We introduce the concept of vhost-backend, which can be either vhost-kernel
or vhost-user. The existing vhost interface to the kernel is abstracted
behind the vhost-kernel backend.
We replace all direct ioctls to the kernel with a vhost_call to the backend.
vhost dev->control is referenced only in the vhost-backend (ioctl, open, close).
Signed-off-by: Antonios Motakis <a.mota...@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikol...@virtualopensystems.com>
---
hw/net/vhost_net.c | 13 +++++---
hw/scsi/vhost-scsi.c | 13 +++++---
hw/virtio/Makefile.objs | 2 +-
hw/virtio/vhost-backend.c | 65 +++++++++++++++++++++++++++++++++++++++
hw/virtio/vhost.c | 47 +++++++++++++++-------------
include/hw/virtio/vhost-backend.h | 37 ++++++++++++++++++++++
include/hw/virtio/vhost.h | 4 ++-
7 files changed, 148 insertions(+), 33 deletions(-)
create mode 100644 hw/virtio/vhost-backend.c
create mode 100644 include/hw/virtio/vhost-backend.h
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 006576d..4aaf0b4 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -27,7 +27,6 @@
#include <sys/socket.h>
#include <linux/kvm.h>
#include <fcntl.h>
-#include <sys/ioctl.h>
#include <linux/virtio_ring.h>
#include <netpacket/packet.h>
#include <net/ethernet.h>
@@ -113,7 +112,8 @@ struct vhost_net *vhost_net_init(NetClientState *backend,
int devfd,
net->dev.nvqs = 2;
net->dev.vqs = net->vqs;
- r = vhost_dev_init(&net->dev, devfd, "/dev/vhost-net", force);
+ r = vhost_dev_init(&net->dev, devfd, "/dev/vhost-net",
+ VHOST_BACKEND_TYPE_KERNEL, force);
if (r < 0) {
goto fail;
}
@@ -170,7 +170,8 @@ static int vhost_net_start_one(struct vhost_net *net,
qemu_set_fd_handler(net->backend, NULL, NULL, NULL);
file.fd = net->backend;
for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
- r = ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file);
+ const VhostOps *vhost_ops = net->dev.vhost_ops;
+ r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND, &file);
if (r < 0) {
r = -errno;
goto fail;
@@ -180,7 +181,8 @@ static int vhost_net_start_one(struct vhost_net *net,
fail:
file.fd = -1;
while (file.index-- > 0) {
- int r = ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file);
+ const VhostOps *vhost_ops = net->dev.vhost_ops;
+ int r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND, &file);
assert(r >= 0);
}
net->nc->info->poll(net->nc, true);
@@ -201,7 +203,8 @@ static void vhost_net_stop_one(struct vhost_net *net,
}
for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
- int r = ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file);
+ const VhostOps *vhost_ops = net->dev.vhost_ops;
+ int r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND, &file);
assert(r >= 0);
}
net->nc->info->poll(net->nc, true);
diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c
index 3983a5b..3faff65 100644
--- a/hw/scsi/vhost-scsi.c
+++ b/hw/scsi/vhost-scsi.c
@@ -27,12 +27,13 @@
static int vhost_scsi_set_endpoint(VHostSCSI *s)
{
VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
+ const VhostOps *vhost_ops = s->dev.vhost_ops;
struct vhost_scsi_target backend;
int ret;
memset(&backend, 0, sizeof(backend));
pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
- ret = ioctl(s->dev.control, VHOST_SCSI_SET_ENDPOINT, &backend);
+ ret = vhost_ops->vhost_call(&s->dev, VHOST_SCSI_SET_ENDPOINT, &backend);
if (ret < 0) {
return -errno;
}
@@ -43,10 +44,11 @@ static void vhost_scsi_clear_endpoint(VHostSCSI *s)
