[PATCH] KVM: arm/arm64: vgic-v3: Fix nr_pre_bits bitfield extraction

[Marc Zyngier]

On 04/06/17 21:20, Christoffer Dall wrote:
> We used to extract PRIbits from the ICH_VT_EL2 which was the upper field
> in the register word, so a mask wasn't necessary, but as we switched to
> looking at PREbits, which is bits 26 through 28 with the PRIbits field
> being potentially non-zero, we really need to mask off the field value,
> otherwise fun things may happen.
> 
> Signed-off-by: Christoffer Dall <cdall at linaro.org>
> ---
>  virt/kvm/arm/hyp/vgic-v3-sr.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/virt/kvm/arm/hyp/vgic-v3-sr.c b/virt/kvm/arm/hyp/vgic-v3-sr.c
> index 32c3295..8794036 100644
> --- a/virt/kvm/arm/hyp/vgic-v3-sr.c
> +++ b/virt/kvm/arm/hyp/vgic-v3-sr.c
> @@ -22,7 +22,7 @@
>  #include <asm/kvm_hyp.h>
>  
>  #define vtr_to_max_lr_idx(v)		((v) & 0xf)
> -#define vtr_to_nr_pre_bits(v)		(((u32)(v) >> 26) + 1)
> +#define vtr_to_nr_pre_bits(v)		((((u32)(v) >> 26) & 7) + 1)
>  
>  static u64 __hyp_text __gic_v3_get_lr(unsigned int lr)
>  {
> 

Oops... I wonder why that didn't result in any other issues in my
code... :-(.

Acked-by: Marc Zyngier <marc.zyngier at arm.com>

	M.
-- 
Jazz is not dead. It just smells funny...