and vfio-pci modules are > > loaded > > - Set intel_iommu=on on the kernel command line and verified it is > > enabled with dmesg > > - kvm-ok prints acceleration is all set, VT-d is supported on the > chipset > > - Verified that the 03:00.0 device does not have a driver currently > > listed under ls -l /sys/bus/pci/devices/0000\:03\:00.0/ though it does > > have a firmware listed. > > > > When attempting to start the VM I get: > > > > virsh # start rivendell > > error: Failed to start domain rivendell > > error: Failed to bind PCI device '0000:03:00.0' to vfio-pci: No such > device > > > > and under syslog I get what I believe to be the PCIe EINVAL code: > > > > Feb 23 19:46:46 tupac kernel: [ 214.159625] vfio-pci: probe of > > 0000:03:00.0 failed with error -22 > > > > Trying to do this manually: I do this to bind the devices to vfio-pci: > > > > # echo "104c a106" > /sys/bus/pci/drivers/vfio-pci/new_id > > # echo "104c 8240" > /sys/bus/pci/drivers/vfio-pci/new_id > > > > Then: > > > > root@tupac:~# echo "0000:03:00.0" > /sys/bus/pci/drivers/vfio-pci/bind > > bash: echo: write error: No such device > > > > However, the multimedia controller appears AOK: > > > > root@tupac:~# ls -l /sys/bus/pci/drivers/vfio-pci/ > > total 0 > > lrwxrwxrwx 1 root root 0 Feb 24 13:07 0000:04:00.0 -> > > ../../../../devices/pci0000:00/0000:00:02.2/0000:03:00.0/0000:04:00.0 > > --w------- 1 root root 4096 Feb 24 13:05 bind > > lrwxrwxrwx 1 root root 0 Feb 24 13:07 module -> > ../../../../module/vfio_pci > > --w------- 1 root root 4096 Feb 24 13:15 new_id > > --w------- 1 root root 4096 Feb 23 19:47 remove_id > > --w------- 1 root root 4096 Feb 23 19:43 uevent > > --w------- 1 root root 4096 Feb 24 13:07 unbind > > > > 03:00.0 (which is a PCIe to PCI adapter) is not showing up under > vfio-pci's > > devices. They're in the same IOMMU group so I don't think I can attach > them > > individually. > > > > What is causing this? Is this some issue with the presence of the regular > > old PCI bus in the system behind the adapter? > > vfio-pci does not support bridges nor is there any reason to bind the > bridge to vfio-pci. The IOMMU group requirement is satisfied by the > bridge not being bound to any drivers. We used to have some bridge > drivers whitelisted to allow the group to be viable with them attached, > newer kernels skip testing the driver of bridge devices. Is there some > specific reason you want to attach this bridge to the VM? Thanks, > > Alex >