{
VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
struct vhost_scsi_target backend;
+ const VhostOps *vhost_ops = s->dev.vhost_ops;
memset(&backend, 0, sizeof(backend));
pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
- ioctl(s->dev.control, VHOST_SCSI_CLEAR_ENDPOINT, &backend);
+ vhost_ops->vhost_call(&s->dev, VHOST_SCSI_CLEAR_ENDPOINT, &backend);
}
static int vhost_scsi_start(VHostSCSI *s)
@@ -55,13 +57,15 @@ static int vhost_scsi_start(VHostSCSI *s)
VirtIODevice *vdev = VIRTIO_DEVICE(s);
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
+ const VhostOps *vhost_ops = s->dev.vhost_ops;
if (!k->set_guest_notifiers) {
error_report("binding does not support guest notifiers");
return -ENOSYS;
}
- ret = ioctl(s->dev.control, VHOST_SCSI_GET_ABI_VERSION, &abi_version);
+ ret = vhost_ops->vhost_call(&s->dev,
+ VHOST_SCSI_GET_ABI_VERSION, &abi_version);
if (ret < 0) {
return -errno;
}
@@ -227,7 +231,8 @@ static void vhost_scsi_realize(DeviceState *dev, Error
**errp)
s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
s->dev.vq_index = 0;
- ret = vhost_dev_init(&s->dev, vhostfd, "/dev/vhost-scsi", true);
+ ret = vhost_dev_init(&s->dev, vhostfd, "/dev/vhost-scsi",
+ VHOST_BACKEND_TYPE_KERNEL, true);
if (ret < 0) {
error_setg(errp, "vhost-scsi: vhost initialization failed: %s",
strerror(-ret));
diff --git a/hw/virtio/Makefile.objs b/hw/virtio/Makefile.objs
index 1ba53d9..51e5bdb 100644
--- a/hw/virtio/Makefile.objs
+++ b/hw/virtio/Makefile.objs
@@ -5,4 +5,4 @@ common-obj-y += virtio-mmio.o
common-obj-$(CONFIG_VIRTIO_BLK_DATA_PLANE) += dataplane/
obj-y += virtio.o virtio-balloon.o
-obj-$(CONFIG_LINUX) += vhost.o
+obj-$(CONFIG_LINUX) += vhost.o vhost-backend.o
diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
new file mode 100644
index 0000000..c0f11e4
--- /dev/null
+++ b/hw/virtio/vhost-backend.c
@@ -0,0 +1,65 @@
+/*
+ * vhost-backend
+ *
+ * Copyright (c) 2013 Virtual Open Systems Sarl.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "hw/virtio/vhost.h"
+#include "hw/virtio/vhost-backend.h"
+#include "qemu/error-report.h"
+
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+
+static int vhost_kernel_call(struct vhost_dev *dev, unsigned long int request,
+ void *arg)
+{
+ int fd = dev->control;
+
+ assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
+
+ return ioctl(fd, request, arg);
+}
+
+static int vhost_kernel_init(struct vhost_dev *dev, const char *devpath)
+{
+ assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
+
+ dev->control = open(devpath, O_RDWR);
+ return dev->control;
+}
+
+static int vhost_kernel_cleanup(struct vhost_dev *dev)
+{
+ assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
+
+ return close(dev->control);
+}
+
+static const VhostOps kernel_ops = {
+ .backend_type = VHOST_BACKEND_TYPE_KERNEL,
+ .vhost_call = vhost_kernel_call,
+ .vhost_backend_init = vhost_kernel_init,
+ .vhost_backend_cleanup = vhost_kernel_cleanup
+};
+
+int vhost_set_backend_type(struct vhost_dev *dev, VhostBackendType
backend_type)
+{
+ int r = 0;
+
+ switch (backend_type) {
+ case VHOST_BACKEND_TYPE_KERNEL:
+ dev->vhost_ops = &kernel_ops;
+ break;
+ default:
+ error_report("Unknown vhost backend type\n");
+ r = -1;
+ }
+
+ return r;
+}
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 9e336ad..a1137e1 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -13,8 +13,8 @@
* GNU GPL, version 2 or (at your option) any later version.
