x86/cpufeatures: Combine word 11 and 12 into a new scattered features word

It's a waste for the four X86_FEATURE_CQM_* feature bits to occupy two
whole feature bits words. To better utilize feature words, re-define
word 11 to host scattered features and move the four X86_FEATURE_CQM_*
features into Linux defined word 11. More scattered features can be
added in word 11 in the future.

Rename leaf 11 in cpuid_leafs to CPUID_LNX_4 to reflect it's a
Linux-defined leaf.

Rename leaf 12 as CPUID_DUMMY which will be replaced by a meaningful
name in the next patch when CPUID.7.1:EAX occupies world 12.

Maximum number of RMID and cache occupancy scale are retrieved from
CPUID.0xf.1 after scattered CQM features are enumerated. Carve out the
code into a separate function.

KVM doesn't support resctrl now. So it's safe to move the
X86_FEATURE_CQM_* features to scattered features word 11 for KVM.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Aaron Lewis <aaronlewis@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Babu Moger <babu.moger@amd.com>
Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: "Sean J Christopherson" <sean.j.christopherson@intel.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Ravi V Shankar <ravi.v.shankar@intel.com>
Cc: Sherry Hurwitz <sherry.hurwitz@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Lendacky <Thomas.Lendacky@amd.com>
Cc: x86 <x86@kernel.org>
Link: https://lkml.kernel.org/r/1560794416-217638-2-git-send-email-fenghua.yu@intel.com

CVE-2019-1125

(backported from commit acec0ce0)
[tyhicks: Backport to Xenial:
 - Adjust context in cpufeatures.h
 - No need to modify cpuid.h since we're missing commit d6321d49
   ("KVM: x86: generalize guest_cpuid_has_ helpers")
 - No need to modify cpuid-deps.c since we're missing commit
   0b00de85 ("x86/cpuid: Add generic table for CPUID dependencies")
 - Change CPUID_EDX to CR_EDX since we're missing commit 47f10a36
   ("x86/cpuid: Cleanup cpuid_regs definitions")]
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

arch/x86/include/asm/cpufeature.h

@@ -21,8 +21,8 @@ enum cpuid_leafs
 	CPUID_LNX_3,
 	CPUID_7_0_EBX,
 	CPUID_D_1_EAX,
-	CPUID_F_0_EDX,
-	CPUID_F_1_EDX,
+	CPUID_LNX_4,
+	CPUID_DUMMY,
 	CPUID_8000_0008_EBX,
 	CPUID_6_EAX,
 	CPUID_8000_000A_EDX,

arch/x86/include/asm/cpufeatures.h

@@ -259,13 +259,16 @@
 #define X86_FEATURE_XGETBV1	(10*32+ 2) /* XGETBV with ECX = 1 */
 #define X86_FEATURE_XSAVES	(10*32+ 3) /* XSAVES/XRSTORS */
 
-/* Intel-defined CPU QoS Sub-leaf, CPUID level 0x0000000F:0 (edx), word 11 */
-#define X86_FEATURE_CQM_LLC	(11*32+ 1) /* LLC QoS if 1 */
-
-/* Intel-defined CPU QoS Sub-leaf, CPUID level 0x0000000F:1 (edx), word 12 */
-#define X86_FEATURE_CQM_OCCUP_LLC (12*32+ 0) /* LLC occupancy monitoring if 1 */
-#define X86_FEATURE_CQM_MBM_TOTAL (12*32+ 1) /* LLC Total MBM monitoring */
-#define X86_FEATURE_CQM_MBM_LOCAL (12*32+ 2) /* LLC Local MBM monitoring */
+/*
+ * Extended auxiliary flags: Linux defined - for features scattered in various
+ * CPUID levels like 0xf, etc.
+ *
+ * Reuse free bits when adding new feature flags!
+ */
+#define X86_FEATURE_CQM_LLC		(11*32+ 0) /* LLC QoS if 1 */
+#define X86_FEATURE_CQM_OCCUP_LLC	(11*32+ 1) /* LLC occupancy monitoring */
+#define X86_FEATURE_CQM_MBM_TOTAL	(11*32+ 2) /* LLC Total MBM monitoring */
+#define X86_FEATURE_CQM_MBM_LOCAL	(11*32+ 3) /* LLC Local MBM monitoring */
 
