Re: [PATCH v2 4/6] x86/mtrr: Fix PAT init handling when MTRR MSR is disabled
From: Borislav Petkov
Date: Tue Mar 22 2016 - 13:01:49 EST
Subject: [PATCH v2 4/6] x86/mtrr: Fix PAT init handling when MTRR MSR is disabled
On Wed, Mar 16, 2016 at 06:46:57PM -0600, Toshi Kani wrote:
> get_mtrr_state() calls pat_init() on BSP even if MTRR is disabled
> by its MSR.
s/by its MSR//
> This causes pat_init() to be called on BSP only since APs do not call
This doesn't cause that - get_mtrr_state() is called only on the BSP by
> pat_init() when MTRR is disabled. This inconsistency between BSP and
> APs leads undefined behavior.
> Move BSP's PAT init code from get_mtrr_state() to mtrr_bp_pat_init().
> Change mtrr_bp_init() to call mtrr_bp_pat_init() if MTRR is enabled.
No need for those.
> This keeps BSP's calling condition to pat_init() consistent with AP's,
> mtrr_ap_init() and mtrr_aps_init().
This one is fine.
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