diff options
Diffstat (limited to 'drivers/hv/hyperv_vmbus.h')
| -rw-r--r-- | drivers/hv/hyperv_vmbus.h | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index b0299da9c2db..cada56a2daa0 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -624,6 +624,30 @@ struct vmbus_channel_message_table_entry { extern struct vmbus_channel_message_table_entry channel_message_table[CHANNELMSG_COUNT]; +/* Free the message slot and signal end-of-message if required */ +static inline void vmbus_signal_eom(struct hv_message *msg) +{ + msg->header.message_type = HVMSG_NONE; + + /* + * Make sure the write to MessageType (ie set to + * HVMSG_NONE) happens before we read the + * MessagePending and EOMing. Otherwise, the EOMing + * will not deliver any more messages since there is + * no empty slot + */ + mb(); + + if (msg->header.message_flags.msg_pending) { + /* + * This will cause message queue rescan to + * possibly deliver another msg from the + * hypervisor + */ + wrmsrl(HV_X64_MSR_EOM, 0); + } +} + /* General vmbus interface */ struct hv_device *vmbus_device_create(const uuid_le *type, |