[PATCH v2 1/3] KVM: arm64: Print warning when cpu erratum can cause guests to deadlock

[Will Deacon]

On Wed, Jul 01, 2020 at 03:53:06PM -0600, Rob Herring wrote:
> If guests don't have certain CPU erratum work-arounds 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 at kernel.org>
> Cc: James Morse <james.morse at arm.com>
> Cc: Julien Thierry <julien.thierry.kdev at gmail.com>
> Cc: Suzuki K Poulose <suzuki.poulose at arm.com>
> Cc: Catalin Marinas <catalin.marinas at arm.com>
> Cc: Will Deacon <will at kernel.org>
> Cc: kvmarm at lists.cs.columbia.edu
> Signed-off-by: Rob Herring <robh at kernel.org>
> ---
>  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..e2f50fa4d825 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_const_cap(ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE))
> +		kvm_info("Guests without required CPU erratum work-arounds can deadlock system!\n" \

work-arounds => workarounds

(mainly for consistency, I have no clue if this is a real word or not!).

I'd also probably do erratum => errata given that you're about to add a
second one.

Will