arm64: KVM: Add workaround for Cortex-A57 erratum 834220
Cortex-A57 parts up to r1p2 can misreport Stage 2 translation faults
when a Stage 1 permission fault or device alignment fault should
have been reported.
This patch implements the workaround (which is to validate that the
Stage-1 translation actually succeeds) by using code patching.
Cc: stable@vger.kernel.org
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 9ac16a4..e55848c 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -316,6 +316,27 @@
If unsure, say Y.
+config ARM64_ERRATUM_834220
+ bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
+ depends on KVM
+ default y
+ help
+ This option adds an alternative code sequence to work around ARM
+ erratum 834220 on Cortex-A57 parts up to r1p2.
+
+ Affected Cortex-A57 parts might report a Stage 2 translation
+ fault as the result of a Stage 1 fault for load crossing a
+ page boundary when there is a permission or device memory
+ alignment fault at Stage 1 and a translation fault at Stage 2.
+
+ The workaround is to verify that the Stage 1 translation
+ doesn't generate a fault before handling the Stage 2 fault.
+ Please note that this does not necessarily enable the workaround,
+ as it depends on the alternative framework, which will only patch
+ the kernel if an affected CPU is detected.
+
+ If unsure, say Y.
+
config ARM64_ERRATUM_845719
bool "Cortex-A53: 845719: a load might read incorrect data"
depends on COMPAT