> > > while I was modifying xen_early_setup, I tried to replace dcr > > > kludge using > > > cpl. Unfortunatly, it doesn't work since cpl is read as 0 > > > (see vcpu.c). > > > So my question is simple: why ? > > > > I think some places in Linux/ia64 determine whether code > > is running in kernel or user mode by checking psr.cpl. > Correct. > One place is user_mode() is ptrace.h. > Currently it is true if cpl != 0. I have made a simple test: > I have changed > the code to cpl == 3, and cpl reads as 2. Linux is booting > (dom0+domU).
IIRC, there was at least one place in assembly code which checked psr.cpl==0 (maybe mca code?) but this was a longtime ago (possibly 2.4.x) so the code may be gone. There is Itanium architecture work going on to establish a mechanism for determining whether an OS is running native or as a (paravirtualized or fully-virtualized) guest. I don't know the status of this but am pretty sure it was checking a currently reserved bit, possibly in cr.dcr. Dan _______________________________________________ Xen-ia64-devel mailing list Xen-ia64-devel@lists.xensource.com http://lists.xensource.com/xen-ia64-devel
