kern/58335: Kernel panic when shutting down a virtual machine with Virtio devices

[roddy.gonzalez.89%gmail.com@localhost]

>Number:         58335
>Category:       kern
>Synopsis:       Kernel panic when shutting down a virtual machine with Virtio devices
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Jun 10 19:55:00 +0000 2024
>Originator:     Roddy
>Release:        10.0
>Organization:
>Environment:
NetBSD marte.local 10.0 NetBSD 10.0 (GENERIC) #0: Thu Mar 28 08:33:33 UTC 2024  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC amd64

>Description:
Sometimes, my virtual machines with virtio devices get kernel panics when shutting down.

This is an example of a power cycle when it happens:

```

boot
21288680+782888+1314264 [939258+1396248+1023001]=0x1b34a30
[   1.0000000] cpu_rng: rdrand/rdseed
[   1.0000000] entropy: ready
[   1.0000000] Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
[   1.0000000]     2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013,
[   1.0000000]     2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023,
[   1.0000000]     2024
[   1.0000000]     The NetBSD Foundation, Inc.  All rights reserved.
[   1.0000000] Copyright (c) 1982, 1986, 1989, 1991, 1993
[   1.0000000]     The Regents of the University of California.  All rights reserved.

[   1.0000000] NetBSD 10.0 (GENERIC) #0: Thu Mar 28 08:33:33 UTC 2024
[   1.0000000] 	mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC
[   1.0000000] total memory = 4095 MB
[   1.0000000] avail memory = 3935 MB
[   1.0000040] mainbus0 (root)
[   1.0000040] ACPI: RSDP 0x00000000000F5AD0 000014 (v00 BOCHS )
[   1.0000040] ACPI: RSDT 0x00000000BFFE1650 000030 (v01 BOCHS  BXPC     00000001 BXPC 00000001)
[   1.0000040] ACPI: FACP 0x00000000BFFE1524 000074 (v01 BOCHS  BXPC     00000001 BXPC 00000001)
[   1.0000040] ACPI: DSDT 0x00000000BFFDFDC0 001764 (v01 BOCHS  BXPC     00000001 BXPC 00000001)
[   1.0000040] ACPI: FACS 0x00000000BFFDFD80 000040
[   1.0000040] ACPI: APIC 0x00000000BFFE1598 000090 (v01 BOCHS  BXPC     00000001 BXPC 00000001)
[   1.0000040] ACPI: WAET 0x00000000BFFE1628 000028 (v01 BOCHS  BXPC     00000001 BXPC 00000001)
[   1.0000040] ACPI: 1 ACPI AML tables successfully acquired and loaded
[   1.0000040] ioapic0 at mainbus0 apid 0
[   1.0000040] cpu0 at mainbus0 apid 0
[   1.0000040] cpu0: Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz, id 0x906ea
[   1.0000040] cpu0: node 0, package 0, core 0, smt 0
[   1.0000040] cpu1 at mainbus0 apid 1
[   1.0000040] cpu1: Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz, id 0x906ea
[   1.0000040] cpu1: node 0, package 1, core 0, smt 0
[   1.0000040] cpu2 at mainbus0 apid 2
[   1.0000040] cpu2: Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz, id 0x906ea
[   1.0000040] cpu2: node 0, package 2, core 0, smt 0
[   1.0000040] cpu3 at mainbus0 apid 3
[   1.0000040] cpu3: Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz, id 0x906ea
[   1.0000040] cpu3: node 0, package 3, core 0, smt 0
[   1.0000040] acpi0 at mainbus0: Intel ACPICA 20221020
[   1.0000040] acpi0: fixed power button present
