> -----Original Message-----
> From: Maxime Coquelin <maxime.coque...@redhat.com>
> Sent: Wednesday, September 30, 2020 12:14 AM
> To: dev@dpdk.org; Xia, Chenbo <chenbo....@intel.com>; Fu, Patrick
> <patrick...@intel.com>; amore...@redhat.com
> Cc: Maxime Coquelin <maxime.coque...@redhat.com>
> Subject: [PATCH v3 4/8] net/virtio: introduce Vhost-vDPA backend type
>
> Backend type is determined by checking char-device major numbers
>
> Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
> Signed-off-by: Adrian Moreno <amore...@redhat.com>
> ---
> .../net/virtio/virtio_user/virtio_user_dev.h | 1 +
> drivers/net/virtio/virtio_user_ethdev.c | 48 +++++++++++++++++--
> 2 files changed, 45 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.h
> b/drivers/net/virtio/virtio_user/virtio_user_dev.h
> index 575bf430c0..1c8c98b1cd 100644
> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.h
> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.h
> @@ -14,6 +14,7 @@ enum virtio_user_backend_type {
> VIRTIO_USER_BACKEND_UNKNOWN,
> VIRTIO_USER_BACKEND_VHOST_USER,
> VIRTIO_USER_BACKEND_VHOST_KERNEL,
> + VIRTIO_USER_BACKEND_VHOST_VDPA,
> };
>
> struct virtio_user_queue {
> diff --git a/drivers/net/virtio/virtio_user_ethdev.c
> b/drivers/net/virtio/virtio_user_ethdev.c
> index 38b49bad5f..3a51afd711 100644
> --- a/drivers/net/virtio/virtio_user_ethdev.c
> +++ b/drivers/net/virtio/virtio_user_ethdev.c
> @@ -6,7 +6,9 @@
> #include <sys/types.h>
> #include <unistd.h>
> #include <fcntl.h>
> +#include <linux/major.h>
> #include <sys/stat.h>
> +#include <sys/sysmacros.h>
> #include <sys/socket.h>
>
> #include <rte_malloc.h>
> @@ -519,17 +521,55 @@ get_integer_arg(const char *key __rte_unused,
> return -errno;
> }
>
> +static uint32_t
> +vdpa_dynamic_major_num(void)
> +{
> + FILE *fp;
> + char *line = NULL;
> + size_t size;
> + char name[11];
> + bool found = false;
> + uint32_t num;
> +
> + fp = fopen("/proc/devices", "r");
> + if (fp == NULL) {
> + PMD_INIT_LOG(ERR, "Cannot open /proc/devices: %s",
> + strerror(errno));
> + return UNNAMED_MAJOR;
> + }
> +
> + while (getline(&line, &size, fp) > 0) {
> + char *stripped = line + strspn(line, " ");
> + if ((sscanf(stripped, "%u %10s", &num, name) == 2) &&
> + (strncmp(name, "vhost-vdpa", 10) == 0)) {
> + found = true;
> + break;
> + }
> + }
> + fclose(fp);
> + return found ? num : UNNAMED_MAJOR;
> +}
> +
> static enum virtio_user_backend_type
> virtio_user_backend_type(const char *path)
> {
> struct stat sb;
>
> - if (stat(path, &sb) == -1)
> + if (stat(path, &sb) == -1) {
> + PMD_INIT_LOG(ERR, "Stat fails: %s (%s)\n", path,
> + strerror(errno));
> return VIRTIO_USER_BACKEND_UNKNOWN;
> + }
>
> - return S_ISSOCK(sb.st_mode) ?
> - VIRTIO_USER_BACKEND_VHOST_USER :
> - VIRTIO_USER_BACKEND_VHOST_KERNEL;
> + if (S_ISSOCK(sb.st_mode)) {
> + return VIRTIO_USER_BACKEND_VHOST_USER;
> + } else if (S_ISCHR(sb.st_mode)) {
> + if (major(sb.st_rdev) == MISC_MAJOR)
> + return VIRTIO_USER_BACKEND_VHOST_KERNEL;
> + if (major(sb.st_rdev) == vdpa_dynamic_major_num())
> + return VIRTIO_USER_BACKEND_VHOST_VDPA;
> + }
> + return VIRTIO_USER_BACKEND_UNKNOWN;
> }
>
> static struct rte_eth_dev *
> --
> 2.26.2
Reviewed-by: Chenbo Xia <chenbo....@intel.com>
