[PULL 13/16] vfio/iommufd: Save vendor specific device info

["Cédric Le Goater" <clg@redhat.com>]

From: Zhenzhong Duan <zhenzhong.duan@intel.com>

Some device information returned by ioctl(IOMMU_GET_HW_INFO) are vendor
specific. Save them as raw data in a union supporting different vendors,
then vendor IOMMU can query the raw data with its fixed format for
capability directly.

Because IOMMU_GET_HW_INFO is only supported in linux, so declare those
capability related structures with CONFIG_LINUX.

Suggested-by: Eric Auger <eric.auger@redhat.com>
Suggested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20250604062115.4004200-5-zhenzhong.duan@intel.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
---
 include/system/host_iommu_device.h | 15 +++++++++++++++
 hw/vfio/iommufd.c                  |  8 +++-----
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/include/system/host_iommu_device.h b/include/system/host_iommu_device.h
index 809cced4ba5c56263132b474a382e4bd0ffdd3cd..ab849a4a82d5f2a2a09c7924791b93c26d9ff902 100644
--- a/include/system/host_iommu_device.h
+++ b/include/system/host_iommu_device.h
@@ -14,6 +14,13 @@
 
 #include "qom/object.h"
 #include "qapi/error.h"
+#ifdef CONFIG_LINUX
+#include "linux/iommufd.h"
+
+typedef union VendorCaps {
+    struct iommu_hw_info_vtd vtd;
+    struct iommu_hw_info_arm_smmuv3 smmuv3;
+} VendorCaps;
 
 /**
  * struct HostIOMMUDeviceCaps - Define host IOMMU device capabilities.
@@ -22,11 +29,17 @@
  *
  * @hw_caps: host platform IOMMU capabilities (e.g. on IOMMUFD this represents
  *           the @out_capabilities value returned from IOMMU_GET_HW_INFO ioctl)
+ *
+ * @vendor_caps: host platform IOMMU vendor specific capabilities (e.g. on
+ *               IOMMUFD this represents a user-space buffer filled by kernel
+ *               with host IOMMU @type specific hardware information data)
  */
 typedef struct HostIOMMUDeviceCaps {
     uint32_t type;
     uint64_t hw_caps;
+    VendorCaps vendor_caps;
 } HostIOMMUDeviceCaps;
+#endif
 
 #define TYPE_HOST_IOMMU_DEVICE "host-iommu-device"
 OBJECT_DECLARE_TYPE(HostIOMMUDevice, HostIOMMUDeviceClass, HOST_IOMMU_DEVICE)
@@ -38,7 +51,9 @@ struct HostIOMMUDevice {
     void *agent; /* pointer to agent device, ie. VFIO or VDPA device */
     PCIBus *aliased_bus;
     int aliased_devfn;
+#ifdef CONFIG_LINUX
     HostIOMMUDeviceCaps caps;
+#endif
 };
 
 /**
diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index 59033028373c82a22b1aaf092503d037a6d7e9b6..c4bbf36241d3ee5c46bca9601688afd742e471f7 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -839,16 +839,14 @@ static bool hiod_iommufd_vfio_realize(HostIOMMUDevice *hiod, void *opaque,
     VFIODevice *vdev = opaque;
     HostIOMMUDeviceIOMMUFD *idev;
     HostIOMMUDeviceCaps *caps = &hiod->caps;
+    VendorCaps *vendor_caps = &caps->vendor_caps;
     enum iommu_hw_info_type type;
-    union {
-        struct iommu_hw_info_vtd vtd;
-    } data;
     uint64_t hw_caps;
 
     hiod->agent = opaque;
 
-    if (!iommufd_backend_get_device_info(vdev->iommufd, vdev->devid,
-                                         &type, &data, sizeof(data),
+    if (!iommufd_backend_get_device_info(vdev->iommufd, vdev->devid, &type,
+                                         vendor_caps, sizeof(*vendor_caps),
                                          &hw_caps, errp)) {
         return false;
     }
-- 
2.49.0