Re: [PATCH] xen/arm : smmuv3: Fix to handle multiple StreamIds per device.

[Bertrand Marquis <Bertrand.Marquis@arm.com>]

Hi Rahul,


> On 17 Feb 2021, at 10:05, Rahul Singh <Rahul.Singh@arm.com> wrote:
> 
> SMMUv3 driver does not handle multiple StreamId if the master device
> supports more than one StreamID.
> 
> This bug was introduced when the driver was ported from Linux to XEN.
> dt_device_set_protected(..) should be called from add_device(..) not
> from the dt_xlate(..).
> 
> Move dt_device_set_protected(..) from dt_xlate(..) to add_device().
> 
> Signed-off-by: Rahul Singh <rahul.singh@arm.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>

Thanks a lot, this is fixing issues with multiple stream ids for one device :-)

Cheers
Bertrand

> ---
> This patch is a candidate for 4.15 as without this patch it is not possible to
> assign multiple StreamIds to the same device when device is protected behind
> SMMUv3.
> ---
> xen/drivers/passthrough/arm/smmu-v3.c | 29 ++++++++++-----------------
> 1 file changed, 11 insertions(+), 18 deletions(-)
> 
> diff --git a/xen/drivers/passthrough/arm/smmu-v3.c b/xen/drivers/passthrough/arm/smmu-v3.c
> index 914cdc1cf4..53d150cdb6 100644
> --- a/xen/drivers/passthrough/arm/smmu-v3.c
> +++ b/xen/drivers/passthrough/arm/smmu-v3.c
> @@ -2207,24 +2207,6 @@ static int arm_smmu_add_device(u8 devfn, struct device *dev)
> 	 */
> 	arm_smmu_enable_pasid(master);
> 
> -	return 0;
> -
> -err_free_master:
> -	xfree(master);
> -	dev_iommu_priv_set(dev, NULL);
> -	return ret;
> -}
> -
> -static int arm_smmu_dt_xlate(struct device *dev,
> -				const struct dt_phandle_args *args)
> -{
> -	int ret;
> -	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
> -
> -	ret = iommu_fwspec_add_ids(dev, args->args, 1);
> -	if (ret)
> -		return ret;
> -
> 	if (dt_device_is_protected(dev_to_dt(dev))) {
> 		dev_err(dev, "Already added to SMMUv3\n");
> 		return -EEXIST;
> @@ -2237,6 +2219,17 @@ static int arm_smmu_dt_xlate(struct device *dev,
> 			dev_name(fwspec->iommu_dev), fwspec->num_ids);
> 
> 	return 0;
> +
> +err_free_master:
> +	xfree(master);
> +	dev_iommu_priv_set(dev, NULL);
> +	return ret;
> +}
> +
> +static int arm_smmu_dt_xlate(struct device *dev,
> +				const struct dt_phandle_args *args)
> +{
> +	return iommu_fwspec_add_ids(dev, args->args, 1);
> }
> 
> /* Probing and initialisation functions */
> -- 
> 2.17.1
>