diff options
| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2019-04-17 16:39:02 -0500 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-04-18 11:20:41 +0200 |
| commit | 5c14068f87d04adc73ba3f41c2a303d3c3d1fa12 (patch) | |
| tree | 65a6566d091dfd1cd13fe183085cebcab87b9aa3 | |
| parent | e9fee6fe08eef51cd9a7455d18b9011f1e463f22 (diff) | |
x86/speculation/mds: Add 'mitigations=' support for MDS
Add MDS to the new 'mitigations=' cmdline option.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -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 9aa3543a8723..18cad2b0392a 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2556,6 +2556,7 @@ 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 @@ -2570,6 +2571,7 @@ 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 3c5c3c3ba734..667c273a66d7 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -233,7 +233,7 @@ 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; } @@ -244,7 +244,8 @@ 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); } |