So I just built a kernel from the ubuntu-intrepid git tree (as of commit e5cb6d2d) with just upstream commit ca373932 (the hypercall fix) patched in by hand, and tried that kernel in my intrepid VM running on hardy kvm 62/2.6.24. Unfortunately that kernel fails in the same way without no-kvmclock, so my guess about the issue was not correct.
So I just built a kernel from the ubuntu-intrepid git tree (as of commit e5cb6d2d) with just upstream commit ca373932 (the hypercall fix) patched in by hand, and tried that kernel in my intrepid VM running on hardy kvm 62/2.6.24. Unfortunately that kernel fails in the same way without no-kvmclock, so my guess about the issue was not correct.