linux-kernel - Re: [PATCH v5 3/7] x86/fpu/xstate: Differentiate default features for host and guest FPUs

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 for Android: free password hash cracker in your pocket

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

Message-ID: <66b3ac69-447c-433f-a907-da20241d55ed@zytor.com>
Date: Sun, 27 Apr 2025 22:51:31 -0700
From: Xin Li <xin@...or.com>
To: "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>,
        "Gao, Chao" <chao.gao@...el.com>
Cc: "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
        "ebiggers@...gle.com" <ebiggers@...gle.com>,
        "Hansen, Dave" <dave.hansen@...el.com>,
        "dave.hansen@...ux.intel.com" <dave.hansen@...ux.intel.com>,
        "Spassov, Stanislav" <stanspas@...zon.de>,
        "levymitchell0@...il.com" <levymitchell0@...il.com>,
        "samuel.holland@...ive.com" <samuel.holland@...ive.com>,
        "Li, Xin3" <xin3.li@...el.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "Yang, Weijiang" <weijiang.yang@...el.com>,
        "mingo@...hat.com" <mingo@...hat.com>,
        "pbonzini@...hat.com" <pbonzini@...hat.com>,
        "tglx@...utronix.de" <tglx@...utronix.de>,
        "john.allen@....com" <john.allen@....com>,
        "mlevitsk@...hat.com" <mlevitsk@...hat.com>,
        "seanjc@...gle.com" <seanjc@...gle.com>,
        "Bae, Chang Seok" <chang.seok.bae@...el.com>,
        "vigbalas@....com" <vigbalas@....com>,
        "peterz@...radead.org" <peterz@...radead.org>,
        "hpa@...or.com"
 <hpa@...or.com>, "bp@...en8.de" <bp@...en8.de>,
        "aruna.ramakrishna@...cle.com" <aruna.ramakrishna@...cle.com>,
        "x86@...nel.org" <x86@...nel.org>
Subject: Re: [PATCH v5 3/7] x86/fpu/xstate: Differentiate default features for
 host and guest FPUs

On 4/25/2025 9:09 AM, Edgecombe, Rick P wrote:
>>    And that will create a bit of a
>>   :snafu if Linux does gain support for SSS.
>>
>> *:https://lore.kernel.org/kvm/ZM1jV3UPL0AMpVDI@google.com/
> I chatted with Xin about this a few weeks ago. It sounds like FRED bare metal
> SSS will not need CET_S state, but it wasn't 100% clear.

FRED reuses one CET_S MSR IA32_PL0_SSP, and give it an alias
IA32_FRED_SSP0.

Thanks!
     Xin