Guest/hypervisor interrupt coalescing for storage adapter virtual function in guest passthrough mode

摘要

A system and method are provided that involve a host computing machine and an SR IOV storage adapter in which the host machine hosts a virtual machine having a guest operating system (guest) coupled for direct passthrough IOV data path and also hosts a virtualization intermediary; a guest operating system (guest) and a virtualization intermediary exchange information concerning IO completions through a shared memory space; the guest writes information to a shared memory space that is indicative of whether an IO completion queue has reached a fill level since the most recently dispatched interrupt at which it is unsafe to coalesce an interrupt; the virtualization intermediary writes information to the shared memory space that is indicative of the interrupt most recently delivered to the guest; the virtualization intermediary reads the information written by the guest to the shared memory space that is indicative of whether an IO completion queue has reached a fill level since the most recently dispatched interrupt at which it is unsafe to coalesce an interrupt; the guest reads the information written to the shared memory space that is indicative of the interrupt most recently delivered to the guest; virtual interrupt coalescing determinations are made based upon the information shred through the shared memory space.