lkml.org 
[lkml]   [2018]   [Feb]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH 00/31 v2] PTI support for x86_32
    From
    Date
    On 09/02/2018 21:09, Pavel Machek wrote:
    > On Fri 2018-02-09 17:47:43, Andy Lutomirski wrote:
    >> PCID bit set in CPUID should print a big fat warning like "WARNING:
    >> you are using 32-bit PTI on a 64-bit PCID-capable CPU. Your
    >> performance will increase dramatically if you switch to a 64-bit
    >> kernel."
    > Hardware supports PCID even on 32-bit kernels, no?

    Attempting to set CR4.PCIDE is disallowed outside of long mode.  It is
    strictly a 64bit-only feature.

    ~Andrew

    \
     
     \ /
      Last update: 2018-02-09 22:28    [W:4.301 / U:0.016 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site