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

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

[Rahul Singh]

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>
---
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

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

[Bertrand Marquis]

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
> 

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

[Stefano Stabellini]

+IanJ

On Wed, 17 Feb 2021, Bertrand Marquis wrote:
> 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 :-)

Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>


> > ---
> > 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.

I agree especially considering that the impact is limited to smmu-v3.c.


> > ---
> > 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
> > 
> 

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

[Julien Grall]

Hi,

On 17/02/2021 23:23, Stefano Stabellini wrote:
> +IanJ
> 
> On Wed, 17 Feb 2021, Bertrand Marquis wrote:
>> 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 :-)
> 
> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
> 
> 
>>> ---
>>> 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.
> 
> I agree especially considering that the impact is limited to smmu-v3.c.

SMMUv3 is in tech preview, so the risk is pretty low as we don't support 
it :).

But, a release ack from Ian is not necessary until tonight (19th 
February) for bug fixes. So I have committed the patch.

Cheers,

-- 
Julien Grall