linux-kernel - Re: [PATCH v7 03/26] x86/fpu/xstate: Add CET supervisor mode state 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: <20231124094502.GL3818@noisy.programming.kicks-ass.net>
Date:   Fri, 24 Nov 2023 10:45:02 +0100
From:   Peter Zijlstra <peterz@...radead.org>
To:     Yang Weijiang <weijiang.yang@...el.com>
Cc:     seanjc@...gle.com, pbonzini@...hat.com, dave.hansen@...el.com,
        kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        chao.gao@...el.com, rick.p.edgecombe@...el.com,
        mlevitsk@...hat.com, john.allen@....com
Subject: Re: [PATCH v7 03/26] x86/fpu/xstate: Add CET supervisor mode state
 support

On Fri, Nov 24, 2023 at 12:53:07AM -0500, Yang Weijiang wrote:

> Note, in KVM case, guest CET supervisor state i.e., IA32_PL{0,1,2}_MSRs,
> are preserved after VM-Exit until host/guest fpstates are swapped, but
> since host supervisor shadow stack is disabled, the preserved MSRs won't
> hurt host.

Just to be clear, with FRED all this changes, right? Then we get more
VMCS fields for SSS state.