linux-kernel - [tip:x86/pti] x86/bugs: Update when to check for the LS

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Message-ID: <tip-845d382bb15c6e7dc5026c0ff919c5b13fc7e11b@git.kernel.org>
Date:   Tue, 3 Jul 2018 01:33:53 -0700
From:   tip-bot for Tom Lendacky <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     peterz@...radead.org, tglx@...utronix.de,
        linux-kernel@...r.kernel.org, thomas.lendacky@....com,
        dwmw@...zon.co.uk, konrad.wilk@...cle.com, hpa@...or.com,
        torvalds@...ux-foundation.org, bpetkov@...e.de, mingo@...nel.org
Subject: [tip:x86/pti] x86/bugs: Update when to check for the LS_CFG SSBD
 mitigation

Commit-ID:  845d382bb15c6e7dc5026c0ff919c5b13fc7e11b
Gitweb:     https://git.kernel.org/tip/845d382bb15c6e7dc5026c0ff919c5b13fc7e11b
Author:     Tom Lendacky <thomas.lendacky@....com>
AuthorDate: Mon, 2 Jul 2018 16:35:53 -0500
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Tue, 3 Jul 2018 09:45:48 +0200

x86/bugs: Update when to check for the LS_CFG SSBD mitigation

If either the X86_FEATURE_AMD_SSBD or X86_FEATURE_VIRT_SSBD features are
present, then there is no need to perform the check for the LS_CFG SSBD
mitigation support.

Signed-off-by: Tom Lendacky <thomas.lendacky@....com>
Cc: Borislav Petkov <bpetkov@...e.de>
Cc: David Woodhouse <dwmw@...zon.co.uk>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Link: http://lkml.kernel.org/r/20180702213553.29202.21089.stgit@tlendack-t1.amdoffice.net
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 arch/x86/kernel/cpu/amd.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 082d7875cef8..38915fbfae73 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -543,7 +543,9 @@ static void bsp_init_amd(struct cpuinfo_x86 *c)
 		nodes_per_socket = ((value >> 3) & 7) + 1;
 	}
 
-	if (c->x86 >= 0x15 && c->x86 <= 0x17) {
+	if (!boot_cpu_has(X86_FEATURE_AMD_SSBD) &&
+	    !boot_cpu_has(X86_FEATURE_VIRT_SSBD) &&
+	    c->x86 >= 0x15 && c->x86 <= 0x17) {
 		unsigned int bit;
 
 		switch (c->x86) {