If guests don't have certain CPU erratum workarounds implemented, then
there is a possibility a guest can deadlock the system. IOW, only trusted
guests should be used on systems with the erratum.
This is the case for Cortex-A57 erratum 832075.
Cc: Marc Zyngier <maz@xxxxxxxxxx>
Cc: James Morse <james.morse@xxxxxxx>
Cc: Julien Thierry <julien.thierry.kdev@xxxxxxxxx>
Cc: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: kvmarm@xxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
---
v4:
- Use cpus_have_final_cap instead of cpus_have_const_cap
v3:
- s/work-arounds/workarounds/
---
arch/arm64/kvm/arm.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 90cb90561446..cbc8365307f2 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1653,6 +1653,10 @@ int kvm_arch_init(void *opaque)
return -ENODEV;
}
+ if (cpus_have_final_cap(ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE))
+ kvm_info("Guests without required CPU erratum workarounds can deadlock system!\n" \
+ "Only trusted guests should be used on this system.\n");
+
for_each_online_cpu(cpu) {
smp_call_function_single(cpu, check_kvm_target_cpu, &ret, 1);
if (ret < 0) {
--
2.25.1
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