linux-kernel - [PATCH v3 2/6] vfio/type1: Check reserve region conflict and update iova list

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Message-ID: <20180215094504.4972-3-shameerali.kolothum.thodi@huawei.com>
Date:   Thu, 15 Feb 2018 09:45:00 +0000
From:   Shameer Kolothum <shameerali.kolothum.thodi@...wei.com>
To:     <alex.williamson@...hat.com>, <eric.auger@...hat.com>,
        <pmorel@...ux.vnet.ibm.com>
CC:     <kvm@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <linuxarm@...wei.com>, <john.garry@...wei.com>,
        <xuwei5@...ilicon.com>,
        Shameer Kolothum <shameerali.kolothum.thodi@...wei.com>
Subject: [PATCH v3 2/6] vfio/type1: Check reserve region conflict and update iova list

This retrieves the reserved regions associated with dev group and
checks for conflicts with any existing dma mappings. Also update
the iova list excluding the reserved regions.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@...wei.com>
---
 drivers/vfio/vfio_iommu_type1.c | 86 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 85 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 4726f55..4db87a9 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -1303,6 +1303,72 @@ static int vfio_iommu_aper_resize(struct list_head *iova,
 	return 0;
 }
 
+/*
+ * Check reserved region conflicts with existing dma mappings
+ */
+static bool vfio_iommu_resv_conflict(struct vfio_iommu *iommu,
+				struct list_head *resv_regions)
+{
+	struct iommu_resv_region *region;
+
+	/* Check for conflict with existing dma mappings */
+	list_for_each_entry(region, resv_regions, list) {
+		if (vfio_find_dma(iommu, region->start, region->length))
+			return true;
+	}
+
+	return false;
+}
+
+/*
+ * Check iova region overlap with  reserved regions and
+ * exclude them from the iommu iova range
+ */
+static int vfio_iommu_resv_exclude(struct list_head *iova,
+					struct list_head *resv_regions)
+{
+	struct iommu_resv_region *resv;
+	struct vfio_iova *n, *next;
+
+	list_for_each_entry(resv, resv_regions, list) {
+		phys_addr_t start, end;
+
+		start = resv->start;
+		end = resv->start + resv->length - 1;
+
+		list_for_each_entry_safe(n, next, iova, list) {
+			int ret = 0;
+
+			/* No overlap */
+			if ((start > n->end) || (end < n->start))
+				continue;
+			/*
+			 * Insert a new node if current node overlaps with the
+			 * reserve region to exlude that from valid iova range.
+			 * Note that, new node is inserted before the current
+			 * node and finally the current node is deleted keeping
+			 * the list updated and sorted.
+			 */
+			if (start > n->start)
+				ret = vfio_insert_iova(n->start, start - 1,
+								 &n->list);
+			if (!ret && end < n->end)
+				ret = vfio_insert_iova(end + 1, n->end,
+							     &n->list);
+			if (ret)
+				return ret;
+
+			list_del(&n->list);
+			kfree(n);
+		}
+	}
+
+	if (list_empty(iova))
+		return -EINVAL;
+
+	return 0;
+}
+
 static int vfio_iommu_get_iova_copy(struct vfio_iommu *iommu,
 				struct list_head *iova_copy)
 {
@@ -1346,7 +1412,8 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 	bool resv_msi, msi_remap;
 	phys_addr_t resv_msi_base;
 	struct iommu_domain_geometry geo;
-	struct list_head iova_copy;
+	struct list_head iova_copy, group_resv_regions;
+	struct iommu_resv_region *resv, *resv_next;
 	struct vfio_iova *iova, *iova_next;
 
 	mutex_lock(&iommu->lock);
@@ -1426,6 +1493,14 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 		goto out_detach;
 	}
 
+	INIT_LIST_HEAD(&group_resv_regions);
+	iommu_get_group_resv_regions(iommu_group, &group_resv_regions);
+
+	if (vfio_iommu_resv_conflict(iommu, &group_resv_regions)) {
+		ret = -EINVAL;
+		goto out_detach;
+	}
+
 	/* Get a copy of the current iova list and work on it */
 	INIT_LIST_HEAD(&iova_copy);
 	ret = vfio_iommu_get_iova_copy(iommu, &iova_copy);
@@ -1437,6 +1512,10 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 	if (ret)
 		goto out_detach;
 
+	ret = vfio_iommu_resv_exclude(&iova_copy, &group_resv_regions);
+	if (ret)
+		goto out_detach;
+
 	resv_msi = vfio_iommu_has_sw_msi(iommu_group, &resv_msi_base);
 
 	INIT_LIST_HEAD(&domain->group_list);
@@ -1497,6 +1576,9 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 	/* Delete the old one and insert new iova list */
 	vfio_iommu_insert_iova_copy(iommu, &iova_copy);
 
+	list_for_each_entry_safe(resv, resv_next, &group_resv_regions, list)
+		kfree(resv);
+
 	mutex_unlock(&iommu->lock);
 
 	return 0;
@@ -1507,6 +1589,8 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 	iommu_domain_free(domain->domain);
 	list_for_each_entry_safe(iova, iova_next, &iova_copy, list)
 		kfree(iova);
+	list_for_each_entry_safe(resv, resv_next, &group_resv_regions, list)
+		kfree(resv);
 out_free:
 	kfree(domain);
 	kfree(group);
-- 
2.7.4