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From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
To: speck@linutronix.de
Subject: [MODERATED] [PATCH v6 7/9] TAAv6 7
Date: Wed, 9 Oct 2019 16:28:56 -0700	[thread overview]
Message-ID: <=?utf-8?q?=3C0103f2d9adfd78341de3cf2cd261bbeb50b607f1=2E157065?= =?utf-8?q?8889=2Egit=2Epawan=2Ekumar=2Egupta=40linux=2Eintel=2Ecom=3E?=> (raw)
In-Reply-To: <cover.1570658888.git.pawan.kumar.gupta@linux.intel.com>

Platforms which are not affected by X86_BUG_TAA may want the TSX feature
enabled. Add "auto" option to the TSX cmdline parameter. When tsx=auto
disable TSX when X86_BUG_TAA is present, otherwise enable TSX.

More details on X86_BUG_TAA can be found here:
https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/tsx_async_abort.html

Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
---
 Documentation/admin-guide/kernel-parameters.txt | 5 +++++
 arch/x86/kernel/cpu/tsx.c                       | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 832537d59562..d7b48c38c6e5 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4821,6 +4821,11 @@
 
 			on	- Enable TSX on the system.
 			off	- Disable TSX on the system.
+			auto	- Disable TSX if X86_BUG_TAA is present,
+				  otherwise enable TSX on the system.
+
+			More details on X86_BUG_TAA are here:
+			Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
 
 			Not specifying this option is equivalent to tsx=off.
 
diff --git a/arch/x86/kernel/cpu/tsx.c b/arch/x86/kernel/cpu/tsx.c
index e39b33b7cef8..e93abe6f0bb9 100644
--- a/arch/x86/kernel/cpu/tsx.c
+++ b/arch/x86/kernel/cpu/tsx.c
@@ -80,6 +80,11 @@ void __init tsx_init(void)
 			tsx_ctrl_state = TSX_CTRL_ENABLE;
 		} else if (!strcmp(arg, "off")) {
 			tsx_ctrl_state = TSX_CTRL_DISABLE;
+		} else if (!strcmp(arg, "auto")) {
+			if (boot_cpu_has_bug(X86_BUG_TAA))
+				tsx_ctrl_state = TSX_CTRL_DISABLE;
+			else
+				tsx_ctrl_state = TSX_CTRL_ENABLE;
 		} else {
 			tsx_ctrl_state = TSX_CTRL_DISABLE;
 			pr_info("tsx: invalid option, defaulting to off\n");
-- 
2.20.1

  parent reply	other threads:[~2019-10-09 23:34 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-09 23:21 [MODERATED] [PATCH v6 0/9] TAAv6 0 Pawan Gupta
2019-10-09 23:22 ` [MODERATED] [PATCH v6 1/9] TAAv6 1 Pawan Gupta
2019-10-09 23:23 ` [MODERATED] [PATCH v6 2/9] TAAv6 2 Pawan Gupta
2019-10-09 23:24 ` [MODERATED] [PATCH v6 3/9] TAAv6 3 Pawan Gupta
2019-10-09 23:25 ` [MODERATED] [PATCH v6 4/9] TAAv6 4 Pawan Gupta
2019-10-09 23:26 ` [MODERATED] [PATCH v6 5/9] TAAv6 5 Pawan Gupta
2019-10-09 23:27 ` [MODERATED] [PATCH v6 6/9] TAAv6 6 Pawan Gupta
2019-10-09 23:28 ` Pawan Gupta [this message]
2019-10-09 23:29 ` [MODERATED] [PATCH v6 8/9] TAAv6 8 Pawan Gupta
2019-10-09 23:30 ` [MODERATED] [PATCH v6 9/9] TAAv6 9 Pawan Gupta
2019-10-09 23:34 ` [MODERATED] Re: [PATCH v6 1/9] TAAv6 1 Pawan Gupta
2019-10-10  1:23   ` Pawan Gupta
2019-10-15 12:54     ` Thomas Gleixner
2019-10-21 20:35       ` [MODERATED] " Pawan Gupta
2019-10-09 23:38 ` Andrew Cooper
2019-10-09 23:40   ` Andrew Cooper
2019-10-09 23:53     ` Luck, Tony
2019-10-10  0:01       ` Andrew Cooper
2019-10-10 16:51         ` Luck, Tony
     [not found] ` <5d9e6daa.1c69fb81.f84ad.88ceSMTPIN_ADDED_BROKEN@mx.google.com>
2019-10-10  6:47   ` [MODERATED] Re: [PATCH v6 3/9] TAAv6 3 Greg KH
2019-10-10 23:44     ` Pawan Gupta
     [not found] ` <5d9e6e22.1c69fb81.6df19.ff55SMTPIN_ADDED_BROKEN@mx.google.com>
2019-10-10  6:50   ` [MODERATED] Re: [PATCH v6 5/9] TAAv6 5 Greg KH
2019-10-10 21:18     ` Pawan Gupta
2019-10-10  6:50   ` Greg KH
     [not found] ` <5d9e6f13.1c69fb81.d7036.be99SMTPIN_ADDED_BROKEN@mx.google.com>
2019-10-10  6:54   ` [MODERATED] Re: [PATCH v6 9/9] TAAv6 9 Greg KH
2019-10-12  1:41     ` Pawan Gupta
2019-10-13 20:05       ` Ben Hutchings
2019-10-13 21:00         ` Ben Hutchings
     [not found] ` <4b15283c29b75be3177eb7c4b8601be5644f630e.157065=?utf-8?q?8889?= .git.pawan.kumar.gupta@linux.intel.com>
2019-10-18  1:21   ` [MODERATED] Re: [PATCH v6 8/9] TAAv6 8 Ben Hutchings
2019-10-21 20:04 ` [MODERATED] Re: [PATCH v6 0/9] TAAv6 0 Josh Poimboeuf
2019-10-21 20:09   ` Pawan Gupta

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