 /* AMD-defined CPU features, CPUID level 0x80000008 (ebx), word 13 */
 #define X86_FEATURE_CLZERO	(13*32+0) /* CLZERO instruction */

arch/x86/kernel/cpu/common.c

@@ -713,34 +713,26 @@ static void init_speculation_control(struct cpuinfo_x86 *c)
 
 static void init_cqm(struct cpuinfo_x86 *c)
 {
-	u32 eax, ebx, ecx, edx;
-
-	/* Additional Intel-defined flags: level 0x0000000F */
-	if (c->cpuid_level >= 0x0000000F) {
-
-		/* QoS sub-leaf, EAX=0Fh, ECX=0 */
-		cpuid_count(0x0000000F, 0, &eax, &ebx, &ecx, &edx);
-		c->x86_capability[CPUID_F_0_EDX] = edx;
+	if (!cpu_has(c, X86_FEATURE_CQM_LLC)) {
+		c->x86_cache_max_rmid  = -1;
+		c->x86_cache_occ_scale = -1;
+		return;
+	}
 
-		if (cpu_has(c, X86_FEATURE_CQM_LLC)) {
 	/* will be overridden if occupancy monitoring exists */
-			c->x86_cache_max_rmid = ebx;
+	c->x86_cache_max_rmid = cpuid_ebx(0xf);
+
+	if (cpu_has(c, X86_FEATURE_CQM_OCCUP_LLC) ||
+	    cpu_has(c, X86_FEATURE_CQM_MBM_TOTAL) ||
+	    cpu_has(c, X86_FEATURE_CQM_MBM_LOCAL)) {
+		u32 eax, ebx, ecx, edx;
 
 		/* QoS sub-leaf, EAX=0Fh, ECX=1 */
-			cpuid_count(0x0000000F, 1, &eax, &ebx, &ecx, &edx);
-			c->x86_capability[CPUID_F_1_EDX] = edx;
+		cpuid_count(0xf, 1, &eax, &ebx, &ecx, &edx);
 
-			if ((cpu_has(c, X86_FEATURE_CQM_OCCUP_LLC)) ||
-			      ((cpu_has(c, X86_FEATURE_CQM_MBM_TOTAL)) ||
-			       (cpu_has(c, X86_FEATURE_CQM_MBM_LOCAL)))) {
 		c->x86_cache_max_rmid  = ecx;
 		c->x86_cache_occ_scale = ebx;
 	}
-		} else {
-			c->x86_cache_max_rmid = -1;
-			c->x86_cache_occ_scale = -1;
-		}
-	}
 }
 
 void get_cpu_cap(struct cpuinfo_x86 *c)

arch/x86/kernel/cpu/scattered.c

@@ -29,6 +29,10 @@ static const struct cpuid_bit cpuid_bits[] = {
 	{ X86_FEATURE_INTEL_PT,		CR_EBX,25, 0x00000007, 0 },
 	{ X86_FEATURE_APERFMPERF,	CR_ECX, 0, 0x00000006, 0 },
 	{ X86_FEATURE_EPB,		CR_ECX, 3, 0x00000006, 0 },
+	{ X86_FEATURE_CQM_LLC,		CR_EDX, 1, 0x0000000f, 0 },
+	{ X86_FEATURE_CQM_OCCUP_LLC,	CR_EDX, 0, 0x0000000f, 1 },
+	{ X86_FEATURE_CQM_MBM_TOTAL,	CR_EDX, 1, 0x0000000f, 1 },
+	{ X86_FEATURE_CQM_MBM_LOCAL,	CR_EDX, 2, 0x0000000f, 1 },
 	{ X86_FEATURE_HW_PSTATE,	CR_EDX, 7, 0x80000007, 0 },
 	{ X86_FEATURE_CPB,		CR_EDX, 9, 0x80000007, 0 },
 	{ X86_FEATURE_PROC_FEEDBACK,	CR_EDX,11, 0x80000007, 0 },