This patchset implements the KVM part of the synthetic interrupt controller (synic) which is a building block of the Hyper-V paravirtualized device bus (vmbus).
Synic is a lapic extension, which is controlled via MSRs and maintains for each vCPU - 16 synthetic interrupt "lines" (SINT's); each can be configured to trigger a specific interrupt vector optionally with auto-EOI semantics - a message page in the guest memory with 16 256-byte per-SINT message slots - an event flag page in the guest memory with 16 2048-bit per-SINT event flag areas The host triggers a SINT whenever it delivers a new message to the corresponding slot or flips an event flag bit in the corresponding area. The guest informs the host that it can try delivering a message by explicitly asserting EOI in lapic or writing to End-Of-Message (EOM) MSR. The userspace (qemu) triggers interrupts and receives EOM notifications via irqfd with resampler; for that, a GSI is allocated for each configured SINT, and irq_routing api is extended to support GSI-SINT mapping. Besides, a new vcpu exit is introduced to notify the userspace of the changes in synic configuraion triggered by guest writing to the corresponding MSRs. Signed-off-by: Andrey Smetanin <[email protected]> Reviewed-by: Roman Kagan <[email protected]> Signed-off-by: Denis V. Lunev <[email protected]> CC: Vitaly Kuznetsov <[email protected]> CC: "K. Y. Srinivasan" <[email protected]> CC: Gleb Natapov <[email protected]> CC: Paolo Bonzini <[email protected]> _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
