[PATCH 1/1] iommu/vt-d: Global devTLB flush when present context entry changed

[PATCH 1/1] iommu/vt-d: Global devTLB flush when present context entry changed

[Lu Baolu]

From: Sanjay Kumar <sanjay.k.kumar@intel.com>

This fixes a bug in context cache clear operation. The code was not
following the correct invalidation flow. A global device TLB invalidation
should be added after the IOTLB invalidation. At the same time, it
uses the domain ID from the context entry. But in scalable mode, the
domain ID is in PASID table entry, not context entry.

Fixes: 7373a8cc38197 ("iommu/vt-d: Setup context and enable RID2PASID support")
Cc: stable@vger.kernel.org # v5.0+
Signed-off-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/intel/iommu.c | 31 ++++++++++++++++++++++---------
 1 file changed, 22 insertions(+), 9 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index a6a07d985709..57270290d62b 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2429,10 +2429,11 @@ __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
 	return 0;
 }
 
-static void domain_context_clear_one(struct intel_iommu *iommu, u8 bus, u8 devfn)
+static void domain_context_clear_one(struct device_domain_info *info, u8 bus, u8 devfn)
 {
-	unsigned long flags;
+	struct intel_iommu *iommu = info->iommu;
 	struct context_entry *context;
+	unsigned long flags;
 	u16 did_old;
 
 	if (!iommu)
@@ -2444,7 +2445,16 @@ static void domain_context_clear_one(struct intel_iommu *iommu, u8 bus, u8 devfn
 		spin_unlock_irqrestore(&iommu->lock, flags);
 		return;
 	}
-	did_old = context_domain_id(context);
+
+	if (sm_supported(iommu)) {
+		if (hw_pass_through && domain_type_is_si(info->domain))
+			did_old = FLPT_DEFAULT_DID;
+		else
+			did_old = info->domain->iommu_did[iommu->seq_id];
+	} else {
+		did_old = context_domain_id(context);
+	}
+
 	context_clear_entry(context);
 	__iommu_flush_cache(iommu, context, sizeof(*context));
 	spin_unlock_irqrestore(&iommu->lock, flags);
@@ -2462,6 +2472,8 @@ static void domain_context_clear_one(struct intel_iommu *iommu, u8 bus, u8 devfn
 				 0,
 				 0,
 				 DMA_TLB_DSI_FLUSH);
+
+	__iommu_flush_dev_iotlb(info, 0, MAX_AGAW_PFN_WIDTH);
 }
 
 static inline void unlink_domain_info(struct device_domain_info *info)
@@ -4425,9 +4437,9 @@ int __init intel_iommu_init(void)
 
 static int domain_context_clear_one_cb(struct pci_dev *pdev, u16 alias, void *opaque)
 {
-	struct intel_iommu *iommu = opaque;
+	struct device_domain_info *info = opaque;
 
-	domain_context_clear_one(iommu, PCI_BUS_NUM(alias), alias & 0xff);
+	domain_context_clear_one(info, PCI_BUS_NUM(alias), alias & 0xff);
 	return 0;
 }
 
@@ -4437,12 +4449,13 @@ static int domain_context_clear_one_cb(struct pci_dev *pdev, u16 alias, void *op
  * devices, unbinding the driver from any one of them will possibly leave
  * the others unable to operate.
  */
-static void domain_context_clear(struct intel_iommu *iommu, struct device *dev)
+static void domain_context_clear(struct device_domain_info *info)
 {
-	if (!iommu || !dev || !dev_is_pci(dev))
+	if (!info->iommu || !info->dev || !dev_is_pci(info->dev))
 		return;
 
-	pci_for_each_dma_alias(to_pci_dev(dev), &domain_context_clear_one_cb, iommu);
+	pci_for_each_dma_alias(to_pci_dev(info->dev),
+			       &domain_context_clear_one_cb, info);
 }
 
 static void __dmar_remove_one_dev_info(struct device_domain_info *info)
@@ -4466,7 +4479,7 @@ static void __dmar_remove_one_dev_info(struct device_domain_info *info)
 
 		iommu_disable_dev_iotlb(info);
 		if (!dev_is_real_dma_subdevice(info->dev))
-			domain_context_clear(iommu, info->dev);
+			domain_context_clear(info);
 		intel_pasid_free_table(info->dev);
 	}
 
-- 
2.25.1

Re: [PATCH 1/1] iommu/vt-d: Global devTLB flush when present context entry changed

[Joerg Roedel]

On Mon, Jul 12, 2021 at 03:13:15PM +0800, Lu Baolu wrote:
> ---
>  drivers/iommu/intel/iommu.c | 31 ++++++++++++++++++++++---------
>  1 file changed, 22 insertions(+), 9 deletions(-)

Applied, thanks.