KVM IOMMU startup error

kobuki

Renowned Member
Dec 30, 2008
473
27
93
I have a problem starting one of my VMs on a server wit a redirected PCIe card. It was working fine previously. I have tried all workarounds I posted here without success. This seems to be related to this bugreport. Is it possible that the related patch hasn't been incorporated in the PVE repo? I've installed pve-qemu-kvm: 2.1-10 from pvetest, but pve-qemu-kvm: 2.1-9 does the same.

The error I have:
Code:
# qm start 100
**
ERROR:qom/object.c:725:object_unref: assertion failed: (obj->ref > 0)
start failed: command '/usr/bin/kvm -id 100 -chardev 'socket,id=qmp,path=/var/run/qemu-server/100.qmp,server,nowait' -mon 'chardev=qmp,mode=control' -vnc unix:/var/run/qemu-server/100.vnc,x509,password -pidfile /var/run/qemu-server/100.pid -daemonize -name host.name.local -smp 'sockets=1,cores=2' -nodefaults -boot 'menu=on' -vga cirrus -cpu kvm64,+lahf_lm,+x2apic,+sep -k en-us -m 4096 -device 'piix3-usb-uhci,id=uhci,bus=pci.0,addr=0x1.0x2' -device 'usb-tablet,id=tablet,bus=uhci.0,port=1' -device 'pci-assign,host=01:00.0,id=hostpci0,bus=pci.0,addr=0x10' -device 'virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3' -iscsi 'initiator-name=iqn.1993-08.org.debian:01:4754c09e9345' -drive 'if=none,id=drive-ide2,media=cdrom,aio=native' -device 'ide-cd,bus=ide.1,unit=0,drive=drive-ide2,id=ide2,bootindex=200' -drive 'file=/var/lib/vz/images/100/vm-100-disk-1.qcow2,if=none,id=drive-virtio0,format=qcow2,aio=native,cache=none' -device 'virtio-blk-pci,drive=drive-virtio0,id=virtio0,bus=pci.0,addr=0xa,bootindex=100' -netdev 'type=tap,id=net0,ifname=tap100i0,script=/var/lib/qemu-server/pve-bridge,downscript=/var/lib/qemu-server/pve-bridgedown,vhost=on' -device 'virtio-net-pci,mac=9B:29:69:58:43:3E,netdev=net0,bus=pci.0,addr=0x12,id=net0,bootindex=300'' failed: exit code 1

Version, config:
Code:
# pveversion -v
proxmox-ve-2.6.32: 3.3-138 (running kernel: 2.6.32-33-pve)
pve-manager: 3.3-2 (running version: 3.3-2/995e687e)
pve-kernel-2.6.32-32-pve: 2.6.32-136
pve-kernel-2.6.32-33-pve: 2.6.32-138
pve-kernel-2.6.32-28-pve: 2.6.32-124
pve-kernel-2.6.32-30-pve: 2.6.32-130
lvm2: 2.02.98-pve4
clvm: 2.02.98-pve4
corosync-pve: 1.4.7-1
openais-pve: 1.1.4-3
libqb0: 0.11.1-2
redhat-cluster-pve: 3.2.0-2
resource-agents-pve: 3.9.2-4
fence-agents-pve: 4.0.10-1
pve-cluster: 3.0-15
qemu-server: 3.1-35
pve-firmware: 1.1-3
libpve-common-perl: 3.0-19
libpve-access-control: 3.0-15
libpve-storage-perl: 3.0-23
pve-libspice-server1: 0.12.4-3
vncterm: 1.1-8
vzctl: 4.0-1pve6
vzprocps: 2.0.11-2
vzquota: 3.1-2
pve-qemu-kvm: 2.1-10
ksm-control-daemon: 1.1-1
glusterfs-client: 3.5.2-1

# grep 33.*mmu /boot/grub/grub.cfg
        linux   /boot/vmlinuz-2.6.32-33-pve root=/dev/mapper/pve-root ro  quiet intel_iommu=igfx_off

Could you please help? I can't start this particular VM since it depends on the PCI passthrough feature working. The vm is a file server and I can't access the files on it.
 
I forgot to provide the VM config, here it is:

Code:
bootdisk: virtio0
cores: 2
hostpci0: 01:00.0
ide2: none,media=cdrom
memory: 4096
name: host.name.local
net0: virtio=8A:79:69:48:33:2E,bridge=vmbr0
onboot: 1
ostype: l26
sockets: 1
virtio0: local:100/vm-100-disk-1.qcow2,format=qcow2,size=8G
 
In hopes that it might be useful for someone else with an Intel DQ67SW motherboard: as the solution I ended up disabling the IGP in the BIOS. Interestingly enough, I still have text console on either a physically attached monitor or the remote KVM (Intel AMT). So now everything is working as before, except for the graphics but it's a headless server anyway so I don't care.

The problem stems from corrupted DMAR tables in the BIOS as I have gathered from the various sources on the net about Intel IOMMU. Disabling the IGP enables me using the newest kvm binary available in the PVE repo, too (2.1.2).
 

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