Guest OS uses ACPI to discover VMBus presence. Add a corresponding
entry to DSDT in case VMBus has been enabled.
Experimentally Windows guests were found to require this entry to
include two IRQ resources. They seem to never be used but they still
have to be there.
Make IRQ numbers user-configurable via corresponding properties; use 7
and 13 by default.
Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com>
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Signed-off-by: Jon Doron <arilou@gmail.com>
Message-Id: <20200424123444.3481728-6-arilou@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add the VMBus infrastructure -- bus, devices, root bridge, vmbus state
machine, vmbus channel interactions, etc.
VMBus is a collection of technologies. At its lowest layer, it's a message
passing and signaling mechanism, allowing efficient passing of messages to and
from guest VMs. A layer higher, it's a mechanism for defining channels of
communication, where each channel is tagged with a type (which implies a
protocol) and a instance ID. A layer higher than that, it's a bus driver,
serving as the basis of device enumeration within a VM, where a channel can
optionally be exposed as a paravirtual device. When a server-side (paravirtual
back-end) component wishes to offer a channel to a guest VM, it does so by
specifying a channel type, a mode, and an instance ID. VMBus then exposes this
in the guest.
More information about VMBus can be found in the file
vmbuskernelmodeclientlibapi.h in Microsoft's WDK.
TODO:
- split into smaller palatable pieces
- more comments
- check and handle corner cases
Kudos to Evgeny Yakovlev (formerly eyakovlev@virtuozzo.com) and Andrey
Smetatin (formerly asmetanin@virtuozzo.com) for research and
prototyping.
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Signed-off-by: Jon Doron <arilou@gmail.com>
Message-Id: <20200424123444.3481728-4-arilou@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>