[PATCH v5 16/26] vhost: add VDUSE device creation and destruction

[Maxime Coquelin <maxime.coquelin@redhat.com>]

This patch adds initial support for VDUSE, which includes
the device creation and destruction.

It does not include the virtqueues configuration, so this is
not functionnal at this point.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>
---
 lib/vhost/meson.build |   4 +
 lib/vhost/socket.c    |  34 ++++---
 lib/vhost/vduse.c     | 201 ++++++++++++++++++++++++++++++++++++++++++
 lib/vhost/vduse.h     |  33 +++++++
 lib/vhost/vhost.h     |   2 +
 5 files changed, 262 insertions(+), 12 deletions(-)
 create mode 100644 lib/vhost/vduse.c
 create mode 100644 lib/vhost/vduse.h

diff --git a/lib/vhost/meson.build b/lib/vhost/meson.build
index d211a0bd37..13e0382c92 100644
--- a/lib/vhost/meson.build
+++ b/lib/vhost/meson.build
@@ -29,6 +29,10 @@ sources = files(
         'virtio_net.c',
         'virtio_net_ctrl.c',
 )
+if cc.has_header('linux/vduse.h')
+    sources += files('vduse.c')
+    cflags += '-DVHOST_HAS_VDUSE'
+endif
 headers = files(
         'rte_vdpa.h',
         'rte_vhost.h',
diff --git a/lib/vhost/socket.c b/lib/vhost/socket.c
index 29f7a8cece..19a7469e45 100644
--- a/lib/vhost/socket.c
+++ b/lib/vhost/socket.c
@@ -19,6 +19,7 @@
 #include <rte_log.h>
 
 #include "fd_man.h"
+#include "vduse.h"
 #include "vhost.h"
 #include "vhost_user.h"
 
@@ -36,6 +37,7 @@ struct vhost_user_socket {
 	int socket_fd;
 	struct sockaddr_un un;
 	bool is_server;
+	bool is_vduse;
 	bool reconnect;
 	bool iommu_support;
 	bool use_builtin_virtio_net;
@@ -991,18 +993,21 @@ rte_vhost_driver_register(const char *path, uint64_t flags)
 #endif
 	}
 
-	if ((flags & RTE_VHOST_USER_CLIENT) != 0) {
-		vsocket->reconnect = !(flags & RTE_VHOST_USER_NO_RECONNECT);
-		if (vsocket->reconnect && reconn_tid == 0) {
-			if (vhost_user_reconnect_init() != 0)
-				goto out_mutex;
-		}
+	if (!strncmp("/dev/vduse/", path, strlen("/dev/vduse/"))) {
+		vsocket->is_vduse = true;
 	} else {
-		vsocket->is_server = true;
-	}
-	ret = create_unix_socket(vsocket);
-	if (ret < 0) {
-		goto out_mutex;
+		if ((flags & RTE_VHOST_USER_CLIENT) != 0) {
+			vsocket->reconnect = !(flags & RTE_VHOST_USER_NO_RECONNECT);
+			if (vsocket->reconnect && reconn_tid == 0) {
+				if (vhost_user_reconnect_init() != 0)
+					goto out_mutex;
+			}
+		} else {
+			vsocket->is_server = true;
+		}
+		ret = create_unix_socket(vsocket);
+		if (ret < 0)
+			goto out_mutex;
 	}
 
 	vhost_user.vsockets[vhost_user.vsocket_cnt++] = vsocket;
@@ -1067,7 +1072,9 @@ rte_vhost_driver_unregister(const char *path)
 		if (strcmp(vsocket->path, path))
 			continue;
 
-		if (vsocket->is_server) {
+		if (vsocket->is_vduse) {
+			vduse_device_destroy(path);
+		} else if (vsocket->is_server) {
 			/*
 			 * If r/wcb is executing, release vhost_user's
 			 * mutex lock, and try again since the r/wcb
@@ -1218,6 +1225,9 @@ rte_vhost_driver_start(const char *path)
 	if (!vsocket)
 		return -1;
 
