Method and system for managing peripheral connection wakeup in a processing system supporting multiple virtual machines
View Patent ↗A method and system for managing peripheral connection wakeup signaling in a processing system supporting multiple virtual machines provides a mechanism by which ownership of a peripheral having system wakeup capability is transferred between virtual machines. The power management event signal is connected to a service processor input that in turn signals a hypervisor to direct the wakeup activity to a particular logical partition in which the virtual machine was last executing. The hypervisor can then determine whether or not to wake up the entire system, or portions thereof and can direct the power management event to the appropriate virtual machine. In particular the peripheral may be an Ethernet adapter supporting Wake-On-LAN capability. State initialization, which is typically ensured by system power cycling is provided instead by controlling power to the standby power source or in some instances by forcing an indication of a disconnect/reconnect of the wakeup signaling connection.
1. A method of managing a peripheral connection wakeup mechanism in a processing system, said processing system supporting execution of multiple operating system images within multiple virtual machines, said method comprising:
receiving a wakeup request at an adapter via said peripheral connection;
signaling a service processor that said wakeup request has been received;
notifying a virtual machine manager program managing said multiple virtual machines that said service processor has been signaled;
controlling the power management state of a virtual machine owning said adapter via said virtual machine manager program in response to said notifying; and
transferring ownership of said adapter from a first one of said virtual machines to a second one of said virtual machines, by unmapping said adapter from said first virtual machine, resetting the state of said adapter, and mapping said adapter in said second virtual machine, whereby said second virtual machine owns said adapter.
2. The method of claim 1 , wherein said adapter is an Ethernet adapter, said wakeup request is a Wake-on-LAN packet, wherein said receiving further comprises decoding said Wake-on-LAN packet, and wherein said signaling is performed responsive to said decoding.
3. The method of claim 2 , wherein said indication is a power management signal output by said Ethernet adapter and said signaling comprises activating said power management signal to interrupt said service processor.
4. The method of claim 1 , wherein said controlling places said virtual machine in power-up state and further comprising:
determining whether or not said processing system is in a power-down state; and
responsive to determining that said processing system is in a power down state, restoring said processing system to a power-up state prior to placing said virtual machine in a power up state.
5. The method of claim 1 , wherein said controlling activates said virtual machine by placing said virtual machine in power-up state, and further comprising determining whether or not said virtual machine owning said adapter should be activated in conformity with a system management policy of said virtual machine manager program, and wherein said controlling is performed only in response to determining that said virtual machine owning said adapter should be activated.
6. The method of claim 1 , wherein said resetting is performed by cycling all power to said adapter, including cycling standby power used for detection of said power management request.
7. The method of claim 1 , wherein said resetting is performed by cycling a power good indication provided to said adapter, whereby a controller within said adapter self-resets.