linux-kernel - Re: [PATCH v1 1/1] x86/tdx: Handle MWAIT, MONITOR and WBINVD

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]

Date:   Sat, 27 Mar 2021 09:03:36 -0700
From:   Andy Lutomirski <luto@...capital.net>
To:     "Kuppuswamy, Sathyanarayanan" 
        <sathyanarayanan.kuppuswamy@...ux.intel.com>
Cc:     Peter Zijlstra <peterz@...radead.org>,
        Andy Lutomirski <luto@...nel.org>,
        Dave Hansen <dave.hansen@...el.com>,
        Andi Kleen <ak@...ux.intel.com>,
        Kirill Shutemov <kirill.shutemov@...ux.intel.com>,
        Kuppuswamy Sathyanarayanan <knsathya@...nel.org>,
        Dan Williams <dan.j.williams@...el.com>,
        Raj Ashok <ashok.raj@...el.com>,
        Sean Christopherson <seanjc@...gle.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1 1/1] x86/tdx: Handle MWAIT, MONITOR and WBINVD




> On Mar 26, 2021, at 8:40 PM, Kuppuswamy, Sathyanarayanan <sathyanarayanan.kuppuswamy@...ux.intel.com> wrote:
> 
> 
> 
> On 3/26/21 7:40 PM, Andy Lutomirski wrote:
>>>> On Mar 26, 2021, at 5:18 PM, Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@...ux.intel.com> wrote:
>>> 
>>> In non-root TDX guest mode, MWAIT, MONITOR and WBINVD instructions
>>> are not supported. So handle #VE due to these instructions as no ops.
>> These should at least be WARN.
> I will change it to WARN.
>> Does TDX send #UD if these instructions have the wrong CPL?  
> No, TDX does not trigger #UD for these instructions.
> If the #VE came from user mode, we should send an appropriate signal instead.
> It will be mapped into #GP(0) fault. This should be enough notification right?

Yes. And I did mean #GP, not #UD.