[Qemu-devel] [PATCH 3/4] vfio: Move container list to iommu MemoryRegion

[David Gibson <david@gibson.dropbear.id.au>]

At the moment, vfio maintains a global list of containers that are assumed
to be more or less interchangeable, since they are all set up with a
MemoryListener to have all of system memory mapped.  However, that only
makes sense if all the containers are used on devices which really do
expect a dma address space identical to system memory.

This patch moves towards that by making the list of containers per
MemoryRegion (which corresponds to a dma address space) instead of global.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 hw/misc/vfio.c         |   48 +++++++++++++++++++++++++++++++++++++++++-------
 include/exec/memory.h  |    4 ++++
 include/hw/misc/vfio.h |   20 ++++++++++++++++++++
 memory.c               |    2 ++
 stubs/Makefile.objs    |    1 +
 stubs/vfio.c           |    5 +++++
 6 files changed, 73 insertions(+), 7 deletions(-)
 create mode 100644 include/hw/misc/vfio.h
 create mode 100644 stubs/vfio.c

diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c
index 9057964..707a63c 100644
--- a/hw/misc/vfio.c
+++ b/hw/misc/vfio.c
@@ -39,6 +39,7 @@
 #include "qemu/range.h"
 #include "sysemu/kvm.h"
 #include "sysemu/sysemu.h"
+#include "hw/misc/vfio.h"
 
 /* #define DEBUG_VFIO */
 #ifdef DEBUG_VFIO
@@ -177,10 +178,11 @@ typedef struct VFIOGroup {
     QLIST_ENTRY(VFIOGroup) container_next;
 } VFIOGroup;
 
-#define MSIX_CAP_LENGTH 12
+typedef struct VFIOIommu {
+    QLIST_HEAD(, VFIOContainer) containers;
+} VFIOIommu;
 
-static QLIST_HEAD(, VFIOContainer)
-    container_list = QLIST_HEAD_INITIALIZER(container_list);
+#define MSIX_CAP_LENGTH 12
 
 static QLIST_HEAD(, VFIOGroup)
     group_list = QLIST_HEAD_INITIALIZER(group_list);
@@ -2615,8 +2617,40 @@ static int vfio_load_rom(VFIODevice *vdev)
     return 0;
 }
 
+static VFIOIommu *iommu_get_vfio(MemoryRegion *iommu)
+{
+    VFIOIommu *vfio_iommu;
+
+    if (iommu->vfio) {
+        return iommu->vfio;
+    }
+
+    vfio_iommu = g_malloc0(sizeof(*vfio_iommu));
+    QLIST_INIT(&vfio_iommu->containers);
+    iommu->vfio = vfio_iommu;
+    return vfio_iommu;
+}
+
+void vfio_iommu_destroy(MemoryRegion *iommu)
+{
+    VFIOIommu *vfio_iommu = iommu->vfio;
+
+    if (!vfio_iommu) {
+        return; /* Nothing to do */
+    }
+
+    iommu->vfio = NULL;
+
+    /* Devices and the groups associated should already have been
+     * disconnected at this point */
+    assert(QLIST_EMPTY(&vfio_iommu->containers));
+
+    g_free(vfio_iommu);
+}
+
 static int vfio_connect_iommu(VFIOGroup *group, MemoryRegion *iommu)
 {
+    VFIOIommu *vfio_iommu = iommu_get_vfio(iommu);
     VFIOContainer *container;
     int ret, fd;
 
@@ -2630,7 +2664,7 @@ static int vfio_connect_iommu(VFIOGroup *group, MemoryRegion *iommu)
         }
     }
 
-    QLIST_FOREACH(container, &container_list, next) {
+    QLIST_FOREACH(container, &vfio_iommu->containers, next) {
         if (!ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &container->fd)) {
             group->container = container;
             QLIST_INSERT_HEAD(&container->group_list, group, container_next);
@@ -2685,7 +2719,7 @@ static int vfio_connect_iommu(VFIOGroup *group, MemoryRegion *iommu)
     }
 
