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From: Borislav Petkov <bp@alien8.de>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>,
	Ingo Molnar <mingo@elte.hu>,
	the arch/x86 maintainers <x86@kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Xen Devel <Xen-devel@lists.xensource.com>,
	Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Subject: Re: [PATCH 0/2] x86/microcode: support for microcode update in Xen dom0
Date: Thu, 3 Feb 2011 19:25:50 +0100	[thread overview]
Message-ID: <20110203182550.GB21488@a1.tnic> (raw)
In-Reply-To: <4D49D0E6.30102@zytor.com>

On Wed, Feb 02, 2011 at 01:47:18PM -0800, H. Peter Anvin wrote:
> On 02/02/2011 12:57 PM, Borislav Petkov wrote:
> > On Wed, Feb 02, 2011 at 11:52:22AM -0800, H. Peter Anvin wrote:
> >> 3. Arguably on native hardware we should still load the microcode into
> >> RAM in the boot loader, and install it on the very early CPU bringup
> >> path.  That means locking down some (currently) 400K of RAM to handle
> >> different combinations of CPUs, or the additional complexity of
> >> jettisoning microcode which cannot be used while still be able to deal
> >> with hotplug.  I think there is a strong case for this model, which
> >> would mean moving the microcode into /boot anyway.
> > 
> > /me like it, sounds very nifty. So how do we want to do that, we add
> > a field to the real-mode kernel header that tells us where to find
> > the microcode image and we take it and apply the ucode somewhere in
> > do_boot_cpu() path?
> > 
> 
> We already have a mechanism for passing arbitrary blobs -- the linked
> list -- so we don't have to add a new field at all.

So, after staring at grub legacy sources a bit, we could load the
microcode image using the grub module's mechanism:

kernel /...
module /boot/microcode.gz type=SETUP_MICROCODE # this is looked at by parse_setup_data()

and let grub write the pointer into setup_data passed through the kernel
header.

This would mean that we need to add support to a bunch of boot loaders
used currently, no? Or is there an even better way?

-- 
Regards/Gruss,
Boris.

  reply	other threads:[~2011-02-03 18:25 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-01-29  0:26 [PATCH 0/2] x86/microcode: support for microcode update in Xen dom0 Jeremy Fitzhardinge
     [not found] ` <cover.1296260656.git.jeremy.fitzhardinge@citrix.com>
2011-01-29  0:26   ` [PATCH 1/2] xen dom0: Add support for the platform_ops hypercall Jeremy Fitzhardinge
2011-01-29  0:26     ` Jeremy Fitzhardinge
2011-01-29  0:26   ` [PATCH 2/2] xen: add CPU microcode update driver Jeremy Fitzhardinge
2011-01-30 11:33 ` [PATCH 0/2] x86/microcode: support for microcode update in Xen dom0 Borislav Petkov
2011-01-31  2:34   ` Jeremy Fitzhardinge
2011-01-31  7:02     ` Borislav Petkov
2011-01-31  7:02       ` Borislav Petkov
2011-01-31 18:17       ` Jeremy Fitzhardinge
2011-01-31 18:17         ` Jeremy Fitzhardinge
2011-01-31 23:41         ` Borislav Petkov
2011-02-01  0:15           ` Jeremy Fitzhardinge
2011-02-01  0:15           ` Jeremy Fitzhardinge
2011-02-01  1:11             ` H. Peter Anvin
2011-02-01 22:52               ` Jeremy Fitzhardinge
2011-02-01 22:52                 ` Jeremy Fitzhardinge
2011-02-02 19:52                 ` H. Peter Anvin
2011-02-02 20:05                   ` Jeremy Fitzhardinge
2011-02-02 20:34                     ` Thomas Gleixner
2011-02-02 20:34                       ` Thomas Gleixner
2011-02-03  0:55                     ` Henrique de Moraes Holschuh
2011-02-03  0:58                       ` H. Peter Anvin
2011-02-03  7:47                       ` Borislav Petkov
2011-02-03 16:05                         ` Henrique de Moraes Holschuh
2011-02-03 16:05                           ` Henrique de Moraes Holschuh
2011-02-02 20:57                   ` Borislav Petkov
2011-02-02 20:57                     ` Borislav Petkov
2011-02-02 21:47                     ` H. Peter Anvin
2011-02-02 21:47                       ` H. Peter Anvin
2011-02-03 18:25                       ` Borislav Petkov [this message]
2011-02-03 18:33                         ` H. Peter Anvin
2011-02-03 18:33                           ` H. Peter Anvin
2011-02-01 11:00             ` Borislav Petkov
2011-02-01 23:12               ` Jeremy Fitzhardinge
2011-02-01 23:12                 ` Jeremy Fitzhardinge
2011-02-02  9:54                 ` Borislav Petkov
2011-02-02  9:54                   ` Borislav Petkov
2011-02-02 12:48                   ` Henrique de Moraes Holschuh
2011-02-02 12:48                   ` Henrique de Moraes Holschuh
2011-02-02 18:05                   ` Jeremy Fitzhardinge
2011-02-02 18:05                   ` Jeremy Fitzhardinge
2011-02-02 18:29                   ` Jeremy Fitzhardinge
2011-02-02 18:29                   ` Jeremy Fitzhardinge
2011-01-31  2:34   ` Jeremy Fitzhardinge

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