[RFC v2 4/7] virtio-iommu: Compute host reserved regions

[Eric Auger]

Compute the host reserved regions in virtio_iommu_set_iommu_device().
The usable IOVA regions are retrieved from the HOSTIOMMUDevice.
The virtio_iommu_set_host_iova_ranges() helper turns usable regions
into complementary reserved regions while testing the inclusion
into existing ones. virtio_iommu_set_host_iova_ranges() reuse the
implementation of virtio_iommu_set_iova_ranges() which will be
removed in subsequent patches. rebuild_resv_regions() is just moved.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
---
 hw/virtio/virtio-iommu.c | 151 ++++++++++++++++++++++++++++++---------
 1 file changed, 117 insertions(+), 34 deletions(-)

diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
index 0680a357f0..33e9682b83 100644
--- a/hw/virtio/virtio-iommu.c
+++ b/hw/virtio/virtio-iommu.c
@@ -494,12 +494,114 @@ get_host_iommu_device(VirtIOIOMMU *viommu, PCIBus *bus, 
int devfn) {
     return g_hash_table_lookup(viommu->host_iommu_devices, &key);
 }
 
+/**
+ * rebuild_resv_regions: rebuild resv regions with both the
+ * info of host resv ranges and property set resv ranges
+ */
+static int rebuild_resv_regions(IOMMUDevice *sdev)
+{
+    GList *l;
+    int i = 0;
+
+    /* free the existing list and rebuild it from scratch */
+    g_list_free_full(sdev->resv_regions, g_free);
+    sdev->resv_regions = NULL;
+
+    /* First add host reserved regions if any, all tagged as RESERVED */
+    for (l = sdev->host_resv_ranges; l; l = l->next) {
+        ReservedRegion *reg = g_new0(ReservedRegion, 1);
+        Range *r = (Range *)l->data;
+
+        reg->type = VIRTIO_IOMMU_RESV_MEM_T_RESERVED;
+        range_set_bounds(&reg->range, range_lob(r), range_upb(r));
+        sdev->resv_regions = resv_region_list_insert(sdev->resv_regions, reg);
+        trace_virtio_iommu_host_resv_regions(sdev->iommu_mr.parent_obj.name, i,
+                                             range_lob(&reg->range),
+                                             range_upb(&reg->range));
+        i++;
+    }
+    /*
+     * then add higher priority reserved regions set by the machine
+     * through properties
+     */
+    add_prop_resv_regions(sdev);
+    return 0;
+}
+
+static int virtio_iommu_set_host_iova_ranges(VirtIOIOMMU *s, PCIBus *bus,
+                                             int devfn, GList *iova_ranges,
+                                             Error **errp)
+{
+    IOMMUPciBus *sbus = g_hash_table_lookup(s->as_by_busptr, bus);
+    IOMMUDevice *sdev;
+    GList *current_ranges;
+    GList *l, *tmp, *new_ranges = NULL;
+    int ret = -EINVAL;
+
+    if (!sbus) {
+        error_report("%s no sbus", __func__);
+    }
+
+    sdev = sbus->pbdev[devfn];
+
+    current_ranges = sdev->host_resv_ranges;
+
+    if (sdev->probe_done) {
+        error_setg(errp,
+                   "%s: Notified about new host reserved regions after probe",
+                   __func__);
+        goto out;
+    }
+
+    /* check that each new resv region is included in an existing one */
+    if (sdev->host_resv_ranges) {
+        range_inverse_array(iova_ranges,
+                            &new_ranges,
+                            0, UINT64_MAX);
+
+        for (tmp = new_ranges; tmp; tmp = tmp->next) {
+            Range *newr = (Range *)tmp->data;
+            bool included = false;
+
+            for (l = current_ranges; l; l = l->next) {
+                Range * r = (Range *)l->data;
+
+                if (range_contains_range(r, newr)) {
+                    included = true;
+                    break;
+                }
+            }
+            if (!included) {
+                goto error;
+            }
+        }
+        /* all new reserved ranges are included in existing ones */
+        ret = 0;
+        goto out;
+    }
+
+    range_inverse_array(iova_ranges,
+                        &sdev->host_resv_ranges,
+                        0, UINT64_MAX);
+    rebuild_resv_regions(sdev);
+
+    return 0;
+error:
+    error_setg(errp, "%s Conflicting host reserved ranges set!",
+               __func__);
+out:
+    g_list_free_full(new_ranges, g_free);
+    return ret;
+}
+
 static bool virtio_iommu_set_iommu_device(PCIBus *bus, void *opaque, int devfn,
                                           HostIOMMUDevice *hiod, Error **errp)
 {
     VirtIOIOMMU *viommu = opaque;
     VirtioHostIOMMUDevice *vhiod;
+    HostIOMMUDeviceClass *hiodc = HOST_IOMMU_DEVICE_GET_CLASS(hiod);
     struct hiod_key *new_key;
+    GList *host_iova_ranges = NULL;
 
