linux-kernel - Re: [PATCH v13 06/14] x86/mm: use broadcast TLB flushing for page reclaim TLB flushing

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Message-ID: <94cf87f65ec74dda2f03fb57a2d958f49e697cf2.camel@surriel.com>
Date: Wed, 26 Feb 2025 17:01:21 -0500
From: Rik van Riel <riel@...riel.com>
To: Tom Lendacky <thomas.lendacky@....com>, Borislav Petkov <bp@...en8.de>
Cc: x86@...nel.org, linux-kernel@...r.kernel.org, peterz@...radead.org, 
	dave.hansen@...ux.intel.com, zhengqi.arch@...edance.com,
 nadav.amit@...il.com, 	kernel-team@...a.com, linux-mm@...ck.org,
 akpm@...ux-foundation.org, 	jackmanb@...gle.com, jannh@...gle.com,
 mhklinux@...look.com, 	andrew.cooper3@...rix.com, Manali.Shukla@....com,
 mingo@...nel.org
Subject: Re: [PATCH v13 06/14] x86/mm: use broadcast TLB flushing for page
 reclaim TLB flushing

On Wed, 2025-02-26 at 12:12 -0600, Tom Lendacky wrote:
> On 2/26/25 11:46, Rik van Riel wrote:
> > 
> > I don't know whether setting the ASID valid bit in
> > rAX will cause a system to crash when SVM is not
> > enabled or initialized.
> 
> As long as you keep the ASID value in EDX[15:0] as 0, then you won't
> #GP. ASID 0 is the host/hypervisor. An ASID > 0 belongs to a guest.

Thank you, that is good to know.

I think I'll wait for feedback on v14 of the series
to figure out whether to post that as part of a new
series, or as a follow-up enhancement.

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