[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Xen-devel] xen pv and cpuid



Silly x86 question of the day:
 
Is it true in a PV domain that there is no way (short of binary translation) to trap a userland cpuid instruction into Xen?
 
I found the routine pv_cpuid() in arch/x86/traps.c and assumed that userland cpuid's would find their way into that code, but it appears to not be the case.  After adding some printks and reading the code more closely, I gather that PV OS's somehow get their cpuid instructions replaced with an invalid op so that kernel-land cpuid's do indeed get trapped? Then looking at the Intel SDM I don't see any way to force cpuid at any privilege level to trap (except in an HVM)?
 
(If this is all correct, then I am sadly back to needing userland hypercalls :-(
 
Thanks,
Dan
 
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.