[PATCH v3 3/3] iommu/vt-d: Fix ineffective devTLB invalidation for subdevices

From: Liu Yi L
Date: Mon Dec 28 2020 - 22:29:36 EST


iommu_flush_dev_iotlb() is called to invalidate caches on device. It only
loops the devices which are full-attached to the domain. For sub-devices,
this is ineffective. This results in invalid caching entries left on the
device. Fix it by adding loop for subdevices as well. Also, the domain->
has_iotlb_device needs to be updated when attaching to subdevices.

Fixes: 67b8e02b5e761 ("iommu/vt-d: Aux-domain specific domain attach/detach")
Signed-off-by: Liu Yi L <yi.l.liu@xxxxxxxxx>
---
drivers/iommu/intel/iommu.c | 53 ++++++++++++++++++++++++++-----------
1 file changed, 37 insertions(+), 16 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index d7720a836268..d48a60b61ba6 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -719,6 +719,8 @@ static int domain_update_device_node(struct dmar_domain *domain)
return nid;
}

+static void domain_update_iotlb(struct dmar_domain *domain);
+
/* Some capabilities may be different across iommus */
static void domain_update_iommu_cap(struct dmar_domain *domain)
{
@@ -744,6 +746,8 @@ static void domain_update_iommu_cap(struct dmar_domain *domain)
domain->domain.geometry.aperture_end = __DOMAIN_MAX_ADDR(domain->gaw - 1);
else
domain->domain.geometry.aperture_end = __DOMAIN_MAX_ADDR(domain->gaw);
+
+ domain_update_iotlb(domain);
}

struct context_entry *iommu_context_addr(struct intel_iommu *iommu, u8 bus,
@@ -1464,17 +1468,22 @@ static void domain_update_iotlb(struct dmar_domain *domain)

assert_spin_locked(&device_domain_lock);

- list_for_each_entry(info, &domain->devices, link) {
- struct pci_dev *pdev;
-
- if (!info->dev || !dev_is_pci(info->dev))
- continue;
-
- pdev = to_pci_dev(info->dev);
- if (pdev->ats_enabled) {
+ list_for_each_entry(info, &domain->devices, link)
+ if (info && info->ats_enabled) {
has_iotlb_device = true;
break;
}
+
+ if (!has_iotlb_device) {
+ struct subdev_domain_info *sinfo;
+
+ list_for_each_entry(sinfo, &domain->subdevices, link_domain) {
+ info = get_domain_info(sinfo->pdev);
+ if (info && info->ats_enabled) {
+ has_iotlb_device = true;
+ break;
+ }
+ }
}

domain->has_iotlb_device = has_iotlb_device;
@@ -1555,25 +1564,37 @@ static void iommu_disable_dev_iotlb(struct device_domain_info *info)
#endif
}

+static void __iommu_flush_dev_iotlb(struct device_domain_info *info,
+ u64 addr, unsigned int mask)
+{
+ u16 sid, qdep;
+
+ if (!info || !info->ats_enabled)
+ return;
+
+ sid = info->bus << 8 | info->devfn;
+ qdep = info->ats_qdep;
+ qi_flush_dev_iotlb(info->iommu, sid, info->pfsid,
+ qdep, addr, mask);
+}
+
static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
u64 addr, unsigned mask)
{
- u16 sid, qdep;
unsigned long flags;
struct device_domain_info *info;
+ struct subdev_domain_info *sinfo;

if (!domain->has_iotlb_device)
return;

spin_lock_irqsave(&device_domain_lock, flags);
- list_for_each_entry(info, &domain->devices, link) {
- if (!info->ats_enabled)
- continue;
+ list_for_each_entry(info, &domain->devices, link)
+ __iommu_flush_dev_iotlb(info, addr, mask);

- sid = info->bus << 8 | info->devfn;
- qdep = info->ats_qdep;
- qi_flush_dev_iotlb(info->iommu, sid, info->pfsid,
- qdep, addr, mask);
+ list_for_each_entry(sinfo, &domain->subdevices, link_domain) {
+ __iommu_flush_dev_iotlb(get_domain_info(sinfo->pdev),
+ addr, mask);
}
spin_unlock_irqrestore(&device_domain_lock, flags);
}
--
2.25.1