[PATCH v4 1/7] iommu/vt-d: Allocate pasid table in device probe path

From: Lu Baolu
Date: Fri Nov 18 2022 - 08:32:51 EST


Whether or not a domain is attached to the device, the pasid table should
always be valid as long as it has been probed. This moves the pasid table
allocation from the domain attaching device path to device probe path and
frees it in the device release path.

Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
---
drivers/iommu/intel/iommu.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 996a8b5ee5ee..6b8a24f68da8 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2475,13 +2475,6 @@ static int domain_add_dev_info(struct dmar_domain *domain, struct device *dev)

/* PASID table is mandatory for a PCI device in scalable mode. */
if (sm_supported(iommu) && !dev_is_real_dma_subdevice(dev)) {
- ret = intel_pasid_alloc_table(dev);
- if (ret) {
- dev_err(dev, "PASID table allocation failed\n");
- dmar_remove_one_dev_info(dev);
- return ret;
- }
-
/* Setup the PASID entry for requests without PASID: */
if (hw_pass_through && domain_type_is_si(domain))
ret = intel_pasid_setup_pass_through(iommu, domain,
@@ -4106,7 +4099,6 @@ static void dmar_remove_one_dev_info(struct device *dev)

iommu_disable_dev_iotlb(info);
domain_context_clear(info);
- intel_pasid_free_table(info->dev);
}

spin_lock_irqsave(&domain->lock, flags);
@@ -4466,6 +4458,7 @@ static struct iommu_device *intel_iommu_probe_device(struct device *dev)
struct device_domain_info *info;
struct intel_iommu *iommu;
u8 bus, devfn;
+ int ret;

iommu = device_to_iommu(dev, &bus, &devfn);
if (!iommu || !iommu->iommu.ops)
@@ -4509,6 +4502,16 @@ static struct iommu_device *intel_iommu_probe_device(struct device *dev)

dev_iommu_priv_set(dev, info);

+ if (sm_supported(iommu) && !dev_is_real_dma_subdevice(dev)) {
+ ret = intel_pasid_alloc_table(dev);
+ if (ret) {
+ dev_err(dev, "PASID table allocation failed\n");
+ dev_iommu_priv_set(dev, NULL);
+ kfree(info);
+ return ERR_PTR(ret);
+ }
+ }
+
return &iommu->iommu;
}

@@ -4517,6 +4520,7 @@ static void intel_iommu_release_device(struct device *dev)
struct device_domain_info *info = dev_iommu_priv_get(dev);

dmar_remove_one_dev_info(dev);
+ intel_pasid_free_table(dev);
dev_iommu_priv_set(dev, NULL);
kfree(info);
set_dma_ops(dev, NULL);
--
2.34.1