Test Day:2010-04-08 Virtualization XenDomU

What to test?
This part of today's Fedora Test Day will focus on testing the area concerned with Xen DomU functionality, which is based on the pv_ops work in upstream Linux.

If you come to this page after the test day is completed, your testing is still valuable, and you can use the information on this page to test Fedora as a Xen DomU and provide feedback.

Who's available
Andrew Jones (Drew) is your host for today.

The following people have also agreed to be available for testing, workarounds, bug fixes, and general discussion:


 * Justin Forbes

What's needed to test

 * A distribution with Xen Dom0 support. This can either be Red Hat Enterprise Linux 5, CentOS 5, Suse, Fedora, etc. We also highly recommend that your distribution is fully updated to the latest released packages. See instructions on the main test day page.
 * At least one guest image installed before the test day (suggested reading - Virtualization_Quick_Start).

Known issues and workarounds
Console may not work ('xm console ') until 'console=hvc0' has been added to the kernel command line in grub.conf.

Note, the following list of issues were compiled while testing on RHEL 5.4. Other host platforms and/or Xen packages may have varying results. Please test :-)


 * RHEL specific: pygrub does not support ext4, however rawhide defaults to ext4. Therefore this must be manually changed to ext3 (at least for /boot) during the installation, or an appropriate kickstart can be used.
 * RHEL specific on machines with GB pages: add 'nogbpages' to the guest kernel command-line for guests with >2GB memory, see bz502826
 * RHEL specific on machines with xsave: add 'noxsave' to the guest kernel command-line for hvm guests, see bz524052

If the above workarounds are done, or RHEL 5.5 is used, then these known issues will still be present.


 * Installing from the F13 compose will fail for 64b PV guests since it uses the 2.6.33 kernel (see bz571241). Workaround this by updating an F12 guest to F13, and then updating the kernel to 2.6.33.2. After updating the kernel for F13 PV guests, ensure also that plymouth is rev. 0.8.1-3.fc13 and that the initrd contains this rev as well (see bz578633). Or convert an FV guest for a faster way to get a working PV guest.*
 * Installing from the F13 compose for 32b PV guests works, but then the initial boot will fail due to the plymouth issue.
 * Installing a FV guest from the F13 boot.iso or attempting to boot the F13 Virt-Test LiveCD will fail (see bz570496). Workaround this by rewriting the iso with 'nohalt 1' added to the top of the isolinux.cfg file.
 * Installing a FV guest will appear to have hung since the graphics in anaconda's virtual terminal 'F6' do not work. Watch the progress on virtual terminal 'F1' to see that the installation is progressing.

''* A fast way to create a working PV guest is to "convert" an FV guest that has an updated kernel and plymouth. To convert, just 1) recreate the initrd with xenblk included (e.g. mkinitrd --with=xenblk  2.6.33.2-38.fc13), 2) change console=ttyS0,115200n8 to console=hvc0, 3) create a Xen PV config file to use. Copy the image file so you can run both the PV and the FV guests at the same time.''

Test cases
Execute the list of test cases for each of the following configurations:

32-bit Dom0
 * 32-bit PV DomU
 * 32-bit HVM DomU

64-bit Dom0
 * 32-bit PV DomU
 * 32-bit HVM DomU
 * 64-bit PV DomU
 * 64-bit HVM DomU

Test cases:


 * 1) Guest install
 * 2) Memory ballooning
 * 3) Save/restore
 * 4) Live migration
 * 5) Guest pause/unpause
 * 6) CPU hotplug
 * 7) Network devices
 * 8) Network Performance
 * 9) Block attach/detach
 * 10) File IO Performance
 * 11) Paravirt framebuffer
 * 12) Guest crash dump
 * 13) Execshield
 * 14) GDB
 * 15) Statically linked binaries
 * 16) Kernel command line parameters
 * 17) Host machine lacking NX support
 * 18) Attempt to use the modify_ldt syscall

See Reporting Virtualization bugs for a guide to reporting bugs.