arm64: KVM: Force VHE for systems affected by erratum 1165522

In order to easily mitigate ARM erratum 1165522, we need to force
affected CPUs to run in VHE mode if using KVM.

Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

arch/arm64/include/asm/cpucaps.h

@@ -54,7 +54,8 @@
 #define ARM64_HAS_CRC32				33
 #define ARM64_SSBS				34
 #define ARM64_WORKAROUND_1188873		35
+#define ARM64_WORKAROUND_1165522		36
 
-#define ARM64_NCAPS				36
+#define ARM64_NCAPS				37
 
 #endif /* __ASM_CPUCAPS_H */

arch/arm64/include/asm/kvm_host.h

@@ -432,6 +432,10 @@ static inline bool kvm_arch_requires_vhe(void)
 	if (system_supports_sve())
 		return true;
 
+	/* Some implementations have defects that confine them to VHE */
+	if (cpus_have_cap(ARM64_WORKAROUND_1165522))
+		return true;
+
 	return false;
 }
 

arch/arm64/kernel/cpu_errata.c

@@ -739,6 +739,14 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 		.capability = ARM64_WORKAROUND_1188873,
 		ERRATA_MIDR_RANGE(MIDR_CORTEX_A76, 0, 0, 2, 0),
 	},
+#endif
+#ifdef CONFIG_ARM64_ERRATUM_1165522
+	{
+		/* Cortex-A76 r0p0 to r2p0 */
+		.desc = "ARM erratum 1165522",
+		.capability = ARM64_WORKAROUND_1165522,
+		ERRATA_MIDR_RANGE(MIDR_CORTEX_A76, 0, 0, 2, 0),
+	},
 #endif
 	{
 	}