[Qemu-devel] [RFC v8 11/18] virtio-iommu: Add an msi_bypass property

[Eric Auger <eric.auger@redhat.com>]

In case the msi_bypass property is set, it means we need
to register the IOAPIC MSI window as a reserved region:
0xFEE00000 - 0xFEEFFFFF.

Signed-off-by: Eric Auger <eric.auger@redhat.com>

---
---
 hw/virtio/virtio-iommu.c         | 52 ++++++++++++++++++++++++++++++++
 include/hw/virtio/virtio-iommu.h |  1 +
 2 files changed, 53 insertions(+)

diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
index 6164b5a7d1..e6ad8a0c61 100644
--- a/hw/virtio/virtio-iommu.c
+++ b/hw/virtio/virtio-iommu.c
@@ -41,6 +41,9 @@
 #define VIOMMU_DEFAULT_QUEUE_SIZE 256
 #define VIOMMU_PROBE_SIZE 512
 
+#define IOAPIC_RANGE_START      (0xfee00000)
+#define IOAPIC_RANGE_SIZE       (0x100000)
+
 #define SUPPORTED_PROBE_PROPERTIES (\
     VIRTIO_IOMMU_PROBE_T_NONE | \
     VIRTIO_IOMMU_PROBE_T_RESV_MEM)
@@ -103,6 +106,25 @@ static void virtio_iommu_detach_endpoint_from_domain(viommu_endpoint *ep)
     ep->domain = NULL;
 }
 
+static void virtio_iommu_register_resv_region(viommu_endpoint *ep,
+                                              uint8_t subtype,
+                                              uint64_t start, uint64_t end)
+{
+    viommu_interval *interval;
+    struct virtio_iommu_probe_resv_mem *reg;
+
+    interval = g_malloc0(sizeof(*interval));
+    interval->low = start;
+    interval->high = end;
+
+    reg = g_malloc0(sizeof(*reg));
+    reg->subtype = subtype;
+    reg->start = cpu_to_le64(start);
+    reg->end = cpu_to_le64(end);
+
+    g_tree_insert(ep->reserved_regions, interval, reg);
+}
+
 static viommu_endpoint *virtio_iommu_get_endpoint(VirtIOIOMMU *s,
                                                   uint32_t ep_id)
 {
@@ -120,6 +142,12 @@ static viommu_endpoint *virtio_iommu_get_endpoint(VirtIOIOMMU *s,
     ep->reserved_regions = g_tree_new_full((GCompareDataFunc)interval_cmp,
                                             NULL, (GDestroyNotify)g_free,
                                             (GDestroyNotify)g_free);
+    if (s->msi_bypass) {
+        virtio_iommu_register_resv_region(ep, VIRTIO_IOMMU_RESV_MEM_T_MSI,
+                                          IOAPIC_RANGE_START,
+                                          IOAPIC_RANGE_SIZE);
+    }
+
     return ep;
 }
 
@@ -864,8 +892,32 @@ static void virtio_iommu_set_status(VirtIODevice *vdev, uint8_t status)
     trace_virtio_iommu_device_status(status);
 }
 
+static bool virtio_iommu_get_msi_bypass(Object *obj, Error **errp)
+{
+    VirtIOIOMMU *s = VIRTIO_IOMMU(obj);
+
+    return s->msi_bypass;
+}
+
+static void virtio_iommu_set_msi_bypass(Object *obj, bool value, Error **errp)
+{
+    VirtIOIOMMU *s = VIRTIO_IOMMU(obj);
+
+    s->msi_bypass = value;
+}
+
 static void virtio_iommu_instance_init(Object *obj)
 {
+    VirtIOIOMMU *s = VIRTIO_IOMMU(obj);
+
+    object_property_add_bool(obj, "msi_bypass", virtio_iommu_get_msi_bypass,
+                             virtio_iommu_set_msi_bypass, NULL);
+    object_property_set_description(obj, "msi_bypass",
+                                    "Indicates whether msis are bypassed by "
+                                    "the IOMMU. Default is YES",
+                                    NULL);
+
+    s->msi_bypass = true;
 }
 
 static const VMStateDescription vmstate_virtio_iommu = {
diff --git a/include/hw/virtio/virtio-iommu.h b/include/hw/virtio/virtio-iommu.h
index f55f48d304..56c8b4e57f 100644
--- a/include/hw/virtio/virtio-iommu.h
+++ b/include/hw/virtio/virtio-iommu.h
@@ -59,6 +59,7 @@ typedef struct VirtIOIOMMU {
     GTree *domains;
     QemuMutex mutex;
     GTree *endpoints;
+    bool msi_bypass;
 } VirtIOIOMMU;
 
 #endif
-- 
2.17.2