Re: [PATCH 0/3] x86/microcode: support for microcode update in Xen dom0

[Jeremy Fitzhardinge <jeremy@goop.org>]

Ping?

On 09/26/2011 11:17 AM, Jeremy Fitzhardinge wrote:
> From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
>
> Hi all,
>
> I'm proposing this for the next merge window v3.2.
>
> I originally posted this early this year, and it prompted a debate
> about what the "proper" way that Linux should do microcode updates,
> with the general concensus being "earlier", ideally in the bootloader
> (or in the case of Xen, as the hypervisor boots before starting any
> domains).  However, as far as I know there has been no progress along
> those lines.
>
> I would like to therefore merge this so that a Linux kernel booting as
> dom0 under Xen can update the microcode in the same manner as a kernel
> booting natively.  When we work out how boot-time microcode updates
> can be done, then we'll look at modifying Xen accordingly.  In the
> meantime, we should have a functional parity.
>
> The only change to this code from the previous posting is some patch
> restructuring so that regardless of how the platform.h ABI header gets
> merged (since there are some other pending branches containing it), it
> will be identical and cause no merge headaches.
>
> From original posting:
>
> This series adds a new "Xen" microcode update type, in addition to
> Intel and AMD.
>
> The Xen hypervisor is responsible for performing the actual microcode
> update (since only it knows what physical CPUs are in the system and
> has sufficient privilege to access them), but it requires the dom0
> kernel to provide the actual microcode update data.
>
> Xen update mechanism is uniform independent of the CPU type, but the
> driver must know where to find the data file, which depends on the CPU
> type.  And since the update hypercall updates all CPUs, we only need
> to execute it once on any CPU - but for simplicity it just runs it only
> on (V)CPU 0.
>
> Thanks,
> 	J
>
> Jeremy Fitzhardinge (2):
>   xen: add dom0_op hypercall
>   xen: add CPU microcode update driver
>
> Yu Ke (1):
>   xen/acpi: Domain0 acpi parser related platform hypercall
>
>  arch/ia64/include/asm/xen/interface.h |    1 +
>  arch/x86/include/asm/microcode.h      |    9 +
>  arch/x86/include/asm/xen/hypercall.h  |    8 +
>  arch/x86/include/asm/xen/interface.h  |    1 +
>  arch/x86/kernel/Makefile              |    1 +
>  arch/x86/kernel/microcode_core.c      |    5 +-
>  arch/x86/kernel/microcode_xen.c       |  198 ++++++++++++++++++++
>  arch/x86/xen/Kconfig                  |    4 +
>  include/xen/interface/platform.h      |  320 +++++++++++++++++++++++++++++++++
>  include/xen/interface/xen.h           |    1 +
>  10 files changed, 547 insertions(+), 1 deletions(-)
>  create mode 100644 arch/x86/kernel/microcode_xen.c
>  create mode 100644 include/xen/interface/platform.h
>