[PATCH 08/10] iommu/vt-d: Add missing dirty tracking set for parent domain

[Lu Baolu]

From: Yi Liu <yi.l.liu@xxxxxxxxx>

Setting dirty tracking for a s2 domain requires to loop all the related
devices and set the dirty tracking enable bit in the PASID table entry.
This includes the devices that are attached to the nested domains of a
s2 domain if this s2 domain is used as parent. However, the existing dirty
tracking set only loops s2 domain's own devices. It will miss dirty page
logs in the parent domain.

Now, the parent domain tracks the nested domains, so it can loop the
nested domains and the devices attached to the nested domains to ensure
dirty tracking on the parent is set completely.

Fixes: b41e38e22539 ("iommu/vt-d: Add nested domain allocation")
Signed-off-by: Yi Sun <yi.y.sun@xxxxxxxxxxxxxxx>
Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>
Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
Link: https://lore.kernel.org/r/20240208082307.15759-9-yi.l.liu@xxxxxxxxx
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
 drivers/iommu/intel/iommu.c | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 2ad8fbe6dc21..11652e0bcab3 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4748,6 +4748,35 @@ static int device_set_dirty_tracking(struct list_head *devices, bool enable)
 	return ret;
 }
 
+static int parent_domain_set_dirty_tracking(struct dmar_domain *domain,
+					    bool enable)
+{
+	struct dmar_domain *s1_domain;
+	unsigned long flags;
+	int ret;
+
+	spin_lock(&domain->s1_lock);
+	list_for_each_entry(s1_domain, &domain->s1_domains, s2_link) {
+		spin_lock_irqsave(&s1_domain->lock, flags);
+		ret = device_set_dirty_tracking(&s1_domain->devices, enable);
+		spin_unlock_irqrestore(&s1_domain->lock, flags);
+		if (ret)
+			goto err_unwind;
+	}
+	spin_unlock(&domain->s1_lock);
+	return 0;
+
+err_unwind:
+	list_for_each_entry(s1_domain, &domain->s1_domains, s2_link) {
+		spin_lock_irqsave(&s1_domain->lock, flags);
+		device_set_dirty_tracking(&s1_domain->devices,
+					  domain->dirty_tracking);
+		spin_unlock_irqrestore(&s1_domain->lock, flags);
+	}
+	spin_unlock(&domain->s1_lock);
+	return ret;
+}
+
 static int intel_iommu_set_dirty_tracking(struct iommu_domain *domain,
 					  bool enable)
 {
@@ -4762,6 +4791,12 @@ static int intel_iommu_set_dirty_tracking(struct iommu_domain *domain,
 	if (ret)
 		goto err_unwind;
 
+	if (dmar_domain->nested_parent) {
+		ret = parent_domain_set_dirty_tracking(dmar_domain, enable);
+		if (ret)
+			goto err_unwind;
+	}
+
 	dmar_domain->dirty_tracking = enable;
 out_unlock:
 	spin_unlock(&dmar_domain->lock);
-- 
2.34.1