     assert(hiod);
 
@@ -509,6 +611,20 @@ static bool virtio_iommu_set_iommu_device(PCIBus *bus, 
void *opaque, int devfn,
         return false;
     }
 
+    if (hiodc->get_iova_ranges) {
+        int ret;
+        host_iova_ranges = hiodc->get_iova_ranges(hiod, errp);
+        if (!host_iova_ranges) {
+            return true; /* some old kernels may not support that capability */
+        }
+        ret = virtio_iommu_set_host_iova_ranges(viommu, bus, devfn,
+                                                host_iova_ranges, errp);
+        if (ret) {
+            g_list_free_full(host_iova_ranges, g_free);
+            return false;
+        }
+    }
+
     vhiod = g_malloc0(sizeof(VirtioHostIOMMUDevice));
     vhiod->bus = bus;
     vhiod->devfn = (uint8_t)devfn;
@@ -521,6 +637,7 @@ static bool virtio_iommu_set_iommu_device(PCIBus *bus, void 
*opaque, int devfn,
 
     object_ref(hiod);
     g_hash_table_insert(viommu->host_iommu_devices, new_key, vhiod);
+    g_list_free_full(host_iova_ranges, g_free);
 
     return true;
 }
@@ -1243,40 +1360,6 @@ static int 
virtio_iommu_set_page_size_mask(IOMMUMemoryRegion *mr,
     return 0;
 }
 
-/**
- * rebuild_resv_regions: rebuild resv regions with both the
- * info of host resv ranges and property set resv ranges
- */
-static int rebuild_resv_regions(IOMMUDevice *sdev)
-{
-    GList *l;
-    int i = 0;
-
-    /* free the existing list and rebuild it from scratch */
-    g_list_free_full(sdev->resv_regions, g_free);
-    sdev->resv_regions = NULL;
-
-    /* First add host reserved regions if any, all tagged as RESERVED */
-    for (l = sdev->host_resv_ranges; l; l = l->next) {
-        ReservedRegion *reg = g_new0(ReservedRegion, 1);
-        Range *r = (Range *)l->data;
-
-        reg->type = VIRTIO_IOMMU_RESV_MEM_T_RESERVED;
-        range_set_bounds(&reg->range, range_lob(r), range_upb(r));
-        sdev->resv_regions = resv_region_list_insert(sdev->resv_regions, reg);
-        trace_virtio_iommu_host_resv_regions(sdev->iommu_mr.parent_obj.name, i,
-                                             range_lob(&reg->range),
-                                             range_upb(&reg->range));
-        i++;
-    }
-    /*
-     * then add higher priority reserved regions set by the machine
-     * through properties
-     */
-    add_prop_resv_regions(sdev);
-    return 0;
-}
-
 /**
  * virtio_iommu_set_iova_ranges: Conveys the usable IOVA ranges
  *
-- 
2.41.0