From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue, 5 Jun 2018 23:00:55 +0000 (+0200)
Subject: x86/cpu/intel: Evaluate smp_num_siblings early
X-Git-Tag: v4.1.12-124.31.3~653
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=e2591e855ca8f9456f7a912d999fe6aba832899b;p=users%2Fjedix%2Flinux-maple.git

x86/cpu/intel: Evaluate smp_num_siblings early

Make use of the new early detection function to initialize smp_num_siblings
on the boot cpu before the MP-Table or ACPI/MADT scan happens. That's
required for force disabling SMT.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ingo Molnar <mingo@kernel.org>

Orabug: 28220674
CVE: CVE-2018-3620

(cherry picked from commit 1910ad5624968f93be48e8e265513c54d66b897c)

Signed-off-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

Conflicts:
	arch/x86/kernel/cpu/intel.c
Contextual
---

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 23f86bde85d1..d6937f649087 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -159,6 +159,13 @@ static void early_init_intel(struct cpuinfo_x86 *c)
 		pr_info("Disabling PGE capability bit\n");
 		setup_clear_cpu_cap(X86_FEATURE_PGE);
 	}
+
+	/*
+	 * Get the number of SMT siblings early from the extended topology
+	 * leaf, if available. Otherwise try the legacy SMT detection.
+	 */
+	if (detect_extended_topology_early(c) < 0)
+		detect_ht_early(c);
 }
 
 #ifdef CONFIG_X86_32