ACK: [PATCH][SRU Artful] KVM: arm/arm64: vgic-its: Fix return value for device table restore

[Kleber Souza]

On 11/09/17 03:19, dann frazier wrote:
> From: wanghaibin <wanghaibin.wang at huawei.com>
> 
> BugLink: https://bugs.launchpad.net/bugs/1710019
> 
> If ITT only contains invalid entries, vgic_its_restore_itt
> returns 1 and this is considered as an an error in
> vgic_its_restore_dte.
> 
> Also in case the device table only contains invalid entries,
> the table restore fails and this is not correct.
> 
> This patch fixes those 2 issues:
> - vgic_its_restore_itt now returns <= 0 values. If all
>   ITEs are invalid, this is considered as successful.
> - vgic_its_restore_device_tables also returns <= 0 values.
> 
> We also simplify the returned value computation in
> handle_l1_dte.
> 
> Signed-off-by: wanghaibin <wanghaibin.wang at huawei.com>
> Signed-off-by: Eric Auger <eric.auger at redhat.com>
> Reviewed-by: Christoffer Dall <christoffer.dall at linaro.org>
> Signed-off-by: Christoffer Dall <christoffer.dall at linaro.org>
> (cherry picked from commit b92382620e33c9f1bcbcd7c169262b9bf0525871)
> Signed-off-by: dann frazier <dann.frazier at canonical.com>

Acked-by: Kleber Sacilotto de Souza <kleber.souza at canonical.com>

> ---
>  virt/kvm/arm/vgic/vgic-its.c | 20 +++++++++++++++-----
>  1 file changed, 15 insertions(+), 5 deletions(-)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index aa6b68db80b4..dedf84b858fb 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -1942,6 +1942,14 @@ static int vgic_its_save_itt(struct vgic_its *its, struct its_device *device)
>  	return 0;
>  }
>  
> +/**
> + * vgic_its_restore_itt - restore the ITT of a device
> + *
> + * @its: its handle
> + * @dev: device handle
> + *
> + * Return 0 on success, < 0 on error
> + */
>  static int vgic_its_restore_itt(struct vgic_its *its, struct its_device *dev)
>  {
>  	const struct vgic_its_abi *abi = vgic_its_get_abi(its);
> @@ -1953,6 +1961,10 @@ static int vgic_its_restore_itt(struct vgic_its *its, struct its_device *dev)
>  	ret = scan_its_table(its, base, max_size, ite_esz, 0,
>  			     vgic_its_restore_ite, dev);
>  
> +	/* scan_its_table returns +1 if all ITEs are invalid */
> +	if (ret > 0)
> +		ret = 0;
> +
>  	return ret;
>  }
>  
> @@ -2109,10 +2121,7 @@ static int handle_l1_dte(struct vgic_its *its, u32 id, void *addr,
>  	ret = scan_its_table(its, gpa, SZ_64K, dte_esz,
>  			     l2_start_id, vgic_its_restore_dte, NULL);
>  
> -	if (ret <= 0)
> -		return ret;
> -
> -	return 1;
> +	return ret;
>  }
>  
>  /**
> @@ -2142,8 +2151,9 @@ static int vgic_its_restore_device_tables(struct vgic_its *its)
>  				     vgic_its_restore_dte, NULL);
>  	}
>  
> +	/* scan_its_table returns +1 if all entries are invalid */
>  	if (ret > 0)
> -		ret = -EINVAL;
> +		ret = 0;
>  
>  	return ret;
>  }
>