Re: [PATCH] [v2] virtio: always enter drivers/virtio/

[Jason Wang]

On Mon, Dec 6, 2021 at 4:50 PM Arnd Bergmann <arnd@xxxxxxxxxx> wrote:
>
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> When neither VIRTIO_PCI_LIB nor VIRTIO are enabled, but the alibaba
> vdpa driver is, the kernel runs into a link error because the legacy
> virtio module never gets built:
>
> x86_64-linux-ld: drivers/vdpa/alibaba/eni_vdpa.o: in function `eni_vdpa_set_features':
> eni_vdpa.c:(.text+0x23f): undefined reference to `vp_legacy_set_features'
> x86_64-linux-ld: drivers/vdpa/alibaba/eni_vdpa.o: in function `eni_vdpa_set_vq_state':
> eni_vdpa.c:(.text+0x2fe): undefined reference to `vp_legacy_get_queue_enable'
> x86_64-linux-ld: drivers/vdpa/alibaba/eni_vdpa.o: in function `eni_vdpa_set_vq_address':
> eni_vdpa.c:(.text+0x376): undefined reference to `vp_legacy_set_queue_address'
> x86_64-linux-ld: drivers/vdpa/alibaba/eni_vdpa.o: in function `eni_vdpa_set_vq_ready':
> eni_vdpa.c:(.text+0x3b4): undefined reference to `vp_legacy_set_queue_address'
> x86_64-linux-ld: drivers/vdpa/alibaba/eni_vdpa.o: in function `eni_vdpa_free_irq':
> eni_vdpa.c:(.text+0x460): undefined reference to `vp_legacy_queue_vector'
> x86_64-linux-ld: eni_vdpa.c:(.text+0x4b7): undefined reference to `vp_legacy_config_vector'
> x86_64-linux-ld: drivers/vdpa/alibaba/eni_vdpa.o: in function `eni_vdpa_reset':
>
> When VIRTIO_PCI_LIB was added, it was correctly added to drivers/Makefile
> as well, but for the legacy module, this is missing.  Solve this by always
> entering drivers/virtio during the build and letting its Makefile take
> care of the individual options, rather than having a separate line for
> each sub-option.
>
> Fixes: 64b9f64f80a6 ("vdpa: introduce virtio pci driver")

I think this is not true. we had:

obj-$(CONFIG_VIRTIO_PCI_LIB)   += virtio/

since then.

The patch looks good to me.

Thanks

> Fixes: e85087beedca ("eni_vdpa: add vDPA driver for Alibaba ENI")
> Fixes: d89c8169bd70 ("virtio-pci: introduce legacy device module")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
>  drivers/Makefile | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/Makefile b/drivers/Makefile
> index be5d40ae1488..a110338c860c 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -41,8 +41,7 @@ obj-$(CONFIG_DMADEVICES)      += dma/
>  # SOC specific infrastructure drivers.
>  obj-y                          += soc/
>
> -obj-$(CONFIG_VIRTIO)           += virtio/
> -obj-$(CONFIG_VIRTIO_PCI_LIB)   += virtio/
> +obj-y                          += virtio/
>  obj-$(CONFIG_VDPA)             += vdpa/
>  obj-$(CONFIG_XEN)              += xen/
>
> --
> 2.29.2
>