Age | Commit message (Collapse) | Author | |
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2020-10-19 | xen-bus: reduce scope of backend watch | Paul Durrant | |
Currently a single watch on /local/domain/X/backend is registered by each QEMU process running in service domain X (where X is usually 0). The purpose of this watch is to ensure that QEMU is notified when the Xen toolstack creates a new device backend area. Such a backend area is specific to a single frontend area created for a specific guest domain and, since each QEMU process is also created to service a specfic guest domain, it is unnecessary and inefficient to notify all QEMU processes. Only the QEMU process associated with the same guest domain need receive the notification. This patch re-factors the watch registration code such that notifications are targetted appropriately. Reported-by: Jerome Leseinne <jerome.leseinne@gmail.com> Signed-off-by: Paul Durrant <pdurrant@amazon.com> Reviewed-by: Anthony PERARD <anthony.perard@citrix.com> Message-Id: <20201001081500.1026-1-paul@xen.org> Signed-off-by: Anthony PERARD <anthony.perard@citrix.com> | |||
2019-01-14 | xen: add a mechanism to automatically create XenDevice-s... | Paul Durrant | |
...that maintains compatibility with existing Xen toolstacks. Xen toolstacks instantiate PV backends by simply writing information into xenstore and expecting a backend implementation to be watching for this. This patch adds a new 'xen-backend' module to allow individual XenDevice implementations to register create and destroy functions. The creator will be called when a tool-stack instantiates a new backend in this way, and the destructor will then be called after the resulting XenDevice object is unrealized. To support this it is also necessary to add new watchers into the XenBus implementation to handle enumeration of new backends and also destruction of XenDevice-s when the toolstack sets the backend 'online' key to 0. NOTE: This patch only adds the framework. A subsequent patch will add a creator function for xen-block devices. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Reviewed-by: Anthony Perard <anthony.perard@citrix.com> Signed-off-by: Anthony PERARD <anthony.perard@citrix.com> |