diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2019-02-18 22:04:08 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-16 19:45:14 +0200 |
| commit | 8c7398befdf1ecb163b5d0f6f5ba27b45c63211e (patch) | |
| tree | 92a8e5f9351e5c38532a233867eea0f8688860ad /arch/x86/include/asm/processor.h | |
| parent | d4c1e6cbbcdca0f4688a58092ecbb81a58fe4421 (diff) | |
x86/speculation/mds: Add mitigation control for MDS
commit bc1241700acd82ec69fde98c5763ce51086269f8 upstream.
Now that the mitigations are in place, add a command line parameter to
control the mitigation, a mitigation selector function and a SMT update
mechanism.
This is the minimal straight forward initial implementation which just
provides an always on/off mode. The command line parameter is:
mds=[full|off]
This is consistent with the existing mitigations for other speculative
hardware vulnerabilities.
The idle invocation is dynamically updated according to the SMT state of
the system similar to the dynamic update of the STIBP mitigation. The idle
mitigation is limited to CPUs which are only affected by MSBDS and not any
other variant, because the other variants cannot be mitigated on SMT
enabled systems.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>
[bwh: Backported to 4.4:
- Drop " __ro_after_init"
- Adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/include/asm/processor.h')
| -rw-r--r-- | arch/x86/include/asm/processor.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 440a948c4feb..af0f576617eb 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -845,4 +845,10 @@ bool xen_set_default_idle(void); void stop_this_cpu(void *dummy); void df_debug(struct pt_regs *regs, long error_code); + +enum mds_mitigations { + MDS_MITIGATION_OFF, + MDS_MITIGATION_FULL, +}; + #endif /* _ASM_X86_PROCESSOR_H */ |