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authorMichael S. Tsirkin <mst@redhat.com>2015-01-15 16:06:26 +0200
committerRusty Russell <rusty@rustcorp.com.au>2015-01-21 16:28:59 +1030
commit46506da5f365efe7fe3e4c9da73ab679c0382fac (patch)
treee8f11e77b344a635815b60968f4f694d3f60af93 /drivers/virtio
parent0327642337fee1dba50fa4d9a45d3a8b8fb2d1c3 (diff)
downloadop-kernel-dev-46506da5f365efe7fe3e4c9da73ab679c0382fac.zip
op-kernel-dev-46506da5f365efe7fe3e4c9da73ab679c0382fac.tar.gz
virtio_pci: add an option to disable legacy driver
Useful for testing device virtio 1 compatibility. Based on patch by Rusty - couldn't resist putting that flying car joke in there! Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'drivers/virtio')
-rw-r--r--drivers/virtio/Kconfig19
-rw-r--r--drivers/virtio/Makefile3
-rw-r--r--drivers/virtio/virtio_pci_common.h10
3 files changed, 31 insertions, 1 deletions
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index 083fb45..b546da5 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -19,6 +19,25 @@ config VIRTIO_PCI
If unsure, say M.
+config VIRTIO_PCI_LEGACY
+ bool "Support for legacy virtio draft 0.9.X and older devices"
+ default y
+ depends on VIRTIO_PCI
+ ---help---
+ Virtio PCI Card 0.9.X Draft (circa 2014) and older device support.
+
+ This option enables building a transitional driver, supporting
+ both devices conforming to Virtio 1 specification, and legacy devices.
+ If disabled, you get a slightly smaller, non-transitional driver,
+ with no legacy compatibility.
+
+ So look out into your driveway. Do you have a flying car? If
+ so, you can happily disable this option and virtio will not
+ break. Otherwise, leave it set. Unless you're testing what
+ life will be like in The Future.
+
+ If unsure, say Y.
+
config VIRTIO_BALLOON
tristate "Virtio balloon driver"
depends on VIRTIO
diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
index bd230d1..d85565b 100644
--- a/drivers/virtio/Makefile
+++ b/drivers/virtio/Makefile
@@ -1,5 +1,6 @@
obj-$(CONFIG_VIRTIO) += virtio.o virtio_ring.o
obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o
obj-$(CONFIG_VIRTIO_PCI) += virtio_pci.o
-virtio_pci-y := virtio_pci_modern.o virtio_pci_legacy.o virtio_pci_common.o
+virtio_pci-y := virtio_pci_modern.o virtio_pci_common.o
+virtio_pci-$(CONFIG_VIRTIO_PCI_LEGACY) += virtio_pci_legacy.o
obj-$(CONFIG_VIRTIO_BALLOON) += virtio_balloon.o
diff --git a/drivers/virtio/virtio_pci_common.h b/drivers/virtio/virtio_pci_common.h
index d391805..28ee4e5 100644
--- a/drivers/virtio/virtio_pci_common.h
+++ b/drivers/virtio/virtio_pci_common.h
@@ -147,8 +147,18 @@ const char *vp_bus_name(struct virtio_device *vdev);
*/
int vp_set_vq_affinity(struct virtqueue *vq, int cpu);
+#if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
int virtio_pci_legacy_probe(struct virtio_pci_device *);
void virtio_pci_legacy_remove(struct virtio_pci_device *);
+#else
+static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
+{
+ return -ENODEV;
+}
+static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
+{
+}
+#endif
int virtio_pci_modern_probe(struct virtio_pci_device *);
void virtio_pci_modern_remove(struct virtio_pci_device *);
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