*/
-#include <sys/ioctl.h>
#include "hw/virtio/vhost.h"
+#include "hw/virtio/vhost-backend.h"
#include "hw/hw.h"
#include "qemu/atomic.h"
#include "qemu/range.h"
@@ -291,7 +291,7 @@ static inline void vhost_dev_log_resize(struct vhost_dev*
dev, uint64_t size)
log = g_malloc0(size * sizeof *log);
log_base = (uint64_t)(unsigned long)log;
- r = ioctl(dev->control, VHOST_SET_LOG_BASE, &log_base);
+ r = dev->vhost_ops->vhost_call(dev, VHOST_SET_LOG_BASE, &log_base);
assert(r >= 0);
/* Sync only the range covered by the old log */
if (dev->log_size) {
@@ -460,7 +460,7 @@ static void vhost_commit(MemoryListener *listener)
}
if (!dev->log_enabled) {
- r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
+ r = dev->vhost_ops->vhost_call(dev, VHOST_SET_MEM_TABLE, dev->mem);
assert(r >= 0);
dev->memory_changed = false;
return;
@@ -473,7 +473,7 @@ static void vhost_commit(MemoryListener *listener)
if (dev->log_size < log_size) {
vhost_dev_log_resize(dev, log_size + VHOST_LOG_BUFFER);
}
- r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
+ r = dev->vhost_ops->vhost_call(dev, VHOST_SET_MEM_TABLE, dev->mem);
assert(r >= 0);
/* To log less, can only decrease log size after table update. */
if (dev->log_size > log_size + VHOST_LOG_BUFFER) {
@@ -541,7 +541,7 @@ static int vhost_virtqueue_set_addr(struct vhost_dev *dev,
.log_guest_addr = vq->used_phys,
.flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0,
};
- int r = ioctl(dev->control, VHOST_SET_VRING_ADDR, &addr);
+ int r = dev->vhost_ops->vhost_call(dev, VHOST_SET_VRING_ADDR, &addr);
if (r < 0) {
return -errno;
}
@@ -555,7 +555,7 @@ static int vhost_dev_set_features(struct vhost_dev *dev,
bool enable_log)
if (enable_log) {
features |= 0x1 << VHOST_F_LOG_ALL;
}
- r = ioctl(dev->control, VHOST_SET_FEATURES, &features);
+ r = dev->vhost_ops->vhost_call(dev, VHOST_SET_FEATURES, &features);
return r < 0 ? -errno : 0;
}
@@ -670,13 +670,13 @@ static int vhost_virtqueue_start(struct vhost_dev *dev,
assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs);
vq->num = state.num = virtio_queue_get_num(vdev, idx);
- r = ioctl(dev->control, VHOST_SET_VRING_NUM, &state);
+ r = dev->vhost_ops->vhost_call(dev, VHOST_SET_VRING_NUM, &state);
if (r) {
return -errno;
}
state.num = virtio_queue_get_last_avail_idx(vdev, idx);
- r = ioctl(dev->control, VHOST_SET_VRING_BASE, &state);
+ r = dev->vhost_ops->vhost_call(dev, VHOST_SET_VRING_BASE, &state);
if (r) {
return -errno;
}
@@ -718,7 +718,7 @@ static int vhost_virtqueue_start(struct vhost_dev *dev,
}
file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq));
- r = ioctl(dev->control, VHOST_SET_VRING_KICK, &file);
+ r = dev->vhost_ops->vhost_call(dev, VHOST_SET_VRING_KICK, &file);
if (r) {
r = -errno;
goto fail_kick;
@@ -756,7 +756,7 @@ static void vhost_virtqueue_stop(struct vhost_dev *dev,
};
int r;
assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs);
- r = ioctl(dev->control, VHOST_GET_VRING_BASE, &state);
+ r = dev->vhost_ops->vhost_call(dev, VHOST_GET_VRING_BASE, &state);
if (r < 0) {
fprintf(stderr, "vhost VQ %d ring restore failed: %d\n", idx, r);
fflush(stderr);
@@ -798,7 +798,7 @@ static int vhost_virtqueue_init(struct vhost_dev *dev,
}
file.fd = event_notifier_get_fd(&vq->masked_notifier);
- r = ioctl(dev->control, VHOST_SET_VRING_CALL, &file);
+ r = dev->vhost_ops->vhost_call(dev, VHOST_SET_VRING_CALL, &file);
if (r) {
r = -errno;
goto fail_call;
@@ -815,24 +815,28 @@ static void vhost_virtqueue_cleanup(struct
vhost_virtqueue *vq)
}
int vhost_dev_init(struct vhost_dev *hdev, int devfd, const char *devpath,
- bool force)
+ VhostBackendType backend_type, bool force)
{
uint64_t features;
int i, r;
+
+ if (vhost_set_backend_type(hdev, backend_type) < 0) {
+ return -1;
+ }
+
if (devfd >= 0) {
