From: Ben Hutchings <ben@decadent.org.uk>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: akpm@linux-foundation.org, Denis Kirjanov <kda@linux-powerpc.org>,
"Borislav Petkov" <bp@suse.de>,
"Josh Poimboeuf" <jpoimboe@redhat.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Tony Luck" <tony.luck@intel.com>,
"Pawan Gupta" <pawan.kumar.gupta@linux.intel.com>
Subject: [PATCH 3.16 09/25] x86/tsx: Add "auto" option to the tsx= cmdline parameter
Date: Tue, 12 Nov 2019 23:48:06 +0000 [thread overview]
Message-ID: <lsq.1573602477.93544792@decadent.org.uk> (raw)
In-Reply-To: <lsq.1573602477.548403712@decadent.org.uk>
3.16.77-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
commit 7531a3596e3272d1f6841e0d601a614555dc6b65 upstream.
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
[ bp: Extend the arg buffer to accommodate "auto\0". ]
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
[bwh: Backported to 4.4: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
Documentation/kernel-parameters.txt | 3 +++
arch/x86/kernel/cpu/tsx.c | 7 ++++++-
2 files changed, 9 insertions(+), 1 deletion(-)
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -3602,6 +3602,9 @@ bytes respectively. Such letter suffixes
update. This new MSR allows for the reliable
deactivation of the TSX functionality.)
+ auto - Disable TSX if X86_BUG_TAA is present,
+ otherwise enable TSX on the system.
+
Not specifying this option is equivalent to tsx=off.
See Documentation/hw-vuln/tsx_async_abort.rst
--- a/arch/x86/kernel/cpu/tsx.c
+++ b/arch/x86/kernel/cpu/tsx.c
@@ -75,7 +75,7 @@ static bool __init tsx_ctrl_is_supported
void __init tsx_init(void)
{
- char arg[4] = {};
+ char arg[5] = {};
int ret;
if (!tsx_ctrl_is_supported())
@@ -87,6 +87,11 @@ 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_err("tsx: invalid option, defaulting to off\n");
next prev parent reply other threads:[~2019-11-12 23:52 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-12 23:47 [PATCH 3.16 00/25] 3.16.77-rc1 review Ben Hutchings
2019-11-12 23:47 ` [PATCH 3.16 01/25] KVM: Introduce kvm_get_arch_capabilities() Ben Hutchings
2019-11-12 23:47 ` [PATCH 3.16 02/25] KVM: x86: use Intel speculation bugs and features as derived in generic x86 code Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 03/25] x86/msr: Add the IA32_TSX_CTRL MSR Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 04/25] x86/cpu: Add a helper function x86_read_arch_cap_msr() Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 05/25] x86/cpu: Add a "tsx=" cmdline option with TSX disabled by default Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 06/25] x86/speculation/taa: Add mitigation for TSX Async Abort Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 07/25] x86/speculation/taa: Add sysfs reporting " Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 08/25] kvm/x86: Export MDS_NO=0 to guests when TSX is enabled Ben Hutchings
2019-11-12 23:48 ` Ben Hutchings [this message]
2019-11-12 23:48 ` [PATCH 3.16 10/25] x86/speculation/taa: Add documentation for TSX Async Abort Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 11/25] x86/tsx: Add config options to set tsx=on|off|auto Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 12/25] x86/speculation/taa: Fix printing of TAA_MSG_SMT on IBRS_ALL CPUs Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 13/25] x86/bugs: Add ITLB_MULTIHIT bug infrastructure Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 14/25] drm/i915/gen8+: Add RC6 CTX corruption WA Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 15/25] net: netem: fix error path for corrupted GSO frames Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 16/25] ath6kl: fix a NULL-ptr-deref bug in ath6kl_usb_alloc_urb_from_pipe() Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 17/25] media: usb:zr364xx:Fix KASAN:null-ptr-deref Read in zr364xx_vidioc_querycap Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 18/25] media: technisat-usb2: break out of loop at end of buffer Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 19/25] ax25: enforce CAP_NET_RAW for raw sockets Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 20/25] ieee802154: " Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 21/25] appletalk: " Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 22/25] mISDN: " Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 23/25] nfc: " Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 24/25] cfg80211: wext: avoid copying malformed SSIDs Ben Hutchings
2019-11-12 23:48 ` [PATCH 3.16 25/25] rtlwifi: Fix potential overflow on P2P code Ben Hutchings
2019-11-13 18:13 ` [PATCH 3.16 00/25] 3.16.77-rc1 review Guenter Roeck
2019-11-13 18:31 ` Ben Hutchings
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