diff mbox series

[v4,06/12] iommu/vt-d: Set the nested domain to a device

Message ID 20230724111335.107427-7-yi.l.liu@intel.com (mailing list archive)
State New, archived
Headers show
Series Add Intel VT-d nested translation | expand

Commit Message

Yi Liu July 24, 2023, 11:13 a.m. UTC 
This adds the helper for setting the nested domain to a device hence
enable nested domain usage on Intel VT-d.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
 drivers/iommu/intel/nested.c | 52 ++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

Comments

Tian, Kevin Aug. 2, 2023, 7:22 a.m. UTC | #1 
> From: Liu, Yi L <yi.l.liu@intel.com>
> Sent: Monday, July 24, 2023 7:13 PM
> +
> +static int intel_nested_attach_dev(struct iommu_domain *domain,
> +				   struct device *dev)
> +{
> +	struct device_domain_info *info = dev_iommu_priv_get(dev);
> +	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
> +	struct intel_iommu *iommu = info->iommu;
> +	unsigned long flags;
> +	int ret = 0;
> +
> +	if (info->domain)
> +		device_block_translation(dev);
> +
> +	if (iommu->agaw < dmar_domain->s2_domain->agaw) {
> +		dev_err_ratelimited(dev, "Adjusted guest address width not
> compatible\n");
> +		return -ENODEV;
> +	}

this is the check duplicated with patch04.

> +
> +	ret = domain_attach_iommu(dmar_domain, iommu);
> +	if (ret) {
> +		dev_err_ratelimited(dev, "Failed to attach domain to
> iommu\n");
> +		return ret;
> +	}
> +

[...]

> +	domain_update_iommu_cap(dmar_domain);

iommu_cap is already updated in domain_attach_iommu().

> 
>  static const struct iommu_domain_ops intel_nested_domain_ops = {
> +	.attach_dev		= intel_nested_attach_dev,
>  	.free			= intel_nested_domain_free,
> +	.enforce_cache_coherency = intel_iommu_enforce_cache_coherency,

this is not required. enforce_cache_coherency() will be called on parent
hwpt when it's being created. patch04 should check parent's force_snooping
to set pgsnp in the pasid entry.

As Jason explained it should be done only for kernel owned page table.
Baolu Lu Aug. 3, 2023, 3:17 a.m. UTC | #2 
On 2023/8/2 15:22, Tian, Kevin wrote:
>> From: Liu, Yi L <yi.l.liu@intel.com>
>> Sent: Monday, July 24, 2023 7:13 PM
>> +
>> +static int intel_nested_attach_dev(struct iommu_domain *domain,
>> +				   struct device *dev)
>> +{
>> +	struct device_domain_info *info = dev_iommu_priv_get(dev);
>> +	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
>> +	struct intel_iommu *iommu = info->iommu;
>> +	unsigned long flags;
>> +	int ret = 0;
>> +
>> +	if (info->domain)
>> +		device_block_translation(dev);
>> +
>> +	if (iommu->agaw < dmar_domain->s2_domain->agaw) {
>> +		dev_err_ratelimited(dev, "Adjusted guest address width not
>> compatible\n");
>> +		return -ENODEV;
>> +	}
> 
> this is the check duplicated with patch04.

Ack. No need for a check here.

> 
>> +
>> +	ret = domain_attach_iommu(dmar_domain, iommu);
>> +	if (ret) {
>> +		dev_err_ratelimited(dev, "Failed to attach domain to
>> iommu\n");
>> +		return ret;
>> +	}
>> +
> 
> [...]
> 
>> +	domain_update_iommu_cap(dmar_domain);
> 
> iommu_cap is already updated in domain_attach_iommu().

Ack. We will eventually remove this helper when every domain is
allocated for a specific device.

>>
>>   static const struct iommu_domain_ops intel_nested_domain_ops = {
>> +	.attach_dev		= intel_nested_attach_dev,
>>   	.free			= intel_nested_domain_free,
>> +	.enforce_cache_coherency = intel_iommu_enforce_cache_coherency,
> 
> this is not required. enforce_cache_coherency() will be called on parent
> hwpt when it's being created. patch04 should check parent's force_snooping
> to set pgsnp in the pasid entry.
> 
> As Jason explained it should be done only for kernel owned page table.

Ack and thanks!

Best regards,
baolu
diff mbox series

Patch

diff --git a/drivers/iommu/intel/nested.c b/drivers/iommu/intel/nested.c
index 80a64ba87d46..98164894f22f 100644
--- a/drivers/iommu/intel/nested.c
+++ b/drivers/iommu/intel/nested.c
@@ -11,8 +11,58 @@ 
 #define pr_fmt(fmt)	"DMAR: " fmt
 
 #include <linux/iommu.h>
+#include <linux/pci.h>
+#include <linux/pci-ats.h>
 
 #include "iommu.h"
+#include "pasid.h"
+
+static int intel_nested_attach_dev(struct iommu_domain *domain,
+				   struct device *dev)
+{
+	struct device_domain_info *info = dev_iommu_priv_get(dev);
+	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+	struct intel_iommu *iommu = info->iommu;
+	unsigned long flags;
+	int ret = 0;
+
+	if (info->domain)
+		device_block_translation(dev);
+
+	if (iommu->agaw < dmar_domain->s2_domain->agaw) {
+		dev_err_ratelimited(dev, "Adjusted guest address width not compatible\n");
+		return -ENODEV;
+	}
+
+	/* Is s2_domain compatible with this IOMMU? */
+	ret = prepare_domain_attach_device(&dmar_domain->s2_domain->domain, dev);
+	if (ret) {
+		dev_err_ratelimited(dev, "s2 domain is not compatible\n");
+		return ret;
+	}
+
+	ret = domain_attach_iommu(dmar_domain, iommu);
+	if (ret) {
+		dev_err_ratelimited(dev, "Failed to attach domain to iommu\n");
+		return ret;
+	}
+
+	ret = intel_pasid_setup_nested(iommu, dev,
+				       PASID_RID2PASID, dmar_domain);
+	if (ret) {
+		domain_detach_iommu(dmar_domain, iommu);
+		dev_err_ratelimited(dev, "Failed to setup pasid entry\n");
+		return ret;
+	}
+
+	info->domain = dmar_domain;
+	spin_lock_irqsave(&dmar_domain->lock, flags);
+	list_add(&info->link, &dmar_domain->devices);
+	spin_unlock_irqrestore(&dmar_domain->lock, flags);
+	domain_update_iommu_cap(dmar_domain);
+
+	return 0;
+}
 
 static void intel_nested_domain_free(struct iommu_domain *domain)
 {
@@ -20,7 +70,9 @@  static void intel_nested_domain_free(struct iommu_domain *domain)
 }
 
 static const struct iommu_domain_ops intel_nested_domain_ops = {
+	.attach_dev		= intel_nested_attach_dev,
 	.free			= intel_nested_domain_free,
+	.enforce_cache_coherency = intel_iommu_enforce_cache_coherency,
 };
 
 struct iommu_domain *intel_nested_domain_alloc(struct iommu_domain *s2_domain,