diff options
| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2019-04-17 16:39:02 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-14 19:18:47 +0200 |
| commit | a9411900c4223cbe4926dd2954e762de1816fcec (patch) | |
| tree | bebb22ac876c400bb7587b8b2f952a1afd659bda | |
| parent | 91788fcb21d008b1b7ac6beae20522725fa78239 (diff) | |
x86/speculation/mds: Add 'mitigations=' support for MDS
commit 5c14068f87d04adc73ba3f41c2a303d3c3d1fa12 upstream
Add MDS to the new 'mitigations=' cmdline option.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 5 |
2 files changed, 5 insertions, 2 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 6fa7895885c9..9240b2caa0b1 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2405,6 +2405,7 @@ spectre_v2_user=off [X86] spec_store_bypass_disable=off [X86,PPC] l1tf=off [X86] + mds=off [X86] auto (default) Mitigate all CPU vulnerabilities, but leave SMT @@ -2419,6 +2420,7 @@ if needed. This is for users who always want to be fully mitigated, even if it means losing SMT. Equivalent to: l1tf=flush,nosmt [X86] + mds=full,nosmt [X86] mminit_loglevel= [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 4891101cf990..2769e0f5c686 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -231,7 +231,7 @@ static const char * const mds_strings[] = { static void __init mds_select_mitigation(void) { - if (!boot_cpu_has_bug(X86_BUG_MDS)) { + if (!boot_cpu_has_bug(X86_BUG_MDS) || cpu_mitigations_off()) { mds_mitigation = MDS_MITIGATION_OFF; return; } @@ -242,7 +242,8 @@ static void __init mds_select_mitigation(void) static_branch_enable(&mds_user_clear); - if (mds_nosmt && !boot_cpu_has(X86_BUG_MSBDS_ONLY)) + if (!boot_cpu_has(X86_BUG_MSBDS_ONLY) && + (mds_nosmt || cpu_mitigations_auto_nosmt())) cpu_smt_disable(false); } |