Add VHOST_USER_GET_CONFIG/VHOST_USER_SET_CONFIG messages which can be
used for live migration of vhost user devices, also vhost user devices
can benefit from the messages to get/set virtio config space from/to the
I/O target. For the purpose to support virtio config space change,
VHOST_USER_SET_CONFIG_FD message is added as the event notifier
in case virtio config space change in the I/O target.
Signed-off-by: Changpeng Liu <changpeng....@intel.com>
---
docs/interop/vhost-user.txt | 44 ++++++++++++++++
hw/virtio/vhost-user.c | 107 ++++++++++++++++++++++++++++++++++++++
hw/virtio/vhost.c | 64 +++++++++++++++++++++++
include/hw/virtio/vhost-backend.h | 14 +++++
include/hw/virtio/vhost.h | 16 ++++++
5 files changed, 245 insertions(+)
diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt
index 954771d..1f9aab0 100644
--- a/docs/interop/vhost-user.txt
+++ b/docs/interop/vhost-user.txt
@@ -116,6 +116,19 @@ Depending on the request type, payload can be:
- 3: IOTLB invalidate
- 4: IOTLB access fail
+ * Virtio device config space
+ -----------------------------------
+ | offset | size | flags | payload |
+ -----------------------------------
+
+ Offset: a 32-bit offset of virtio device's configuration space
+ Size: a 32-bit configuration space access size in bytes
+ Flags: a 32-bit value:
+ - 0: Vhost master messages used for writeable fields
+ - 1: Vhost master messages used for live migration
+ Payload: Size bytes array holding the contents of the virtio
+ device's configuration space
+
In QEMU the vhost-user message is implemented with the following struct:
typedef struct VhostUserMsg {
@@ -129,6 +142,7 @@ typedef struct VhostUserMsg {
VhostUserMemory memory;
VhostUserLog log;
struct vhost_iotlb_msg iotlb;
+ VhostUserConfig config;
};
} QEMU_PACKED VhostUserMsg;
@@ -596,6 +610,36 @@ Master message types
and expect this message once (per VQ) during device configuration
(ie. before the master starts the VQ).
+ * VHOST_USER_GET_CONFIG
+ Id: 24
+ Equivalent ioctl: N/A
+ Master payload: virtio device config space
+
+ Submitted by the vhost-user master to fetch the contents of the virtio
+ device configuration space. The vhost-user master may cache the contents
+ to avoid repeated VHOST_USER_GET_CONFIG calls.
+
+* VHOST_USER_SET_CONFIG
+ Id: 25
+ Equivalent ioctl: N/A
+ Master payload: virtio device config space
+
+ Submitted by the vhost-user master when the Guest changes the virtio
+ device configuration space and also can be used for live migration
+ on the destination host. The vhost-user slave must check the flags
+ filed, and slaves MUST NOT accept SET_CONFIG for read-only
+ configuration space fields unless the live migration bit is set.
+
+* VHOST_USER_SET_CONFIG_FD
+ Id: 26
+ Equivalent ioctl: N/A
+ Master payload: N/A
+
+ Sets the notifier file descriptor, which is passed as ancillary data.
+ The vhost-user slave uses the file descriptor to notify the vhost-user
+ master of changes to the virtio configuration space. The vhost-user
+ master can read the virtio configuration space to get the latest update.
+
Slave message types
-------------------
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 093675e..bdb236c 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -26,6 +26,11 @@
#define VHOST_MEMORY_MAX_NREGIONS 8
#define VHOST_USER_F_PROTOCOL_FEATURES 30
+/*
+ * Maximum size of virtio device config space
+ */
+#define VHOST_USER_MAX_CONFIG_SIZE 256
+
enum VhostUserProtocolFeature {
VHOST_USER_PROTOCOL_F_MQ = 0,
VHOST_USER_PROTOCOL_F_LOG_SHMFD = 1,
@@ -65,6 +70,9 @@ typedef enum VhostUserRequest {
VHOST_USER_SET_SLAVE_REQ_FD = 21,
VHOST_USER_IOTLB_MSG = 22,
VHOST_USER_SET_VRING_ENDIAN = 23,
+ VHOST_USER_GET_CONFIG = 24,
+ VHOST_USER_SET_CONFIG = 25,
+ VHOST_USER_SET_CONFIG_FD = 26,
VHOST_USER_MAX
} VhostUserRequest;
@@ -92,6 +100,18 @@ typedef struct VhostUserLog {
uint64_t mmap_offset;
} VhostUserLog;
+typedef struct VhostUserConfig {
