Comment 0 for bug 1536969

I'm using Ubuntu 16.04 amd64.

Host system executes command like:

    qemu-system-x86_64 -initrd ./hyper-initrd.img -kernel ./kernel -m 512 -smp 1 -fsdev local,id=virtio9p,path=`pwd`/rootfs,security_model=none -device virtio-9p-pci,fsdev=virtio9p,mount_tag=share_dir

Qemu Intern system executes API like:

    mkdir("/nfs", 0755);
    mount("share_dir", "/nfs", "9p", MS_MGC_VAL| MS_NODEV, "trans=virtio,cache=loose")

Then, external qemu-system_x86-64 crashes!

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: qemu-kvm 1:2.5+dfsg-1ubuntu3
ProcVersionSignature: Ubuntu 4.3.0-5.16-generic 4.3.3
Uname: Linux 4.3.0-5-generic x86_64
ApportVersion: 2.19.3-0ubuntu3
Architecture: amd64
CurrentDesktop: GNOME-Flashback
Date: Fri Jan 22 17:08:41 2016
JournalErrors:
 Error: command ['journalctl', '-b', '--priority=warning', '--lines=1000'] failed with exit code 1: Hint: You are currently not seeing messages from other users and the system.
       Users in the 'systemd-journal' group can see all messages. Pass -q to
       turn off this notice.
 No journal files were opened due to insufficient permissions.
KvmCmdLine:
 COMMAND STAT EUID RUID PID PPID %CPU COMMAND
 kvm-irqfd-clean S< 0 0 10793 2 0.0 [kvm-irqfd-clean]
Lspci: Error: [Errno 2] 没有那个文件或目录: 'lspci'
Lsusb: Error: [Errno 2] 没有那个文件或目录: 'lsusb'
MachineType: LENOVO ThinkCentre M8400t
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.3.0-5-generic root=UUID=da1b1143-7e41-4242-a0a5-5c5b748b3bfe ro quiet cgroup_enable=memory swapaccount=1
SourcePackage: qemu
UdevLog: Error: [Errno 2] 没有那个文件或目录: '/var/log/udev'
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 09/17/2013
dmi.bios.vendor: LENOVO
dmi.bios.version: 9SKT75AUS
dmi.board.name: MAHOBAY
dmi.board.vendor: LENOVO
dmi.board.version: NOK
dmi.chassis.type: 3
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.modalias: dmi:bvnLENOVO:bvr9SKT75AUS:bd09/17/2013:svnLENOVO:pnThinkCentreM8400t:pvrLenovoProduct:rvnLENOVO:rnMAHOBAY:rvrNOK:cvnLENOVO:ct3:cvrNone:
dmi.product.name: ThinkCentre M8400t
dmi.product.version: Lenovo Product
dmi.sys.vendor: LENOVO