IOMMU Fixes for Linux v5.3-rc4

Including:
 
 	- A couple more fixes for the Intel VT-d driver for bugs
 	  introduced during the recent conversion of this driver to use
 	  IOMMU core default domains.
 
 	- Fix for common dma-iommu code to make sure MSI mappings happen
 	  in the correct domain for a device.
 
 	- Fix a corner case in the handling of sg-lists in dma-iommu
 	  code that might cause dma_length to be truncated.
 
 	- Mark a switch as fall-through in arm-smmu code.
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEr9jSbILcajRFYWYyK/BELZcBGuMFAl1UFQIACgkQK/BELZcB
 GuNW1A//Y86ZFRSVCA/+ZiHgADwqsof1/Cdc1Ou1tXMbINbyWvWyT5t8JtplYsEJ
 17xlS7l2M9x1VCljzr3fTfBMGu8+CQY2KT6YJliLQZzrQ6LKoxmscCmg6DmH4Gjy
 CfoRLBXCKTm1F8aNt7f/XupuI+OGpq8h/VPDxYqZZIGKxsMfOH8ZIzF7DjDO2MxS
 NROjwAyVMZdzR5X/dM1dYK0zwxQvgRGEx8gdGssoyUCJvGdAyQXym30j8esNWJ6J
 okXVpuQoX/CJQLZP/xF8psWcL+0IJSyd3G90ToBRsoLDc50a4qTdelGvGkVHmU8L
 WVm+x7GjJrWZieqUtFnW/X7p4qSZdNMIK9c/+/cKg+BxyAKE9FqUJzg6UaSpzTbk
 XVh0jSiSq7/txU8pyGhEDQxgg4xbIUA5x1gqnqFm8k9Noz1/+AhfdyEUFzIHeE0s
 XwBfVVGzP2NW5zi97NebEuYsbHgDDSnR9sEKxhhq6G30vrwHEfg/MzdvNp6EupNp
 J1DnWD0DgMlYMxjZ8YskrSI7/MFB5PCxj/InwAXRZmlPPmlWIRTJfUtwYmhlkoLS
 zCxfS/sIof9C1pU7noe1WwOz8ylVPeQO3KvBIVhy3WJcVnCDlYX7/Uf/z/sU/d0Z
 Hd3/PQ6F6xTUEBzXKOFG/3y9EUQuoYP/fckFM4vmH9OEvYWmWqc=
 =+b4H
 -----END PGP SIGNATURE-----

Merge tag 'iommu-fixes-v5.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

Pull iommu fixes from Joerg Roedel:

 - A couple more fixes for the Intel VT-d driver for bugs introduced
   during the recent conversion of this driver to use IOMMU core default
   domains.

 - Fix for common dma-iommu code to make sure MSI mappings happen in the
   correct domain for a device.

 - Fix a corner case in the handling of sg-lists in dma-iommu code that
   might cause dma_length to be truncated.

 - Mark a switch as fall-through in arm-smmu code.

* tag 'iommu-fixes-v5.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/vt-d: Fix possible use-after-free of private domain
  iommu/vt-d: Detach domain before using a private one
  iommu/dma: Handle SG length overflow better
  iommu/vt-d: Correctly check format of page table in debugfs
  iommu/vt-d: Detach domain when move device out of group
  iommu/arm-smmu: Mark expected switch fall-through
  iommu/dma: Handle MSI mappings separately

drivers/iommu/arm-smmu-v3.c

@@ -1186,8 +1186,8 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid,
 			ste_live = true;
 			break;
 		case STRTAB_STE_0_CFG_ABORT:
-			if (disable_bypass)
-				break;
+			BUG_ON(!disable_bypass);
+			break;
 		default:
 			BUG(); /* STE corruption */
 		}

drivers/iommu/dma-iommu.c

@@ -459,13 +459,11 @@ static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,
 {
 	struct iommu_domain *domain = iommu_get_dma_domain(dev);
 	struct iommu_dma_cookie *cookie = domain->iova_cookie;
-	size_t iova_off = 0;
+	struct iova_domain *iovad = &cookie->iovad;
+	size_t iova_off = iova_offset(iovad, phys);
 	dma_addr_t iova;
 
-	if (cookie->type == IOMMU_DMA_IOVA_COOKIE) {
-		iova_off = iova_offset(&cookie->iovad, phys);
-		size = iova_align(&cookie->iovad, size + iova_off);
-	}
+	size = iova_align(iovad, size + iova_off);
 
 	iova = iommu_dma_alloc_iova(domain, size, dma_get_mask(dev), dev);
 	if (!iova)
@@ -764,7 +762,7 @@ static int __finalise_sg(struct device *dev, struct scatterlist *sg, int nents,
 		 * - and wouldn't make the resulting output segment too long
 		 */
 		if (cur_len && !s_iova_off && (dma_addr & seg_mask) &&
-		    (cur_len + s_length <= max_len)) {
+		    (max_len - cur_len >= s_length)) {
 			/* ...then concatenate it with the previous one */
 			cur_len += s_length;
 		} else {
@@ -1147,16 +1145,21 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
 	if (!msi_page)
 		return NULL;
 
