Re: [PATCH v6 5/8] libvduse: Add VDUSE (vDPA Device in Userspace) library

[Maxime Coquelin]

Hi Yongji,

On 5/23/22 10:46, Xie Yongji wrote:
> VDUSE [1] is a linux framework that makes it possible to implement
> software-emulated vDPA devices in userspace. This adds a library
> as a subproject to help implementing VDUSE backends in QEMU.
>
> [1] https://www.kernel.org/doc/html/latest/userspace-api/vduse.html
>
> Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
> ---
>   MAINTAINERS                                 |    5 +
>   meson.build                                 |   15 +
>   meson_options.txt                           |    2 +
>   scripts/meson-buildoptions.sh               |    3 +
>   subprojects/libvduse/include/atomic.h       |    1 +
>   subprojects/libvduse/include/compiler.h     |    1 +
>   subprojects/libvduse/libvduse.c             | 1167 +++++++++++++++++++
>   subprojects/libvduse/libvduse.h             |  235 ++++
>   subprojects/libvduse/linux-headers/linux    |    1 +
>   subprojects/libvduse/meson.build            |   10 +
>   subprojects/libvduse/standard-headers/linux |    1 +
>   11 files changed, 1441 insertions(+)
>   create mode 120000 subprojects/libvduse/include/atomic.h
>   create mode 120000 subprojects/libvduse/include/compiler.h
>   create mode 100644 subprojects/libvduse/libvduse.c
>   create mode 100644 subprojects/libvduse/libvduse.h
>   create mode 120000 subprojects/libvduse/linux-headers/linux
>   create mode 100644 subprojects/libvduse/meson.build
>   create mode 120000 subprojects/libvduse/standard-headers/linux

...

> diff --git a/subprojects/libvduse/libvduse.c b/subprojects/libvduse/libvduse.c
> new file mode 100644
> index 0000000000..fa4822b9a9
> --- /dev/null
> +++ b/subprojects/libvduse/libvduse.c
> @@ -0,0 +1,1167 @@

...

> +
> +int vduse_dev_destroy(VduseDev *dev)
> +{
> +    int ret = 0;
> +
> +    free(dev->vqs);
> +    if (dev->fd > 0) {

if (dev->fd >= 0) {

> +        close(dev->fd);
> +        dev->fd = -1;
> +    }
> +    if (dev->ctrl_fd > 0) {

if (dev->ctrl_fd >= 0) {

> +        if (ioctl(dev->ctrl_fd, VDUSE_DESTROY_DEV, dev->name)) {
> +            ret = -errno;
> +        }
> +        close(dev->ctrl_fd);
> +        dev->ctrl_fd = -1;
> +    }
> +    free(dev->name);
> +    free(dev);
> +
> +    return ret;
> +}

Maxime