[PATCH v2 0/4] XEN: fix vmx exception mistake

[Xudong Hao <xudong.hao@intel.com>]

Changes from v1:
- Define new struct hvm_trap to represent information of trap, include
  instruction length. 
- Renames hvm_inject_exception to hvm_inject_trap. Then define a couple of
  wrappers around that function for existing callers, so that their parameter
  lists actually *shrink*.


This series of patches fix the mistake for debug exception(#DB), overflow
exception(#OF) and INT3(#BP), INTn instruction emulation. 

PATCH 3 and PATCH 4 supply an interface for userspace to inject trap.


PATCH 1: Define new struct hvm_trap and cleanup vmx exception.

PATCH 2: Fix the mistake for debug exception(#DB), overflow exception(#OF) and
INT3(#BP), INTn instruction emulation. Add inslen field in struct hvm_trap.

PATCH 3: Add parameter inslen for hypercall HVMOP_inject_trap, supply interface
used by passing instruction length from userspace.

PATCH 4: Add a parameter to represent instruction length in function
  xc_hvm_inject_trap(), user should set this value when this
  function is called.