Re: [PATCH] x86, microcode, AMD: Fix patch level reporting forfamily15h

From: Borislav Petkov
Date: Thu Sep 26 2013 - 18:13:42 EST

On Thu, Sep 26, 2013 at 04:54:32PM -0500, suravee.suthikulpanit@xxxxxxx wrote:
> From: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
> On AMD family15h, applying microcode patch on the a core (core0)
> would also affect the other core (core1) in the same compute unit.
> The driver would skip applying the patch on core1, but it still
> need to update kernel structures to reflect the proper patch level.
> The current logic is not updating the struct ucode_cpu_info.cpu_sig.rev
> of the skipped core. This causes the /sys/devices/system/cpu/cpu1/microcode/version
> to report incorrect patch level as shown below:
> [ 10.708841] microcode: CPU0: new patch_level=0x0600063d
> [ 10.714256] microcode: CPU1: patch_level=0x06000626
> [ 10.719345] microcode: CPU2: patch_level=0x06000626
> [ 10.748095] microcode: CPU2: new patch_level=0x0600063d
> [ 10.753365] microcode: CPU3: patch_level=0x06000626
> [ 10.758264] microcode: CPU4: patch_level=0x06000626
> [ 10.786999] microcode: CPU4: new patch_level=0x0600063d

Actually, this is collect_cpu_info_amd()'s normal operation and shows
that there's no need to apply a microcode patch on the odd core since
the even core's ucode has been updated.

Actually you need something like that:

$ grep . cpu?/microcode/version

which shows the bug. Other than that, the patch is correct so please fix
the commit message and add x86@xxxxxxxxxx to CC on the next submission
so that it gets picked by x86 people.



Sent from a fat crate under my desk. Formatting is fine.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at