diff mbox series

[RFC,v2,02/10] iommu/vt-d: Add multiple domains per device query

Message ID 20180830040922.30426-3-baolu.lu@linux.intel.com (mailing list archive)
State New, archived
Headers show
Series vfio/mdev: IOMMU aware mediated device | expand

Commit Message

Baolu Lu Aug. 30, 2018, 4:09 a.m. UTC
Add the response to IOMMU_CAP_AUX_DOMAIN capability query
through iommu_capable(). Return true if IOMMUs support the
scalable mode, return false otherwise.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/intel-iommu.c | 31 +++++++++++++++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

Comments

Alex Williamson Sept. 5, 2018, 7:35 p.m. UTC | #1
On Thu, 30 Aug 2018 12:09:14 +0800
Lu Baolu <baolu.lu@linux.intel.com> wrote:

> Add the response to IOMMU_CAP_AUX_DOMAIN capability query
> through iommu_capable(). Return true if IOMMUs support the
> scalable mode, return false otherwise.
> 
> Cc: Ashok Raj <ashok.raj@intel.com>
> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Cc: Kevin Tian <kevin.tian@intel.com>
> Cc: Liu Yi L <yi.l.liu@intel.com>
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
>  drivers/iommu/intel-iommu.c | 31 +++++++++++++++++++++++++++++--
>  1 file changed, 29 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index 3e49d4029058..891ae70e7bf2 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -5193,12 +5193,39 @@ static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain,
>  	return phys;
>  }
>  
> +static inline bool scalable_mode_support(void)
> +{
> +	struct dmar_drhd_unit *drhd;
> +	struct intel_iommu *iommu;
> +	bool ret = true;
> +
> +	rcu_read_lock();
> +	for_each_active_iommu(iommu, drhd) {
> +		if (!sm_supported(iommu)) {
> +			ret = false;
> +			break;
> +		}
> +	}
> +	rcu_read_unlock();
> +
> +	return ret;
> +}
> +
>  static bool intel_iommu_capable(enum iommu_cap cap)
>  {
> -	if (cap == IOMMU_CAP_CACHE_COHERENCY)
> +	switch (cap) {
> +	case IOMMU_CAP_CACHE_COHERENCY:
>  		return domain_update_iommu_snooping(NULL) == 1;
> -	if (cap == IOMMU_CAP_INTR_REMAP)
> +	case IOMMU_CAP_INTR_REMAP:
>  		return irq_remapping_enabled == 1;
> +	case IOMMU_CAP_AUX_DOMAIN:
> +		return scalable_mode_support();
> +	case IOMMU_CAP_NOEXEC:
> +	/* PASSTHROUGH */
> +	default:
> +		pr_info("Unsupported capability query %d\n", cap);
> +		break;

Please don't do this, there's no reason to be noisy about a query of a
capability that VT-d doesn't know about.  We implement capabilities
exactly so that relevant drivers can expose a feature and others can
happily (and quietly) ignore them.  Thanks,

Alex
Baolu Lu Sept. 6, 2018, 12:54 a.m. UTC | #2
Hi,

On 09/06/2018 03:35 AM, Alex Williamson wrote:
> On Thu, 30 Aug 2018 12:09:14 +0800
> Lu Baolu <baolu.lu@linux.intel.com> wrote:
> 
>> Add the response to IOMMU_CAP_AUX_DOMAIN capability query
>> through iommu_capable(). Return true if IOMMUs support the
>> scalable mode, return false otherwise.
>>
>> Cc: Ashok Raj <ashok.raj@intel.com>
>> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
>> Cc: Kevin Tian <kevin.tian@intel.com>
>> Cc: Liu Yi L <yi.l.liu@intel.com>
>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>> ---
>>   drivers/iommu/intel-iommu.c | 31 +++++++++++++++++++++++++++++--
>>   1 file changed, 29 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
>> index 3e49d4029058..891ae70e7bf2 100644
>> --- a/drivers/iommu/intel-iommu.c
>> +++ b/drivers/iommu/intel-iommu.c
>> @@ -5193,12 +5193,39 @@ static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain,
>>   	return phys;
>>   }
>>   
>> +static inline bool scalable_mode_support(void)
>> +{
>> +	struct dmar_drhd_unit *drhd;
>> +	struct intel_iommu *iommu;
>> +	bool ret = true;
>> +
>> +	rcu_read_lock();
>> +	for_each_active_iommu(iommu, drhd) {
>> +		if (!sm_supported(iommu)) {
>> +			ret = false;
>> +			break;
>> +		}
>> +	}
>> +	rcu_read_unlock();
>> +
>> +	return ret;
>> +}
>> +
>>   static bool intel_iommu_capable(enum iommu_cap cap)
>>   {
>> -	if (cap == IOMMU_CAP_CACHE_COHERENCY)
>> +	switch (cap) {
>> +	case IOMMU_CAP_CACHE_COHERENCY:
>>   		return domain_update_iommu_snooping(NULL) == 1;
>> -	if (cap == IOMMU_CAP_INTR_REMAP)
>> +	case IOMMU_CAP_INTR_REMAP:
>>   		return irq_remapping_enabled == 1;
>> +	case IOMMU_CAP_AUX_DOMAIN:
>> +		return scalable_mode_support();
>> +	case IOMMU_CAP_NOEXEC:
>> +	/* PASSTHROUGH */
>> +	default:
>> +		pr_info("Unsupported capability query %d\n", cap);
>> +		break;
> 
> Please don't do this, there's no reason to be noisy about a query of a
> capability that VT-d doesn't know about.  We implement capabilities
> exactly so that relevant drivers can expose a feature and others can
> happily (and quietly) ignore them.  Thanks,

Fair enough. I will remove it in the next version.

Best regards,
Lu Baolu
diff mbox series

Patch

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 3e49d4029058..891ae70e7bf2 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5193,12 +5193,39 @@  static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain,
 	return phys;
 }
 
+static inline bool scalable_mode_support(void)
+{
+	struct dmar_drhd_unit *drhd;
+	struct intel_iommu *iommu;
+	bool ret = true;
+
+	rcu_read_lock();
+	for_each_active_iommu(iommu, drhd) {
+		if (!sm_supported(iommu)) {
+			ret = false;
+			break;
+		}
+	}
+	rcu_read_unlock();
+
+	return ret;
+}
+
 static bool intel_iommu_capable(enum iommu_cap cap)
 {
-	if (cap == IOMMU_CAP_CACHE_COHERENCY)
+	switch (cap) {
+	case IOMMU_CAP_CACHE_COHERENCY:
 		return domain_update_iommu_snooping(NULL) == 1;
-	if (cap == IOMMU_CAP_INTR_REMAP)
+	case IOMMU_CAP_INTR_REMAP:
 		return irq_remapping_enabled == 1;
+	case IOMMU_CAP_AUX_DOMAIN:
+		return scalable_mode_support();
+	case IOMMU_CAP_NOEXEC:
+	/* PASSTHROUGH */
+	default:
+		pr_info("Unsupported capability query %d\n", cap);
+		break;
+	}
 
 	return false;
 }