diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h
index 1c6f6ac52ad0..aad3181c9b7b 100644
--- a/arch/x86/include/asm/fpu/types.h
+++ b/arch/x86/include/asm/fpu/types.h
@@ -108,6 +108,7 @@ enum xfeature {
 	XFEATURE_OPMASK,
 	XFEATURE_ZMM_Hi256,
 	XFEATURE_Hi16_ZMM,
+	XFEATURE_PT_UNIMPLEMENTED_SO_FAR,
 
 	XFEATURE_MAX,
 };
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index d425cda5ae6d..c2e2349dbcfe 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -13,6 +13,11 @@
 
 #include <asm/tlbflush.h>
 
+/*
+ * Although we spell it out in here, the Processor Trace
+ * xfeature is completely unused.  We use other mechanisms
+ * to save/restore PT state in Linux.
+ */
 static const char *xfeature_names[] =
 {
 	"x87 floating point registers"	,
@@ -23,7 +28,7 @@ static const char *xfeature_names[] =
 	"AVX-512 opmask"		,
 	"AVX-512 Hi256"			,
 	"AVX-512 ZMM_Hi256"		,
-	"unknown xstate feature"	,
+	"Processor Trace (unused)"	,
 };
 
 /*
@@ -470,7 +475,8 @@ static void check_xstate_against_struct(int nr)
 	 * numbers.
 	 */
 	if ((nr < XFEATURE_YMM) ||
-	    (nr >= XFEATURE_MAX)) {
+	    (nr >= XFEATURE_MAX) ||
+	    (nr == XFEATURE_PT_UNIMPLEMENTED_SO_FAR)) {
 		WARN_ONCE(1, "no structure for xstate: %d\n", nr);
 		XSTATE_WARN_ON(1);
 	}