At 03/30/2012 05:41 AM, Jaap Winius Wrote: > Hi folks, > > Has anyone encountered the following PCI passthrough error? > > error: internal error Process exited while reading console \ > log output: char device redirected to /dev/pts/1 > assigned_dev_pci_read: pread failed, ret = 0 errno = 2 IIRC, the errno is wrong. ret 0 means that there is no more data in pci config space. the qemu process's user/group is qemu, and it can only read first 64/128bytes of the config space. When you use PCI passthrough, qemu will read PCI device's capabilities. All the capabilities's offset > 64/128 bits. Thanks Wen Congyang > > It's produced after I've detached the PCI device from the base OS and > have tried to start up the guest domain. > > To get to this point, I mostly followed these instructions: > > http://docs.fedoraproject.org/en-US/Fedora/13/html/Virtualization_Guide/chap-Virtualization-PCI_passthrough.html#sect-Virtualization-PCI_passthrough-AI_device_to_a_host > > > The distro I'm using is Debian squeeze, which by default comes with > libvirt 0.8.3 and qemu-kvm 0.12.5, although to avoid a different PCI > passthrough error, I used Debian backports for squeeze to upgrade them > to libvirt 0.9.8 and qemu-kvm 1.0. > > The motherboard involved has VT-d support, which I've enabled with the > "intel_iommu=on" kernel option (dmesg shows "Intel-IOMMU: enabled"). I > did not bother with setsebool because SELinux is disabled. > > According to lspci, the device I want to pass through to the guest > domain, a USB controller, has bus/slot/function 00:1a.0, so I added the > following stanza to the <devices> section of my guest domain: > > <hostdev mode='subsystem' type='pci' managed='yes'> > <source> > <address domain='0x0000' bus='0x00' > slot='0x1a' function='0x0'/> > </source> > </hostdev> > > Actually, every time I save this configuration, libvirt changes it to: > > <hostdev mode='subsystem' type='pci' managed='yes'> > <source> > <address domain='0x0000' bus='0x00' > slot='0x1a' function='0x0'/> > </source> > <address type='pci' domain='0x0000' bus='0x00' > slot='0x05' function='0x0'/> > </hostdev> > > Huh, slot 5? I don't have any PCI devices that use slot 5. Well, at > least the system doesn't complain, but I worry that this might be a > symptom of something more serious. > > Anyway, I'd be very grateful if anyone has any tips on how I might avoid > the aforementioned error and get PCI passthrough to to work. > > Thanks, > > Jaap > > _______________________________________________ > libvirt-users mailing list > libvirt-users@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/libvirt-users >
