[Qemu-devel] [RFC PATCH 1/3] vfio: Add a funtion to return a specific irq capabilities

[Tina Zhang <tina.zhang@intel.com>]

vfio_get_dev_irq_info is introduced to return a specific irq
capabilities.

Signed-off-by: Tina Zhang <tina.zhang@intel.com>
---
 hw/vfio/common.c              | 78 +++++++++++++++++++++++++++++++++++
 include/hw/vfio/vfio-common.h |  3 ++
 2 files changed, 81 insertions(+)

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 4374cc6176..928ea54411 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -748,6 +748,25 @@ vfio_get_region_info_cap(struct vfio_region_info *info, uint16_t id)
     return NULL;
 }
 
+static struct vfio_info_cap_header *
+vfio_get_irq_info_cap(struct vfio_irq_info *info, uint16_t id)
+{
+    struct vfio_info_cap_header *hdr;
+    void *ptr = info;
+
+    if (!(info->flags & VFIO_IRQ_INFO_FLAG_CAPS)) {
+        return NULL;
+    }
+
+    for (hdr = ptr + info->cap_offset; hdr != ptr; hdr = ptr + hdr->next) {
+        if (hdr->id == id) {
+            return hdr;
+        }
+    }
+
+    return NULL;
+}
+
 static int vfio_setup_region_sparse_mmaps(VFIORegion *region,
                                           struct vfio_region_info *info)
 {
@@ -1539,6 +1558,33 @@ retry:
     return 0;
 }
 
+static int vfio_get_irq_info(VFIODevice *vbasedev, int index,
+                         struct vfio_irq_info **info)
+{
+    size_t argsz = sizeof(struct vfio_irq_info);
+
+    *info = g_malloc0(argsz);
+
+    (*info)->index = index;
+retry:
+    (*info)->argsz = argsz;
+
+    if (ioctl(vbasedev->fd, VFIO_DEVICE_GET_IRQ_INFO, *info)) {
+        g_free(*info);
+        *info = NULL;
+        return -errno;
+    }
+
+    if ((*info)->argsz > argsz) {
+        argsz = (*info)->argsz;
+        *info = g_realloc(*info, argsz);
+
+        goto retry;
+    }
+
+    return 0;
+}
+
 int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type,
                              uint32_t subtype, struct vfio_region_info **info)
 {
@@ -1574,6 +1620,38 @@ int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type,
     return -ENODEV;
 }
 
+int vfio_get_dev_irq_info(VFIODevice *vbasedev, uint32_t type,
+                             uint32_t subtype, struct vfio_irq_info **info)
+{
+    int i;
+
+    for (i = 0; i < vbasedev->num_irqs; i++) {
+        struct vfio_info_cap_header *hdr;
+        struct vfio_irq_info_cap_type *cap_type;
+
+        if (vfio_get_irq_info(vbasedev, i, info)) {
+            continue;
+        }
+
+        hdr = vfio_get_irq_info_cap(*info, VFIO_IRQ_INFO_CAP_TYPE);
+        if (!hdr) {
+            g_free(*info);
+            continue;
+        }
+
+        cap_type = container_of(hdr, struct vfio_irq_info_cap_type, header);
+
+        if (cap_type->type == type && cap_type->subtype == subtype) {
+            return 0;
+        }
+
+        g_free(*info);
+    }
+
+    *info = NULL;
+    return -ENODEV;
+}
+
 bool vfio_has_region_cap(VFIODevice *vbasedev, int region, uint16_t cap_type)
 {
     struct vfio_region_info *info = NULL;
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 1155b79678..5cab6a1b81 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -195,6 +195,9 @@ int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type,
 bool vfio_has_region_cap(VFIODevice *vbasedev, int region, uint16_t cap_type);
 struct vfio_info_cap_header *
 vfio_get_region_info_cap(struct vfio_region_info *info, uint16_t id);
+
+int vfio_get_dev_irq_info(VFIODevice *vbasedev, uint32_t type,
+                          uint32_t subtype, struct vfio_irq_info **info);
 #endif
 extern const MemoryListener vfio_prereg_listener;
 
-- 
2.17.1