kvm/x86: Hyper-V SynIC message slot pending clearing at SINT ack

The SynIC message protocol mandates that the message slot is claimed
by atomically setting message type to something other than HVMSG_NONE.
If another message is to be delivered while the slot is still busy,
message pending flag is asserted to indicate to the guest that the
hypervisor wants to be notified when the slot is released.

To make sure the protocol works regardless of where the message
sources are (kernel or userspace), clear the pending flag on SINT ACK
notification, and let the message sources compete for the slot again.

Signed-off-by: Andrey Smetanin <[email protected]>
Reviewed-by: Roman Kagan <[email protected]>
CC: Gleb Natapov <[email protected]>
CC: Paolo Bonzini <[email protected]>
CC: "K. Y. Srinivasan" <[email protected]>
CC: Haiyang Zhang <[email protected]>
CC: Vitaly Kuznetsov <[email protected]>
CC: Roman Kagan <[email protected]>
CC: Denis V. Lunev <[email protected]>
CC: [email protected]
Signed-off-by: Paolo Bonzini <[email protected]>

0 files changed, 0 insertions, 0 deletions