Re: [libvirt-users] Using hostdev to plug a PCI-E host device into Q35 pcie-root port

Am 19.11.2013 11:36, schrieb Laine Stump: > On 11/15/2013 03:35 PM, Thomas Kuther wrote: >> Hello, >> >> I'm trying to migrate a working qemu command line configuration to >> libvirt. >> The part I'm currently failing on is: >> >> $ qemu-system-x86_64 -M Q35 ... -device vfio-pci,host=05:00.0,bus=pcie.0 >> >> The right way to translate this into libvirt XML seems to be using >> <hostdev>, but I seem to be unable to plug it into the pcie-root port >> >> This is how the interesting part looks like when I let "virsh edit" >> generate an <address> >> >> <controller type='pci' index='0' model='pcie-root'/> >> <controller type='pci' index='1' model='dmi-to-pci-bridge'> >> <address type='pci' domain='0x0000' bus='0x00' slot='0x02' >> function='0x0'/> >> </controller> >> <controller type='pci' index='2' model='pci-bridge'> >> <address type='pci' domain='0x0000' bus='0x01' slot='0x01' >> function='0x0'/> >> </controller> >> [...] >> <hostdev mode='subsystem' type='pci' managed='yes'> >> <driver name='vfio'/> >> <source> >> <address domain='0x0000' bus='0x03' slot='0x00' function='0x0'/> >> </source> >> <address type='pci' domain='0x0000' bus='0x02' slot='0x06' >> function='0x0'/> >> </hostdev> >> [...] >> >> To my understanding, this will plug the host device into the >> pci-bridge controller. >> The guest OS doesn't boot with this and resets right after bios. > > Ugh. That's very unfortunate. This is the first report I've heard of > something failing in such a bad way due to being plugged into a > pci-bridge slot; up until now I'd only heard that there is some extra > PCIe functionality that would be missing if a device was plugged into a > PCI slot vs. PCIe. > > Can I ask what type of device this is? > It's a Marvell 88SE9172 SATA controller, here is the lspci -vvv

The second one I'm trying to pass through is a Renesas uPD720201 USB 3.0 Host Controller, but first I wanted to get the SATA controller working in libvirt. I will try to leave out the SATA controller and see what happens with only the USB3 controller.

> I'm wondering as I type if possibly we could relax the enforcement of > the "PCI only" rule such that we allow explicitly placing any device on > any type of bus, but only auto-assign to a plain PCI slot. That may be a > reasonable compromise until qemu has the required new device/controller > introspection info available. > I like the idea.