[PATCH v5 5/7] iommu/vt-d: Prepare PASID attachment beyond RID_PASID

Jacob Pan
2023-04-27T17:46:05Z

Currently, device and default domain attaching process includes RID_PASID
setup whenever PASID is supported.
To prepare for non-RID_PASID usage such as ENQCMDS, we can factor out helper
functions such that they can be reused in any order between PASID and
device attachment. i.e. non-RID_PASID attachment via device_set_pasid()
can happen prior to device_attach().
It was agreed that upper level APIs should not make assumptions about
ordering.
Link: https://lore.kernel.org/lkml/ZAY4zd4OlgSz+puZ@nvidia.com/

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
drivers/iommu/intel/iommu.c | 106 ++++++++++++++++++++++++++++++++----
drivers/iommu/intel/iommu.h | 8 +++
2 files changed, 102 insertions(+), 12 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index cb586849a1ee..388453a7415e 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1365,6 +1365,7 @@ domain_lookup_dev_info(struct dmar_domain *domain,

static void domain_update_iotlb(struct dmar_domain *domain)
{
+ struct device_pasid_info *dev_pasid;
struct device_domain_info *info;
bool has_iotlb_device = false;
unsigned long flags;
@@ -1376,6 +1377,14 @@ static void domain_update_iotlb(struct dmar_domain *domain)
break;
}
}
+
+ list_for_each_entry(dev_pasid, &domain->dev_pasids, link_domain) {
+ info = dev_iommu_priv_get(dev_pasid->dev);
+ if (info->ats_enabled) {
+ has_iotlb_device = true;
+ break;
+ }
+ }
domain->has_iotlb_device = has_iotlb_device;
spin_unlock_irqrestore(&domain->lock, flags);
}
@@ -1486,6 +1495,7 @@ static void __iommu_flush_dev_iotlb(struct device_domain_info *info,
static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
u64 addr, unsigned mask)
{
+ struct device_pasid_info *dev_pasid;
struct device_domain_info *info;
unsigned long flags;

@@ -1495,6 +1505,39 @@ static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
spin_lock_irqsave(&domain->lock, flags);
list_for_each_entry(info, &domain->devices, link)
__iommu_flush_dev_iotlb(info, addr, mask);
+
+ list_for_each_entry(dev_pasid, &domain->dev_pasids, link_domain) {
+ /* device TLB is not aware of the use of RID PASID is for DMA w/o PASID */
+ if (dev_pasid->pasid == IOMMU_DEF_RID_PASID)
+ continue;
+
+ info = dev_iommu_priv_get(dev_pasid->dev);
+ qi_flush_dev_iotlb_pasid(info->iommu,
+ PCI_DEVID(info->bus, info->devfn),
+ info->pfsid, dev_pasid->pasid,
+ info->ats_qdep, addr,
+ mask);
+ }
+ spin_unlock_irqrestore(&domain->lock, flags);
+}
+
+/*
+ * The VT-d spec requires to use PASID-based-IOTLB Invalidation to
+ * invalidate IOTLB and the paging-structure-caches for a first-stage
+ * page table.
+ */
+static void domain_flush_pasid_iotlb(struct intel_iommu *iommu,
+ struct dmar_domain *domain, u64 addr,
+ unsigned long npages, bool ih)
+{
+ u16 did = domain_id_iommu(domain, iommu);
+ struct device_pasid_info *dev_pasid;
+ unsigned long flags;
+
+ spin_lock_irqsave(&domain->lock, flags);
+ list_for_each_entry(dev_pasid, &domain->dev_pasids, link_domain)
+ qi_flush_piotlb(iommu, did, dev_pasid->pasid, addr, npages, ih);
+
spin_unlock_irqrestore(&domain->lock, flags);
}

@@ -1514,7 +1557,7 @@ static void iommu_flush_iotlb_psi(struct intel_iommu *iommu,
ih = 1 << 6;

if (domain->use_first_level) {
- qi_flush_piotlb(iommu, did, IOMMU_DEF_RID_PASID, addr, pages, ih);
+ domain_flush_pasid_iotlb(iommu, domain, addr, pages, ih);
} else {
unsigned long bitmask = aligned_pages - 1;

@@ -1584,7 +1627,7 @@ static void intel_flush_iotlb_all(struct iommu_domain *domain)
u16 did = domain_id_iommu(dmar_domain, iommu);

if (dmar_domain->use_first_level)
- qi_flush_piotlb(iommu, did, IOMMU_DEF_RID_PASID, 0, -1, 0);
+ domain_flush_pasid_iotlb(iommu, dmar_domain, 0, -1, 0);
else
iommu->flush.flush_iotlb(iommu, did, 0, 0,
DMA_TLB_DSI_FLUSH);
@@ -1756,6 +1799,7 @@ static struct dmar_domain *alloc_domain(unsigned int type)
domain->use_first_level = true;
domain->has_iotlb_device = false;
INIT_LIST_HEAD(&domain->devices);
+ INIT_LIST_HEAD(&domain->dev_pasids);
spin_lock_init(&domain->lock);
xa_init(&domain->iommu_array);

@@ -2433,12 +2477,17 @@ static int dmar_domain_attach_device_pasid(struct dmar_domain *domain,
struct intel_iommu *iommu,
struct device *dev, ioasid_t pasid)
{
+ struct device_pasid_info *dev_pasid;
+ unsigned long flags;
int ret;

