Re: [RFC PATCH 3/3] kvm: arm/arm64: vgic-its: fix return value for restore

[Christoffer Dall <cdall@linaro.org>]

Hi Wanghaibin,

On Wed, Sep 06, 2017 at 09:05:10PM +0800, wanghaibin wrote:
> This patch fix the migrate restore tables failure.
> 
> The same scene, at the destination, the restore tables interface traversal guest
> memory, and check the dte/ite is valid or not.
> If all dtes/ites are invalid, we will do try next one, and the last it will take
> the 1 return value, but currently, it be treated as error. That's not correct.
> 
> This patch try to fix this problem.

This commit message needs some work.  It could sound something like
this:

When restoring the ITS, and scanning the ITS tables, we currently treat
empty tables as an error and cancel the restore process.

The problem is that we don't handle a return value == 1 from
scan_its_table as indicating that we have simply scanned an empty table.

Hope this helps,
-Christoffer

> 
> Signed-off-by: wanghaibin <wanghaibin.wang@huawei.com>
> ---
>  virt/kvm/arm/vgic/vgic-its.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index 5c20352..2c69aeb 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -2025,7 +2025,7 @@ static int vgic_its_restore_dte(struct vgic_its *its, u32 id,
>  		return PTR_ERR(dev);
>  
>  	ret = vgic_its_restore_itt(its, dev);
> -	if (ret) {
> +	if (ret < 0) {
>  		vgic_its_free_device(its->dev->kvm, dev);
>  		return ret;
>  	}
> @@ -2147,9 +2147,6 @@ static int vgic_its_restore_device_tables(struct vgic_its *its)
>  				     vgic_its_restore_dte, NULL);
>  	}
>  
> -	if (ret > 0)
> -		ret = -EINVAL;
> -
>  	return ret;
>  }
>  
> -- 
> 1.8.3.1
> 
>