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Re: [PATCH v2] x86/xen/64: Rearrange the SYSCALL entries

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On 08/08/17 05:59, Andy Lutomirski wrote:
> Xen's raw SYSCALL entries are much less weird than native.  Rather
> than fudging them to look like native entries, use the Xen-provided
> stack frame directly.
> 
> This lets us eliminate entry_SYSCALL_64_after_swapgs and two uses of
> the SWAPGS_UNSAFE_STACK paravirt hook.  The SYSENTER code would
> benefit from similar treatment.
> 
> This makes one change to the native code path: the compat
> instruction that clears the high 32 bits of %rax is moved slightly
> later.  I'd be surprised if this affects performance at all.
> 
> Signed-off-by: Andy Lutomirski <luto@kernel.org>

Reviewed-by: Juergen Gross <jgross@suse.com>
Tested-by: Juergen Gross <jgross@suse.com>


Thanks,

Juergen

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[PATCH v2] x86/xen/64: Rearrange the SYSCALL entries Andy Lutomirski <luto@kernel.org> - 2017-08-08 06:00 +0200
  Re: [PATCH v2] x86/xen/64: Rearrange the SYSCALL entries Juergen Gross <jgross@suse.com> - 2017-08-09 17:40 +0200
  [tip:x86/asm] x86/xen/64: Rearrange the SYSCALL entries tip-bot for Andy Lutomirski <tipbot@zytor.com> - 2017-08-10 14:30 +0200

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