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.th...@huawei.com>
---
 drivers/vfio/vfio_iommu_type1.c | 161 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 159 insertions(+), 2 deletions(-)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 11cbd49..7609070 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -28,6 +28,7 @@
 #include <linux/device.h>
 #include <linux/fs.h>
 #include <linux/iommu.h>
+#include <linux/list_sort.h>
 #include <linux/module.h>
 #include <linux/mm.h>
 #include <linux/rbtree.h>
@@ -1199,6 +1200,20 @@ static bool vfio_iommu_has_sw_msi(struct iommu_group 
*group, phys_addr_t *base)
        return ret;
 }
 
+static int vfio_resv_cmp(void *priv, struct list_head *a, struct list_head *b)
+{
+       struct iommu_resv_region *ra, *rb;
+
+       ra = container_of(a, struct iommu_resv_region, list);
+       rb = container_of(b, struct iommu_resv_region, list);
+
+       if (ra->start < rb->start)
+               return -1;
+       if (ra->start > rb->start)
+               return 1;
+       return 0;
+}
+
 static int vfio_insert_iova(phys_addr_t start, phys_addr_t end,
                                struct list_head *head)
 {
@@ -1274,6 +1289,24 @@ static int vfio_iommu_valid_aperture(struct vfio_iommu 
*iommu,
 }
 
 /*
+ * Check reserved region conflicts with existing dma mappings
+ */
+static int vfio_iommu_resv_region_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_overlap(iommu, region->start,
+                                   region->start + region->length - 1))
+                       return -EINVAL;
+       }
+
+       return 0;
+}
+
+/*
  * Adjust the iommu aperture window if new aperture is a valid one
  */
 static int vfio_iommu_iova_aper_adjust(struct vfio_iommu *iommu,
@@ -1316,6 +1349,51 @@ static int vfio_iommu_iova_aper_adjust(struct vfio_iommu 
*iommu,
        return 0;
 }
 
+/*
+ * Check and update iova region list in case a reserved region
+ * overlaps the iommu iova range
+ */
+static int vfio_iommu_iova_resv_adjust(struct vfio_iommu *iommu,
+                                       struct list_head *resv_regions)
+{
+       struct iommu_resv_region *resv;
+       struct list_head *iova = &iommu->iova_list;
+       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) {
+                       phys_addr_t a, b;
+                       int ret = 0;
+
+                       a = n->start;
+                       b = n->end;
+                       /* No overlap */
+                       if ((start > b) || (end < a))
+                               continue;
+                       /* Split the current node and create holes */
+                       if (start > a)
+                               ret = vfio_insert_iova(a, start - 1, &n->list);
+                       if (!ret && end < b)
+                               ret = vfio_insert_iova(end + 1, b, &n->list);
+                       if (ret)
+                               return ret;
+
+                       list_del(&n->list);
+                       kfree(n);
+               }
+       }
+
+       if (list_empty(iova))
+               return -EINVAL;
+
+       return 0;
+}
+
 static int vfio_iommu_type1_attach_group(void *iommu_data,
                                         struct iommu_group *iommu_group)
 {
@@ -1327,6 +1405,8 @@ 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 group_resv_regions;
+       struct iommu_resv_region *resv, *resv_next;
 
        mutex_lock(&iommu->lock);
 
@@ -1404,6 +1484,14 @@ static int vfio_iommu_type1_attach_group(void 
*iommu_data,
        if (ret)
                goto out_detach;
 
+       INIT_LIST_HEAD(&group_resv_regions);
+       iommu_get_group_resv_regions(iommu_group, &group_resv_regions);
+       list_sort(NULL, &group_resv_regions, vfio_resv_cmp);
+
+       ret = vfio_iommu_resv_region_conflict(iommu, &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);
@@ -1434,11 +1522,15 @@ static int vfio_iommu_type1_attach_group(void 
*iommu_data,
                    d->prot == domain->prot) {
                        iommu_detach_group(domain->domain, iommu_group);
                        if (!iommu_attach_group(d->domain, iommu_group)) {
+                               ret = vfio_iommu_iova_resv_adjust(iommu,
+                                                       &group_resv_regions);
+                               if (!ret)
+                                       goto out_domain;
+
                                list_add(&group->next, &d->group_list);
                                iommu_domain_free(domain->domain);
                                kfree(domain);
-                               mutex_unlock(&iommu->lock);
-                               return 0;
+                               goto done;
                        }
 
