Remove the CPL and IOPL check in the I/O handling code in x86_emulate().
  - For Realmode I/O emulation, this check is not needed because any I/O
    operation should be permitted in this mode.
    For I/O emulation in vmx_vmexit_handler() code path, this check is also
    not needed because processor has already checked the I/O permission before
    vmx_vmexit_handler() is called.

Signed-off-by: Xu Dongxiao <dongxiao.xu@intel.com>

diff -r 59b8768d0d0d xen/arch/x86/x86_emulate.c
--- a/xen/arch/x86/x86_emulate.c	Wed Mar 05 11:18:25 2008 +0000
+++ b/xen/arch/x86/x86_emulate.c	Tue Mar 18 09:42:20 2008 +0800
@@ -2255,7 +2255,6 @@ x86_emulate(
 
     case 0x6c ... 0x6d: /* ins %dx,%es:%edi */ {
         unsigned long nr_reps = get_rep_prefix();
-        generate_exception_if(!mode_iopl(), EXC_GP, 0);
         dst.bytes = !(b & 1) ? 1 : (op_bytes == 8) ? 4 : op_bytes;
         dst.mem.seg = x86_seg_es;
         dst.mem.off = truncate_ea(_regs.edi);
@@ -2285,7 +2284,6 @@ x86_emulate(
 
     case 0x6e ... 0x6f: /* outs %esi,%dx */ {
         unsigned long nr_reps = get_rep_prefix();
-        generate_exception_if(!mode_iopl(), EXC_GP, 0);
         dst.bytes = !(b & 1) ? 1 : (op_bytes == 8) ? 4 : op_bytes;
         if ( (nr_reps > 1) && (ops->rep_outs != NULL) &&
              ((rc = ops->rep_outs(ea.mem.seg, truncate_ea(_regs.esi),
@@ -2818,7 +2816,6 @@ x86_emulate(
         unsigned int port = ((b < 0xe8)
                              ? insn_fetch_type(uint8_t)
                              : (uint16_t)_regs.edx);
-        generate_exception_if(!mode_iopl(), EXC_GP, 0);
         op_bytes = !(b & 1) ? 1 : (op_bytes == 8) ? 4 : op_bytes;
         if ( b & 2 )
         {