x86/cpufeatures: Move X86_FEATURE_CALL_DEPTH from bit 18 to bit 19 of word 11, to leave space for WIP X86_FEATURE_SGX_EDECCSSA bit

Reallocate a soft-cpufeatures bit allocated for call-depth tracking
code, which clashes with this recent KVM/SGX patch being worked on:

        KVM/VMX: Allow exposing EDECCSSA user leaf function to KVM guest

Instead of reallocating cpufeatures bits in evil merges, make the
allocation explicit.

Acked-by: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: [email protected]
Cc: Linus Torvalds <[email protected]>
Cc: [email protected]
Signed-off-by: Ingo Molnar <[email protected]>

Author: Ingo Molnar

arch/x86/include/asm/cpufeatures.h

@@ -304,7 +304,8 @@
 #define X86_FEATURE_UNRET		(11*32+15) /* "" AMD BTB untrain return */
 #define X86_FEATURE_USE_IBPB_FW		(11*32+16) /* "" Use IBPB during runtime firmware calls */
 #define X86_FEATURE_RSB_VMEXIT_LITE	(11*32+17) /* "" Fill RSB on VM exit when EIBRS is enabled */
-#define X86_FEATURE_CALL_DEPTH		(11*32+18) /* "" Call depth tracking for RSB stuffing */
+						   /* Hole left for X86_FEATURE_SGX_EDECCSSA */
+#define X86_FEATURE_CALL_DEPTH		(11*32+19) /* "" Call depth tracking for RSB stuffing */
 
 /* Intel-defined CPU features, CPUID level 0x00000007:1 (EAX), word 12 */
 #define X86_FEATURE_AVX_VNNI		(12*32+ 4) /* AVX VNNI instructions */