Re: [PATCH 00/22] Direct decode in emulator

[Marcelo Tosatti <mtosatti@redhat.com>]

On Thu, Jul 29, 2010 at 03:11:33PM +0300, Avi Kivity wrote:
> Currently the emulator decoder is indirect in two ways: groups are looked up
> in a separate table based on group number; and opcode execution is looked up
> in a big switch (actually two) after the opcode flags lookup.
> 
> This patchset converts groups to direct decode and begins the work for opcode
> decode.
> 
> The motivations are:
> - reduce errors from discrepancies between the two tables (like we had for
>   IRET)
> - make the code easier to read, removing many switch () statements
> - eventually remove the #UD mini-decoder in x86.c by adding subgroup support
>   to the emulator
> 
> Avi Kivity (22):
>   KVM: x86 emulator: drop parentheses in repreat macros
>   KVM: x86 emulator: introduce 'struct opcode'
>   KVM: x86 emulator: Add wrappers for easily defining opcodes
>   KVM: x86 emulator: move group tables to top
>   KVM: x86 emulator: reserve group code 0
>   KVM: x86 emulator: allow specifying group directly in opcode
>   KVM: x86 emulator: convert group 1 to new style
>   KVM: x86 emulator: convert group 1A to new style
>   KVM: x86 emulator: convert group 3 to new style
>   KVM: x86 emulator: convert group 4 to new style
>   KVM: x86 emulator: convert group 5 to new style
>   KVM: x86 emulator: convert group 7 to new style
>   KVM: x86 emulator: convert group 8 to new style
>   KVM: x86 emulator: convert group 9 to new style
>   KVM: x86 emulator: drop support for old-style groups
>   KVM: x86 emulator: move ByteOp and Dst back to bits 0:3
>   KVM: x86 emulator: store x86_emulate_ops in emulation context
>   KVM: x86 emulator: allow storing emulator execution function in
>     decode tables
>   KVM: x86 emulator: move x86_decode_insn() downwards
>   KVM: x86 emulator: move decode tables downwards
>   KVM: x86 emulator: allow repeat macro arguments to contain commas
>   KVM: x86 emulator: convert some push instructions to direct decode
> 
>  arch/x86/include/asm/kvm_emulate.h |   10 +-
>  arch/x86/kvm/emulate.c             | 1253 +++++++++++++++++++-----------------
>  arch/x86/kvm/x86.c                 |    7 +-
>  3 files changed, 661 insertions(+), 609 deletions(-)

Applied, thanks.