From: Denys Vlasenko <dvlasenk@redhat.com>
To: Borislav Petkov <bp@alien8.de>
Cc: Ingo Molnar <mingo@redhat.com>, Andy Lutomirski <luto@kernel.org>,
Brian Gerst <brgerst@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
"H. Peter Anvin" <hpa@linux.intel.com>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86, msr: Better document AMD "tweak MSRs", rename MSR_F15H_IC_CFG
Date: Tue, 25 Apr 2017 15:05:41 +0200 [thread overview]
Message-ID: <5ef2c044-3044-4983-61d7-68f651dd8ee9@redhat.com> (raw)
In-Reply-To: <20170425125913.5nnd436dz54q7cld@pd.tnic>
On 04/25/2017 02:59 PM, Borislav Petkov wrote:
> On Tue, Apr 25, 2017 at 02:16:55PM +0200, Denys Vlasenko wrote:
>> However, all IBS registers are in this range.
>
> I knew you were gonna say that. But IBS registers are architectural too
> in the sense that they are behind a CPUID bit.
>
>> DRi_ADDR_MASK are in this range - and these are very useful, likely to
>> stay.
>
> Those are too behind a CPUID bit.
>
>> In the arch/x86/include/asm/msr-index.h file we already have
>> three "tweak" MSRs defined with "AMD64":
>>
>> #define MSR_AMD64_LS_CFG 0xc0011020
>> #define MSR_AMD64_DC_CFG 0xc0011022
>> #define MSR_AMD64_BU_CFG2 0xc001102a
>>
>> I just noticed that we have a fourth one in
>> arch/x86/kernel/cpu/amd.c:
>>
>> #define MSR_AMD64_DE_CFG 0xC0011029
>
> That's wrong. I think we should call those something else but not
> "AMD64".
Okay. Propose a naming scheme for these which looks god to you.
> Perhaps the families for which the workaround is being applied.
> In the last case, MSR_F12H_DE_CFG, for example. And yes, I should've
> paid attention to that but ...
A bit problematic:
MSR C001_1020 is used (mentioned in Rev Guides as a possible way
to work around an errata) by all Fams starting from K8, except Fam15h.
MSR C001_1022 is used by K8, 10h, 15h.
Etc...
next prev parent reply other threads:[~2017-04-25 13:05 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-25 11:45 [PATCH] x86, msr: Better document AMD "tweak MSRs", rename MSR_F15H_IC_CFG Denys Vlasenko
2017-04-25 11:59 ` Borislav Petkov
2017-04-25 12:16 ` Denys Vlasenko
2017-04-25 12:59 ` Borislav Petkov
2017-04-25 13:05 ` Denys Vlasenko [this message]
2017-04-25 13:18 ` Borislav Petkov
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