linux-kernel - Re: [Xen-devel] [PATCH v2 2/3] x86 Test and expose CPUID faulting capabilities in /proc/cpuinfo

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: <CAP045ArvswdVk7ypAJ_cPuB2Ab0fKMxxjGVmEQpTzt5bJz6mhg@mail.gmail.com>
Date:   Thu, 15 Sep 2016 12:11:53 -0700
From:   Kyle Huey <me@...ehuey.com>
To:     Jan Beulich <JBeulich@...e.com>
Cc:     David Vrabel <david.vrabel@...rix.com>,
        Aravind Gopalakrishnan <aravind.gopalakrishnan@....com>,
        Huang Rui <ray.huang@....com>,
        Peter Zijlstra <peterz@...radead.org>,
        Len Brown <len.brown@...el.com>,
        "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
        Andy Lutomirski <luto@...nel.org>,
        "maintainer:X86 ARCHITECTURE 32-BIT AND 64-BIT" <x86@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        DaveHansen <dave.hansen@...ux.intel.com>,
        Kristen Carlson Accardi <kristen@...ux.intel.com>,
        Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
        "moderated list:XEN HYPERVISOR INTERFACE" 
        <xen-devel@...ts.xenproject.org>,
        Vladimir Zapolskiy <vladimir_zapolskiy@...tor.com>,
        "Robert O'Callahan" <robert@...llahan.org>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        Ingo Molnar <mingo@...hat.com>,
        Juergen Gross <JGross@...e.com>, Borislav Petkov <bp@...e.de>,
        "open list:X86 ARCHITECTURE 32-BIT AND 64-BIT" 
        <linux-kernel@...r.kernel.org>, "H. PeterAnvin" <hpa@...or.com>
Subject: Re: [Xen-devel] [PATCH v2 2/3] x86 Test and expose CPUID faulting
 capabilities in /proc/cpuinfo

On Thu, Sep 15, 2016 at 3:25 AM, Jan Beulich <JBeulich@...e.com> wrote:
>>>> On 15.09.16 at 12:05, <david.vrabel@...rix.com> wrote:
>> On 14/09/16 22:01, Kyle Huey wrote:
>>> Xen advertises the underlying support for CPUID faulting but not does pass
>>> through writes to the relevant MSR, nor does it virtualize it, so it does
>>> not actually work. For now mask off the relevant bit on MSR_PLATFORM_INFO.
>>
>> Could you clarify in the commit message that it is PV guests that are
>> affected.
>
> What makes you think HVM ones aren't?

Testing on EC2, HVM guests are affected as well.  Not sure what to do
about that.

- Kyle