From 2e519fd8c1e3e7ae5370a6638615d2a52169db28 Mon Sep 17 00:00:00 2001
From: Bertrand Marquis <bertrand.marquis@arm.com>
Date: Wed, 23 Feb 2022 09:42:18 +0000
Subject: xen/arm: Add ECBHB and CLEARBHB ID fields

Introduce ID coprocessor register ID_AA64ISAR2_EL1.
Add definitions in cpufeature and sysregs of ECBHB field in mmfr1 and
CLEARBHB in isar2 ID coprocessor registers.

This is part of XSA-398 / CVE-2022-23960.

Signed-off-by: Bertrand Marquis <bertrand.marquis@arm.com>
Acked-by: Julien Grall <julien@xen.org>
(cherry picked from commit 4b68d12d98b8790d8002fcc2c25a9d713374a4d7)

diff --git a/xen/arch/arm/cpufeature.c b/xen/arch/arm/cpufeature.c
index 44126dbf0723..13dac7ccaf94 100644
--- a/xen/arch/arm/cpufeature.c
+++ b/xen/arch/arm/cpufeature.c
@@ -117,6 +117,7 @@ void identify_cpu(struct cpuinfo_arm *c)
 
         c->isa64.bits[0] = READ_SYSREG64(ID_AA64ISAR0_EL1);
         c->isa64.bits[1] = READ_SYSREG64(ID_AA64ISAR1_EL1);
+        c->isa64.bits[2] = READ_SYSREG64(ID_AA64ISAR2_EL1);
 #endif
 
         c->pfr32.bits[0] = READ_SYSREG32(ID_PFR0_EL1);
diff --git a/xen/include/asm-arm/arm64/sysregs.h b/xen/include/asm-arm/arm64/sysregs.h
index 08585a969ebd..5f1e9b998f33 100644
--- a/xen/include/asm-arm/arm64/sysregs.h
+++ b/xen/include/asm-arm/arm64/sysregs.h
@@ -57,6 +57,10 @@
 #define ICH_AP1R2_EL2             __AP1Rx_EL2(2)
 #define ICH_AP1R3_EL2             __AP1Rx_EL2(3)
 
+#ifndef ID_AA64ISAR2_EL1
+#define ID_AA64ISAR2_EL1            S3_0_C0_C6_2
+#endif
+
 /* Access to system registers */
 
 #define READ_SYSREG32(name) ({                          \
diff --git a/xen/include/asm-arm/cpufeature.h b/xen/include/asm-arm/cpufeature.h
index 60e677d84200..c748fc17fe66 100644
--- a/xen/include/asm-arm/cpufeature.h
+++ b/xen/include/asm-arm/cpufeature.h
@@ -182,12 +182,26 @@ struct cpuinfo_arm {
             unsigned long lo:4;
             unsigned long pan:4;
             unsigned long __res1:8;
-            unsigned long __res2:32;
+            unsigned long __res2:28;
+            unsigned long ecbhb:4;
         };
     } mm64;
 
-    struct {
-        uint64_t bits[2];
+    union {
+        uint64_t bits[3];
+        struct {
+            /* ISAR0 */
+            unsigned long __res0:64;
+
+            /* ISAR1 */
+            unsigned long __res1:64;
+
+            /* ISAR2 */
+            unsigned long __res3:28;
+            unsigned long clearbhb:4;
+
+            unsigned long __res4:32;
+        };
     } isa64;
 
 #endif