KVM: arm64: Workaround Cortex-A510's single-step and PAC trap errata

Cortex-A510's erratum #2077057 causes SPSR_EL2 to be corrupted when
single-stepping authenticated ERET instructions. A single step is
expected, but a pointer authentication trap is taken instead. The
erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
EL1 to cause a return to EL2 with a guest controlled ELR_EL2.

Because the conditions require an ERET into active-not-pending state,
this is only a problem for the EL2 when EL2 is stepping EL1. In this case
the previous SPSR_EL2 value is preserved in struct kvm_vcpu, and can be
restored.

Cc: stable@vger.kernel.org # 53960faf2b73: arm64: Add Cortex-A510 CPU part definition
Cc: stable@vger.kernel.org
Signed-off-by: James Morse <james.morse@arm.com>
[maz: fixup cpucaps ordering]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220127122052.1584324-5-james.morse@arm.com
diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps
index e7719e8..9c65b1e 100644
--- a/arch/arm64/tools/cpucaps
+++ b/arch/arm64/tools/cpucaps
@@ -55,9 +55,10 @@
 WORKAROUND_1463225
 WORKAROUND_1508412
 WORKAROUND_1542419
-WORKAROUND_2064142
-WORKAROUND_2038923
 WORKAROUND_1902691
+WORKAROUND_2038923
+WORKAROUND_2064142
+WORKAROUND_2077057
 WORKAROUND_TRBE_OVERWRITE_FILL_MODE
 WORKAROUND_TSB_FLUSH_FAILURE
 WORKAROUND_TRBE_WRITE_OUT_OF_RANGE