Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

The TEST instruction doesn't write its destination operand.  This
could cause problems if an MMIO register was accessed using the TEST
instruction.  Recently Windows XP was observed to use TEST against
the APIC ICR; this can cause spurious IPIs.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

emulate_1op_rax_rdx() is always called with the same parameters.  Simplify
by passing just the emulation context.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

We have two emulate-with-extended-accumulator implementations: once
which expect traps (_ex) and one which doesn't (plain).  Drop the
plain implementation and always use the one which expects traps;
it will simply return 0 in the _ex argument and we can happily ignore
it.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

emulate_1op() is always called with the same parameters.  Simplify
by passing just the emulation context.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

emulate_2op_cl() is always called with the same parameters.  Simplify
by passing just the emulation context.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

emulate_2op_cl() is always called with the same parameters.  Simplify
by passing just the emulation context.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

emulate_2op_SrcV(), and its siblings, emulate_2op_SrcV_nobyte()
and emulate_2op_SrcB(), all use the same calling conventions
and all get passed exactly the same parameters.  Simplify them
by passing just the emulation context.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Return EMULATION_OK/FAILED consistently.  Also treat instruction fetch
errors, not restricted to X86EMUL_UNHANDLEABLE, as EMULATION_FAILED;
although this cannot happen in practice, the current logic will continue
the emulation even if the decoder fails to fetch the instruction.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Fetching the instruction which was to be executed by the guest cannot
fail normally.  So compiler should always predict that it will succeed.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NAvi Kivity <avi@redhat.com>

_type is enough to know the size.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Instead of passing ctxt->_eip from insn_fetch() call sites, get it from
ctxt in do_insn_fetch_byte().  This is done by replacing the argument
_eip of insn_fetch() with _ctxt, which should be better than letting the
macro use ctxt silently in its body.

Though this changes the place where ctxt->_eip is incremented from
insn_fetch() to do_insn_fetch_byte(), this does not have any real
effect.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Src2CL decode (used for double width shifts) erronously decodes only bit 3
of %rcx, instead of bits 7:0.

Fix by decoding %cl in its entirety.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

This saves a lot of pointless casts x86_emulate_ctxt and decode_cache.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

The name eip conflicts with a field of the same name in x86_emulate_ctxt,
which we plan to fold decode_cache into.

The name _eip is unfortunate, but what's really needed is a refactoring
here, not a better name.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

  LOOP/LOOPcc      : E0-E2
  JCXZ/JECXZ/JRCXZ : E3
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Call emulate_int() directly to avoid spaghetti goto's.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Different functions for those which take segment register operands.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

In addition, replace one "goto xchg" with an em_xchg() call.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Move the following functions to the opcode tables:

  RET (Far return) : CB
  IRET             : CF
  JMP (Jump far)   : EA

  SYSCALL          : 0F 05
  CLTS             : 0F 06
  SYSENTER         : 0F 34
  SYSEXIT          : 0F 35
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

The next patch will change these to be called by opcode::execute.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

We should use the local variables ctxt and c when the emulate_ctxt and
decode appears many times.  At least, we need to be consistent about
how we use these in a function.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Fix:

 warning: ‘cs_sel’ may be used uninitialized in this function
 warning: ‘ss_sel’ may be used uninitialized in this function
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Dereference it in the actual users.

This not only cleans up the emulator but also makes it easy to convert
the old emulation functions to the new em_xxx() form later.

Note: Remove some inline keywords to let the compiler decide inlining.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Dereference it in the actual users: only do_insn_fetch_byte().

This is consistent with the way __linearize() dereferences it.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

The two macros need special care to use:
  Assume rc, ctxt, ops and done exist outside of them.
  Can goto outside.

Considering the fact that these are used only in decode functions,
moving these right after do_insn_fetch() seems to be a right thing
to improve the readability.

We also rename do_fetch_insn_byte() to do_insn_fetch_byte() to be
consistent.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

%rip-relative addressing is relative to the first byte of the next instruction,
so we need to add %rip only after we've fetched any immediate bytes.

Based on original patch by Li Xin <xin.li@intel.com>.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Acked-by: NLi Xin <xin.li@intel.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Commit f6511935 moved the permission check for io instructions
to the ->check_perm callback. It failed to copy the port value from RDX
register for string and "in,out ax,dx" instructions.

Fix it by reading RDX register at decode stage when appropriate.

Fixes FC8.32 installation.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

We introduce em_jmp_far().

We also call this from em_grp45() to stop treating modrm_reg == 5 case
separately in the group 5 emulation.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The prototypes are changed appropriately.

We also replaces "goto grp45;" with simple em_grp45() call.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The opt of emulate_grp1a() is also removed.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Remove inline at this chance.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NAvi Kivity <avi@redhat.com>

In addition, one comma at the end of a statement is replaced with a
semicolon.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Instead of separate accessors for the segment selector and cached descriptor,
use one accessor for both.  This simplifies the code somewhat.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Move all groups into a single field and handle them in a single place.  This
saves bits when we add more group types (3 bits -> 7 groups types).
Signed-off-by: NAvi Kivity <avi@redhat.com>