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From: Toshi Kani <toshi.kani@hpe.com>
To: mingo@kernel.org, bp@suse.de, hpa@zytor.com, tglx@linutronix.de
Cc: jgross@suse.com, Toshi Kani <toshi.kani@hpe.com>,
	mcgrof@suse.com, x86@kernel.org, linux-kernel@vger.kernel.org,
	paul.gortmaker@windriver.com, xen-devel@lists.xenproject.org,
	elliott@hpe.com
Subject: [PATCH v2 4/6] x86/mtrr: Fix PAT init handling when MTRR MSR is disabled
Date: Wed, 16 Mar 2016 18:46:57 -0600	[thread overview]
Message-ID: <1458175619-32206-3-git-send-email-toshi.kani__28598.8348689445$1458172564$gmane$org@hpe.com> (raw)
In-Reply-To: <1458175619-32206-1-git-send-email-toshi.kani@hpe.com>

get_mtrr_state() calls pat_init() on BSP even if MTRR is disabled
by its MSR.  This causes pat_init() to be called on BSP only since
APs do not call 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.
This keeps BSP's calling condition to pat_init() consistent with AP's,
mtrr_ap_init() and mtrr_aps_init().

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/kernel/cpu/mtrr/generic.c |   24 ++++++++++++++----------
 arch/x86/kernel/cpu/mtrr/main.c    |    3 +++
 arch/x86/kernel/cpu/mtrr/mtrr.h    |    1 +
 3 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c
index fcbcb2f..a9d2e54 100644
--- a/arch/x86/kernel/cpu/mtrr/generic.c
+++ b/arch/x86/kernel/cpu/mtrr/generic.c
@@ -444,11 +444,24 @@ static void __init print_mtrr_state(void)
 		pr_debug("TOM2: %016llx aka %lldM\n", mtrr_tom2, mtrr_tom2>>20);
 }
 
+/* PAT setup for BP. We need to go through sync steps here */
+void __init mtrr_bp_pat_init(void)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	prepare_set();
+
+	pat_init();
+
+	post_set();
+	local_irq_restore(flags);
+}
+
 /* Grab all of the MTRR state for this CPU into *state */
 bool __init get_mtrr_state(void)
 {
 	struct mtrr_var_range *vrs;
-	unsigned long flags;
 	unsigned lo, dummy;
 	unsigned int i;
 
@@ -481,15 +494,6 @@ bool __init get_mtrr_state(void)
 
 	mtrr_state_set = 1;
 
-	/* PAT setup for BP. We need to go through sync steps here */
-	local_irq_save(flags);
-	prepare_set();
-
-	pat_init();
-
-	post_set();
-	local_irq_restore(flags);
-
 	return !!(mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED);
 }
 
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index 2d7d8d7..6186ff4 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -752,6 +752,9 @@ void __init mtrr_bp_init(void)
 			/* BIOS may override */
 			__mtrr_enabled = get_mtrr_state();
 
+			if (mtrr_enabled())
+				mtrr_bp_pat_init();
+
 			if (mtrr_cleanup(phys_addr)) {
 				changed_by_mtrr_cleanup = 1;
 				mtrr_if->set_all();
diff --git a/arch/x86/kernel/cpu/mtrr/mtrr.h b/arch/x86/kernel/cpu/mtrr/mtrr.h
index 951884d..6c7ced0 100644
--- a/arch/x86/kernel/cpu/mtrr/mtrr.h
+++ b/arch/x86/kernel/cpu/mtrr/mtrr.h
@@ -52,6 +52,7 @@ void set_mtrr_prepare_save(struct set_mtrr_context *ctxt);
 void fill_mtrr_var_range(unsigned int index,
 		u32 base_lo, u32 base_hi, u32 mask_lo, u32 mask_hi);
 bool get_mtrr_state(void);
+void mtrr_bp_pat_init(void);
 
 extern void set_mtrr_ops(const struct mtrr_ops *ops);
 

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  parent reply	other threads:[~2016-03-16 23:54 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-17  0:46 [PATCH v2 2/6] x86/mm/pat: Add pat_disable() interface Toshi Kani
2016-03-17  0:46 ` [PATCH v2 3/6] x86/mtrr: Fix Xorg crashes in Qemu sessions Toshi Kani
2016-03-17  0:46 ` Toshi Kani [this message]
2016-03-17  0:46 ` [PATCH v2 5/6] x86/xen, pat: Remove PAT table init code from Xen Toshi Kani
2016-03-17  0:46 ` [PATCH v2 6/6] x86/pat: Document PAT initializations Toshi Kani
2016-03-22 16:59 ` [PATCH v2 2/6] x86/mm/pat: Add pat_disable() interface Borislav Petkov
     [not found] ` <1458175619-32206-2-git-send-email-toshi.kani@hpe.com>
2016-03-22 17:00   ` [PATCH v2 3/6] x86/mtrr: Fix Xorg crashes in Qemu sessions Borislav Petkov
     [not found]   ` <20160322170047.GD5656@pd.tnic>
2016-03-22 21:53     ` Toshi Kani
     [not found]     ` <1458683610.6393.624.camel@hpe.com>
2016-03-23  8:44       ` Borislav Petkov
     [not found]       ` <20160323084437.GB8031@pd.tnic>
2016-03-23 15:53         ` Toshi Kani
     [not found]         ` <1458748393.6393.653.camel@hpe.com>
2016-03-23 21:47           ` Toshi Kani
     [not found] ` <1458175619-32206-3-git-send-email-toshi.kani@hpe.com>
2016-03-22 17:01   ` [PATCH v2 4/6] x86/mtrr: Fix PAT init handling when MTRR MSR is disabled Borislav Petkov
     [not found]   ` <20160322170135.GE5656@pd.tnic>
2016-03-22 22:02     ` Toshi Kani
     [not found] ` <1458175619-32206-4-git-send-email-toshi.kani@hpe.com>
2016-03-22 17:02   ` [PATCH v2 5/6] x86/xen, pat: Remove PAT table init code from Xen Borislav Petkov
     [not found]   ` <20160322170206.GF5656@pd.tnic>
2016-03-23  6:08     ` Juergen Gross
     [not found] ` <1458175619-32206-5-git-send-email-toshi.kani@hpe.com>
2016-03-22 17:02   ` [PATCH v2 6/6] x86/pat: Document PAT initializations Borislav Petkov
     [not found]   ` <20160322170222.GG5656@pd.tnic>
2016-03-22 22:15     ` Toshi Kani
     [not found] ` <20160322165944.GC5656@pd.tnic>
2016-03-22 21:40   ` [PATCH v2 2/6] x86/mm/pat: Add pat_disable() interface Toshi Kani
     [not found]   ` <1458682845.6393.614.camel@hpe.com>
2016-03-23  8:51     ` Borislav Petkov
     [not found]     ` <20160323085141.GC8031@pd.tnic>
2016-03-23 15:49       ` Toshi Kani

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