specific device not available in client (passthrough) with high cpu load on host, none in client

Thanks for reporting this bug. Would it be possible for you to test this with the upstream qemu?

Did this used to work consistently with older versions of qemu (say in precise)?

Is there any pattern - for instance a full shutdown followed by power-on of the host results in the sound card being usable in the guest, while a reboot results in the sound card not being usable in the guest?

Hi Serge,

I cannot see any pattern on boot or reboot of the host. One cold boot (the first after not using the pci device for a long time) of the host resulted into the device working properly on the client, but then shutting down the client again reverted to problem described. I should have tried a restart of the client first to keep the same kvm process.

After that I've performed several poweroff's, including disconnecting from the mains for over a minute, but never seen the device working properly.

An upstream install of qemu is okay if you have the proper apt commands (and sources.list alterations if needed) available.

Gerben

The way to check upstream qemu's git HEAD is:

    sudo apt-get build-dep qemu-kvm
    sudo apt-get install git
    git clone git://git.qemu.org/qemu.git
    cd qemu
    ./configure --target-list=x86_64-softmmu
    make

then run it as

    cd x86_64-softmmu
    ./qemu-system-x86_64 --enable-kvm (existing-arguments)

or if you are using libvirt, you should be able to

    cd x86_64-softmmu
    sudo mv /usr/bin/kvm /usr/bin/kvm.orig
    sudo ln -s $(pwd)/qemu-system-x86_64 /usr/bin/kvm

then test, then

    sudo rm /usr/bin/kvm
    sudo mv /usr/bin/kvm.orig /usr/bin/kvm

I'm getting a failure message when starting using virsh start (/usr/bin/kvm is altered to point to upstream as described)
# virsh start Win7one
error: Failed to start domain Win7one
error: internal error Child process (LC_ALL=C PATH=/usr/local/sbin:/usr/local/bin:/usr/bin:/usr/sbin:/sbin:/bin /usr/bin/kvm -help) status unexpected: exit status 1

I had problems on the network tap device when startting via
./qemu-system-x86_64 --enable-kvm -name Win7one -S -M pc-0.12 -enable-kvm -m 2048 -smp 2...

# ./testqemuup
char device redirected to /dev/pts/3
qemu-system-x86_64: -netdev tap,fd=36,id=hostnet0,vhost=on,vhostfd=37: TUNGETIFF ioctl() failed: Bad file descriptor
TUNSETOFFLOAD ioctl() failed: Bad file descriptor
qemu-system-x86_64: -netdev tap,fd=36,id=hostnet0,vhost=on,vhostfd=37: vhost-net requested but could not be initialized
qemu-system-x86_64: -netdev tap,fd=36,id=hostnet0,vhost=on,vhostfd=37: Device 'tap' could not be initialized

Did remove the tap device definition and it's usage as a pci device. After that I got a core dump message, but probably coresize is set to zero.
See the attached file for details of qemu-system-x86_64

ldd on the file looks okay.

Probably apparmor is blocking the executable.

in /var/log/apport.log I can see the line:
ERROR: apport (pid 4224) Fri Oct 26 22:29:35 2012: executable does not belong to a package, ignoring

When copying qemu-system-x86_64 into /usr/bin
and executing within that directory ( ./qemu-system-x86_64 --enable-kvm -nam...)
still a coredump message is shown,
apport.log ends in wrote report /var/crash/_usr_bin_qemu-system-x86_64.0.crash

I hadn't noticed this before:

[ 761.143056] ------------[ cut here ]------------
[ 761.143064] WARNING: at /build/buildd/linux-3.5.0/kernel/irq/manage.c:436 __enable_irq+0x3b/0xd0()
[ 761.143066] Hardware name: To be filled by O.E.M.
[ 761.143067] Unbalanced enable for IRQ 41
[ 761.143068] Modules linked in: pci_stub vhost_net macvtap macvlan ip6table_filter ip6_tables ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack ipt_REJECT xt_CHECKSUM iptable_mangle xt_tcpudp iptable_filter ip_tables x_tables bridge stp llc snd_hda_codec_hdmi eeepc_wmi asus_wmi sparse_keymap mxm_wmi kvm_amd kvm ghash_clmulni_intel aesni_intel cryptd aes_x86_64 sp5100_tco microcode snd_hda_codec_realtek edac_core psmouse edac_mce_amd fam15h_power serio_raw k10temp i2c_piix4 snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_timer snd radeon soundcore joydev snd_page_alloc ttm drm_kms_helper drm i2c_algo_bit mac_hid wmi lp parport hid_generic usbhid hid firewire_ohci firewire_core crc_itu_t r8169
[ 761.143103] Pid: 4015, comm: kvm Not tainted 3.5.0-17-generic #28-Ubuntu
[ 761.143104] Call Trace:
[ 761.143109] [<ffffffff81051c4f>] warn_slowpath_common+0x7f/0xc0
[ 761.143112] [<ffffffff81051d46>] warn_slowpath_fmt+0x46/0x50
[ 761.143115] [<ffffffff8103fa39>] ? default_spin_lock_flags+0x9/0x10
[ 761.143117] [<ffffffff810e050b>] __enable_irq+0x3b/0xd0
[ 761.143119] [<ffffffff810e05e2>] enable_irq+0x42/0x80
[ 761.143133] [<ffffffffa0324d3b>] kvm_vm_ioctl_assigned_device+0xa1b/0xb70 [kvm]
[ 761.143135] [<ffffffff81065f37>] ? __set_task_blocked+0x37/0x80
[ 761.143144] [<ffffffffa033298b>] ? x86_emulate_instruction+0x13b/0x570 [kvm]
[ 761.143147] [<ffffffff81068512>] ? __set_current_blocked+0x52/0x70
[ 761.143154] [<ffffffffa031ff6c>] kvm_vm_ioctl+0x4ec/0x520 [kvm]
[ 761.143160] [<ffffffffa031e568>] ? kvm_vcpu_ioctl+0x118/0x610 [kvm]
[ 761.143164] [<ffffffff8135b90a>] ? pci_read_config+0x24a/0x270
[ 761.143167] [<ffffffff811f436c>] ? read+0x7c/0x1f0
[ 761.143169] [<ffffffff81193909>] do_vfs_ioctl+0x99/0x590
[ 761.143172] [<ffffffff81193e99>] sys_ioctl+0x99/0xa0
[ 761.143175] [<ffffffff81689d29>] system_call_fastpath+0x16/0x1b
[ 761.143176] ---[ end trace 6bd5dd1c5df4018d ]---
[ 802.129162] br0: port 14(vnet12) entered disabled state

Will mark this as affecting the kernel.

Thanks, Gerben. If it were possible for you to run it by hand that would be easier. But to do it through libvirt without a package becomes more complicated. To undo your changes (in particular copying the qemu-system-x86_64 into /usr/bin), please do

sudo apt-get install --reinstall qemu-kvm

Gerben, as per http://www.asus.com/Motherboards/SABERTOOTH_990FX/#support_Download_8 an update is available for your BIOS (1604). If you update to this, does it change anything?

If not, could you please both specify what happened, and provide the output of the following terminal command:
sudo dmidecode -s bios-version && sudo dmidecode -s bios-release-date

Thank you for your understanding.