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-rw-r--r--arch/x86/kernel/cpu/amd.c5
-rw-r--r--arch/x86/kernel/process.c5
2 files changed, 9 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index bad0fa4c1779..0c0b09796ced 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -556,6 +556,8 @@ static void early_detect_mem_encrypt(struct cpuinfo_x86 *c)
* the SME physical address space reduction value.
* If BIOS has not enabled SME then don't advertise the
* SME feature (set in scattered.c).
+ * If the kernel has not enabled SME via any means then
+ * don't advertise the SME feature.
* For SEV: If BIOS has not enabled SEV then don't advertise the
* SEV and SEV_ES feature (set in scattered.c).
*
@@ -578,6 +580,9 @@ static void early_detect_mem_encrypt(struct cpuinfo_x86 *c)
if (IS_ENABLED(CONFIG_X86_32))
goto clear_all;
+ if (!sme_me_mask)
+ setup_clear_cpu_cap(X86_FEATURE_SME);
+
rdmsrl(MSR_K7_HWCR, msr);
if (!(msr & MSR_K7_HWCR_SMMLOCK))
goto clear_sev;
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 81d8ef036637..e131d71b3cae 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -765,8 +765,11 @@ void stop_this_cpu(void *dummy)
* without the encryption bit, they don't race each other when flushed
* and potentially end up with the wrong entry being committed to
* memory.
+ *
+ * Test the CPUID bit directly because the machine might've cleared
+ * X86_FEATURE_SME due to cmdline options.
*/
- if (boot_cpu_has(X86_FEATURE_SME))
+ if (cpuid_eax(0x8000001f) & BIT(0))
native_wbinvd();
for (;;) {
/*