On Fri, Apr 05, 2019 at 08:18:09AM -0700, Randy Dunlap wrote: > On 4/5/19 6:57 AM, Borislav Petkov wrote: > > On Thu, Apr 04, 2019 at 11:44:12AM -0500, Josh Poimboeuf wrote: > >> Configure x86 runtime CPU speculation bug mitigations in accordance with > >> the 'cpu_spec_mitigations=' cmdline options. This affects Meltdown, > >> Spectre v2, Speculative Store Bypass, and L1TF. > >> > >> The default behavior is unchanged. > >> > >> Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> > >> --- > >> .../admin-guide/kernel-parameters.txt | 15 +++++++++ > >> arch/x86/include/asm/processor.h | 1 + > >> arch/x86/kernel/cpu/bugs.c | 32 ++++++++++++++++--- > >> arch/x86/kvm/vmx/vmx.c | 2 ++ > >> arch/x86/mm/pti.c | 4 ++- > >> 5 files changed, 49 insertions(+), 5 deletions(-) > >> > >> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > >> index ac42e510bd6e..29dc03971630 100644 > >> --- a/Documentation/admin-guide/kernel-parameters.txt > >> +++ b/Documentation/admin-guide/kernel-parameters.txt > >> @@ -2552,6 +2552,11 @@ > >> > >> off > >> Disable all speculative CPU mitigations. > >> + Equivalent to: nopti [x86] > >> + nospectre_v2 [x86] > >> + spectre_v2_user=off [x86] > >> + spec_store_bypass_disable=off [x86] > >> + l1tf=off [x86] > >> > >> auto (default) > >> Mitigate all speculative CPU vulnerabilities, > >> @@ -2560,12 +2565,22 @@ > >> surprised by SMT getting disabled across kernel > >> upgrades, or who have other ways of avoiding > >> SMT-based attacks. > >> + Equivalent to: pti=auto [x86] > >> + spectre_v2=auto [x86] > >> + spectre_v2_user=auto [x86] > >> + spec_store_bypass_disable=auto [x86] > >> + l1tf=flush [x86] > >> > >> auto,nosmt > >> Mitigate all speculative CPU vulnerabilities, > >> disabling SMT if needed. This is for users who > >> always want to be fully mitigated, even if it > >> means losing SMT. > >> + Equivalent to: pti=auto [x86] > >> + spectre_v2=auto [x86] > >> + spectre_v2_user=auto [x86] > >> + spec_store_bypass_disable=auto [x86] > >> + l1tf=flush,nosmt [x86] > >> > >> mminit_loglevel= > >> [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this > > > > Yap, those sets look ok. > > nit: s/x86/X86/g > according to Documentation/admin-guide/kernel-parameters.rst Ah, I didn't realize I was conforming to a standard. I will update the other arch strings as well. Thanks. -- Josh
