linux-kernel - Re: [PATCH v3 1/6] x86/sme: Use percpu boolean to control wbinvd during kexec

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Message-ID: <b368fb3399d1e64e98fb9ad6a7a214387c097825.camel@intel.com>
Date: Thu, 26 Jun 2025 18:42:01 +0000
From: "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>
To: "Hansen, Dave" <dave.hansen@...el.com>, "Huang, Kai"
	<kai.huang@...el.com>, "bp@...en8.de" <bp@...en8.de>, "peterz@...radead.org"
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	<x86@...nel.org>, "sagis@...gle.com" <sagis@...gle.com>, "Chatre, Reinette"
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Subject: Re: [PATCH v3 1/6] x86/sme: Use percpu boolean to control wbinvd
 during kexec

On Thu, 2025-06-26 at 10:59 -0700, Rick Edgecombe wrote:
> Since the race is related to stop_this_cpu() it doesn't affect it. But it does
> mean that the bring up CPU may not flush the cache if takes a kdump kexec before
> the per-cpu var is set? Of course the existing logic doesn't trigger until
> cpuinfo_x86 is populated. What is the consequence?

Oh, doh! This stuff all happens before kdump could load. Right?