[Qemu-devel] [PATCH v8 2/4] vfio: Add vfio_container_ioctl()

[Alexey Kardashevskiy <aik@ozlabs.ru>]

While most operations with VFIO IOMMU driver are generic and used inside
vfio.c, there are still some operations which only specific VFIO IOMMU
drivers implement. The first example of it will be reading a DMA window
start from the host.

This adds a helper which passes an ioctl request to the container's fd.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
Changes:
v8:
* s/vfio_container_spapr_get_info/vfio_container_ioctl/ - now it is
generalized

v7:
* do not return a group fd from the helper

v6:
* added dup() to protect group_fd from accidental disposal

v5:
* reworked to reflect change in vfio_get_group() from one
of previous patches change

v4:
* fixed possible leaks on error paths
---
 hw/misc/vfio.c         | 28 ++++++++++++++++++++++++++++
 include/hw/misc/vfio.h |  9 +++++++++
 2 files changed, 37 insertions(+)
 create mode 100644 include/hw/misc/vfio.h

diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c
index 7437c2e..bb77934 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
@@ -4318,3 +4319,30 @@ static void register_vfio_pci_dev_type(void)
 }
 
 type_init(register_vfio_pci_dev_type)
+
+int vfio_container_ioctl(AddressSpace *as, int32_t groupid,
+                         int req, void *param)
+{
+    VFIOGroup *group;
+    VFIOContainer *container;
+    int ret = -1;
+
+    group = vfio_get_group(groupid, as);
+    if (!group) {
+        error_report("vfio: group %d not registered", groupid);
+        return ret;
+    }
+
+    container = group->container;
+    if (group->container) {
+        ret = ioctl(container->fd, req, param);
+        if (ret < 0) {
+            error_report("vfio: failed to ioctl container: ret=%d, %s",
+                         ret, strerror(errno));
+        }
+    }
+
+    vfio_put_group(group);
+
+    return ret;
+}
diff --git a/include/hw/misc/vfio.h b/include/hw/misc/vfio.h
new file mode 100644
index 0000000..0b26cd8
--- /dev/null
+++ b/include/hw/misc/vfio.h
@@ -0,0 +1,9 @@
+#ifndef VFIO_API_H
+#define VFIO_API_H
+
+#include "qemu/typedefs.h"
+
+extern int vfio_container_ioctl(AddressSpace *as, int32_t groupid,
+                                int req, void *param);
+
+#endif
-- 
2.0.0