[libvirt-users] Broken OS when booting rootfs from 9p share
Kashyap Chamarthy
kchamart at redhat.com
Thu Feb 26 15:05:48 UTC 2015
On Tue, Feb 24, 2015 at 11:56:50PM +0100, Olivier Mauras wrote:
>
>
> On Tue, 2015-02-24 at 16:05 -0500, Laine Stump wrote:
> > On 02/24/2015 03:37 PM, Olivier Mauras wrote:
> > >> Hello,
> > >>
> > >> I've been trying to boot a VM with the rootfs being a 9P share from
> > >> the host. The VM OS is centos 7.
> > >> The OS boots but no services can work and it appears that the
> > >> authentication system is broken.
> > >>
> > >> Now the funny thing is that booting the same OS on the same 9P share
> > >> manually with Qemu works as expected with a fully functionnal OS... So
> > >> I'm wondering what could libvirt do that render the OS on the share
> > >> broken - Something with rights ?
> > >> Selinux is disabled on the host, and accessmode to the share is set to
> > >> passthrough in both cases.
> > >>
> > >> Here's my working Qemu line:
> > >> qemu
> > >> -kernel /srv/overlay/kernels/grsec-3.14.33-101/vmlinuz-3.14.33-101.el6.x86_64 \
> > >>
> > >> -initrd /srv/overlay/kernels/grsec-3.14.33-101/initramfs-3.14.33-101.el6.x86_64.img \
> > >> -fsdev
> > >> local,id=r,path=/srv/overlay/run/irc,security_model=passthrough \
> > >> -device virtio-9p-pci,fsdev=r,mount_tag=root \
> > >> -nographic \
> > >> -m 256M \
> > >> -machine pc-i440fx-2.1,accel=kvm \
> > >> -netdev tap,id=net0 -device
> > >> virtio-net,netdev=net0,mac=52:54:00:12:36:34 \
> > >> -smp 1,sockets=1,cores=1 \
> > >> -append 'root=virtfs:root rootflags=trans=virtio,version=9p2000.u ro
> > >> rootfstype=9p console=ttyS0'
> > >>
> > >> And here my libvirt VM config:
> > >> <domain type='kvm'>
> > >> <name>irc</name>
> > >> <uuid>ffbd32eb-a693-eadd-8923-18de80137472</uuid>
> > >> <memory unit='KiB'>262144</memory>
> > >> <currentMemory unit='KiB'>262144</currentMemory>
> > >> <vcpu placement='static'>1</vcpu>
> > >> <os>
> > >> <type arch='x86_64' machine='pc-i440fx-2.1'>hvm</type>
> > >>
> > >> <kernel>/srv/overlay/kernels/grsec-3.14.33-101/vmlinuz-3.14.33-101.el6.x86_64</kernel>
> > >>
> > >> <initrd>/srv/overlay/kernels/grsec-3.14.33-101/initramfs-3.14.33-101.el6.x86_64.img</initrd>
> > >> <cmdline>root=virtfs:root rootflags=trans=virtio,version=9p2000.u
> > >> ro rootfstype=9p</cmdline>
> > >> <boot dev='hd'/>
> > >> </os>
> > >> <features>
> > >> <acpi/>
> > >> <apic/>
> > >> <pae/>
> > >> </features>
> > >> <clock offset='utc'/>
> > >> <on_poweroff>destroy</on_poweroff>
> > >> <on_reboot>restart</on_reboot>
> > >> <on_crash>restart</on_crash>
> > >> <devices>
> > >> <emulator>/usr/bin/qemu-system-x86_64</emulator>
> > >> <controller type='usb' index='0'>
> > >> <address type='pci' domain='0x0000' bus='0x00' slot='0x01'
> > >> function='0x2'/>
> > >> </controller>
> > >> <controller type='pci' index='0' model='pci-root'/>
> > >> <filesystem type='mount' accessmode='passthrough'>
> > >> <source dir='/srv/overlay/run/irc'/>
> > >> <target dir='root'/>
> > >> <address type='pci' domain='0x0000' bus='0x00' slot='0x05'
> > >> function='0x0'/>
> > >> </filesystem>
> > >> <interface type='bridge'>
> > >> <mac address='52:54:00:00:36:34'/>
> > >> <source bridge='br0'/>