-	iova = __iommu_dma_map(dev, msi_addr, size, prot);
-	if (iova == DMA_MAPPING_ERROR)
+	iova = iommu_dma_alloc_iova(domain, size, dma_get_mask(dev), dev);
+	if (!iova)
 		goto out_free_page;
 
+	if (iommu_map(domain, iova, msi_addr, size, prot))
+		goto out_free_iova;
+
 	INIT_LIST_HEAD(&msi_page->list);
 	msi_page->phys = msi_addr;
 	msi_page->iova = iova;
 	list_add(&msi_page->list, &cookie->msi_page_list);
 	return msi_page;
 
+out_free_iova:
+	iommu_dma_free_iova(cookie, iova, size);
 out_free_page:
 	kfree(msi_page);
 	return NULL;

drivers/iommu/intel-iommu-debugfs.c

@@ -235,7 +235,7 @@ static void ctx_tbl_walk(struct seq_file *m, struct intel_iommu *iommu, u16 bus)
 		tbl_wlk.ctx_entry = context;
 		m->private = &tbl_wlk;
 
-		if (pasid_supported(iommu) && is_pasid_enabled(context)) {
+		if (dmar_readq(iommu->reg + DMAR_RTADDR_REG) & DMA_RTADDR_SMT) {
 			pasid_dir_ptr = context->lo & VTD_PAGE_MASK;
 			pasid_dir_size = get_pasid_dir_size(context);
 			pasid_dir_walk(m, pasid_dir_ptr, pasid_dir_size);

drivers/iommu/intel-iommu.c

@@ -3449,6 +3449,7 @@ static bool iommu_need_mapping(struct device *dev)
 				dmar_domain = to_dmar_domain(domain);
 				dmar_domain->flags |= DOMAIN_FLAG_LOSE_CHILDREN;
 			}
+			dmar_remove_one_dev_info(dev);
 			get_private_domain_for_dev(dev);
 		}
 
@@ -4790,7 +4791,8 @@ static void __dmar_remove_one_dev_info(struct device_domain_info *info)
 
 	/* free the private domain */
 	if (domain->flags & DOMAIN_FLAG_LOSE_CHILDREN &&
-	    !(domain->flags & DOMAIN_FLAG_STATIC_IDENTITY))
+	    !(domain->flags & DOMAIN_FLAG_STATIC_IDENTITY) &&
+	    list_empty(&domain->devices))
 		domain_exit(info->domain);
 
 	free_devinfo_mem(info);
@@ -4803,7 +4805,8 @@ static void dmar_remove_one_dev_info(struct device *dev)
 
 	spin_lock_irqsave(&device_domain_lock, flags);
 	info = dev->archdata.iommu;
-	__dmar_remove_one_dev_info(info);
+	if (info)
+		__dmar_remove_one_dev_info(info);
 	spin_unlock_irqrestore(&device_domain_lock, flags);
 }
 
@@ -5281,6 +5284,7 @@ static int intel_iommu_add_device(struct device *dev)
 		if (device_def_domain_type(dev) == IOMMU_DOMAIN_IDENTITY) {
 			ret = iommu_request_dm_for_dev(dev);
 			if (ret) {
+				dmar_remove_one_dev_info(dev);
 				dmar_domain->flags |= DOMAIN_FLAG_LOSE_CHILDREN;
 				domain_add_dev_info(si_domain, dev);
 				dev_info(dev,
@@ -5291,6 +5295,7 @@ static int intel_iommu_add_device(struct device *dev)
 		if (device_def_domain_type(dev) == IOMMU_DOMAIN_DMA) {
 			ret = iommu_request_dma_domain_for_dev(dev);
 			if (ret) {
+				dmar_remove_one_dev_info(dev);
 				dmar_domain->flags |= DOMAIN_FLAG_LOSE_CHILDREN;
 				if (!get_private_domain_for_dev(dev)) {
 					dev_warn(dev,
@@ -5316,6 +5321,8 @@ static void intel_iommu_remove_device(struct device *dev)
 	if (!iommu)
 		return;
 
+	dmar_remove_one_dev_info(dev);
+
 	iommu_group_remove_device(dev);
 
 	iommu_device_unlink(&iommu->iommu, dev);