hdev->control = devfd;
} else {
- hdev->control = open(devpath, O_RDWR);
- if (hdev->control < 0) {
+ if (hdev->vhost_ops->vhost_backend_init(hdev, devpath) < 0) {
return -errno;
}
}
- r = ioctl(hdev->control, VHOST_SET_OWNER, NULL);
+ r = hdev->vhost_ops->vhost_call(hdev, VHOST_SET_OWNER, NULL);
if (r < 0) {
goto fail;
}
- r = ioctl(hdev->control, VHOST_GET_FEATURES, &features);
+ r = hdev->vhost_ops->vhost_call(hdev, VHOST_GET_FEATURES, &features);
if (r < 0) {
goto fail;
}
@@ -877,7 +881,7 @@ fail_vq:
}
fail:
r = -errno;
- close(hdev->control);
+ hdev->vhost_ops->vhost_backend_cleanup(hdev);
return r;
}
@@ -890,7 +894,7 @@ void vhost_dev_cleanup(struct vhost_dev *hdev)
memory_listener_unregister(&hdev->memory_listener);
g_free(hdev->mem);
g_free(hdev->mem_sections);
- close(hdev->control);
+ hdev->vhost_ops->vhost_backend_cleanup(hdev);
}
bool vhost_dev_query(struct vhost_dev *hdev, VirtIODevice *vdev)
@@ -992,7 +996,7 @@ void vhost_virtqueue_mask(struct vhost_dev *hdev,
VirtIODevice *vdev, int n,
} else {
file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq));
}
- r = ioctl(hdev->control, VHOST_SET_VRING_CALL, &file);
+ r = hdev->vhost_ops->vhost_call(hdev, VHOST_SET_VRING_CALL, &file);
assert(r >= 0);
}
@@ -1007,7 +1011,7 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice
*vdev)
if (r < 0) {
goto fail_features;
}
- r = ioctl(hdev->control, VHOST_SET_MEM_TABLE, hdev->mem);
+ r = hdev->vhost_ops->vhost_call(hdev, VHOST_SET_MEM_TABLE, hdev->mem);
if (r < 0) {
r = -errno;
goto fail_mem;
@@ -1026,8 +1030,7 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice
*vdev)
hdev->log_size = vhost_get_log_size(hdev);
hdev->log = hdev->log_size ?
g_malloc0(hdev->log_size * sizeof *hdev->log) : NULL;
- r = ioctl(hdev->control, VHOST_SET_LOG_BASE,
- (uint64_t)(unsigned long)hdev->log);
+ r = hdev->vhost_ops->vhost_call(hdev, VHOST_SET_LOG_BASE, hdev->log);
if (r < 0) {
r = -errno;
goto fail_log;
diff --git a/include/hw/virtio/vhost-backend.h
b/include/hw/virtio/vhost-backend.h
new file mode 100644
index 0000000..93fc55b
--- /dev/null
+++ b/include/hw/virtio/vhost-backend.h
@@ -0,0 +1,37 @@
+/*
+ * vhost-backend
+ *
+ * Copyright (c) 2013 Virtual Open Systems Sarl.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef VHOST_BACKEND_H_
+#define VHOST_BACKEND_H_
+
+typedef enum VhostBackendType {
+ VHOST_BACKEND_TYPE_NONE = 0,
+ VHOST_BACKEND_TYPE_KERNEL = 1,
+ VHOST_BACKEND_TYPE_MAX = 2,
+} VhostBackendType;
+
+struct vhost_dev;
+
+typedef int (*vhost_call)(struct vhost_dev *dev, unsigned long int request,
+ void *arg);
+typedef int (*vhost_backend_init)(struct vhost_dev *dev, const char *devpath);
+typedef int (*vhost_backend_cleanup)(struct vhost_dev *dev);
+
+typedef struct VhostOps {
+ VhostBackendType backend_type;
+ vhost_call vhost_call;
+ vhost_backend_init vhost_backend_init;
+ vhost_backend_cleanup vhost_backend_cleanup;
+} VhostOps;
+
+int vhost_set_backend_type(struct vhost_dev *dev,
+ VhostBackendType backend_type);
+
+#endif /* VHOST_BACKEND_H_ */
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index de24746..bd650a5 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -2,6 +2,7 @@
#define VHOST_H
#include "hw/hw.h"
+#include "hw/virtio/vhost-backend.h"
#include "hw/virtio/virtio.h"
#include "exec/memory.h"
@@ -48,10 +49,11 @@ struct vhost_dev {
bool memory_changed;
hwaddr mem_changed_start_addr;
hwaddr mem_changed_end_addr;
+ const VhostOps *vhost_ops;
};
int vhost_dev_init(struct vhost_dev *hdev, int devfd, const char *devpath,
- bool force);
+ VhostBackendType backend_type, bool force);
void vhost_dev_cleanup(struct vhost_dev *hdev);
bool vhost_dev_query(struct vhost_dev *hdev, VirtIODevice *vdev);
int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
--
1.8.3.2
