[PATCH] arm64: KVM: Turn kvm_ksym_ref into a NOP on VHE

[Catalin Marinas]

On Fri, Mar 18, 2016 at 05:25:59PM +0000, Marc Zyngier wrote:
> When running with VHE, there is no need to translate kernel pointers
> to the EL2 memory space, since we're already there (and we have a much
> saner memory map to start with).
> 
> Unfortunately, kvm_ksym_ref is getting in the way, and the first
> call into the "hypervisor" section is going to end up in fireworks,
> since we're now branching into nowhereland. Meh.
> 
> A potential solution is to test if VHE is engaged or not, and only
> perform the translation in the negative case. With this in place,
> VHE is able to run again.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
> ---
>  arch/arm64/include/asm/kvm_asm.h | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
> index 226f49d..282f907 100644
> --- a/arch/arm64/include/asm/kvm_asm.h
> +++ b/arch/arm64/include/asm/kvm_asm.h
> @@ -26,7 +26,13 @@
>  #define KVM_ARM64_DEBUG_DIRTY_SHIFT	0
>  #define KVM_ARM64_DEBUG_DIRTY		(1 << KVM_ARM64_DEBUG_DIRTY_SHIFT)
>  
> -#define kvm_ksym_ref(sym)		phys_to_virt((u64)&sym - kimage_voffset)
> +#define kvm_ksym_ref(sym)						\
> +	({								\
> +		void *val = sym;					\

Should we not use &sym, for consistency and just in case we ever pass
something other than a function.

> +		if (!is_kernel_in_hyp_mode())				\
> +			val = phys_to_virt((u64)&sym - kimage_voffset);	\
> +		val;							\
> +	 })

Otherwise:

Acked-by: Catalin Marinas <catalin.marinas at arm.com>