+	if (vsocket->is_vduse)
+		return vduse_device_create(path);
+
 	if (fdset_tid == 0) {
 		/**
 		 * create a pipe which will be waited by poll and notified to
diff --git a/lib/vhost/vduse.c b/lib/vhost/vduse.c
new file mode 100644
index 0000000000..d67818bfb5
--- /dev/null
+++ b/lib/vhost/vduse.c
@@ -0,0 +1,201 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright (c) 2023 Red Hat, Inc.
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+
+#include <linux/vduse.h>
+#include <linux/virtio_net.h>
+
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+
+#include <rte_common.h>
+
+#include "vduse.h"
+#include "vhost.h"
+
+#define VHOST_VDUSE_API_VERSION 0
+#define VDUSE_CTRL_PATH "/dev/vduse/control"
+
+#define VDUSE_NET_SUPPORTED_FEATURES ((1ULL << VIRTIO_NET_F_MRG_RXBUF) | \
+				(1ULL << VIRTIO_F_ANY_LAYOUT) | \
+				(1ULL << VIRTIO_F_VERSION_1)   | \
+				(1ULL << VIRTIO_NET_F_GSO) | \
+				(1ULL << VIRTIO_NET_F_HOST_TSO4) | \
+				(1ULL << VIRTIO_NET_F_HOST_TSO6) | \
+				(1ULL << VIRTIO_NET_F_HOST_UFO) | \
+				(1ULL << VIRTIO_NET_F_HOST_ECN) | \
+				(1ULL << VIRTIO_NET_F_CSUM)    | \
+				(1ULL << VIRTIO_NET_F_GUEST_CSUM) | \
+				(1ULL << VIRTIO_NET_F_GUEST_TSO4) | \
+				(1ULL << VIRTIO_NET_F_GUEST_TSO6) | \
+				(1ULL << VIRTIO_NET_F_GUEST_UFO) | \
+				(1ULL << VIRTIO_NET_F_GUEST_ECN) | \
+				(1ULL << VIRTIO_RING_F_INDIRECT_DESC) | \
+				(1ULL << VIRTIO_F_IN_ORDER) | \
+				(1ULL << VIRTIO_F_IOMMU_PLATFORM))
+
+static struct vhost_backend_ops vduse_backend_ops = {
+};
+
+int
+vduse_device_create(const char *path)
+{
+	int control_fd, dev_fd, vid, ret;
+	uint32_t i;
+	struct virtio_net *dev;
+	uint64_t ver = VHOST_VDUSE_API_VERSION;
+	struct vduse_dev_config *dev_config = NULL;
+	const char *name = path + strlen("/dev/vduse/");
+
+	control_fd = open(VDUSE_CTRL_PATH, O_RDWR);
+	if (control_fd < 0) {
+		VHOST_LOG_CONFIG(name, ERR, "Failed to open %s: %s\n",
+				VDUSE_CTRL_PATH, strerror(errno));
+		return -1;
+	}
+
+	if (ioctl(control_fd, VDUSE_SET_API_VERSION, &ver)) {
+		VHOST_LOG_CONFIG(name, ERR, "Failed to set API version: %" PRIu64 ": %s\n",
+				ver, strerror(errno));
+		ret = -1;
+		goto out_ctrl_close;
+	}
+
+	dev_config = malloc(offsetof(struct vduse_dev_config, config));
+	if (!dev_config) {
+		VHOST_LOG_CONFIG(name, ERR, "Failed to allocate VDUSE config\n");
+		ret = -1;
+		goto out_ctrl_close;
+	}
+
+	memset(dev_config, 0, sizeof(struct vduse_dev_config));
+
+	strncpy(dev_config->name, name, VDUSE_NAME_MAX - 1);
+	dev_config->device_id = VIRTIO_ID_NET;
+	dev_config->vendor_id = 0;
+	dev_config->features = VDUSE_NET_SUPPORTED_FEATURES;
+	dev_config->vq_num = 2;
+	dev_config->vq_align = sysconf(_SC_PAGE_SIZE);
+	dev_config->config_size = 0;
+
+	ret = ioctl(control_fd, VDUSE_CREATE_DEV, dev_config);
+	if (ret < 0) {
+		VHOST_LOG_CONFIG(name, ERR, "Failed to create VDUSE device: %s\n",
+				strerror(errno));
+		goto out_free;
+	}
+
+	dev_fd = open(path, O_RDWR);
+	if (dev_fd < 0) {
+		VHOST_LOG_CONFIG(name, ERR, "Failed to open device %s: %s\n",
+				path, strerror(errno));
+		ret = -1;
+		goto out_dev_close;
+	}
+
+	ret = fcntl(dev_fd, F_SETFL, O_NONBLOCK);
+	if (ret < 0) {