- /* PASID table is mandatory for a PCI device in scalable mode. */
if (!sm_supported(iommu) && dev_is_real_dma_subdevice(dev))
return -EOPNOTSUPP;

+ dev_pasid = kzalloc(sizeof(*dev_pasid), GFP_KERNEL);
+ if (!dev_pasid)
+ return -ENOMEM;
+
if (hw_pass_through && domain_type_is_si(domain))
ret = intel_pasid_setup_pass_through(iommu, domain, dev, pasid);
else if (domain->use_first_level)
@@ -2446,6 +2495,17 @@ static int dmar_domain_attach_device_pasid(struct dmar_domain *domain,
else
ret = intel_pasid_setup_second_level(iommu, domain, dev, pasid);

+ if (ret) {
+ kfree(dev_pasid);
+ return ret;
+ }
+
+ dev_pasid->pasid = pasid;
+ dev_pasid->dev = dev;
+ spin_lock_irqsave(&domain->lock, flags);
+ list_add(&dev_pasid->link_domain, &domain->dev_pasids);
+ spin_unlock_irqrestore(&domain->lock, flags);
+
return 0;
}

@@ -2467,16 +2527,13 @@ static int dmar_domain_attach_device(struct dmar_domain *domain,
return ret;
info->domain = domain;
spin_lock_irqsave(&domain->lock, flags);
+ if (info->dev_attached) {
+ spin_unlock_irqrestore(&domain->lock, flags);
+ return 0;
+ }
list_add(&info->link, &domain->devices);
spin_unlock_irqrestore(&domain->lock, flags);

- ret = dmar_domain_attach_device_pasid(domain, iommu, dev,
- IOMMU_DEF_RID_PASID);
- if (ret) {
- dev_err(dev, "Setup RID2PASID failed\n");
- device_block_translation(dev);
- }
-
ret = domain_context_mapping(domain, dev);
if (ret) {
dev_err(dev, "Domain context map failed\n");
@@ -2485,8 +2542,9 @@ static int dmar_domain_attach_device(struct dmar_domain *domain,
}

iommu_enable_pci_caps(info);
+ info->dev_attached = 1;

- return 0;
+ return ret;
}

static bool device_has_rmrr(struct device *dev)
@@ -4044,6 +4102,7 @@ static void device_block_translation(struct device *dev)

spin_lock_irqsave(&info->domain->lock, flags);
list_del(&info->link);
+ info->dev_attached = 0;
spin_unlock_irqrestore(&info->domain->lock, flags);

domain_detach_iommu(info->domain, iommu);
@@ -4175,8 +4234,15 @@ static int intel_iommu_attach_device(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;
+ u8 bus, devfn;
int ret;

+ iommu = device_to_iommu(dev, &bus, &devfn);
+ if (!iommu)
+ return -ENODEV;
+
if (domain->type == IOMMU_DOMAIN_UNMANAGED &&
device_is_rmrr_locked(dev)) {
dev_warn(dev, "Device is ineligible for IOMMU domain attach due to platform RMRR requirement. Contact your platform vendor.\n");
@@ -4190,7 +4256,23 @@ static int intel_iommu_attach_device(struct iommu_domain *domain,
if (ret)
return ret;

- return dmar_domain_attach_device(to_dmar_domain(domain), dev);
+ ret = dmar_domain_attach_device(to_dmar_domain(domain), dev);
+ if (ret) {
+ dev_err(dev, "Attach device failed\n");
+ return ret;
+ }
+
+ /* PASID table is mandatory for a PCI device in scalable mode. */
+ if (sm_supported(iommu) && !dev_is_real_dma_subdevice(dev)) {
+ /* Setup the PASID entry for requests without PASID: */
+ ret = dmar_domain_attach_device_pasid(dmar_domain, iommu, dev,
+ IOMMU_DEF_RID_PASID);
+ if (ret) {
+ dev_err(dev, "Setup RID2PASID failed\n");
+ device_block_translation(dev);
+ }
+ }
+ return ret;
}

static int intel_iommu_map(struct iommu_domain *domain,
diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index 65b15be72878..b6c26f25d1ba 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -595,6 +595,7 @@ struct dmar_domain {

spinlock_t lock; /* Protect device tracking lists */
struct list_head devices; /* all devices' list */
+ struct list_head dev_pasids; /* all attached pasids */

struct dma_pte *pgd; /* virtual address */
int gaw; /* max guest address width */
@@ -708,6 +709,7 @@ struct device_domain_info {
u8 ats_supported:1;
u8 ats_enabled:1;
u8 dtlb_extra_inval:1; /* Quirk for devices need extra flush */
+ u8 dev_attached:1; /* Device context activated */
u8 ats_qdep;
struct device *dev; /* it's NULL for PCIe-to-PCI bridge */
struct intel_iommu *iommu; /* IOMMU used by this device */
@@ -715,6 +717,12 @@ struct device_domain_info {
struct pasid_table *pasid_table; /* pasid table */
};

+struct device_pasid_info {
+ struct list_head link_domain; /* link to domain siblings */
+ struct device *dev; /* physical device derived from */
+ ioasid_t pasid; /* PASID on physical device */
+};
+
static inline void __iommu_flush_cache(
struct intel_iommu *iommu, void *addr, int size)
{
--
2.25.1