CVS commit: src/sys/arch

["Cherry G. Mathew" <cherry%netbsd.org@localhost>]

Module Name:    src
Committed By:   cherry
Date:           Wed Feb 13 05:36:59 UTC 2019

Modified Files:
        src/sys/arch/amd64/amd64: locore.S
        src/sys/arch/i386/i386: locore.S

Log Message:
Rig the hypercall callback page such that when the kernel happens to
run without a XEN domain loader having previously overwritten the
hypercall page with its hypercall trampoline machine code, we still
get to detect its presence by calling the xen_version hypercall stub.

We use this hack to detect the presence or absence of the hypervisor,
without relying on the MSR support on HVM domains.

This works as an added sanity check that the hypercall page
registration has indeed succeeded in HVM mode.


To generate a diff of this commit:
cvs rdiff -u -r1.176 -r1.177 src/sys/arch/amd64/amd64/locore.S
cvs rdiff -u -r1.163 -r1.164 src/sys/arch/i386/i386/locore.S

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.