At 13:35 +0000 on 25 Jan (1295962540), James Harper wrote: > So the problem is somewhere past hvm_set_segment_register, and because > it's amd only, probably in or beyond svm_set_segment_register. The first > thing I notice in that routine is that there is a case for those 4 > registers... although all it seems to do is svm_sync_vmcb before and > svm_vmload after setting. I don't know what those two do though. Hmm; I suspect the bug here is actually in the save side -- the syncing of the vmcb in the save routine is not conditional on v == current, and the "already synced" bit that it would otherwise gate on isn't properly initialized. Try the attached patch; I'm sorry to say that I suspect it will fix the odd output of xen_hvmctx but probably won't fix the BSOD. :( Cheers, Tim. -- Tim Deegan Principal Software Engineer, Xen Platform Team Citrix Systems UK Ltd. (Company #02937203, SL9 0BG)