[   1.0513583] com0 at acpi0 (COM1, PNP0501-1): io 0x3f8-0x3ff irq 4
[   1.0513583] com0: ns16550a, 16-byte FIFO
[   1.0513583] com0: console
[   1.0513583] pckbc1 at acpi0 (KBD, PNP0303) (kbd port): io 0x60,0x64 irq 1
[   1.0513583] pckbc2 at acpi0 (MOU, PNP0F13) (aux port): irq 12
[   1.0513583] fdc0 at acpi0 (FDC0, PNP0700): io 0x3f2-0x3f5,0x3f7 irq 6 drq 2
[   1.0513583] qemufwcfg0 at acpi0 (FWCF, QEMU0002): io 0x510-0x51b
[   1.0513583] ACPI: Enabled 2 GPEs in block 00 to 0F
[   1.0513583] pckbd0 at pckbc1 (kbd slot)
[   1.0513583] pckbc1: using irq 1 for kbd slot
[   1.0513583] wskbd0 at pckbd0 mux 1
[   1.0513583] pms0 at pckbc1 (aux slot)
[   1.0513583] pckbc1: using irq 12 for aux slot
[   1.0513583] wsmouse0 at pms0 mux 0
[   1.0513583] pci0 at mainbus0 bus 0: configuration mode 1
[   1.0513583] pchb0 at pci0 dev 0 function 0: Intel 82441FX (PMC) PCI and Memory Controller (rev. 0x02)
[   1.0513583] pcib0 at pci0 dev 1 function 0: Intel 82371SB (PIIX3) PCI-ISA Bridge (rev. 0x00)
[   1.0513583] piixide0 at pci0 dev 1 function 1: Intel 82371SB IDE Interface (PIIX3) (rev. 0x00)
[   1.0513583] piixide0: primary channel interrupting at ioapic0 pin 14
[   1.0513583] atabus0 at piixide0 channel 0
[   1.0513583] piixide0: secondary channel interrupting at ioapic0 pin 15
[   1.0513583] atabus1 at piixide0 channel 1
[   1.0513583] piixpm0 at pci0 dev 1 function 3: Intel 82371AB (PIIX4) Power Management Controller (rev. 0x03)
[   1.0513583] piixpm0: 24-bit timer
[   1.0513583] piixpm0: interrupting at ioapic0 pin 9
[   1.0513583] iic0 at piixpm0 port 0: I2C bus
[   1.0513583] virtio0 at pci0 dev 2 function 0
[   1.0513583] virtio0: Unknown device (id 16, rev. 0x01)
[   1.0513583] virtio0: no matching child driver; not configured
[   1.0513583] wm0 at pci0 dev 3 function 0: Intel i82540EM 1000BASE-T Ethernet (rev. 0x03)
[   1.0513583] wm0: interrupting at ioapic0 pin 11
[   1.0513583] wm0: Ethernet address 52:54:00:0f:0c:bb
[   1.0513583] makphy0 at wm0 phy 1: Marvell 88E1011 Gigabit PHY, rev. 0
[   1.0513583] makphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT, 1000baseT-FDX, auto
[   1.0513583] hdaudio0 at pci0 dev 4 function 0: HD Audio Controller
[   1.0513583] hdaudio0: interrupting at msi0 vec 0
[   1.0513583] hdaudio0: HDA ver. 1.0, OSS 4, ISS 4, BSS 0, SDO 1, 64-bit
[   1.0513583] hdafg0 at hdaudio0: vendor 1af4 product 0022
[   1.0513583] hdafg0: DAC00 2ch: Speaker [Jack]
[   1.0513583] hdafg0: ADC01 2ch: Line In [Jack]
[   1.0513583] hdafg0: 2ch/2ch 16000Hz 22050Hz 32000Hz 44100Hz 48000Hz 88200Hz 96000Hz PCM16
[   1.0513583] audio0 at hdafg0: playback, capture, full duplex, independent
[   1.0513583] audio0: slinear_le:16 2ch 48000Hz, blk 1920 bytes (10ms) for playback
[   1.0513583] audio0: slinear_le:16 2ch 48000Hz, blk 1920 bytes (10ms) for recording
[   1.0513583] spkr0 at audio0: PC Speaker (synthesized)
[   1.0513583] wsbell at spkr0 not configured
[   1.0513583] uhci0 at pci0 dev 5 function 0: Intel 82801I USB UHCI Controller (rev. 0x03)
[   1.0513583] uhci0: interrupting at ioapic0 pin 10
[   1.0513583] usb0 at uhci0: USB revision 1.0
