[PATCH 00/10] x86/xsaves: Fix XSAVES known issues

[PATCH 00/10] x86/xsaves: Fix XSAVES known issues

[Yu-cheng Yu]

XSAVES is a kernel-mode instruction. It offers a compacted format and
memory-write optimization. These patches fix known issues in the first
implementation. They are intended for discussion and getting feedback
before actually getting applied.  

Patch 1, 2, and 4 are for converting between kernel-mode xstate area and
signal frames.

Patch 8 is for converting between kernel-mode xstate area and ptrace
frames.

Patch 3 and 7 fix optimization issues introduced by XSAVES to the buffer
init_fpstate.

Patch 5 and 6 are related to xstate component offsets.

Patch 9 fixes xstate area print out.

Patch 10 re-enables XSAVES.

Yu-cheng Yu (10):
  x86/xsaves: Define and use user_xstate_size for xstate size in signal
    context
  x86/xsaves: Rename xstate_size to kernel_xstate_size to explicitly
    distinguish xstate size in kernel from user space
  x86/xsaves: Keep init_fpstate.xsave.header.xfeatures as zero for init
    optimization
  x86/xsaves: Introduce a new check that allows correct xstates copy
    from kernel to user directly
  x86/xsaves: Align xstate components according to CPUID
  x86/xsaves: Supervisor state component offset
  x86/xsaves: Fix init_fpstate.header.xcomp_bv
  x86/xsaves: Fix PTRACE frames for XSAVES
  x86/xsaves: Fix XSTATE component offset print out
  x86/xsaves: Re-enable XSAVES

 arch/x86/include/asm/fpu/types.h  |   2 +
 arch/x86/include/asm/fpu/xstate.h |   8 +-
 arch/x86/include/asm/processor.h  |   3 +-
 arch/x86/kernel/fpu/core.c        |   6 +-
 arch/x86/kernel/fpu/init.c        |  32 +---
 arch/x86/kernel/fpu/regset.c      |  56 ++++--
 arch/x86/kernel/fpu/signal.c      |  69 ++++++-
 arch/x86/kernel/fpu/xstate.c      | 388 +++++++++++++++++++++++++++++---------
 8 files changed, 425 insertions(+), 139 deletions(-)

-- 
1.9.1

Re: [PATCH 00/10] x86/xsaves: Fix XSAVES known issues

[Ingo Molnar]

* Yu-cheng Yu <yu-cheng.yu@intel.com> wrote:

> XSAVES is a kernel-mode instruction. It offers a compacted format and
> memory-write optimization. These patches fix known issues in the first
> implementation. They are intended for discussion and getting feedback
> before actually getting applied.  
> 
> Patch 1, 2, and 4 are for converting between kernel-mode xstate area and
> signal frames.
> 
> Patch 8 is for converting between kernel-mode xstate area and ptrace
> frames.
> 
> Patch 3 and 7 fix optimization issues introduced by XSAVES to the buffer
> init_fpstate.
> 
> Patch 5 and 6 are related to xstate component offsets.
> 
> Patch 9 fixes xstate area print out.
> 
> Patch 10 re-enables XSAVES.
> 
> Yu-cheng Yu (10):
>   x86/xsaves: Define and use user_xstate_size for xstate size in signal
>     context
>   x86/xsaves: Rename xstate_size to kernel_xstate_size to explicitly
>     distinguish xstate size in kernel from user space
>   x86/xsaves: Keep init_fpstate.xsave.header.xfeatures as zero for init
>     optimization
>   x86/xsaves: Introduce a new check that allows correct xstates copy
>     from kernel to user directly
>   x86/xsaves: Align xstate components according to CPUID
>   x86/xsaves: Supervisor state component offset
>   x86/xsaves: Fix init_fpstate.header.xcomp_bv
>   x86/xsaves: Fix PTRACE frames for XSAVES
>   x86/xsaves: Fix XSTATE component offset print out
>   x86/xsaves: Re-enable XSAVES
> 
>  arch/x86/include/asm/fpu/types.h  |   2 +
>  arch/x86/include/asm/fpu/xstate.h |   8 +-
>  arch/x86/include/asm/processor.h  |   3 +-
>  arch/x86/kernel/fpu/core.c        |   6 +-
>  arch/x86/kernel/fpu/init.c        |  32 +---
>  arch/x86/kernel/fpu/regset.c      |  56 ++++--
>  arch/x86/kernel/fpu/signal.c      |  69 ++++++-
>  arch/x86/kernel/fpu/xstate.c      | 388 +++++++++++++++++++++++++++++---------
>  8 files changed, 425 insertions(+), 139 deletions(-)

Small housekeeping request: could you please make sure your series is properly 
threaded for email clients? This submission was sent as singular patches, without 
any References header.

I don't even know how you coaxed git-send-email into doing that - did you use 
--no-thread?

The recommended flags are --thread --no-chain-reply-to.

Thanks!

	Ingo

Re: [PATCH 00/10] x86/xsaves: Fix XSAVES known issues

[Yu-cheng Yu]

On Wed, Feb 24, 2016 at 09:43:36AM +0100, Ingo Molnar wrote:
> 
> Small housekeeping request: could you please make sure your series is properly 
> threaded for email clients? This submission was sent as singular patches, without 
> any References header.
> 
> I don't even know how you coaxed git-send-email into doing that - did you use 
> --no-thread?
> 
> The recommended flags are --thread --no-chain-reply-to.
> 
> Thanks!
> 
> 	Ingo

I will fix it when sending out the next version.
Thanks!

-- Yu-cheng