Re: [Qemu-devel] [PATCH v4 00/14] tcg: Add support for fence generation

[Paolo Bonzini <pbonzini@redhat.com>]

> Ping for review!

Hi,

we're on hard freeze so it's normal that maintainers focus on bugfixes
at this time.

Paolo

> On Thu, Jul 14, 2016 at 4:20 PM, Pranith Kumar <bobby.prani@gmail.com> wrote:
> > Hello,
> >
> > The following series adds fence instruction generation support to
> > TCG. Based on feedback to the last series, I added the four
> > combinations of orderings modeled after Sparc membar.
> >
> > This has been tested and confirmed to fix ordering issues on
> > x86/armv7/aarch64 hosts with MTTCG enabled for an ARMv7 guest using
> > KVM unit tests. It has also been tested with litmus tests provided by
> > Alex Bennée.
> >
> > TODO:
> >
> > * The acquire/release order is not utilized yet. Currently we generate
> >   SC barriers even for acquire/release barriers. The idea is to write
> >   a pass which combines acquire/release barrier with its corresponding
> >   load/store operation to generate the load acquire/store release
> >   instruction on hosts which have such instruction(aarch64 for
> >   now).
> >
> > v4:
> >
> > - Update with comments from v3
> > - Use 'lock orl' instead of mfence on x86. Remove sse2 checks.
> > - Rebase on qemu/master instead of MTTCG
> > - Rename acquire barrier to load-acquire and release to store-release
> >   to avoid confusion with prevailing terminology
> >
> > v3:
> >
> > - Create different types of barriers. The barrier tcg opcode now takes
> >   an argument to generate the appropriate barrier instruction.
> > - Also add acquire/release/sc ordering flag to argument.
> >
> > v2:
> >
> > - Rebase on Richard's patches generating fences for other
> >   architectures.
> >
> > v1:
> >
> > - Initial version: Introduce memory barrier tcg opcode.
> >
> > Pranith Kumar (14):
> >   Introduce TCGOpcode for memory barrier
> >   tcg/i386: Add support for fence
> >   tcg/aarch64: Add support for fence
> >   tcg/arm: Add support for fence
> >   tcg/ia64: Add support for fence
> >   tcg/mips: Add support for fence
> >   tcg/ppc: Add support for fence
> >   tcg/s390: Add support for fence
> >   tcg/sparc: Add support for fence
> >   tcg/tci: Add support for fence
> >   target-arm: Generate fences in ARMv7 frontend
> >   target-alpha: Generate fence op
> >   target-aarch64: Generate fences for aarch64
> >   target-i386: Generate fences for x86
> >
> >  target-alpha/translate.c     |  4 ++--
> >  target-arm/translate-a64.c   | 14 +++++++++++++-
> >  target-arm/translate.c       |  4 ++--
> >  target-i386/translate.c      |  8 ++++++++
> >  tcg/README                   | 17 +++++++++++++++++
> >  tcg/aarch64/tcg-target.inc.c | 26 ++++++++++++++++++++++++++
> >  tcg/arm/tcg-target.inc.c     | 18 ++++++++++++++++++
> >  tcg/i386/tcg-target.inc.c    | 18 ++++++++++++++++++
> >  tcg/ia64/tcg-target.inc.c    |  5 +++++
> >  tcg/mips/tcg-target.inc.c    |  6 ++++++
> >  tcg/ppc/tcg-target.inc.c     | 22 ++++++++++++++++++++++
> >  tcg/s390/tcg-target.inc.c    | 11 +++++++++++
> >  tcg/sparc/tcg-target.inc.c   | 25 +++++++++++++++++++++++++
> >  tcg/tcg-op.c                 | 17 +++++++++++++++++
> >  tcg/tcg-op.h                 |  2 ++
> >  tcg/tcg-opc.h                |  2 ++
> >  tcg/tcg.h                    | 19 +++++++++++++++++++
> >  tcg/tci/tcg-target.inc.c     |  3 +++
> >  tci.c                        |  4 ++++
> >  19 files changed, 220 insertions(+), 5 deletions(-)
> >
> > --
> > 2.9.0
> >
> 
> 
> 
> --
> Pranith
>