                        ret = iommu_attach_group(domain->domain, iommu_group);
@@ -1465,8 +1557,15 @@ static int vfio_iommu_type1_attach_group(void 
*iommu_data,
        if (ret)
                goto out_detach;
 
+       ret = vfio_iommu_iova_resv_adjust(iommu, &group_resv_regions);
+       if (ret)
+               goto out_detach;
+
        list_add(&domain->next, &iommu->domain_list);
 
+done:
+       list_for_each_entry_safe(resv, resv_next, &group_resv_regions, list)
+               kfree(resv);
        mutex_unlock(&iommu->lock);
 
        return 0;
@@ -1475,6 +1574,8 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
        iommu_detach_group(domain->domain, iommu_group);
 out_domain:
        iommu_domain_free(domain->domain);
+       list_for_each_entry_safe(resv, resv_next, &group_resv_regions, list)
+               kfree(resv);
 out_free:
        kfree(domain);
        kfree(group);
@@ -1559,6 +1660,60 @@ static void vfio_iommu_iova_aper_refresh(struct 
vfio_iommu *iommu)
        node->end = end;
 }
 
+/*
+ * Called when a group is detached. The reserved regions for that
+ * group can be part of valid iova now. But since reserved regions
+ * may be duplicated among groups, populate the iova valid regions
+   list again.
+ */
+static void vfio_iommu_iova_resv_refresh(struct vfio_iommu *iommu)
+{
+       struct vfio_domain *d;
+       struct vfio_group *g;
+       struct vfio_iova *node, *tmp;
+       struct iommu_resv_region *resv, *resv_next;
+       struct list_head resv_regions;
+       phys_addr_t start, end;
+
+       INIT_LIST_HEAD(&resv_regions);
+
+       list_for_each_entry(d, &iommu->domain_list, next) {
+               list_for_each_entry(g, &d->group_list, next)
+                       iommu_get_group_resv_regions(g->iommu_group,
+                                                        &resv_regions);
+       }
+
+       if (list_empty(&resv_regions))
+               return;
+
+       list_sort(NULL, &resv_regions, vfio_resv_cmp);
+
+       node = list_first_entry(&iommu->iova_list, struct vfio_iova, list);
+       start = node->start;
+       node = list_last_entry(&iommu->iova_list, struct vfio_iova, list);
+       end = node->end;
+
+       /* purge the iova list and create new one */
+       list_for_each_entry_safe(node, tmp, &iommu->iova_list, list) {
+               list_del(&node->list);
+               kfree(node);
+       }
+
+       if (vfio_iommu_iova_aper_adjust(iommu, start, end)) {
+               pr_warn("%s: Failed to update iova aperture. VFIO DMA map 
request may fail\n",
+                       __func__);
+               goto done;
+       }
+
+       /* adjust the iova with current reserved regions */
+       if (vfio_iommu_iova_resv_adjust(iommu, &resv_regions))
+               pr_warn("%s: Failed to update iova list with reserve regions. 
VFIO DMA map request may fail\n",
+                       __func__);
+done:
+       list_for_each_entry_safe(resv, resv_next, &resv_regions, list)
+               kfree(resv);
+}
+
 static void vfio_iommu_type1_detach_group(void *iommu_data,
                                          struct iommu_group *iommu_group)
 {
@@ -1617,6 +1772,8 @@ static void vfio_iommu_type1_detach_group(void 
*iommu_data,
                break;
        }
 
+       vfio_iommu_iova_resv_refresh(iommu);
+
 detach_group_done:
        mutex_unlock(&iommu->lock);
 }
-- 
1.9.1


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