Remove mmio_stale_data kernel parameter since it can be set with the common
clear_cpu_buffers parameter.
Signed-off-by: Daniel Sneddon <daniel.sneddon@xxxxxxxxxxxxxxx>
---
.../admin-guide/kernel-parameters.txt | 34 -------------------
arch/x86/kernel/cpu/bugs.c | 21 ------------
2 files changed, 55 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 961e637b8126..7afccd044fb8 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3498,40 +3498,6 @@
log everything. Information is printed at KERN_DEBUG
so loglevel=8 may also need to be specified.
- mmio_stale_data=
- [X86,INTEL,EARLY] Control mitigation for the Processor
- MMIO Stale Data vulnerabilities.
-
- Processor MMIO Stale Data is a class of
- vulnerabilities that may expose data after an MMIO
- operation. Exposed data could originate or end in
- the same CPU buffers as affected by MDS and TAA.
- Therefore, similar to MDS and TAA, the mitigation
- is to clear the affected CPU buffers.
-
- This parameter controls the mitigation. The
- options are:
-
- full - Enable mitigation on vulnerable CPUs
-
- full,nosmt - Enable mitigation and disable SMT on
- vulnerable CPUs.
-
- off - Unconditionally disable mitigation
-
- On MDS or TAA affected machines,
- mmio_stale_data=off can be prevented by an active
- MDS or TAA mitigation as these vulnerabilities are
- mitigated with the same mechanism so in order to
- disable this mitigation, you need to specify
- mds=off and tsx_async_abort=off too.
-
- Not specifying this option is equivalent to
- mmio_stale_data=full.
-
- For details see:
- Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst
-
<module>.async_probe[=<bool>] [KNL]
If no <bool> value is specified or if the value
specified is not a valid <bool>, enable asynchronous
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 0a09f0d1a343..63a8cda2fe30 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -414,27 +414,6 @@ static void __init mmio_select_mitigation(void)
cpu_smt_disable(false);
}
-static int __init mmio_stale_data_parse_cmdline(char *str)
-{
- if (!boot_cpu_has_bug(X86_BUG_MMIO_STALE_DATA))
- return 0;
-
- if (!str)
- return -EINVAL;
-
- if (!strcmp(str, "off")) {
- mmio_mitigation = MMIO_MITIGATION_OFF;
- } else if (!strcmp(str, "full")) {
- mmio_mitigation = MMIO_MITIGATION_VERW;
- } else if (!strcmp(str, "full,nosmt")) {
- mmio_mitigation = MMIO_MITIGATION_VERW;
- mmio_nosmt = true;
- }
-
- return 0;
-}
-early_param("mmio_stale_data", mmio_stale_data_parse_cmdline);
-
#undef pr_fmt
#define pr_fmt(fmt) "Register File Data Sampling: " fmt
--
2.25.1
