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vhost-user: add new vhost user messages to support virtio config space

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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_SLAVE_CONFIG_CHANGE_MSG message is added as the event notifier
in case virtio config space change in the slave I/O target.

Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Changpeng Liu 2018-01-04 09:53:31 +08:00 committed by Michael S. Tsirkin
parent 1bcf209154
commit 4c3e257b5e
5 changed files with 232 additions and 0 deletions
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55
docs/interop/vhost-user.txt
View File

@ -119,6 +119,19 @@ 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 {
@ -132,6 +145,7 @@ typedef struct VhostUserMsg {
VhostUserMemory memory;
VhostUserLog log;
struct vhost_iotlb_msg iotlb;
VhostUserConfig config;
};
} QEMU_PACKED VhostUserMsg;
@ -623,6 +637,32 @@ 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
Slave payload: virtio device config space
Submitted by the vhost-user master to fetch the contents of the virtio
device configuration space, vhost-user slave's payload size MUST match
master's request, vhost-user slave uses zero length of payload to
indicate an error to vhost-user master. 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
Slave payload: N/A
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
field, and slaves MUST NOT accept SET_CONFIG for read-only
configuration space fields unless the live migration bit is set.
Slave message types
-------------------
@ -641,6 +681,21 @@ Slave message types
This request should be send only when VIRTIO_F_IOMMU_PLATFORM feature
has been successfully negotiated.
* VHOST_USER_SLAVE_CONFIG_CHANGE_MSG
Id: 2
Equivalent ioctl: N/A
Slave payload: N/A
Master payload: N/A
Vhost-user slave sends such messages to notify that the virtio device's
configuration space has changed, for those host devices which can support
such feature, host driver can send VHOST_USER_GET_CONFIG message to slave
to get the latest content. If VHOST_USER_PROTOCOL_F_REPLY_ACK is
negotiated, and slave set the VHOST_USER_NEED_REPLY flag, master must
respond with zero when operation is successfully completed, or non-zero
otherwise.
VHOST_USER_PROTOCOL_F_REPLY_ACK:
-------------------------------
The original vhost-user specification only demands replies for certain

118
hw/virtio/vhost-user.c
View File

@ -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,
@ -65,12 +70,15 @@ 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_MAX
} VhostUserRequest;
typedef enum VhostUserSlaveRequest {
VHOST_USER_SLAVE_NONE = 0,
VHOST_USER_SLAVE_IOTLB_MSG = 1,
VHOST_USER_SLAVE_CONFIG_CHANGE_MSG = 2,
VHOST_USER_SLAVE_MAX
} VhostUserSlaveRequest;
@ -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;
@ -608,6 +629,21 @@ static int vhost_user_reset_device(struct vhost_dev *dev)
return 0;
}
static int vhost_user_slave_handle_config_change(struct vhost_dev *dev)
{
int ret = -1;
if (!dev->config_ops) {
return -1;
}
if (dev->config_ops->vhost_dev_config_notifier) {
ret = dev->config_ops->vhost_dev_config_notifier(dev);
}
return ret;
}
static void slave_read(void *opaque)
{
struct vhost_dev *dev = opaque;
@ -640,6 +676,9 @@ static void slave_read(void *opaque)
case VHOST_USER_SLAVE_IOTLB_MSG:
ret = vhost_backend_handle_iotlb_msg(dev, &msg.payload.iotlb);
break;
case VHOST_USER_SLAVE_CONFIG_CHANGE_MSG :
ret = vhost_user_slave_handle_config_change(dev);
break;
default:
error_report("Received unexpected msg type.");
ret = -EINVAL;
@ -922,6 +961,83 @@ 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,
};
if (config_len > VHOST_USER_MAX_CONFIG_SIZE) {
return -1;
}
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 *data,
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;
}
if (size > VHOST_USER_MAX_CONFIG_SIZE) {
return -1;
}
msg.payload.config.offset = offset,
msg.payload.config.size = size,
msg.payload.config.flags = flags,
p = msg.payload.config.region;
memcpy(p, data, size);
if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
return -1;
}
if (reply_supported) {
return process_message_reply(dev, &msg);
}
return 0;
}
const VhostOps user_ops = {
.backend_type = VHOST_BACKEND_TYPE_USER,
.vhost_backend_init = vhost_user_init,
@ -948,4 +1064,6 @@ 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,
};

32
hw/virtio/vhost.c
View File

@ -1505,6 +1505,38 @@ 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 -1;
}
int vhost_dev_set_config(struct vhost_dev *hdev, const uint8_t *data,
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, data, offset,
size, flags);
}
return -1;
}
void vhost_dev_set_config_notifier(struct vhost_dev *hdev,
const VhostDevConfigOps *ops)
{
assert(hdev->vhost_ops);
hdev->config_ops = ops;
}
/* Host notifiers must be enabled at this point. */
int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
{

12
include/hw/virtio/vhost-backend.h
View File

@ -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 +89,11 @@ 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 *data,
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 struct VhostOps {
VhostBackendType backend_type;
@ -118,6 +128,8 @@ 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;
} VhostOps;
extern const VhostOps user_ops;

15
include/hw/virtio/vhost.h
View File

@ -46,6 +46,12 @@ struct vhost_iommu {
QLIST_ENTRY(vhost_iommu) iommu_next;
};
typedef struct VhostDevConfigOps {
/* Vhost device config space changed callback
*/
int (*vhost_dev_config_notifier)(struct vhost_dev *dev);
} VhostDevConfigOps;
struct vhost_memory;
struct vhost_dev {
VirtIODevice *vdev;
@ -76,6 +82,7 @@ struct vhost_dev {
QLIST_ENTRY(vhost_dev) entry;
QLIST_HEAD(, vhost_iommu) iommu_list;
IOMMUNotifier n;
const VhostDevConfigOps *config_ops;
};
int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
@ -106,4 +113,12 @@ 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 *data,
uint32_t offset, uint32_t size, uint32_t flags);
/* notifier callback in case vhost device config space changed
*/
void vhost_dev_set_config_notifier(struct vhost_dev *dev,
const VhostDevConfigOps *ops);
#endif