[   1.0513583] uhci1 at pci0 dev 5 function 1: Intel 82801I USB UHCI Controller (rev. 0x03)
[   1.0513583] uhci1: interrupting at ioapic0 pin 10
[   1.0513583] usb1 at uhci1: USB revision 1.0
[   1.0513583] uhci2 at pci0 dev 5 function 2: Intel 82801I USB UHCI Controller (rev. 0x03)
[   1.0513583] uhci2: interrupting at ioapic0 pin 11
[   1.0513583] usb2 at uhci2: USB revision 1.0
[   1.0513583] ehci0 at pci0 dev 5 function 7: Intel 82801I USB EHCI Controller (rev. 0x03)
[   1.0513583] ehci0: interrupting at ioapic0 pin 11
[   1.0513583] ehci0: 3 companion controllers, 2 ports each: uhci0 uhci1 uhci2
[   1.0513583] ehci0: Using DMA subregion for control data structures
[   1.0513583] usb3 at ehci0: USB revision 2.0
[   1.0513583] virtio1 at pci0 dev 6 function 0
[   1.0513583] virtio1: console device (id 3, rev. 0x00)
[   1.0513583] virtio1: no matching child driver; not configured
[   1.0513583] virtio2 at pci0 dev 7 function 0
[   1.0513583] virtio2: memory balloon device (id 5, rev. 0x00)
[   1.0513583] viomb0 at virtio2: features: 0x10000000<INDIRECT_DESC>
[   1.0513583] virtio2: interrupting at ioapic0 pin 11
[   1.0513583] virtio3 at pci0 dev 8 function 0
[   1.0513583] virtio3: Unknown device (id 19, rev. 0x01)
[   1.0513583] virtio3: no matching child driver; not configured
[   1.0513583] isa0 at pcib0
[   1.0513583] attimer0 at isa0 port 0x40-0x43
[   1.0513583] pcppi0 at isa0 port 0x61
[   1.0513583] spkr1 at pcppi0: PC Speaker
[   1.0513583] wsbell at spkr1 not configured
[   1.0513583] midi0 at pcppi0: PC speaker
[   1.0513583] sysbeep0 at pcppi0
[   1.0513583] attimer0: attached to pcppi0
[   1.0513583] acpicpu0 at cpu0: ACPI CPU
[   1.0513583] acpicpu1 at cpu1: ACPI CPU
[   1.0513583] acpicpu2 at cpu2: ACPI CPU
[   1.0513583] acpicpu3 at cpu3: ACPI CPU
[   1.9604157] atapibus0 at atabus0: 2 targets
[   1.9706785] uhub0 at usb0: NetBSD (0x0000) UHCI root hub (0x0000), class 9/0, rev 1.00/1.00, addr 1
[   1.9808482] uhub1 at usb3: NetBSD (0x0000) EHCI root hub (0x0000), class 9/0, rev 2.00/1.00, addr 1
[   1.9911392] uhub2 at usb1: NetBSD (0x0000) UHCI root hub (0x0000), class 9/0, rev 1.00/1.00, addr 1
[   2.0013475] uhub3 at usb2: NetBSD (0x0000) UHCI root hub (0x0000), class 9/0, rev 1.00/1.00, addr 1
[   2.0149936] cd0 at atapibus0 drive 1: <QEMU DVD-ROM, QM00002, 2.5+> cdrom removable
[   2.0217540] wd0 at atabus0 drive 0
[   2.0217540] wd0: <QEMU HARDDISK>
[   2.0217540] wd0: 24576 MB, 49932 cyl, 16 head, 63 sec, 512 bytes/sect x 50331648 sectors
[   2.0626726] dk0 at wd0: "14278129-a49e-44f0-ba70-53c132d50ce6", 41942912 blocks at 64, type: ffs
[   2.0728158] dk1 at wd0: "b41146b7-841a-4c6a-9614-a7f87f7b4afe", 8388608 blocks at 41942976, type: swap
[   3.1660681] uhidev0 at uhub1 port 1 configuration 1 interface 0
[   3.1779467] uhidev0: QEMU (0x0627) QEMU USB Tablet (0x0001), rev 2.00/0.00, addr 2, iclass 3/0
[   3.1881497] ums0 at uhidev0: 3 buttons and Z dir
[   3.1973598] wsmouse1 at ums0 mux 0
[   3.1973598] swwdog0: software watchdog initialized
[   3.2375185] WARNING: 3 errors while detecting hardware; check system log.
