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Date: Thu, 22 May 2008 14:32:06 -0700
From: Chris Wright <chrisw@sous-sol.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>,
       Mikael Pettersson <mikpe@it.uu.se>, Andi Kleen <andi@firstfloor.org>,
       mingo@elte.hu, tglx@linutronix.de, torvalds@linux-foundation.org,
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       Hongjiu.lu@intel.com, linux-kernel@vger.kernel.org,
       arjan@linux.intel.com, rmk+lkml@arm.linux.org.uk, dan@debian.org,
       asit.k.mallick@intel.com
Subject: Re: [RFC] x86: xsave/xrstor support, ucontext_t extensions
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References: <20080520015723.GD30034@linux-os.sc.intel.com> <4832A173.6020203@firstfloor.org> <18482.53246.642835.894623@harpo.it.uu.se> <4832E705.2010900@zytor.com> <18482.60491.764019.292031@harpo.it.uu.se> <20080520175325.GE30034@linux-os.sc.intel.com> <4834BE39.2000904@zytor.com> <18485.13663.51624.694435@harpo.it.uu.se> <20080522205619.GB7998@linux-os.sc.intel.com> <4835DF64.6080104@zytor.com>
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* H. Peter Anvin (hpa@zytor.com) wrote:
> Suresh Siddha wrote:
>>
>> hpa, What is the virtualization problem? Are you referring to perf problem?
>> As you noted, regular non-rt signal handlers won't need this cpuid check. It's
>> needed only for those who manually look at non-rt signal frames and interpret it.
>> And also, they can do this check only once and not everytime.
>>
>
> No, relying on CPUID and vdso both have implications for virtualization.

hmm, what implications?  cpuid is dealt with already.