Re: [Qemu-devel] [PATCH v2] 9pfs: fix dependencies

[Thomas Huth <thuth@redhat.com>]

On 09.08.2017 09:17, Cornelia Huck wrote:
> Nothing in fsdev/ or hw/9pfs/ depends on pci; it should rather depend
> on CONFIG_VIRTFS and on the presence of an appropriate virtio transport
> device.
> 
> Let's introduce CONFIG_VIRTIO_CCW to cover s390x and check for
> CONFIG_VIRTFS && (CONFIG_VIRTIO_PCI || CONFIG_VIRTIO_CCW).
> 
> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
> ---
> 
> Changes v1->v2: drop extraneous spaces, fix build on cris
> 
> ---
>  default-configs/s390x-softmmu.mak | 1 +
>  fsdev/Makefile.objs               | 9 +++------
>  hw/Makefile.objs                  | 2 +-
>  3 files changed, 5 insertions(+), 7 deletions(-)
> 
> diff --git a/default-configs/s390x-softmmu.mak b/default-configs/s390x-softmmu.mak
> index 51191b77df..e4c5236ceb 100644
> --- a/default-configs/s390x-softmmu.mak
> +++ b/default-configs/s390x-softmmu.mak
> @@ -8,3 +8,4 @@ CONFIG_S390_FLIC=y
>  CONFIG_S390_FLIC_KVM=$(CONFIG_KVM)
>  CONFIG_VFIO_CCW=$(CONFIG_LINUX)
>  CONFIG_WDT_DIAG288=y
> +CONFIG_VIRTIO_CCW=y
> diff --git a/fsdev/Makefile.objs b/fsdev/Makefile.objs
> index 659df6e187..3d157add31 100644
> --- a/fsdev/Makefile.objs
> +++ b/fsdev/Makefile.objs
> @@ -1,10 +1,7 @@
> -ifeq ($(CONFIG_VIRTIO)$(CONFIG_VIRTFS)$(CONFIG_PCI),yyy)
>  # Lots of the fsdev/9pcode is pulled in by vl.c via qemu_fsdev_add.
> -# only pull in the actual virtio-9p device if we also enabled virtio.
> -common-obj-y = qemu-fsdev.o 9p-marshal.o 9p-iov-marshal.o
> -else
> -common-obj-y = qemu-fsdev-dummy.o
> -endif
> +# only pull in the actual virtio-9p device if we also enabled a virtio backend.
> +common-obj-$(call land,$(CONFIG_VIRTFS),$(call lor,$(CONFIG_VIRTIO_PCI),$(CONFIG_VIRTIO_CCW)))= qemu-fsdev.o 9p-marshal.o 9p-iov-marshal.o
> +common-obj-$(call lnot,$(call land,$(CONFIG_VIRTFS),$(call lor,$(CONFIG_VIRTIO_PCI),$(CONFIG_VIRTIO_CCW)))) = qemu-fsdev-dummy.o
>  common-obj-y += qemu-fsdev-opts.o qemu-fsdev-throttle.o
>  
>  # Toplevel always builds this; targets without virtio will put it in
> diff --git a/hw/Makefile.objs b/hw/Makefile.objs
> index a2c61f6b09..335f26b65e 100644
> --- a/hw/Makefile.objs
> +++ b/hw/Makefile.objs
> @@ -1,4 +1,4 @@
> -devices-dirs-$(call land, $(CONFIG_VIRTIO),$(call land,$(CONFIG_VIRTFS),$(CONFIG_PCI))) += 9pfs/
> +devices-dirs-$(call land,$(CONFIG_VIRTFS),$(call lor,$(CONFIG_VIRTIO_PCI),$(CONFIG_VIRTIO_CCW))) += 9pfs/
>  devices-dirs-$(CONFIG_SOFTMMU) += acpi/
>  devices-dirs-$(CONFIG_SOFTMMU) += adc/
>  devices-dirs-$(CONFIG_SOFTMMU) += audio/

Patch should be fine now, I think...

But thinking about this again, I wonder whether it would be enough to
simply check for CONFIG_VIRTIO=y here instead. CONFIG_VIRTIO=y should be
sufficient to assert that there is also at least one kind of virtio
transport available, right?
Otherwise this will look really horrible as soon as somebody also tries
to add support for virtio-mmio here later ;-)

 Thomas