+ uint32_t offset;
+ uint32_t size;
+ uint32_t flags;
+ uint8_t region[VHOST_USER_MAX_CONFIG_SIZE];
+} VhostUserConfig;
+
+static VhostUserConfig c __attribute__ ((unused));
+#define VHOST_USER_CONFIG_HDR_SIZE (sizeof(c.offset) \
+ + sizeof(c.size) \
+ + sizeof(c.flags))
+
typedef struct VhostUserMsg {
VhostUserRequest request;
@@ -109,6 +129,7 @@ typedef struct VhostUserMsg {
VhostUserMemory memory;
VhostUserLog log;
struct vhost_iotlb_msg iotlb;
+ VhostUserConfig config;
} payload;
} QEMU_PACKED VhostUserMsg;
@@ -922,6 +943,89 @@ static void vhost_user_set_iotlb_callback(struct vhost_dev
*dev, int enabled)
/* No-op as the receive channel is not dedicated to IOTLB messages. */
}
+static int vhost_user_get_config(struct vhost_dev *dev, uint8_t *config,
+ uint32_t config_len)
+{
+ VhostUserMsg msg = {
+ msg.request = VHOST_USER_GET_CONFIG,
+ msg.flags = VHOST_USER_VERSION,
+ msg.size = VHOST_USER_CONFIG_HDR_SIZE + config_len,
+ };
+
+ msg.payload.config.offset = 0;
+ msg.payload.config.size = config_len;
+ if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
+ return -1;
+ }
+
+ if (vhost_user_read(dev, &msg) < 0) {
+ return -1;
+ }
+
+ if (msg.request != VHOST_USER_GET_CONFIG) {
+ error_report("Received unexpected msg type. Expected %d received %d",
+ VHOST_USER_GET_CONFIG, msg.request);
+ return -1;
+ }
+
+ if (msg.size != VHOST_USER_CONFIG_HDR_SIZE + config_len) {
+ error_report("Received bad msg size.");
+ return -1;
+ }
+
+ memcpy(config, msg.payload.config.region, config_len);
+
+ return 0;
+}
+
+static int vhost_user_set_config(struct vhost_dev *dev, const uint8_t *config,
+ uint32_t offset, uint32_t size, uint32_t
flags)
+{
+ uint8_t *p;
+ bool reply_supported = virtio_has_feature(dev->protocol_features,
+ VHOST_USER_PROTOCOL_F_REPLY_ACK);
+
+ VhostUserMsg msg = {
+ msg.request = VHOST_USER_SET_CONFIG,
+ msg.flags = VHOST_USER_VERSION,
+ msg.size = VHOST_USER_CONFIG_HDR_SIZE + size,
+ };
+
+ if (reply_supported) {
+ msg.flags |= VHOST_USER_NEED_REPLY_MASK;
+ }
+
+ msg.payload.config.offset = offset,
+ msg.payload.config.size = size,
+ msg.payload.config.flags = flags,
+ p = msg.payload.config.region;
+ memcpy(p, config + offset, size);
+
+ if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
+ return -1;
+ }
+
+ if (reply_supported) {
+ return process_message_reply(dev, &msg);
+ }
+
+ return 0;
+}
+
+static int vhost_user_set_config_fd(struct vhost_dev *dev, int fd)
+{
+ VhostUserMsg msg = {
+ .request = VHOST_USER_SET_CONFIG_FD,
+ .flags = VHOST_USER_VERSION,
+ };
+
+ if (vhost_user_write(dev, &msg, &fd, 1) < 0) {
+ return -1;
+ }
+
+ return 0;
+}
+
const VhostOps user_ops = {
.backend_type = VHOST_BACKEND_TYPE_USER,
.vhost_backend_init = vhost_user_init,
@@ -948,4 +1052,7 @@ const VhostOps user_ops = {
.vhost_net_set_mtu = vhost_user_net_set_mtu,
.vhost_set_iotlb_callback = vhost_user_set_iotlb_callback,
.vhost_send_device_iotlb_msg = vhost_user_send_device_iotlb_msg,
+ .vhost_get_config = vhost_user_get_config,
+ .vhost_set_config = vhost_user_set_config,
+ .vhost_set_config_fd = vhost_user_set_config_fd,
};
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index e4290ce..35996a8 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1358,6 +1358,9 @@ void vhost_dev_cleanup(struct vhost_dev *hdev)
for (i = 0; i < hdev->nvqs; ++i) {
vhost_virtqueue_cleanup(hdev->vqs + i);
}
+ if (hdev->config_ops) {
+ event_notifier_cleanup(&hdev->config_notifier);
+ }
if (hdev->mem) {
/* those are only safe after successful init */
memory_listener_unregister(&hdev->memory_listener);
@@ -1505,6 +1508,67 @@ void vhost_ack_features(struct vhost_dev *hdev, const
int *feature_bits,
}
}
+int vhost_dev_get_config(struct vhost_dev *hdev, uint8_t *config,
+ uint32_t config_len)
+{
+ assert(hdev->vhost_ops);
+
+ if (hdev->vhost_ops->vhost_get_config) {
+ return hdev->vhost_ops->vhost_get_config(hdev, config, config_len);
+ }
+
+ return 0;