     QLIST_INIT(&container->group_list);
-    QLIST_INSERT_HEAD(&container_list, container, next);
+    QLIST_INSERT_HEAD(&vfio_iommu->containers, container, next);
 
     group->container = container;
     QLIST_INSERT_HEAD(&container->group_list, group, container_next);
@@ -2693,7 +2727,7 @@ static int vfio_connect_iommu(VFIOGroup *group, MemoryRegion *iommu)
     return 0;
 }
 
-static void vfio_disconnect_context(VFIOGroup *group)
+static void vfio_disconnect_iommu(VFIOGroup *group)
 {
     VFIOContainer *container = group->container;
 
@@ -2783,7 +2817,7 @@ static void vfio_put_group(VFIOGroup *group)
         return;
     }
 
-    vfio_disconnect_context(group);
+    vfio_disconnect_iommu(group);
     QLIST_REMOVE(group, next);
     DPRINTF("vfio_put_group: close group->fd\n");
     close(group->fd);
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 99d51b7..259b8eb 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -129,6 +129,9 @@ struct MemoryRegionIOMMUOps {
 typedef struct CoalescedMemoryRange CoalescedMemoryRange;
 typedef struct MemoryRegionIoeventfd MemoryRegionIoeventfd;
 
+typedef struct VFIOIommu VFIOIommu;
+struct VFIOIommu;
+
 struct MemoryRegion {
     /* All fields are private - violators will be prosecuted */
     const MemoryRegionOps *ops;
@@ -160,6 +163,7 @@ struct MemoryRegion {
     unsigned ioeventfd_nb;
     MemoryRegionIoeventfd *ioeventfds;
     struct AddressSpace *iommu_target_as;
+    VFIOIommu *vfio;
 };
 
 struct MemoryRegionPortio {
diff --git a/include/hw/misc/vfio.h b/include/hw/misc/vfio.h
new file mode 100644
index 0000000..602e2f9
--- /dev/null
+++ b/include/hw/misc/vfio.h
@@ -0,0 +1,20 @@
+/*
+ * vfio based device assignment
+ *
+ * Copyright 2013 David Gibson, IBM Corporation.
+ * Copyright Red Hat, Inc. 2012
+ *
+ * This work is licensed under the terms of the GNU GPL, version
+ * 2. See the COPYING file in the top-level directory.
+ */
+#ifndef QEMU_VFIO_H
+#define QEMU_VFIO_H
+
+#include "qemu/queue.h"
+
+typedef struct MemoryRegion MemoryRegion;
+struct MemoryRegion;
+
+void vfio_iommu_destroy(MemoryRegion *iommu);
+
+#endif /* QEMU_VFIO_H */
diff --git a/memory.c b/memory.c
index cee3e59..50889d5 100644
--- a/memory.c
+++ b/memory.c
@@ -21,6 +21,7 @@
 #include <assert.h>
 
 #include "exec/memory-internal.h"
+#include "hw/misc/vfio.h"
 
 static unsigned memory_region_transaction_depth;
 static bool memory_region_update_pending;
@@ -1043,6 +1044,7 @@ void memory_region_init_reservation(MemoryRegion *mr,
 
 void memory_region_destroy(MemoryRegion *mr)
 {
+    vfio_iommu_destroy(mr);
     assert(QTAILQ_EMPTY(&mr->subregions));
     assert(memory_region_transaction_depth == 0);
     mr->destructor(mr);
diff --git a/stubs/Makefile.objs b/stubs/Makefile.objs
index 9c55b34..858ca6b 100644
--- a/stubs/Makefile.objs
+++ b/stubs/Makefile.objs
@@ -20,6 +20,7 @@ stub-obj-y += reset.o
 stub-obj-y += set-fd-handler.o
 stub-obj-y += slirp.o
 stub-obj-y += sysbus.o
+stub-obj-y += vfio.o
 stub-obj-y += vm-stop.o
 stub-obj-y += vmstate.o
 stub-obj-$(CONFIG_WIN32) += fd-register.o
diff --git a/stubs/vfio.c b/stubs/vfio.c
new file mode 100644
index 0000000..6aacaf6
--- /dev/null
+++ b/stubs/vfio.c
@@ -0,0 +1,5 @@
+#include "hw/misc/vfio.h"
+
+void vfio_iommu_destroy(MemoryRegion *iommu)
+{
+}
-- 
1.7.10.4