linux-kernel - Re: [PATCH 1/2] KVM: SEV: IBPB-on-Entry guest support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20260129105116.GBaXs7pBF-k4x_5_W1@fat_crate.local>
Date: Thu, 29 Jan 2026 11:51:16 +0100
From: Borislav Petkov <bp@...en8.de>
To: Kim Phillips <kim.phillips@....com>
Cc: linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
	linux-coco@...ts.linux.dev, x86@...nel.org,
	Sean Christopherson <seanjc@...gle.com>,
	Paolo Bonzini <pbonzini@...hat.com>,
	K Prateek Nayak <kprateek.nayak@....com>,
	Nikunj A Dadhania <nikunj@....com>,
	Tom Lendacky <thomas.lendacky@....com>,
	Michael Roth <michael.roth@....com>,
	Naveen Rao <naveen.rao@....com>,
	David Kaplan <david.kaplan@....com>, stable@...nel.org
Subject: Re: [PATCH 1/2] KVM: SEV: IBPB-on-Entry guest support

On Wed, Jan 28, 2026 at 06:38:29PM -0600, Kim Phillips wrote:
> For that last paragraph, how about:
> 
> "Allow guests to make use of IBPB-on-Entry when supported by the
> hypervisor, as the bit is now architecturally defined and safe to
> expose."

Better.

> SNP_FEATURES_PRESENT is for the non-trivial variety: Its bits get set as
> part of the patchseries that add the explicit guest support *code*.

Yes, and I'm asking why can't SNP_FEATURES_PRESENT contain *all* SNP features?

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette