Re: [PATCH v2 09/11] vfio/iommufd: Make iommufd_cdev_*() return bool

[Cédric Le Goater]

On 5/7/24 08:42, Zhenzhong Duan wrote:

This is to follow the coding standand to return bool if 'Error **'
is used to pass error.

The changed functions include:

iommufd_cdev_kvm_device_add
iommufd_cdev_connect_and_bind
iommufd_cdev_attach_ioas_hwpt
iommufd_cdev_detach_ioas_hwpt
iommufd_cdev_attach_container
iommufd_cdev_get_info_iova_range

After the change, all functions in hw/vfio/iommufd.c follows the
standand.

Suggested-by: Cédric Le Goater <c...@redhat.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.d...@intel.com>

Reviewed-by: Cédric Le Goater <c...@redhat.com>

Thanks,

C.

---
  hw/vfio/iommufd.c | 88 +++++++++++++++++++++--------------------------
  1 file changed, 39 insertions(+), 49 deletions(-)

diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index 4c6992fca1..84c86b970e 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -49,9 +49,9 @@ static int iommufd_cdev_unmap(const VFIOContainerBase 
*bcontainer,
                                       container->ioas_id, iova, size);
  }

-static int iommufd_cdev_kvm_device_add(VFIODevice *vbasedev, Error **errp)

+static bool iommufd_cdev_kvm_device_add(VFIODevice *vbasedev, Error **errp)
  {
-    return vfio_kvm_device_add_fd(vbasedev->fd, errp);
+    return !vfio_kvm_device_add_fd(vbasedev->fd, errp);
  }

static void iommufd_cdev_kvm_device_del(VFIODevice *vbasedev)

@@ -63,18 +63,16 @@ static void iommufd_cdev_kvm_device_del(VFIODevice 
*vbasedev)
      }
  }

-static int iommufd_cdev_connect_and_bind(VFIODevice *vbasedev, Error **errp)

+static bool iommufd_cdev_connect_and_bind(VFIODevice *vbasedev, Error **errp)
  {
      IOMMUFDBackend *iommufd = vbasedev->iommufd;
      struct vfio_device_bind_iommufd bind = {
          .argsz = sizeof(bind),
          .flags = 0,
      };
-    int ret;

- ret = iommufd_backend_connect(iommufd, errp);

-    if (ret) {
-        return ret;
+    if (iommufd_backend_connect(iommufd, errp)) {
+        return false;
      }

/*

@@ -82,15 +80,13 @@ static int iommufd_cdev_connect_and_bind(VFIODevice 
*vbasedev, Error **errp)
       * in KVM. Especially for some emulated devices, it requires
       * to have kvm information in the device open.
       */
-    ret = iommufd_cdev_kvm_device_add(vbasedev, errp);
-    if (ret) {
+    if (!iommufd_cdev_kvm_device_add(vbasedev, errp)) {
          goto err_kvm_device_add;
      }

/* Bind device to iommufd */

      bind.iommufd = iommufd->fd;
-    ret = ioctl(vbasedev->fd, VFIO_DEVICE_BIND_IOMMUFD, &bind);
-    if (ret) {
+    if (ioctl(vbasedev->fd, VFIO_DEVICE_BIND_IOMMUFD, &bind)) {
          error_setg_errno(errp, errno, "error bind device fd=%d to iommufd=%d",
                           vbasedev->fd, bind.iommufd);
          goto err_bind;
@@ -99,12 +95,12 @@ static int iommufd_cdev_connect_and_bind(VFIODevice 
*vbasedev, Error **errp)
      vbasedev->devid = bind.out_devid;
      trace_iommufd_cdev_connect_and_bind(bind.iommufd, vbasedev->name,
                                          vbasedev->fd, vbasedev->devid);
-    return ret;
+    return true;
  err_bind:
      iommufd_cdev_kvm_device_del(vbasedev);
  err_kvm_device_add:
      iommufd_backend_disconnect(iommufd);
-    return ret;
+    return false;
  }

static void iommufd_cdev_unbind_and_disconnect(VFIODevice *vbasedev)

@@ -176,10 +172,10 @@ out:
      return ret;
  }

-static int iommufd_cdev_attach_ioas_hwpt(VFIODevice *vbasedev, uint32_t id,

+static bool iommufd_cdev_attach_ioas_hwpt(VFIODevice *vbasedev, uint32_t id,
                                           Error **errp)
  {
-    int ret, iommufd = vbasedev->iommufd->fd;
+    int iommufd = vbasedev->iommufd->fd;
      struct vfio_device_attach_iommufd_pt attach_data = {
          .argsz = sizeof(attach_data),
          .flags = 0,
@@ -187,38 +183,38 @@ static int iommufd_cdev_attach_ioas_hwpt(VFIODevice 
*vbasedev, uint32_t id,
      };

/* Attach device to an IOAS or hwpt within iommufd */

-    ret = ioctl(vbasedev->fd, VFIO_DEVICE_ATTACH_IOMMUFD_PT, &attach_data);
-    if (ret) {
+    if (ioctl(vbasedev->fd, VFIO_DEVICE_ATTACH_IOMMUFD_PT, &attach_data)) {
          error_setg_errno(errp, errno,
                           "[iommufd=%d] error attach %s (%d) to id=%d",
                           iommufd, vbasedev->name, vbasedev->fd, id);
-    } else {
-        trace_iommufd_cdev_attach_ioas_hwpt(iommufd, vbasedev->name,
-                                            vbasedev->fd, id);
+        return false;
      }
-    return ret;
+
+    trace_iommufd_cdev_attach_ioas_hwpt(iommufd, vbasedev->name,
+                                        vbasedev->fd, id);
+    return true;
  }

-static int iommufd_cdev_detach_ioas_hwpt(VFIODevice *vbasedev, Error **errp)

+static bool iommufd_cdev_detach_ioas_hwpt(VFIODevice *vbasedev, Error **errp)
  {
-    int ret, iommufd = vbasedev->iommufd->fd;
+    int iommufd = vbasedev->iommufd->fd;
      struct vfio_device_detach_iommufd_pt detach_data = {
          .argsz = sizeof(detach_data),
          .flags = 0,
      };

- ret = ioctl(vbasedev->fd, VFIO_DEVICE_DETACH_IOMMUFD_PT, &detach_data);

-    if (ret) {
+    if (ioctl(vbasedev->fd, VFIO_DEVICE_DETACH_IOMMUFD_PT, &detach_data)) {
          error_setg_errno(errp, errno, "detach %s failed", vbasedev->name);
-    } else {
-        trace_iommufd_cdev_detach_ioas_hwpt(iommufd, vbasedev->name);
+        return false;
      }
-    return ret;
+
+    trace_iommufd_cdev_detach_ioas_hwpt(iommufd, vbasedev->name);
+    return true;
  }

-static int iommufd_cdev_attach_container(VFIODevice *vbasedev,

-                                         VFIOIOMMUFDContainer *container,
-                                         Error **errp)
+static bool iommufd_cdev_attach_container(VFIODevice *vbasedev,
+                                          VFIOIOMMUFDContainer *container,
+                                          Error **errp)
  {
      return iommufd_cdev_attach_ioas_hwpt(vbasedev, container->ioas_id, errp);
  }
@@ -228,7 +224,7 @@ static void iommufd_cdev_detach_container(VFIODevice 
*vbasedev,
  {
      Error *err = NULL;

- if (iommufd_cdev_detach_ioas_hwpt(vbasedev, &err)) {

+    if (!iommufd_cdev_detach_ioas_hwpt(vbasedev, &err)) {
          error_report_err(err);
      }
  }
@@ -254,20 +250,19 @@ static int iommufd_cdev_ram_block_discard_disable(bool 
state)
      return ram_block_uncoordinated_discard_disable(state);
  }

-static int iommufd_cdev_get_info_iova_range(VFIOIOMMUFDContainer *container,

-                                            uint32_t ioas_id, Error **errp)
+static bool iommufd_cdev_get_info_iova_range(VFIOIOMMUFDContainer *container,
+                                             uint32_t ioas_id, Error **errp)
  {
      VFIOContainerBase *bcontainer = &container->bcontainer;
      g_autofree struct iommu_ioas_iova_ranges *info = NULL;
      struct iommu_iova_range *iova_ranges;
-    int ret, sz, fd = container->be->fd;
+    int sz, fd = container->be->fd;

info = g_malloc0(sizeof(*info));

      info->size = sizeof(*info);
      info->ioas_id = ioas_id;

- ret = ioctl(fd, IOMMU_IOAS_IOVA_RANGES, info);

-    if (ret && errno != EMSGSIZE) {
+    if (ioctl(fd, IOMMU_IOAS_IOVA_RANGES, info) && errno != EMSGSIZE) {
          goto error;
      }

@@ -275,8 +270,7 @@ static int iommufd_cdev_get_info_iova_range(VFIOIOMMUFDContainer *container,

      info = g_realloc(info, sizeof(*info) + sz);
      info->allowed_iovas = (uintptr_t)(info + 1);

- ret = ioctl(fd, IOMMU_IOAS_IOVA_RANGES, info);

-    if (ret) {
+    if (ioctl(fd, IOMMU_IOAS_IOVA_RANGES, info)) {
          goto error;
      }

@@ -291,12 +285,11 @@ static int iommufd_cdev_get_info_iova_range(VFIOIOMMUFDContainer *container,

      }
      bcontainer->pgsizes = info->out_iova_alignment;

- return 0;

+    return true;

error:

-    ret = -errno;
      error_setg_errno(errp, errno, "Cannot get IOVA ranges");
-    return ret;
+    return false;
  }

static bool iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,

@@ -322,8 +315,7 @@ static bool iommufd_cdev_attach(const char *name, 
VFIODevice *vbasedev,
          devfd = vbasedev->fd;
      }

- ret = iommufd_cdev_connect_and_bind(vbasedev, errp);

-    if (ret) {
+    if (!iommufd_cdev_connect_and_bind(vbasedev, errp)) {
          goto err_connect_bind;
      }

@@ -336,7 +328,7 @@ static bool iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,

              vbasedev->iommufd != container->be) {
              continue;
          }
-        if (iommufd_cdev_attach_container(vbasedev, container, &err)) {
+        if (!iommufd_cdev_attach_container(vbasedev, container, &err)) {
              const char *msg = error_get_pretty(err);

trace_iommufd_cdev_fail_attach_existing_container(msg);

@@ -369,8 +361,7 @@ static bool iommufd_cdev_attach(const char *name, 
VFIODevice *vbasedev,
      vfio_container_init(bcontainer, space, iommufd_vioc);
      QLIST_INSERT_HEAD(&space->containers, bcontainer, next);

- ret = iommufd_cdev_attach_container(vbasedev, container, errp);

-    if (ret) {
+    if (!iommufd_cdev_attach_container(vbasedev, container, errp)) {
          goto err_attach_container;
      }

@@ -379,8 +370,7 @@ static bool iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,

          goto err_discard_disable;
      }

- ret = iommufd_cdev_get_info_iova_range(container, ioas_id, &err);

-    if (ret) {
+    if (!iommufd_cdev_get_info_iova_range(container, ioas_id, &err)) {
          error_append_hint(&err,
                     "Fallback to default 64bit IOVA range and 4K page size\n");
          warn_report_err(err);