[   3.2539846] boot device: wd0
[   3.2539846] root on dk0 dumps on dk1
[   3.2681747] root file system type: ffs
[   3.2681747] kern.module.path=/stand/amd64/10.0/modules
Mon Jun 10 21:27:21 CEST 2024
Starting root file system check:
/dev/rdk0: file system is clean; not checking
Loading modules.
[   3.8709884] nvmm0: attached, using backend x86-vmx
Setting sysctl variables:
ddb.onpanic: 1 -> 0
swapctl: setting dump device to /dev/dk1
swapctl: adding /dev/dk1 as swap device at priority 0
Starting file system checks:
Loaded entropy from /var/db/entropy-file.
Waiting for entropy...done
Setting tty flags.
Starting network.
Hostname: marte.local
IPv6 mode: host
Configuring network interfaces: wm0.
Adding interface aliases:.
Waiting for duplicate address detection to finish...
Starting dhcpcd.
Building databases: dev, utmp, utmpx.
wsconscfg: Cannot open `/dev/ttyEcfg': Device not configured
wsconscfg: Cannot open `/dev/ttyEcfg': Device not configured
wsconscfg: Cannot open `/dev/ttyEcfg': Device not configured
wsconscfg: Cannot open `/dev/ttyEcfg': Device not configured
Starting syslogd.
Setting date via ntp.
Mounting all file systems...
Clearing temporary files.
Updating fontconfig cache: done.
Checking quotas: done.
swapctl: setting dump device to /dev/dk1
Starting virecover.
Checking for core dump...
savecore: no core dump
Starting local daemons:.
Updating motd.
Starting ntpd.
Starting powerd.
Starting sshd.
Starting dbus.
Starting slim.
Starting postfix.
postfix/postlog: starting the Postfix mail system
Starting libvirtd.
Starting inetd.
Starting cron.
Mon Jun 10 21:27:46 CEST 2024
Jun 10 21:27:46 marte getty[406]: /dev/ttyE1: Device not configured
Jun 10 21:27:46 marte getty[408]: /dev/ttyE3: Device not configured
Jun 10 21:27:46 marte getty[407]: /dev/ttyE2: Device not configured

NetBSD/amd64 (marte.local) (constty)

login: Jun 10 21:28:51 marte shutdown: poweroff by root: power button pressed 
Jun 10 21:28:59 marte syslogd[1019]: Exiting on signal 15
[ 105.8760835] syncing disks... done
[ 106.3358485] cd0: detached
[ 106.3358485] sysbeep0: detached
[ 106.3460615] midi0: detached
[ 106.3460615] uhub3: detached
[ 106.3460615] uhub2: detached
[ 106.3562927] uhub0: detached
[ 106.3562927] atapibus0: detached
[ 106.3562927] usb2: detached
[ 106.3664630] usb1: detached
[ 106.3664630] usb0: detached
[ 106.3664630] iic0: detached
[ 106.3778639] atabus1: detached
[ 106.3778639] virtio3: detached
[ 106.3878898] virtio1: detached
[ 106.3971479] uhci2: detached
[ 106.3971479] uhci1: detached
[ 106.4089229] uhci0: detached
[ 106.4089229] makphy0: detached
[ 106.4278426] wm0: detached
[ 106.4278426] extent `iomem' (0x0 - 0xffffffffffff), flags = 0x3
[ 106.4278426]      0x0 - 0x9fbff
[ 106.4278426]      0x100000 - 0xbffdefff
[ 106.4380481]      0xfe800000 - 0xfe803fff
[ 106.4380481]      0xfebb0000 - 0xfebb3fff
[ 106.4380481]      0xfebb5000 - 0xfebb5fff
[ 106.4482081]      0x100000000 - 0x13fffffff
[ 106.4482081] extent_free: start 0xfe801000, end 0xfe804fff
[ 106.4482081] Skipping crash dump on recursive panic
[ 106.4584259] panic: extent_free: region not found
[ 106.4584259] cpu1: Begin traceback...
