[Qemu-devel] [RFC PATCH qemu 2/4] vfio: Generalize IOMMU memory listener

[Alexey Kardashevskiy <aik@ozlabs.ru>]

At the moment VFIOContainer has an union for per IOMMU type data which
is now an IOMMU memory listener and setup flags. The listener listens
on PCI address space for both Type1 and sPAPR IOMMUs. The setup flags
(@initialized and @error) are only used by Type1 now but the next patch
will use it on sPAPR too.

This introduces VFIOMemoryListener which is wrapper for MemoryListener
and stores a pointer to the container. This allows having multiple
memory listeners for the same container. This replaces Type1 listener
with @iommu_listener.

This moves @initialized and @error out of @iommu_data as these will be
used soon for memory pre-registration.

As there is only release() left in @iommu_data, this moves it to
VFIOContainer and removes @iommu_data and VFIOType1.

This stores @iommu_type in VFIOContainer. The prereg patch will use it
to know whether or not to do proper cleanup.

This should cause no change in behavior.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
Changes:
v4:
* used to be "vfio: Store IOMMU type in container"
* moved VFIOType1 content to container as it is not IOMMU type specific
---
 hw/vfio/common.c              | 74 +++++++++++++++++++++++++++----------------
 include/hw/vfio/vfio-common.h | 25 +++++++--------
 2 files changed, 59 insertions(+), 40 deletions(-)

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 85ee9b0..6eb85c7 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -312,11 +312,10 @@ out:
     rcu_read_unlock();
 }
 
-static void vfio_listener_region_add(MemoryListener *listener,
+static void vfio_listener_region_add(VFIOMemoryListener *vlistener,
                                      MemoryRegionSection *section)
 {
-    VFIOContainer *container = container_of(listener, VFIOContainer,
-                                            iommu_data.type1.listener);
+    VFIOContainer *container = vlistener->container;
     hwaddr iova, end;
     Int128 llend;
     void *vaddr;
@@ -406,9 +405,9 @@ static void vfio_listener_region_add(MemoryListener *listener,
          * can gracefully fail.  Runtime, there's not much we can do other
          * than throw a hardware error.
          */
-        if (!container->iommu_data.type1.initialized) {
-            if (!container->iommu_data.type1.error) {
-                container->iommu_data.type1.error = ret;
+        if (!container->initialized) {
+            if (!container->error) {
+                container->error = ret;
             }
         } else {
             hw_error("vfio: DMA mapping failed, unable to continue");
@@ -416,11 +415,10 @@ static void vfio_listener_region_add(MemoryListener *listener,
     }
 }
 
-static void vfio_listener_region_del(MemoryListener *listener,
+static void vfio_listener_region_del(VFIOMemoryListener *vlistener,
                                      MemoryRegionSection *section)
 {
-    VFIOContainer *container = container_of(listener, VFIOContainer,
-                                            iommu_data.type1.listener);
+    VFIOContainer *container = vlistener->container;
     hwaddr iova, end;
     int ret;
 
@@ -478,14 +476,33 @@ static void vfio_listener_region_del(MemoryListener *listener,
     }
 }
 
-static const MemoryListener vfio_memory_listener = {
-    .region_add = vfio_listener_region_add,
-    .region_del = vfio_listener_region_del,
+static void vfio_iommu_listener_region_add(MemoryListener *listener,
+                                           MemoryRegionSection *section)
+{
+    VFIOMemoryListener *vlistener = container_of(listener, VFIOMemoryListener,
+                                                 listener);
+
+    vfio_listener_region_add(vlistener, section);
+}
+
+
+static void vfio_iommu_listener_region_del(MemoryListener *listener,
+                                           MemoryRegionSection *section)
+{
+    VFIOMemoryListener *vlistener = container_of(listener, VFIOMemoryListener,
+                                                 listener);
+
+    vfio_listener_region_del(vlistener, section);
+}
+
+static const MemoryListener vfio_iommu_listener = {
+    .region_add = vfio_iommu_listener_region_add,
+    .region_del = vfio_iommu_listener_region_del,
 };
 
 static void vfio_listener_release(VFIOContainer *container)
 {
-    memory_listener_unregister(&container->iommu_data.type1.listener);
+    memory_listener_unregister(&container->iommu_listener.listener);
 }
 
 int vfio_mmap_region(Object *obj, VFIORegion *region,
@@ -676,27 +693,28 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as)
             goto free_container_exit;
         }
 