+}
+
+int vhost_dev_set_config(struct vhost_dev *hdev, const uint8_t *config,
+ uint32_t offset, uint32_t size, uint32_t flags)
+{
+ assert(hdev->vhost_ops);
+
+ if (hdev->vhost_ops->vhost_set_config) {
+ return hdev->vhost_ops->vhost_set_config(hdev, config, offset,
+ size, flags);
+ }
+
+ return 0;
+}
+
+static void vhost_dev_config_notifier_read(EventNotifier *n)
+{
+ struct vhost_dev *hdev = container_of(n, struct vhost_dev,
+ config_notifier);
+
+ if (event_notifier_test_and_clear(n)) {
+ if (hdev->config_ops) {
+ hdev->config_ops->vhost_dev_config_notifier(hdev);
+ }
+ }
+}
+
+int vhost_dev_set_config_notifier(struct vhost_dev *hdev,
+ const VhostDevConfigOps *ops)
+{
+ int r, fd;
+
+ assert(hdev->vhost_ops);
+
+ r = event_notifier_init(&hdev->config_notifier, 0);
+ if (r < 0) {
+ return r;
+ }
+
+ hdev->config_ops = ops;
+ event_notifier_set_handler(&hdev->config_notifier,
+ vhost_dev_config_notifier_read);
+
+ if (hdev->vhost_ops->vhost_set_config_fd) {
+ fd = event_notifier_get_fd(&hdev->config_notifier);
+ return hdev->vhost_ops->vhost_set_config_fd(hdev, fd);
+ }
+
+ return 0;
+}
+
/* Host notifiers must be enabled at this point. */
int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
{
diff --git a/include/hw/virtio/vhost-backend.h
b/include/hw/virtio/vhost-backend.h
index a7a5f22..070dd03 100644
--- a/include/hw/virtio/vhost-backend.h
+++ b/include/hw/virtio/vhost-backend.h
@@ -20,6 +20,11 @@ typedef enum VhostBackendType {
VHOST_BACKEND_TYPE_MAX = 3,
} VhostBackendType;
+typedef enum VhostSetConfigType {
+ VHOST_SET_CONFIG_TYPE_MASTER = 0,
+ VHOST_SET_CONFIG_TYPE_MIGRATION = 1,
+} VhostSetConfigType;
+
struct vhost_dev;
struct vhost_log;
struct vhost_memory;
@@ -84,6 +89,12 @@ typedef void (*vhost_set_iotlb_callback_op)(struct vhost_dev
*dev,
int enabled);
typedef int (*vhost_send_device_iotlb_msg_op)(struct vhost_dev *dev,
struct vhost_iotlb_msg *imsg);
+typedef int (*vhost_set_config_op)(struct vhost_dev *dev, const uint8_t
*config,
+ uint32_t offset, uint32_t size,
+ uint32_t flags);
+typedef int (*vhost_get_config_op)(struct vhost_dev *dev, uint8_t *config,
+ uint32_t config_len);
+typedef int (*vhost_set_config_fd_op)(struct vhost_dev *dev, int fd);
typedef struct VhostOps {
VhostBackendType backend_type;
@@ -118,6 +129,9 @@ typedef struct VhostOps {
vhost_vsock_set_running_op vhost_vsock_set_running;
vhost_set_iotlb_callback_op vhost_set_iotlb_callback;
vhost_send_device_iotlb_msg_op vhost_send_device_iotlb_msg;
+ vhost_get_config_op vhost_get_config;
+ vhost_set_config_op vhost_set_config;
+ vhost_set_config_fd_op vhost_set_config_fd;
} VhostOps;
extern const VhostOps user_ops;
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index 467dc77..719491e 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -46,6 +46,12 @@ struct vhost_iommu {
QLIST_ENTRY(vhost_iommu) iommu_next;
};
+typedef struct VhostDevConfigOps {
+ /* Vhost device config space changed callback
+ */
+ void (*vhost_dev_config_notifier)(struct vhost_dev *dev);
+} VhostDevConfigOps;
+
struct vhost_memory;
struct vhost_dev {
VirtIODevice *vdev;
@@ -76,6 +82,8 @@ struct vhost_dev {
QLIST_ENTRY(vhost_dev) entry;
QLIST_HEAD(, vhost_iommu) iommu_list;
IOMMUNotifier n;
+ EventNotifier config_notifier;
+ const VhostDevConfigOps *config_ops;
};
int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
@@ -106,4 +114,12 @@ int vhost_net_set_backend(struct vhost_dev *hdev,
struct vhost_vring_file *file);
int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write);
+int vhost_dev_get_config(struct vhost_dev *dev, uint8_t *config,
+ uint32_t config_len);
+int vhost_dev_set_config(struct vhost_dev *dev, const uint8_t *config,
+ uint32_t offset, uint32_t size, uint32_t flags);
+/* notifier callback in case vhost device config space changed
+ */
+int vhost_dev_set_config_notifier(struct vhost_dev *dev,
+ const VhostDevConfigOps *ops);
#endif
--
1.9.3
