From Fedora Project Wiki
This test case verifies that various Xen DomU specific kernel command line parameters work correctly in Fedora guests.
How to test
- Inside the rawhide domU, edit /boot/grub/grub.conf. Add a new, non-default entry for testing, something like:
title Fedora testing (2.6.31-2.fc12.i686) root (hd0,0) kernel /vmlinuz-2.6.31-2.fc12.i686 ro root=/dev/HostGroup/LogVol00 mem=700M initrd /initrd-2.6.31-2.fc12.i686.img
- Shut down the guest. Start the guest again, and choose "Fedora testing" boot entry. The guest should boot with 700M of memory, instead of the default.
- (32-bit guests only) Inside the guest, edit /boot/grub/grub.conf again, and edit the "testing" to have "highmem=200M" as well. Shut down the guest, start it again, and choose the "Fedora testing" boot entry again.
- When booting with the mem= parameter, the guest should boot with 700M of memory, and return the difference between the mem= parameter and the configured memory to the hypervisor.
- (32-bit guests only) When booting with the highmem= parameter, the guest should not use more than 200M of high memory.