Hi Marc,
On 05/11/2018 14:36, Marc Zyngier wrote:
Early versions of Cortex-A76 can end-up with corrupt TLBs if they
speculate an AT instruction in during a guest switch while the
S1/S2 system registers are in an inconsistent state.
Work around it by:
- Mandating VHE
- Make sure that S1 and S2 system registers are consistent before
clearing HCR_EL2.TGE, which allows AT to target the EL1 translation
regime
These two things together ensure that we cannot hit this erratum.
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
Documentation/arm64/silicon-errata.txt | 1 +
arch/arm64/Kconfig | 12 ++++++++++++
arch/arm64/include/asm/cpucaps.h | 3 ++-
arch/arm64/include/asm/kvm_host.h | 3 +++
arch/arm64/include/asm/kvm_hyp.h | 6 ++++++
arch/arm64/kernel/cpu_errata.c | 8 ++++++++
arch/arm64/kvm/hyp/switch.c | 14 ++++++++++++++
7 files changed, 46 insertions(+), 1 deletion(-)
diff --git a/Documentation/arm64/silicon-errata.txt b/Documentation/arm64/silicon-errata.txt
index 76ccded8b74c..04f0bc4690c6 100644
--- a/Documentation/arm64/silicon-errata.txt
+++ b/Documentation/arm64/silicon-errata.txt
@@ -57,6 +57,7 @@ stable kernels.
| ARM | Cortex-A73 | #858921 | ARM64_ERRATUM_858921 |
| ARM | Cortex-A55 | #1024718 | ARM64_ERRATUM_1024718 |
| ARM | Cortex-A76 | #1188873 | ARM64_ERRATUM_1188873 |
+| ARM | Cortex-A76 | #1165522 | ARM64_ERRATUM_1165522 |
| ARM | MMU-500 | #841119,#826419 | N/A |
| | | | |
| Cavium | ThunderX ITS | #22375, #24313 | CAVIUM_ERRATUM_22375 |
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 787d7850e064..a68bc6cc2167 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -497,6 +497,18 @@ config ARM64_ERRATUM_1188873
If unsure, say Y.
+config ARM64_ERRATUM_1165522
+ bool "Cortex-A76: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
+ default y
+ help
+ This option adds work arounds for ARM Cortex-A76 erratum 1165522
+
+ Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
+ corrupted TLBs by speculating an AT instruction during a guest
+ context switch.
+
+ If unsure, say Y.
Most of the code in the patch is not guarded by #ifdef ARM64_*. So is there any
benefits to add a Kconfig for this option?
Cheers,
--
Julien Grall