> > >> <model type='virtio'/>
> > >> <address type='pci' domain='0x0000' bus='0x00' slot='0x03'
> > >> function='0x0'/>
> > >> </interface>
> > >> <serial type='pty'>
> > >> <target port='0'/>
> > >> </serial>
> > >> <console type='pty'>
> > >> <target type='serial' port='0'/>
> > >> </console>
> > >> <input type='mouse' bus='ps2'/>
> > >> <input type='keyboard' bus='ps2'/>
> > >> <graphics type='vnc' port='-1' autoport='yes'/>
> > >> <video>
> > >> <model type='cirrus' vram='9216' heads='1'/>
> > >> <address type='pci' domain='0x0000' bus='0x00' slot='0x02'
> > >> function='0x0'/>
> > >> </video>
> > >> <memballoon model='virtio'>
> > >> <address type='pci' domain='0x0000' bus='0x00' slot='0x04'
> > >> function='0x0'/>
> > >> </memballoon>
> > >> </devices>
> > >> </domain>
> > >>
> > >>
> > >> My libvirt version is 1.2.9, and qemu is 2.1.2.
> > >>
> > >> Thanks for your help,
> > >>
> > >> Olivier
> > >>
> > >>
> > >> _______________________________________________
> > >> libvirt-users mailing list
> > >> libvirt-users at redhat.com
> > >> https://www.redhat.com/mailman/listinfo/libvirt-users
> > > So I updated libvirt to 1.2.12 and qemu to 2.1.3 and it still gives me
> > > the exact same behaviour ...
> > > Could it be that the share was created with an old version of
> > > virt-manager redenring in old/broken XML? From Qemu config example i
> > > don't see how my XML could be incorrect.
> > >
> > > Any idea ?
> >
> > I know nothing about the 9p filesystem, but since you have a qemu
> > commandline that works and a libvirt config that doesn't, the next
> > logical step would be to provide the non-working qemu commandline
> > generated by libvirt. You can find this at the end of the log file
> > /var/log/libvirt/qemu/irc.log.
> Here it is... A bit more complex :)
>
> LC_ALL=C PATH=/sbin:/usr/sbin:/bin:/usr/bin
> QEMU_AUDIO_DRV=none /usr/bin/qemu-system-x86_64 -name irc -S -machine
> pc-i440fx-2.1,accel=kvm,usb=off -m 256 -realtime mlock=off -smp
> 1,sockets=1,cores=1,threads=1 -uuid ffbd32eb-a693-eadd-8923-18de80137472
> -no-user-config -nodefaults -chardev
> socket,id=charmonitor,path=/var/lib/libvirt/qemu/irc.monitor,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc -no-shutdown -no-acpi -boot strict=on -kernel /srv/overlay/kernels/grsec-3.14.33-101/vmlinuz-3.14.33-101.el6.x86_64 -initrd /srv/overlay/kernels/grsec-3.14.33-101/initramfs-3.14.33-101.el6.x86_64.img -append root=virtfs:root rootflags=trans=virtio,version=9p2000.u rw rootfstype=9p -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -fsdev local,security_model=passthrough,id=fsdev-fs0,path=/srv/overlay/run/irc -device virtio-9p-pci,id=fs0,fsdev=fsdev-fs0,mount_tag=root,bus=pci.0,addr=0x5 -netdev tap,fd=27,id=hostnet0,vhost=on,vhostfd=28 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:00:10:10,bus=pci.0,addr=0x3 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -vnc 127.0.0.1:3 -device cirrus-vga,id=video0,bus=pci.0,addr=0x2 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x4 -msg timestamp=on
>
Maybe you can try enabling Debug logs/filters in libvirt
http://wiki.libvirt.org/page/DebugLogs
and see if that helps you narrow down?
--
/kashyap
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