This patch implements a software vDPA networking device. The datapath
is implemented through vringh and workqueue. The device has an on-chip
IOMMU which translates IOVA to PA. For kernel virtio drivers, vDPA
simulator driver provides dma_ops. For vhost driers, set_map() methods
of vdpa_config_ops is implemented to accept mappings from vhost.
Currently, vDPA device simulator will loopback TX traffic to RX. So
the main use case for the device is vDPA feature testing, prototyping
and development.
Note, there's no management API implemented, a vDPA device will be
registered once the module is probed. We need to handle this in the
future development.
Signed-off-by: Jason Wang
---
drivers/virtio/vdpa/Kconfig | 18 +
drivers/virtio/vdpa/Makefile| 1 +
drivers/virtio/vdpa/vdpa_sim/Makefile | 2 +
drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c | 660
4 files changed, 681 insertions(+)
create mode 100644 drivers/virtio/vdpa/vdpa_sim/Makefile
create mode 100644 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c
diff --git a/drivers/virtio/vdpa/Kconfig b/drivers/virtio/vdpa/Kconfig
index 7a99170e6c30..e3656b722654 100644
--- a/drivers/virtio/vdpa/Kconfig
+++ b/drivers/virtio/vdpa/Kconfig
@@ -7,3 +7,21 @@ config VDPA
datapath which complies with virtio specifications with
vendor specific control path.
+menuconfig VDPA_MENU
+ bool "VDPA drivers"
+ default n
+
+if VDPA_MENU
+
+config VDPA_SIM
+ tristate "vDPA device simulator"
+select VDPA
+depends on RUNTIME_TESTING_MENU
+default n
+help
+ vDPA networking device simulator which loop TX traffic back
+ to RX. This device is used for testing, prototyping and
+ development of vDPA.
+
+endif # VDPA_MENU
+
diff --git a/drivers/virtio/vdpa/Makefile b/drivers/virtio/vdpa/Makefile
index ee6a35e8a4fb..3814af8e097b 100644
--- a/drivers/virtio/vdpa/Makefile
+++ b/drivers/virtio/vdpa/Makefile
@@ -1,2 +1,3 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_VDPA) += vdpa.o
+obj-$(CONFIG_VDPA_SIM) += vdpa_sim/
diff --git a/drivers/virtio/vdpa/vdpa_sim/Makefile
b/drivers/virtio/vdpa/vdpa_sim/Makefile
new file mode 100644
index ..b40278f65e04
--- /dev/null
+++ b/drivers/virtio/vdpa/vdpa_sim/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_VDPA_SIM) += vdpa_sim.o
diff --git a/drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c
b/drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c
new file mode 100644
index ..59d464f72ac2
--- /dev/null
+++ b/drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c
@@ -0,0 +1,660 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * VDPA networking device simulator.
+ *
+ * Copyright (c) 2020, Red Hat Inc. All rights reserved.
+ * Author: Jason Wang
+ *
+ */
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#define DRV_VERSION "0.1"
+#define DRV_AUTHOR "Jason Wang "
+#define DRV_DESC "vDPA Device Simulator"
+#define DRV_LICENSE "GPL v2"
+
+struct vdpasim_virtqueue {
+ struct vringh vring;
+ struct vringh_kiov iov;
+ unsigned short head;
+ bool ready;
+ u64 desc_addr;
+ u64 device_addr;
+ u64 driver_addr;
+ u32 num;
+ void *private;
+ irqreturn_t (*cb)(void *data);
+};
+
+#define VDPASIM_QUEUE_ALIGN PAGE_SIZE
+#define VDPASIM_QUEUE_MAX 256
+#define VDPASIM_DEVICE_ID 0x1
+#define VDPASIM_VENDOR_ID 0
+#define VDPASIM_VQ_NUM 0x2
+#define VDPASIM_NAME "vdpasim-netdev"
+
+static u64 vdpasim_features = (1ULL << VIRTIO_F_ANY_LAYOUT) |
+ (1ULL << VIRTIO_F_VERSION_1) |
+ (1ULL << VIRTIO_F_IOMMU_PLATFORM);
+
+/* State of each vdpasim device */
+struct vdpasim {
+ struct vdpasim_virtqueue vqs[2];
+ struct work_struct work;
+ /* spinlock to synchronize virtqueue state */
+ spinlock_t lock;
+ struct vdpa_device *vdpa;
+ struct device dev;
+ struct virtio_net_config config;
+ struct vhost_iotlb *iommu;
+ void *buffer;
+ u32 status;
+ u32 generation;
+ u64 features;
+};
+
+struct vdpasim *vdpasim_dev;
+
+static struct vdpasim *dev_to_sim(struct device *dev)
+{
+ return container_of(dev, struct vdpasim, dev);
+}
+
+static struct vdpasim *vdpa_to_sim(struct vdpa_device *vdpa)
+{
+ struct device *d = >dev;
+
+ return dev_to_sim(d->parent);
+}
+
+static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx)
+{
+ struct vdpasim_virtqueue *vq = >vqs[idx];
+ int ret;
+
+ ret = vringh_init_iotlb(>vring, vdpasim_features,
+ VDPASIM_QUEUE_MAX, false,
+ (struct vring_desc *)(uintptr_t)vq->desc_addr,
+ (struct vring_avail *)
+
