OvmfPkg/XenBusDxe: Introduce XenBus support itself.

This is a bus-like on top of XenStore. It will look for advertised
ParaVirtualized devices and initialize them by producing XenBus
protocol.

Change in V4:
- Replace the license by the commonly used file header text.
- Clean XenBus.h header (remove copyright that does not belong to the
  file anymore; and rewrite the brief description of the file)
- Fix description on the function

Change in V3:
- Insert to ChildList later, once populated.
- Remove XENBUS_XENSTORE_NODE macro.
- add comment to XenBusAddDevice and XenBusEnumerateBus about
  concurrency calls.
- Add a description to the introduced member to the protocol.

Change in V2:
- comment, file header
- Fix comment style
- Error handling in the main init function
- coding style
- Fix error path in add device.

Origin: FreeBSD 10.0
License: This patch adds XenBus.c which is under the MIT licence.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Jordan Justen <jordan.l.justen@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16270 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 19 insertions, 0 deletions

diff --git a/OvmfPkg/Include/Protocol/XenBus.h b/OvmfPkg/Include/Protocol/XenBus.h
index 5693b3f284..8d1fb52c22 100644
--- a/OvmfPkg/Include/Protocol/XenBus.h
+++ b/OvmfPkg/Include/Protocol/XenBus.h
@@ -199,6 +199,24 @@ XENSTORE_STATUS
   );

 

 /**

+  Set a new state for the frontend of the PV driver.

+

+  @param This         A pointer to XENBUS_PROTOCOL instance.

+  @param Transaction  The transaction to end/commit.

+  @param State        The new state to apply.

+

+  @return  On success, XENSTORE_STATUS_SUCCESS. Otherwise an errno value

+           indicating the type of failure.

+**/

+typedef

+XENSTORE_STATUS

+(EFIAPI *XENBUS_SET_STATE)(

+  IN XENBUS_PROTOCOL        *This,

+  IN XENSTORE_TRANSACTION   Transaction,

+  IN XenBusState            State

+  );

+

+/**

   Grant access to the page Frame to the domain DomainId.

 

   @param This       A pointer to XENBUS_PROTOCOL instance.

@@ -322,6 +340,7 @@ struct _XENBUS_PROTOCOL {
   XENBUS_XS_REMOVE              XsRemove;

   XENBUS_XS_TRANSACTION_START   XsTransactionStart;

   XENBUS_XS_TRANSACTION_END     XsTransactionEnd;

+  XENBUS_SET_STATE              SetState;

 

   XENBUS_GRANT_ACCESS           GrantAccess;

   XENBUS_GRANT_END_ACCESS       GrantEndAccess;