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From: Borislav Petkov <bp@alien8.de>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: X86 ML <x86@kernel.org>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 02/13] x86/microcode: Use own MSR accessors
Date: Tue, 17 Jan 2017 19:11:20 +0100	[thread overview]
Message-ID: <20170117181120.cvg7b66txq7qhbi3@pd.tnic> (raw)
In-Reply-To: <alpine.DEB.2.20.1701171847560.3495@nanos>

On Tue, Jan 17, 2017 at 06:51:06PM +0100, Thomas Gleixner wrote:
> That would get rid of all the extra microcode specific MSR accessors which
> are just yet another copy of stuff in msr.h.

Well, I did think about reusing those but last time I did, they received
those tracepoints (apparently, we're sprinkling dumb tracepoints left
and right because good ol' staring at the code is just too hard) which
simply doesn't work on 32-bit before paging is enabled.

Then, __native_write_msr_notrace() has exception handling which doesn't
work before paging has been enabled on 32-bit - this is when the 32-bit
microcode update path happens due to paging hardware bugs in CPUs which
are fixed in microcode. So we must run that early on 32-bit.

So before someone decides to add more "functionality" to the generic MSR
accessors and break the microcode loader once more, I'd really really
prefer to have private accessors. They're small enough so shouldn't be
that much of a bloat.

Thanks.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

  reply	other threads:[~2017-01-17 18:20 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-01-17 17:37 [PATCH 00/13] x86/microcode: 4.11 queue Borislav Petkov
2017-01-17 17:37 ` [PATCH 01/13] x86/microcode/intel: Drop stashed AP patch pointer optimization Borislav Petkov
2017-01-17 19:59   ` Thomas Gleixner
2017-01-17 17:37 ` [PATCH 02/13] x86/microcode: Use own MSR accessors Borislav Petkov
2017-01-17 17:51   ` Thomas Gleixner
2017-01-17 18:11     ` Borislav Petkov [this message]
2017-01-17 19:12       ` Thomas Gleixner
2017-01-17 22:33         ` Borislav Petkov
2017-01-18  9:46           ` Thomas Gleixner
2017-01-17 17:37 ` [PATCH 03/13] x86/microcode/AMD: Clean up find_equiv_id() Borislav Petkov
2017-01-17 17:54   ` Thomas Gleixner
2017-01-17 18:49     ` Borislav Petkov
2017-01-17 19:02       ` Thomas Gleixner
2017-01-17 23:12         ` Borislav Petkov
2017-01-17 17:37 ` [PATCH 04/13] x86/microcode/AMD: Shorten function parameter's name Borislav Petkov
2017-01-17 19:59   ` Thomas Gleixner
2017-01-17 17:37 ` [PATCH 05/13] x86/microcode/AMD: Extend the container struct Borislav Petkov
2017-01-17 20:02   ` Thomas Gleixner
2017-01-17 17:37 ` [PATCH 06/13] x86/microcode/AMD: Rework container parsing Borislav Petkov
2017-01-17 20:29   ` Thomas Gleixner
2017-01-17 23:31     ` Borislav Petkov
2017-01-18 14:44       ` Borislav Petkov
2017-01-18 14:58         ` Borislav Petkov
2017-01-17 17:37 ` [PATCH 07/13] x86/microcode: Decrease CPUID use Borislav Petkov
2017-01-17 20:34   ` Thomas Gleixner
2017-01-17 17:37 ` [PATCH 08/13] x86/microcode/AMD: Get rid of global this_equiv_id Borislav Petkov
2017-01-17 20:36   ` Thomas Gleixner
2017-01-17 17:37 ` [PATCH 09/13] x86/microcode/AMD: Use find_microcode_in_initrd() Borislav Petkov
2017-01-17 20:36   ` Thomas Gleixner
2017-01-17 17:37 ` [PATCH 10/13] x86/microcode/AMD: Check patch level only on the BSP Borislav Petkov
2017-01-17 20:43   ` Thomas Gleixner
2017-01-17 17:37 ` [PATCH 11/13] x86/microcode/AMD: Unify load_ucode_amd_ap() Borislav Petkov
2017-01-17 20:58   ` Thomas Gleixner
2017-01-17 21:18     ` Thomas Gleixner
2017-01-17 17:37 ` [PATCH 12/13] x86/microcode/AMD: Simplify saving from initrd Borislav Petkov
2017-01-17 21:19   ` Thomas Gleixner
2017-01-17 17:37 ` [PATCH 13/13] x86/microcode/AMD: Remove AP scanning optimization Borislav Petkov
2017-01-17 21:24   ` Thomas Gleixner

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