[PATCH RFC V2 0/6] Basic guest memory introspection support

[Razvan Cojocaru <rcojocaru@bitdefender.com>]

Hello,

First of all, thank you all for your reviews! Based on what we've
discussed, a new series follows.

Changes since V1:
 - Removed, for the time being, the Linux-borrowed code for
   computing instruction length.
 - Removed the code that attempted to get around emulator limitations
   by setting the 'accessed' and 'dirty' bits and re-executing
   problematic instructions.
 - Skipped the "[PATCH RFC 9/9] mm: mark pages that have their
   permissions controlled by a domain" patch, hopefully this has
   been fixed in Xen 4.5.
 - Took out the trivial C++ patch (previously "[PATCH RFC 4/9]
   xenctrl: Make the headers C++ friendly"), also posted
   separately and hopefully scheduled for inclusion soon.
 - Removed code redundancy.
 - Addressed discussed issues (in the code itself, and patch
   descriptions - please see individual patches for details).

Patches:

xen: Handle resumed instruction based on previous mem_event reply
xen, libxc: Request page fault injection via libxc
xen: Support for VMCALL mem_events
xen: Force-enable relevant MSR events; optimize the number of sent MSR
events
xen: Optimize introspection access to guest state
xen: Emulate with no writes


Thanks,
Razvan Cojocaru