From: Bobby Eshleman <bobbyeshleman@meta.com>

The config fragment already sets CONFIG_UDMABUF=y, but kconfig silently
drops it. UDMABUF/NET_DEVMEM both depend on DMA_SHARED_BUFFER, which we
can't enable directly, so we need to enable a config that selects it. We
use SYNC_FILE for that purpose here.

Additionally, we flip on CONFIG_NET_DEVMEM as well.

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
 tools/testing/selftests/drivers/net/hw/config | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/testing/selftests/drivers/net/hw/config b/tools/testing/selftests/drivers/net/hw/config
index ed8642b68094..d89a9ba17655 100644
--- a/tools/testing/selftests/drivers/net/hw/config
+++ b/tools/testing/selftests/drivers/net/hw/config
@@ -15,11 +15,13 @@ CONFIG_IPV6_SIT=y
 CONFIG_IPV6_TUNNEL=y
 CONFIG_NET_CLS_ACT=y
 CONFIG_NET_CLS_BPF=y
+CONFIG_NET_DEVMEM=y
 CONFIG_NET_IPGRE=y
 CONFIG_NET_IPGRE_DEMUX=y
 CONFIG_NET_IPIP=y
 CONFIG_NETKIT=y
 CONFIG_NET_SCH_INGRESS=y
+CONFIG_SYNC_FILE=y
 CONFIG_UDMABUF=y
 CONFIG_USER_NS=y
 CONFIG_VXLAN=y

---
base-commit: 2fbade66245059c78daeaccfce13ecf499fffb51
change-id: 20260731-selftests-devmem-config-f4f843f0f0ad

Best regards,
-- 
Bobby Eshleman <bobbyeshleman@meta.com>

On Fri, Jul 31, 2026 at 4:38 PM Bobby Eshleman <bobbyeshleman@gmail.com> wrote:
>
> From: Bobby Eshleman <bobbyeshleman@meta.com>
>
> The config fragment already sets CONFIG_UDMABUF=y, but kconfig silently
> drops it. UDMABUF/NET_DEVMEM both depend on DMA_SHARED_BUFFER, which we
> can't enable directly, so we need to enable a config that selects it. We
> use SYNC_FILE for that purpose here.
>
> Additionally, we flip on CONFIG_NET_DEVMEM as well.
>
> Suggested-by: Jakub Kicinski <kuba@kernel.org>
> Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>

While hacky, I think it's okay to find something that enables
DMA_SHARED_BUFFER for us here.

Reviewed-by: Mina Almasry <almasrymina@google.com>

> ---
>  tools/testing/selftests/drivers/net/hw/config | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/tools/testing/selftests/drivers/net/hw/config b/tools/testing/selftests/drivers/net/hw/config
> index ed8642b68094..d89a9ba17655 100644
> --- a/tools/testing/selftests/drivers/net/hw/config
> +++ b/tools/testing/selftests/drivers/net/hw/config
> @@ -15,11 +15,13 @@ CONFIG_IPV6_SIT=y
>  CONFIG_IPV6_TUNNEL=y
>  CONFIG_NET_CLS_ACT=y
>  CONFIG_NET_CLS_BPF=y
> +CONFIG_NET_DEVMEM=y
>  CONFIG_NET_IPGRE=y
>  CONFIG_NET_IPGRE_DEMUX=y
>  CONFIG_NET_IPIP=y
>  CONFIG_NETKIT=y
>  CONFIG_NET_SCH_INGRESS=y
> +CONFIG_SYNC_FILE=y
>  CONFIG_UDMABUF=y
>  CONFIG_USER_NS=y
>  CONFIG_VXLAN=y
>
> ---
> base-commit: 2fbade66245059c78daeaccfce13ecf499fffb51
> change-id: 20260731-selftests-devmem-config-f4f843f0f0ad
>
> Best regards,
> --
> Bobby Eshleman <bobbyeshleman@meta.com>
>
>


-- 
Thanks,
Mina