Merge tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd

Pull iommufd updates from Jason Gunthorpe:
 "Some polishing and small fixes for iommufd:

   - Remove IOMMU_CAP_INTR_REMAP, instead rely on the interrupt
     subsystem

   - Use GFP_KERNEL_ACCOUNT inside the iommu_domains

   - Support VFIO_NOIOMMU mode with iommufd

   - Various typos

   - A list corruption bug if HWPTs are used for attach"

* tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd:
  iommufd: Do not add the same hwpt to the ioas->hwpt_list twice
  iommufd: Make sure to zero vfio_iommu_type1_info before copying to user
  vfio: Support VFIO_NOIOMMU with iommufd
  iommufd: Add three missing structures in ucmd_buffer
  selftests: iommu: Fix test_cmd_destroy_access() call in user_copy
  iommu: Remove IOMMU_CAP_INTR_REMAP
  irq/s390: Add arch_is_isolated_msi() for s390
  iommu/x86: Replace IOMMU_CAP_INTR_REMAP with IRQ_DOMAIN_FLAG_ISOLATED_MSI
  genirq/msi: Rename IRQ_DOMAIN_MSI_REMAP to IRQ_DOMAIN_ISOLATED_MSI
  genirq/irqdomain: Remove unused irq_domain_check_msi_remap() code
  iommufd: Convert to msi_device_has_isolated_msi()
  vfio/type1: Convert to iommu_group_has_isolated_msi()
  iommu: Add iommu_group_has_isolated_msi()
  genirq/msi: Add msi_device_has_isolated_msi()

1 files changed, 87 insertions, 20 deletions

diff --git a/drivers/iommu/iommufd/vfio_compat.c b/drivers/iommu/iommufd/vfio_compat.c
index 3ceca0e8311c..514494a0025b 100644
--- a/drivers/iommu/iommufd/vfio_compat.c
+++ b/drivers/iommu/iommufd/vfio_compat.c
@@ -26,39 +26,84 @@ out_unlock:
 }
 
 /**
- * iommufd_vfio_compat_ioas_id - Return the IOAS ID that vfio should use
+ * iommufd_vfio_compat_ioas_get_id - Ensure a compat IOAS exists
+ * @ictx: Context to operate on
+ * @out_ioas_id: The IOAS ID of the compatibility IOAS
+ *
+ * Return the ID of the current compatibility IOAS. The ID can be passed into
+ * other functions that take an ioas_id.
+ */
+int iommufd_vfio_compat_ioas_get_id(struct iommufd_ctx *ictx, u32 *out_ioas_id)
+{
+	struct iommufd_ioas *ioas;
+
+	ioas = get_compat_ioas(ictx);
+	if (IS_ERR(ioas))
+		return PTR_ERR(ioas);
+	*out_ioas_id = ioas->obj.id;
+	iommufd_put_object(&ioas->obj);
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_vfio_compat_ioas_get_id, IOMMUFD_VFIO);
+
+/**
+ * iommufd_vfio_compat_set_no_iommu - Called when a no-iommu device is attached
+ * @ictx: Context to operate on
+ *
+ * This allows selecting the VFIO_NOIOMMU_IOMMU and blocks normal types.
+ */
+int iommufd_vfio_compat_set_no_iommu(struct iommufd_ctx *ictx)
+{
+	int ret;
+
+	xa_lock(&ictx->objects);
+	if (!ictx->vfio_ioas) {
+		ictx->no_iommu_mode = 1;
+		ret = 0;
+	} else {
+		ret = -EINVAL;
+	}
+	xa_unlock(&ictx->objects);
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_vfio_compat_set_no_iommu, IOMMUFD_VFIO);
+
+/**
+ * iommufd_vfio_compat_ioas_create - Ensure the compat IOAS is created
  * @ictx: Context to operate on
- * @out_ioas_id: The ioas_id the caller should use
  *
  * The compatibility IOAS is the IOAS that the vfio compatibility ioctls operate
  * on since they do not have an IOAS ID input in their ABI. Only attaching a
- * group should cause a default creation of the internal ioas, this returns the
- * existing ioas if it has already been assigned somehow.
+ * group should cause a default creation of the internal ioas, this does nothing
+ * if an existing ioas has already been assigned somehow.
  */
-int iommufd_vfio_compat_ioas_id(struct iommufd_ctx *ictx, u32 *out_ioas_id)
+int iommufd_vfio_compat_ioas_create(struct iommufd_ctx *ictx)
 {
 	struct iommufd_ioas *ioas = NULL;
-	struct iommufd_ioas *out_ioas;
+	int ret;
 
