From 1dd498e5e26ad71e3e9130daf72cfb6a693fee03 Mon Sep 17 00:00:00 2001 From: James Morse Date: Thu, 27 Jan 2022 12:20:52 +0000 Subject: 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 [maz: fixup cpucaps ordering] Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220127122052.1584324-5-james.morse@arm.com --- arch/arm64/Kconfig | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'arch/arm64/Kconfig') diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index f2b5a4abef21..cbcd42decb2a 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -680,6 +680,22 @@ config ARM64_ERRATUM_2051678 If unsure, say Y. +config ARM64_ERRATUM_2077057 + bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" + help + This option adds the workaround for ARM Cortex-A510 erratum 2077057. + Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception 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. + + This can only happen when EL2 is stepping EL1. + + When these conditions occur, the SPSR_EL2 value is unchanged from the + previous guest entry, and can be restored from the in-memory copy. + + If unsure, say Y. + config ARM64_ERRATUM_2119858 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" default y -- cgit v1.2.3