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From: "Van De Ven, Arjan" <arjan.van.de.ven@intel.com>
To: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
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Subject: RE: RSB Alternative bit in IA32_ARCH_CAPABILITIES Was:Re: [PATCH
 2/2] x86/speculation: Support "Enhanced IBRS" on future CPUs
Thread-Topic: RSB Alternative bit in IA32_ARCH_CAPABILITIES Was:Re: [PATCH
 2/2] x86/speculation: Support "Enhanced IBRS" on future CPUs
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Date: Fri, 23 Feb 2018 18:18:52 +0000
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> To add a bit more to this, Intel just updated their
> IA32_ARCH_CAPABILITIES_MSR
> to have a new bit to sample to figure out whether you need IBRS or not
> during runtime.

actually we updated the document when you need RSB stuffing.
based on the request of various folks here on LKML.