[ 106.4687266] vpanic() at netbsd:vpanic+0x183
[ 106.4789207] panic() at netbsd:panic+0x3c
[ 106.4891186] extent_free() at netbsd:extent_free+0x117
[ 106.4891186] bus_space_release() at netbsd:bus_space_release+0x4a
[ 106.4993216] bus_space_unmap() at netbsd:bus_space_unmap+0x57
[ 106.5094972] virtio_pci_detach() at netbsd:virtio_pci_detach+0x67
[ 106.5197460] config_detach() at netbsd:config_detach+0xfc
[ 106.5299093] config_detach_all() at netbsd:config_detach_all+0xc8
[ 106.5401480] cpu_reboot() at netbsd:cpu_reboot+0x1c0
[ 106.5503510] kern_reboot() at netbsd:kern_reboot+0x6c
[ 106.5606009] sys_reboot() at netbsd:sys_reboot+0x63
[ 106.5707902] syscall() at netbsd:syscall+0x1fc
[ 106.5707902] --- syscall (number 208) ---
[ 106.5810476] netbsd:syscall+0x1fc:
[ 106.5810476] cpu1: End traceback...
[ 106.6831523] rebooting...
[ 106.6831523] fatal breakpoint trap in supervisor mode
[ 106.6831523] trap type 1 code 0 rip 0xffffffff80235385 cs 0x8 rflags 0x2 cr2 0x7f45e19d0924 ilevel 0x8 rsp 0xffffb4813869dbc0
[ 106.6831523] curlwp 0xfffffea00e25b640 pid 411.411 lowest kstack 0xffffb481386992c0
Stopped in pid 411.411 (halt) at        netbsd:breakpoint+0x5:  leave
breakpoint() at netbsd:breakpoint+0x5
cpu_reset() at netbsd:cpu_reset+0x68
cpu_reboot() at netbsd:cpu_reboot+0xc3
kern_reboot() at netbsd:kern_reboot+0x6c
vpanic() at netbsd:vpanic+0x18d
panic() at netbsd:panic+0x3c
extent_free() at netbsd:extent_free+0x117
bus_space_release() at netbsd:bus_space_release+0x4a
bus_space_unmap() at netbsd:bus_space_unmap+0x57
virtio_pci_detach() at netbsd:virtio_pci_detach+0x67
config_detach() at netbsd:config_detach+0xfc
config_detach_all() at netbsd:config_detach_all+0xc8
cpu_reboot() at netbsd:cpu_reboot+0x1c0
kern_reboot() at netbsd:kern_reboot+0x6c
sys_reboot() at netbsd:sys_reboot+0x63
syscall() at netbsd:syscall+0x1fc
--- syscall (number 208) ---
netbsd:syscall+0x1fc:
ds          dba0
es          0
fs          0
gs          4758
--db_more--

```

>How-To-Repeat:
This is the libvirt domain I use to run it.
Although other virtual machines with different video/storage suffer the same. I haven't be able to isolate the problematic virtio device.

Also, I assume the problem lies in a virtio device, because of the panic trace, but I'm not really sure.

