Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1356144

Re: runtime regression with "x86/mm/pat: Emulate PAT when it is disabled"

From Paolo Bonzini <pbonzini@redhat.com>
Newsgroups linux.kernel
Subject Re: runtime regression with "x86/mm/pat: Emulate PAT when it is disabled"
Date 2016-03-11 20:20 +0100
Message-ID <rbALo-2lN-17@gated-at.bofh.it> (permalink)
References (6 earlier) <rbczp-1Pk-17@gated-at.bofh.it> <rbe8a-2SM-17@gated-at.bofh.it> <rberw-312-17@gated-at.bofh.it> <rbviH-6Sm-21@gated-at.bofh.it> <rbvC1-70o-1@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw



On 11/03/2016 14:40, Borislav Petkov wrote:
> On Fri, Mar 11, 2016 at 01:23:56PM +0000, One Thousand Gnomes wrote:
>> > Pentium Pro has MTRR, PAT came later.
> Yep, this page says so too:
> 
> http://www.cpu-world.com/CPUs/Pentium-II/Intel-Pentium%20Pro%20200%201%20MB%20-%20GJ80521EX200%201M%20%28BP80521200%201M%29.html
> 
>> > I believe the qemu32 CPU isn't a "real" CPU type therefore.
> And why is that so? I suspect it has again something to do with
> migration and fun. Let me add the kvm ML.
> 
> Guys, does anyone have an idea why
> 
> #define PPRO_FEATURES (CPUID_FP87 | CPUID_DE | CPUID_PSE | CPUID_TSC | \
>           CPUID_MSR | CPUID_MCE | CPUID_CX8 | CPUID_PGE | CPUID_CMOV | \
>           CPUID_PAT | CPUID_FXSR | CPUID_MMX | CPUID_SSE | CPUID_SSE2 | \
>           CPUID_PAE | CPUID_SEP | CPUID_APIC)
> 
> has CPUID_PAT *instead* of CPUID_MTRR?

Somebody got it wrong 10-ish years ago, and nobody has ever checked since.

But, don't use qemu32 or qemu64.  Use kvm32 and kvm64, or better
something like the host you run on ("-cpu Nehalem", "-cpu SandyBridge",
"-cpu Haswell-noTSX" etc.).

I really, really should fix those defaults...

Paolo

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Paul Gortmaker <paul.gortmaker@windriver.com> - 2016-03-04 19:40 +0100
  Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Toshi Kani <toshi.kani@hpe.com> - 2016-03-04 22:30 +0100
    Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Paul Gortmaker <paul.gortmaker@windriver.com> - 2016-03-07 01:40 +0100
      Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Toshi Kani <toshi.kani@hpe.com> - 2016-03-07 16:20 +0100
        Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Toshi Kani <toshi.kani@hpe.com> - 2016-03-07 23:50 +0100
          Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Paul Gortmaker <paul.gortmaker@windriver.com> - 2016-03-08 01:00 +0100
            Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Toshi Kani <toshi.kani@hpe.com> - 2016-03-08 01:10 +0100
              Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Toshi Kani <toshi.kani@hpe.com> - 2016-03-08 01:50 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Paul Gortmaker <paul.gortmaker@windriver.com> - 2016-03-08 04:30 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Toshi Kani <toshi.kani@hpe.com> - 2016-03-08 16:50 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Paul Gortmaker <paul.gortmaker@windriver.com> - 2016-03-10 15:50 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Toshi Kani <toshi.kani@hpe.com> - 2016-03-10 17:00 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Borislav Petkov <bp@suse.de> - 2016-03-10 18:30 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Paul Gortmaker <paul.gortmaker@windriver.com> - 2016-03-10 20:10 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Toshi Kani <toshi.kani@hpe.com> - 2016-03-10 20:20 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Borislav Petkov <bp@suse.de> - 2016-03-10 20:30 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> - 2016-03-11 14:30 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Borislav Petkov <bp@suse.de> - 2016-03-11 14:50 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Paolo Bonzini <pbonzini@redhat.com> - 2016-03-11 20:20 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Borislav Petkov <bp@suse.de> - 2016-03-11 23:20 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Bruce Ashfield <bruce.ashfield@windriver.com> - 2016-03-11 23:30 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Richard Purdie <richard.purdie@linuxfoundation.org> - 2016-03-12 00:50 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Borislav Petkov <bp@suse.de> - 2016-03-12 13:10 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Toshi Kani <toshi.kani@hpe.com> - 2016-03-10 20:20 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Borislav Petkov <bp@suse.de> - 2016-03-10 20:30 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Toshi Kani <toshi.kani@hpe.com> - 2016-03-10 20:40 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Borislav Petkov <bp@suse.de> - 2016-03-10 22:10 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Toshi Kani <toshi.kani@hpe.com> - 2016-03-10 23:30 +0100
              Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Paul Gortmaker <paul.gortmaker@windriver.com> - 2016-03-08 04:20 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Toshi Kani <toshi.kani@hpe.com> - 2016-03-08 16:30 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Toshi Kani <toshi.kani@hpe.com> - 2016-03-08 17:10 +0100
                Re: runtime regression with "x86/mm/pat: Emulate PAT when it is  disabled" Paul Gortmaker <paul.gortmaker@windriver.com> - 2016-03-08 17:10 +0100

csiph-web