+		VHOST_LOG_CONFIG(name, ERR, "Failed to set chardev as non-blocking: %s\n",
+				strerror(errno));
+		goto out_dev_close;
+	}
+
+	vid = vhost_new_device(&vduse_backend_ops);
+	if (vid < 0) {
+		VHOST_LOG_CONFIG(name, ERR, "Failed to create new Vhost device\n");
+		ret = -1;
+		goto out_dev_close;
+	}
+
+	dev = get_device(vid);
+	if (!dev) {
+		ret = -1;
+		goto out_dev_close;
+	}
+
+	strncpy(dev->ifname, path, IF_NAME_SZ - 1);
+	dev->vduse_ctrl_fd = control_fd;
+	dev->vduse_dev_fd = dev_fd;
+	vhost_setup_virtio_net(dev->vid, true, true, true, true);
+
+	for (i = 0; i < 2; i++) {
+		struct vduse_vq_config vq_cfg = { 0 };
+
+		ret = alloc_vring_queue(dev, i);
+		if (ret) {
+			VHOST_LOG_CONFIG(name, ERR, "Failed to alloc vring %d metadata\n", i);
+			goto out_dev_destroy;
+		}
+
+		vq_cfg.index = i;
+		vq_cfg.max_size = 1024;
+
+		ret = ioctl(dev->vduse_dev_fd, VDUSE_VQ_SETUP, &vq_cfg);
+		if (ret) {
+			VHOST_LOG_CONFIG(name, ERR, "Failed to set-up VQ %d\n", i);
+			goto out_dev_destroy;
+		}
+	}
+
+	free(dev_config);
+
+	return 0;
+
+out_dev_destroy:
+	vhost_destroy_device(vid);
+out_dev_close:
+	if (dev_fd >= 0)
+		close(dev_fd);
+	ioctl(control_fd, VDUSE_DESTROY_DEV, name);
+out_free:
+	free(dev_config);
+out_ctrl_close:
+	close(control_fd);
+
+	return ret;
+}
+
+int
+vduse_device_destroy(const char *path)
+{
+	const char *name = path + strlen("/dev/vduse/");
+	struct virtio_net *dev;
+	int vid, ret;
+
+	for (vid = 0; vid < RTE_MAX_VHOST_DEVICE; vid++) {
+		dev = vhost_devices[vid];
+
+		if (dev == NULL)
+			continue;
+
+		if (!strcmp(path, dev->ifname))
+			break;
+	}
+
+	if (vid == RTE_MAX_VHOST_DEVICE)
+		return -1;
+
+	if (dev->vduse_dev_fd >= 0) {
+		close(dev->vduse_dev_fd);
+		dev->vduse_dev_fd = -1;
+	}
+
+	if (dev->vduse_ctrl_fd >= 0) {
+		ret = ioctl(dev->vduse_ctrl_fd, VDUSE_DESTROY_DEV, name);
+		if (ret)
+			VHOST_LOG_CONFIG(name, ERR, "Failed to destroy VDUSE device: %s\n",
+					strerror(errno));
+		close(dev->vduse_ctrl_fd);
+		dev->vduse_ctrl_fd = -1;
+	}
+
+	vhost_destroy_device(vid);
+
+	return 0;
+}
diff --git a/lib/vhost/vduse.h b/lib/vhost/vduse.h
new file mode 100644
index 0000000000..a15e5d4c16
--- /dev/null
+++ b/lib/vhost/vduse.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright (c) 2023 Red Hat, Inc.
+ */
+
+#ifndef _VDUSE_H
+#define _VDUSE_H
+
+#include "vhost.h"
+
+#ifdef VHOST_HAS_VDUSE
+
+int vduse_device_create(const char *path);
+int vduse_device_destroy(const char *path);
+
+#else
+
+static inline int
+vduse_device_create(const char *path)
+{
+	VHOST_LOG_CONFIG(path, ERR, "VDUSE support disabled at build time\n");
+	return -1;
+}
+
+static inline int
+vduse_device_destroy(const char *path)
+{
+	VHOST_LOG_CONFIG(path, ERR, "VDUSE support disabled at build time\n");
+	return -1;
+}
+
+#endif /* VHOST_HAS_VDUSE */
+
+#endif /* _VDUSE_H */
diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h
index 04267a3ac5..9ecede0f30 100644
--- a/lib/vhost/vhost.h
+++ b/lib/vhost/vhost.h
@@ -526,6 +526,8 @@ struct virtio_net {
 
 	int			postcopy_ufd;
 	int			postcopy_listening;
+	int			vduse_ctrl_fd;
+	int			vduse_dev_fd;
 
 	struct vhost_virtqueue	*cvq;
 
-- 
2.40.1