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

2018-09-05 Thread Lu Baolu 

Hi,

On 09/06/2018 03:35 AM, Alex Williamson wrote:

On Thu, 30 Aug 2018 12:09:14 +0800
Lu Baolu  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 
Cc: Jacob Pan 
Cc: Kevin Tian 
Cc: Liu Yi L 
Signed-off-by: Lu Baolu 
---
  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
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Re: [RFC PATCH v2 02/10] iommu/vt-d: Add multiple domains per device query

2018-09-05 Thread Alex Williamson 
On Thu, 30 Aug 2018 12:09:14 +0800
Lu Baolu  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 
> Cc: Jacob Pan 
> Cc: Kevin Tian 
> Cc: Liu Yi L 
> Signed-off-by: Lu Baolu 
> ---
>  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
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[RFC PATCH v2 02/10] iommu/vt-d: Add multiple domains per device query

2018-08-29 Thread Lu Baolu 
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 
Cc: Jacob Pan 
Cc: Kevin Tian 
Cc: Liu Yi L 
Signed-off-by: Lu Baolu 
---
 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;
+   }
 
return false;
 }
-- 
2.17.1

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