[PATCH v3 5/8] arm64: KVM: Force VHE for systems affected by erratum 1165522

[Marc Zyngier]

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

Signed-off-by: Marc Zyngier <marc.zyng...@arm.com>
---
 arch/arm64/include/asm/cpucaps.h  | 3 ++-
 arch/arm64/include/asm/kvm_host.h | 4 ++++
 arch/arm64/kernel/cpu_errata.c    | 8 ++++++++
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
index 6e2d254c09eb..62d8cd15fdf2 100644
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/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 */
diff --git a/arch/arm64/include/asm/kvm_host.h 
b/arch/arm64/include/asm/kvm_host.h
index d6d9aa76a943..9217759afa6b 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/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;
 }
 
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index a509e35132d2..476e738e6c46 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/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
        {
        }
-- 
2.19.2

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