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MAkefile: dont rebuild vhost for each target

PATCH In review Michael S. Tsirkin 3 participants 4 messages Dec 20, 2012 – Jan 4, 2013 Kbuild

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Michael S. Tsirkin

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#0 lore raw

PATCH 1/1 MAkefile: dont rebuild vhost for each target

We rebuild vhost_net for each target, but there's no real reason to, we only have 2 variants: with and without vhost-net.

Signed-off-by Michael S. Tsirkin <[email protected]>
---
 Makefile.target     | 1 +
 hw/Makefile.objs    | 5 +++--
 hw/vhost_net_stub.c | 1 +
 3 files changed, 5 insertions(+), 2 deletions(-)
 create mode 100644 hw/vhost_net_stub.c
Makefile.target +1 -0
index 8bbad38..f6fddbd 100644
@@ -103,6 +103,7 @@ endif #CONFIG_BSD_USER
 #########################################################
 # System emulator target
 ifdef CONFIG_SOFTMMU
+CONFIG_NO_VHOST_NET = $(if $(subst n,,$(CONFIG_VHOST_NET)),n,y)
 CONFIG_NO_PCI = $(if $(subst n,,$(CONFIG_PCI)),n,y)
 CONFIG_NO_KVM = $(if $(subst n,,$(CONFIG_KVM)),n,y)
 CONFIG_NO_XEN = $(if $(subst n,,$(CONFIG_XEN)),n,y)
hw/Makefile.objs +3 -2
index 2778035..360a43c 100644
@@ -3,6 +3,9 @@ common-obj-y += loader.o
 common-obj-$(CONFIG_VIRTIO) += virtio-console.o
 common-obj-$(CONFIG_VIRTIO) += virtio-rng.o
 common-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
+common-obj-$(CONFIG_VHOST_NET) += vhost_net.o
+common-obj-$(CONFIG_VHOST_NET) += vhost.o
+common-obj-$(CONFIG_NO_VHOST_NET) += vhost_net_stub.o
 common-obj-y += fw_cfg.o
 common-obj-$(CONFIG_PCI) += pci_bridge_dev.o
 common-obj-$(CONFIG_PCI) += ioh3420.o xio3130_upstream.o xio3130_downstream.o

@@ -192,8 +195,6 @@ common-obj-$(CONFIG_XEN_BACKEND) += xen_console.o xenfb.o xen_disk.o xen_nic.o
 # need to fix this properly
 obj-$(CONFIG_VIRTIO) += virtio.o virtio-blk.o virtio-balloon.o virtio-net.o
 obj-$(CONFIG_VIRTIO) += virtio-serial-bus.o virtio-scsi.o
-obj-$(CONFIG_SOFTMMU) += vhost_net.o
-obj-$(CONFIG_VHOST_NET) += vhost.o
 obj-$(CONFIG_REALLY_VIRTFS) += 9pfs/
 obj-$(CONFIG_VGA) += vga.o
 obj-$(CONFIG_SOFTMMU) += device-hotplug.o
hw/vhost_net_stub.c new file +1 -0
new file mode 100644
index 0000000..387b578
@@ -0,0 +1 @@
+#include "vhost_net.c"
Signature · 1 line
MST
#1 lore raw

Il 20/12/2012 15:20, Michael S. Tsirkin ha scritto:

hw/vhost_net_stub.c line 1

Quoted 7 lines
hw/vhost_net_stub.c new file +1 -0
new file mode 100644
index 0000000..387b578
@@ -0,0 +1 @@
+#include "vhost_net.c"

Nice. As a follow-up, can you perhaps split the vhost_net.c file in two following the model of other *-stub.c files?

Paolo

author
#2 lore raw
Quoted 12 lines · Paolo Bonzini

Il 20/12/2012 15:20, Michael S. Tsirkin ha scritto:

hw/vhost_net_stub.c line 1

Quoted 7 lines
hw/vhost_net_stub.c new file +1 -0
new file mode 100644
index 0000000..387b578
@@ -0,0 +1 @@
+#include "vhost_net.c"

Nice. As a follow-up, can you perhaps split the vhost_net.c file in two following the model of other *-stub.c files?

Quoted 1 line

Paolo

Still thinking about this - keeping it all in a single file makes it easier to change interfaces, OTOH making stub separate means less platforms need to be rebuilt when only implementation changes.

#3 lore raw
In reply to Michael S. Tsirkin
Quoted 15 lines · Michael S. Tsirkin
hw/Makefile.objs +3 -0
index 2778035..360a43c 100644
@@ -3,6 +3,9 @@ common-obj-y += loader.o
 common-obj-$(CONFIG_VIRTIO) += virtio-console.o
 common-obj-$(CONFIG_VIRTIO) += virtio-rng.o
 common-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
+common-obj-$(CONFIG_VHOST_NET) += vhost_net.o
+common-obj-$(CONFIG_VHOST_NET) += vhost.o
+common-obj-$(CONFIG_NO_VHOST_NET) += vhost_net_stub.o
 common-obj-y += fw_cfg.o
 common-obj-$(CONFIG_PCI) += pci_bridge_dev.o
 common-obj-$(CONFIG_PCI) += ioh3420.o xio3130_upstream.o xio3130_downstream.o

hw/Makefile.objs common-obj-$(CONFIG_XEN_BACKEND) += xen_console.o xenfb.o xen_disk.o xen_nic.o · line 200

Quoted 8 lines
hw/Makefile.objs +0 -2
@@ -192,8 +195,6 @@ common-obj-$(CONFIG_XEN_BACKEND) += xen_console.o xenfb.o xen_disk.o xen_nic.o
 # need to fix this properly
 obj-$(CONFIG_VIRTIO) += virtio.o virtio-blk.o virtio-balloon.o virtio-net.o
 obj-$(CONFIG_VIRTIO) += virtio-serial-bus.o virtio-scsi.o
-obj-$(CONFIG_SOFTMMU) += vhost_net.o
-obj-$(CONFIG_VHOST_NET) += vhost.o
 obj-$(CONFIG_REALLY_VIRTFS) += 9pfs/
 obj-$(CONFIG_VGA) += vga.o
 obj-$(CONFIG_SOFTMMU) += device-hotplug.o

Careful, this change means that you're now including the system-wide /usr/include/linux/vhost.h header file instead of QEMU's linux-headers/linux/vhost.h.

I recently hit this with the dataplane patches since they include virtio_ring.h.

On an outdated build host we may run into trouble when relying on the system-wide header file.

(The -I linux-headers/ is only added in Makefile.target.)

Stefan