 	ioas = iommufd_ioas_alloc(ictx);
 	if (IS_ERR(ioas))
 		return PTR_ERR(ioas);
 
 	xa_lock(&ictx->objects);
-	if (ictx->vfio_ioas && iommufd_lock_obj(&ictx->vfio_ioas->obj))
-		out_ioas = ictx->vfio_ioas;
-	else {
-		out_ioas = ioas;
-		ictx->vfio_ioas = ioas;
+	/*
+	 * VFIO won't allow attaching a container to both iommu and no iommu
+	 * operation
+	 */
+	if (ictx->no_iommu_mode) {
+		ret = -EINVAL;
+		goto out_abort;
 	}
-	xa_unlock(&ictx->objects);
 
-	*out_ioas_id = out_ioas->obj.id;
-	if (out_ioas != ioas) {
-		iommufd_put_object(&out_ioas->obj);
-		iommufd_object_abort(ictx, &ioas->obj);
-		return 0;
+	if (ictx->vfio_ioas && iommufd_lock_obj(&ictx->vfio_ioas->obj)) {
+		ret = 0;
+		iommufd_put_object(&ictx->vfio_ioas->obj);
+		goto out_abort;
 	}
+	ictx->vfio_ioas = ioas;
+	xa_unlock(&ictx->objects);
+
 	/*
 	 * An automatically created compat IOAS is treated as a userspace
 	 * created object. Userspace can learn the ID via IOMMU_VFIO_IOAS_GET,
@@ -67,8 +112,13 @@ int iommufd_vfio_compat_ioas_id(struct iommufd_ctx *ictx, u32 *out_ioas_id)
 	 */
 	iommufd_object_finalize(ictx, &ioas->obj);
 	return 0;
+
+out_abort:
+	xa_unlock(&ictx->objects);
+	iommufd_object_abort(ictx, &ioas->obj);
+	return ret;
 }
-EXPORT_SYMBOL_NS_GPL(iommufd_vfio_compat_ioas_id, IOMMUFD_VFIO);
+EXPORT_SYMBOL_NS_GPL(iommufd_vfio_compat_ioas_create, IOMMUFD_VFIO);
 
 int iommufd_vfio_ioas(struct iommufd_ucmd *ucmd)
 {
@@ -235,6 +285,9 @@ static int iommufd_vfio_check_extension(struct iommufd_ctx *ictx,
 	case VFIO_UNMAP_ALL:
 		return 1;
 
+	case VFIO_NOIOMMU_IOMMU:
+		return IS_ENABLED(CONFIG_VFIO_NOIOMMU);
+
 	case VFIO_DMA_CC_IOMMU:
 		return iommufd_vfio_cc_iommu(ictx);
 
@@ -261,10 +314,24 @@ static int iommufd_vfio_check_extension(struct iommufd_ctx *ictx,
 
 static int iommufd_vfio_set_iommu(struct iommufd_ctx *ictx, unsigned long type)
 {
+	bool no_iommu_mode = READ_ONCE(ictx->no_iommu_mode);
 	struct iommufd_ioas *ioas = NULL;
 	int rc = 0;
 
-	if (type != VFIO_TYPE1_IOMMU && type != VFIO_TYPE1v2_IOMMU)
+	/*
+	 * Emulation for NOIOMMU is imperfect in that VFIO blocks almost all
+	 * other ioctls. We let them keep working but they mostly fail since no
+	 * IOAS should exist.
+	 */
+	if (IS_ENABLED(CONFIG_VFIO_NOIOMMU) && type == VFIO_NOIOMMU_IOMMU &&
+	    no_iommu_mode) {
+		if (!capable(CAP_SYS_RAWIO))
+			return -EPERM;
+		return 0;
+	}
+
+	if ((type != VFIO_TYPE1_IOMMU && type != VFIO_TYPE1v2_IOMMU) ||
+	    no_iommu_mode)
 		return -EINVAL;
 
 	/* VFIO fails the set_iommu if there is no group */
@@ -381,7 +448,7 @@ static int iommufd_vfio_iommu_get_info(struct iommufd_ctx *ictx,
 	};
 	size_t minsz = offsetofend(struct vfio_iommu_type1_info, iova_pgsizes);
 	struct vfio_info_cap_header __user *last_cap = NULL;
-	struct vfio_iommu_type1_info info;
+	struct vfio_iommu_type1_info info = {};
 	struct iommufd_ioas *ioas;
 	size_t total_cap_size;
 	int rc;