-        ret = ioctl(fd, VFIO_SET_IOMMU,
-                    v2 ? VFIO_TYPE1v2_IOMMU : VFIO_TYPE1_IOMMU);
+        container->iommu_type = v2 ? VFIO_TYPE1v2_IOMMU : VFIO_TYPE1_IOMMU;
+        ret = ioctl(fd, VFIO_SET_IOMMU, container->iommu_type);
         if (ret) {
             error_report("vfio: failed to set iommu for container: %m");
             ret = -errno;
             goto free_container_exit;
         }
 
-        container->iommu_data.type1.listener = vfio_memory_listener;
-        container->iommu_data.release = vfio_listener_release;
+        container->iommu_listener.container = container;
+        container->iommu_listener.listener = vfio_iommu_listener;
+        container->release = vfio_listener_release;
 
-        memory_listener_register(&container->iommu_data.type1.listener,
+        memory_listener_register(&container->iommu_listener.listener,
                                  container->space->as);
 
-        if (container->iommu_data.type1.error) {
-            ret = container->iommu_data.type1.error;
+        if (container->error) {
+            ret = container->error;
             error_report("vfio: memory listener initialization failed for container");
             goto listener_release_exit;
         }
 
-        container->iommu_data.type1.initialized = true;
+        container->initialized = true;
 
     } else if (ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_IOMMU)) {
         ret = ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &fd);
@@ -705,7 +723,8 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as)
             ret = -errno;
             goto free_container_exit;
         }
-        ret = ioctl(fd, VFIO_SET_IOMMU, VFIO_SPAPR_TCE_IOMMU);
+        container->iommu_type = VFIO_SPAPR_TCE_IOMMU;
+        ret = ioctl(fd, VFIO_SET_IOMMU, container->iommu_type);
         if (ret) {
             error_report("vfio: failed to set iommu for container: %m");
             ret = -errno;
@@ -724,10 +743,11 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as)
             goto free_container_exit;
         }
 
-        container->iommu_data.type1.listener = vfio_memory_listener;
-        container->iommu_data.release = vfio_listener_release;
+        container->iommu_listener.container = container;
+        container->iommu_listener.listener = vfio_iommu_listener;
+        container->release = vfio_listener_release;
 
-        memory_listener_register(&container->iommu_data.type1.listener,
+        memory_listener_register(&container->iommu_listener.listener,
                                  container->space->as);
 
     } else {
@@ -774,8 +794,8 @@ static void vfio_disconnect_container(VFIOGroup *group)
         VFIOAddressSpace *space = container->space;
         VFIOGuestIOMMU *giommu, *tmp;
 
-        if (container->iommu_data.release) {
-            container->iommu_data.release(container);
+        if (container->release) {
+            container->release(container);
         }
         QLIST_REMOVE(container, next);
 
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 59a321d..a0f9d36 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -62,24 +62,23 @@ typedef struct VFIOAddressSpace {
     QLIST_ENTRY(VFIOAddressSpace) list;
 } VFIOAddressSpace;
 
+typedef struct VFIOContainer VFIOContainer;
+
+typedef struct VFIOMemoryListener {
+    struct MemoryListener listener;
+    VFIOContainer *container;
+} VFIOMemoryListener;
+
 struct VFIOGroup;
 
-typedef struct VFIOType1 {
-    MemoryListener listener;
-    int error;
-    bool initialized;
-} VFIOType1;
-
 typedef struct VFIOContainer {
     VFIOAddressSpace *space;
     int fd; /* /dev/vfio/vfio, empowered by the attached groups */
-    struct {
-        /* enable abstraction to support various iommu backends */
-        union {
-            VFIOType1 type1;
-        };
-        void (*release)(struct VFIOContainer *);
-    } iommu_data;
+    unsigned iommu_type;
+    int error;
+    bool initialized;
+    VFIOMemoryListener iommu_listener;
+    void (*release)(struct VFIOContainer *);
     QLIST_HEAD(, VFIOGuestIOMMU) giommu_list;
     QLIST_HEAD(, VFIOGroup) group_list;
     QLIST_ENTRY(VFIOContainer) next;
-- 
2.4.0.rc3.8.gfb3e7d5