[PATCH 4/6] iommu/vt-d: Make intel_iommu_set_dev_pasid() to handle domain replacement

Yi Liu
2024-06-28T08:55:44Z

set_dev_pasid op is going to support domain replacement and keep the old
hardware config if it fails. Make the Intel iommu driver be prepared for
it.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
drivers/iommu/intel/debugfs.c | 2 +
drivers/iommu/intel/iommu.c | 94 +++++++++++++++++++++++------------
2 files changed, 64 insertions(+), 32 deletions(-)

diff --git a/drivers/iommu/intel/debugfs.c b/drivers/iommu/intel/debugfs.c
index affbf4a1558d..8deb6bc262c5 100644
--- a/drivers/iommu/intel/debugfs.c
+++ b/drivers/iommu/intel/debugfs.c
@@ -806,5 +806,7 @@ void intel_iommu_debugfs_create_dev_pasid(struct dev_pasid_info *dev_pasid)
/* Remove the device pasid debugfs directory. */
void intel_iommu_debugfs_remove_dev_pasid(struct dev_pasid_info *dev_pasid)
{
+ if (!dev_pasid->debugfs_dentry)
+ return;
debugfs_remove_recursive(dev_pasid->debugfs_dentry);
}
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index dd3de95c7122..8ef6c06f7e73 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4031,8 +4031,8 @@ static int intel_iommu_iotlb_sync_map(struct iommu_domain *domain,
return 0;
}

-static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid,
- struct iommu_domain *domain)
+static void domain_undo_dev_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid)
{
struct device_domain_info *info = dev_iommu_priv_get(dev);
struct dev_pasid_info *curr, *dev_pasid = NULL;
@@ -4040,9 +4040,6 @@ static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid,
struct dmar_domain *dmar_domain;
unsigned long flags;

- if (domain->type == IOMMU_DOMAIN_IDENTITY)
- goto out_tear_down;
-
dmar_domain = to_dmar_domain(domain);
spin_lock_irqsave(&dmar_domain->lock, flags);
list_for_each_entry(curr, &dmar_domain->dev_pasids, link_domain) {
@@ -4059,13 +4056,23 @@ static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid,
domain_detach_iommu(dmar_domain, iommu);
intel_iommu_debugfs_remove_dev_pasid(dev_pasid);
kfree(dev_pasid);
-out_tear_down:
+}
+
+static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid,
+ struct iommu_domain *domain)
+{
+ struct device_domain_info *info = dev_iommu_priv_get(dev);
+ struct intel_iommu *iommu = info->iommu;
+
intel_pasid_tear_down_entry(iommu, dev, pasid, false, true);
+ if (domain->type == IOMMU_DOMAIN_IDENTITY)
+ return;
+ domain_undo_dev_pasid(domain, dev, pasid);
}

-static int intel_iommu_set_dev_pasid(struct iommu_domain *domain,
- struct device *dev, ioasid_t pasid,
- struct iommu_domain *old)
+static struct dev_pasid_info *
+domain_prepare_dev_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid)
{
struct device_domain_info *info = dev_iommu_priv_get(dev);
struct dmar_domain *dmar_domain = to_dmar_domain(domain);
@@ -4074,22 +4081,13 @@ static int intel_iommu_set_dev_pasid(struct iommu_domain *domain,
unsigned long flags;
int ret;

- if (!pasid_supported(iommu) || dev_is_real_dma_subdevice(dev))
- return -EOPNOTSUPP;
-
- if (domain->dirty_ops)
- return -EINVAL;
-
- if (context_copied(iommu, info->bus, info->devfn))
- return -EBUSY;
-
ret = prepare_domain_attach_device(domain, dev);
if (ret)
- return ret;
+ return ERR_PTR(ret);

dev_pasid = kzalloc(sizeof(*dev_pasid), GFP_KERNEL);
if (!dev_pasid)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);

ret = domain_attach_iommu(dmar_domain, iommu);
if (ret)
@@ -4099,6 +4097,43 @@ static int intel_iommu_set_dev_pasid(struct iommu_domain *domain,
if (ret)
goto out_detach_iommu;

+ dev_pasid->dev = dev;
+ dev_pasid->pasid = pasid;
+ spin_lock_irqsave(&dmar_domain->lock, flags);
+ list_add(&dev_pasid->link_domain, &dmar_domain->dev_pasids);
+ spin_unlock_irqrestore(&dmar_domain->lock, flags);
+
+ return dev_pasid;
+out_detach_iommu:
+ domain_detach_iommu(dmar_domain, iommu);
+out_free:
+ kfree(dev_pasid);
+ return ERR_PTR(ret);
+}
+
+static int intel_iommu_set_dev_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid,
+ struct iommu_domain *old)
+{
+ 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;
+ struct dev_pasid_info *dev_pasid;
+ int ret;
+
+ if (!pasid_supported(iommu) || dev_is_real_dma_subdevice(dev))
+ return -EOPNOTSUPP;
+
+ if (domain->dirty_ops)
+ return -EINVAL;
+
+ if (context_copied(iommu, info->bus, info->devfn))
+ return -EBUSY;
+
+ dev_pasid = domain_prepare_dev_pasid(domain, dev, pasid);
+ if (IS_ERR(dev_pasid))
+ return PTR_ERR(dev_pasid);
+
if (dmar_domain->use_first_level)
ret = domain_setup_first_level(iommu, dmar_domain,
dev, pasid);
@@ -4106,24 +4141,19 @@ static int intel_iommu_set_dev_pasid(struct iommu_domain *domain,
ret = intel_pasid_setup_second_level(iommu, dmar_domain,
dev, pasid);
if (ret)
- goto out_unassign_tag;
+ goto out_undo_dev_pasid;

- dev_pasid->dev = dev;
- dev_pasid->pasid = pasid;
- spin_lock_irqsave(&dmar_domain->lock, flags);
- list_add(&dev_pasid->link_domain, &dmar_domain->dev_pasids);
- spin_unlock_irqrestore(&dmar_domain->lock, flags);
+ /* Undo the association between the old domain and pasid of a device */
+ if (old)
+ domain_undo_dev_pasid(old, dev, pasid);

if (domain->type & __IOMMU_DOMAIN_PAGING)
intel_iommu_debugfs_create_dev_pasid(dev_pasid);

return 0;
-out_unassign_tag:
- cache_tag_unassign_domain(dmar_domain, dev, pasid);
-out_detach_iommu:
- domain_detach_iommu(dmar_domain, iommu);
-out_free:
- kfree(dev_pasid);
+
+out_undo_dev_pasid:
+ domain_undo_dev_pasid(domain, dev, pasid);
return ret;
}

--
2.34.1