This patch introduces a vDPA transport for virtio. This is used to
use kernel virtio driver to drive the vDPA device that is capable
of populating virtqueue directly.
A new virtio-vdpa driver will be registered to the vDPA bus, when a
new virtio-vdpa device is probed, it will register the device with
vdpa based config ops. This means it is a software transport between
vDPA driver and vDPA device. The transport was implemented through
bus_ops of vDPA parent.
Signed-off-by: Jason Wang
---
drivers/virtio/Kconfig | 13 ++
drivers/virtio/Makefile | 1 +
drivers/virtio/virtio_vdpa.c | 392 +++
3 files changed, 406 insertions(+)
create mode 100644 drivers/virtio/virtio_vdpa.c
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index 9c4fdb64d9ac..99e424570644 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -43,6 +43,19 @@ config VIRTIO_PCI_LEGACY
If unsure, say Y.
+config VIRTIO_VDPA
+ tristate "vDPA driver for virtio devices"
+ select VDPA
+ select VIRTIO
+ help
+ This driver provides support for virtio based paravirtual
+ device driver over vDPA bus. For this to be useful, you need
+ an appropriate vDPA device implementation that operates on a
+ physical device to allow the datapath of virtio to be
+ offloaded to hardware.
+
+ If unsure, say M.
+
config VIRTIO_PMEM
tristate "Support for virtio pmem driver"
depends on VIRTIO
diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
index fdf5eacd0d0a..3407ac03fe60 100644
--- a/drivers/virtio/Makefile
+++ b/drivers/virtio/Makefile
@@ -6,4 +6,5 @@ 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
obj-$(CONFIG_VIRTIO_INPUT) += virtio_input.o
+obj-$(CONFIG_VIRTIO_VDPA) += virtio_vdpa.o
obj-$(CONFIG_VDPA) += vdpa/
diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c
new file mode 100644
index ..077796087abf
--- /dev/null
+++ b/drivers/virtio/virtio_vdpa.c
@@ -0,0 +1,392 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * VIRTIO based driver for vDPA device
+ *
+ * Copyright (c) 2020, Red Hat. All rights reserved.
+ * Author: Jason Wang
+ *
+ */
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#define MOD_VERSION "0.1"
+#define MOD_AUTHOR "Jason Wang "
+#define MOD_DESC "vDPA bus driver for virtio devices"
+#define MOD_LICENSE "GPL v2"
+
+struct virtio_vdpa_device {
+ struct virtio_device vdev;
+ struct vdpa_device *vdpa;
+ u64 features;
+
+ /* The lock to protect virtqueue list */
+ spinlock_t lock;
+ /* List of virtio_vdpa_vq_info */
+ struct list_head virtqueues;
+};
+
+struct virtio_vdpa_vq_info {
+ /* the actual virtqueue */
+ struct virtqueue *vq;
+
+ /* the list node for the virtqueues list */
+ struct list_head node;
+};
+
+static inline struct virtio_vdpa_device *
+to_virtio_vdpa_device(struct virtio_device *dev)
+{
+ return container_of(dev, struct virtio_vdpa_device, vdev);
+}
+
+static struct vdpa_device *vd_get_vdpa(struct virtio_device *vdev)
+{
+ return to_virtio_vdpa_device(vdev)->vdpa;
+}
+
+static void virtio_vdpa_get(struct virtio_device *vdev, unsigned offset,
+ void *buf, unsigned len)
+{
+ struct vdpa_device *vdpa = vd_get_vdpa(vdev);
+ const struct vdpa_config_ops *ops = vdpa->config;
+
+ ops->get_config(vdpa, offset, buf, len);
+}
+
+static void virtio_vdpa_set(struct virtio_device *vdev, unsigned offset,
+ const void *buf, unsigned len)
+{
+ struct vdpa_device *vdpa = vd_get_vdpa(vdev);
+ const struct vdpa_config_ops *ops = vdpa->config;
+
+ ops->set_config(vdpa, offset, buf, len);
+}
+
+static u32 virtio_vdpa_generation(struct virtio_device *vdev)
+{
+ struct vdpa_device *vdpa = vd_get_vdpa(vdev);
+ const struct vdpa_config_ops *ops = vdpa->config;
+
+ if (ops->get_generation)
+ return ops->get_generation(vdpa);
+
+ return 0;
+}
+
+static u8 virtio_vdpa_get_status(struct virtio_device *vdev)
+{
+ struct vdpa_device *vdpa = vd_get_vdpa(vdev);
+ const struct vdpa_config_ops *ops = vdpa->config;
+
+ return ops->get_status(vdpa);
+}
+
+static void virtio_vdpa_set_status(struct virtio_device *vdev, u8 status)
+{
+ struct vdpa_device *vdpa = vd_get_vdpa(vdev);
+ const struct vdpa_config_ops *ops = vdpa->config;
+
+ return ops->set_status(vdpa, status);
+}
+
+static void virtio_vdpa_reset(struct virtio_device *vdev)
+{
+ struct vdpa_device *vdpa = vd_get_vdpa(vdev);
+ const struct vdpa_config_ops *ops = vdpa->config;
+
+ return ops->set_status(vdpa, 0);
+}
+
+static bool virtio_vdpa
