linux-kernel - Re: [RFC v2 08/32] x86/traps: Add #VE support for TDX guest

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: <4635488d-b98b-330f-1485-fecfcf6e72ff@intel.com>
Date:   Tue, 8 Jun 2021 11:15:26 -0700
From:   Dave Hansen <dave.hansen@...el.com>
To:     Andi Kleen <ak@...ux.intel.com>,
        Sean Christopherson <seanjc@...gle.com>
Cc:     Kuppuswamy Sathyanarayanan 
        <sathyanarayanan.kuppuswamy@...ux.intel.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Andy Lutomirski <luto@...nel.org>,
        Dan Williams <dan.j.williams@...el.com>,
        Tony Luck <tony.luck@...el.com>,
        Kirill Shutemov <kirill.shutemov@...ux.intel.com>,
        Kuppuswamy Sathyanarayanan <knsathya@...nel.org>,
        Raj Ashok <ashok.raj@...el.com>, linux-kernel@...r.kernel.org
Subject: Re: [RFC v2 08/32] x86/traps: Add #VE support for TDX guest

On 6/8/21 11:12 AM, Andi Kleen wrote:
> I believe neither does mmio/msr normally (except maybe
> ftrace+tp_printk, but that will likely work because it shouldn't
> recurse more than once due to ftrace's reentry protection)

Can it do MMIO:

> +DEFINE_IDTENTRY(exc_virtualization_exception)
> +{
=======> HERE
> +    ret = tdg_get_ve_info(&ve); 

Recursion isn't the problem.  It would double-fault there, right?