```
<domain type="kvm">
  <name>marte</name>
  <uuid>58c50088-de9d-4002-897c-54f38f259cba</uuid>
  <metadata>
    <libosinfo:libosinfo xmlns:libosinfo="http://libosinfo.org/xmlns/libvirt/domain/1.0";>
      <libosinfo:os id="http://netbsd.org/netbsd/9.0"/>
    </libosinfo:libosinfo>
  </metadata>
  <memory unit="KiB">4194304</memory>
  <currentMemory unit="KiB">4194304</currentMemory>
  <vcpu placement="static">4</vcpu>
  <os>
    <type arch="x86_64" machine="pc-i440fx-jammy">hvm</type>
  </os>
  <features>
    <acpi/>
    <apic/>
    <vmport state="off"/>
  </features>
  <cpu mode="host-passthrough" check="none" migratable="on"/>
  <clock offset="utc">
    <timer name="rtc" tickpolicy="catchup"/>
    <timer name="pit" tickpolicy="delay"/>
    <timer name="hpet" present="no"/>
  </clock>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>destroy</on_crash>
  <pm>
    <suspend-to-mem enabled="no"/>
    <suspend-to-disk enabled="no"/>
  </pm>
  <devices>
    <emulator>/usr/bin/qemu-system-x86_64</emulator>
    <disk type="file" device="disk">
      <driver name="qemu" type="qcow2" discard="unmap"/>
      <source file="/var/lib/libvirt/images/marte.qcow2"/>
      <target dev="hda" bus="ide"/>
      <boot order="2"/>
      <address type="drive" controller="0" bus="0" target="0" unit="0"/>
    </disk>
    <disk type="file" device="cdrom">
      <driver name="qemu" type="raw"/>
      <target dev="hdb" bus="ide"/>
      <readonly/>
      <boot order="1"/>
      <address type="drive" controller="0" bus="0" target="0" unit="1"/>
    </disk>
    <controller type="usb" index="0" model="ich9-ehci1">
      <address type="pci" domain="0x0000" bus="0x00" slot="0x05" function="0x7"/>
    </controller>
    <controller type="usb" index="0" model="ich9-uhci1">
      <master startport="0"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x05" function="0x0" multifunction="on"/>
    </controller>
    <controller type="usb" index="0" model="ich9-uhci2">
      <master startport="2"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x05" function="0x1"/>
    </controller>
    <controller type="usb" index="0" model="ich9-uhci3">
      <master startport="4"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x05" function="0x2"/>
    </controller>
    <controller type="pci" index="0" model="pci-root"/>
    <controller type="ide" index="0">
      <address type="pci" domain="0x0000" bus="0x00" slot="0x01" function="0x1"/>
    </controller>
    <controller type="virtio-serial" index="0">
      <address type="pci" domain="0x0000" bus="0x00" slot="0x06" function="0x0"/>
    </controller>
    <interface type="network">
      <mac address="52:54:00:0f:0c:bb"/>
      <source network="default"/>
      <model type="e1000"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x03" function="0x0"/>
    </interface>
    <serial type="pty">
      <target type="isa-serial" port="0">
        <model name="isa-serial"/>
      </target>
    </serial>
    <console type="pty">
      <target type="serial" port="0"/>
    </console>
    <channel type="spicevmc">
      <target type="virtio" name="com.redhat.spice.0"/>
      <address type="virtio-serial" controller="0" bus="0" port="1"/>
    </channel>
    <channel type="unix">
      <target type="virtio" name="org.qemu.guest_agent.0"/>
      <address type="virtio-serial" controller="0" bus="0" port="2"/>
    </channel>
    <input type="tablet" bus="usb">
      <address type="usb" bus="0" port="1"/>
    </input>
    <input type="mouse" bus="ps2"/>
    <input type="keyboard" bus="ps2"/>
    <graphics type="spice">
      <listen type="none"/>
      <gl enable="yes"/>
    </graphics>
    <sound model="ich6">
      <address type="pci" domain="0x0000" bus="0x00" slot="0x04" function="0x0"/>
    </sound>
    <audio id="1" type="spice"/>
    <video>
      <model type="virtio" heads="1" primary="yes">
        <acceleration accel3d="yes"/>
      </model>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x0"/>
    </video>
    <redirdev bus="usb" type="spicevmc">
      <address type="usb" bus="0" port="2"/>
    </redirdev>
    <redirdev bus="usb" type="spicevmc">
      <address type="usb" bus="0" port="3"/>
    </redirdev>
    <memballoon model="virtio">
      <address type="pci" domain="0x0000" bus="0x00" slot="0x07" function="0x0"/>
    </memballoon>
    <vsock model="virtio">
      <cid auto="yes" address="3"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x08" function="0x0"/>
    </vsock>
  </devices>
</domain>
```
>Fix: