Adds VSS provider and requester as a qga-vss.dll, which is loaded by
Windows VSS service as well as by qemu-ga.
"provider.cpp" implements a basic stub of a software VSS provider.
Currently, this module only relays a frozen event from VSS service to the
agent, and thaw event from the agent to VSS service, to block VSS process
to keep the system frozen while snapshots are taken at the host.
To register the provider to the guest system as COM+ application, the type
library (.tlb) for qga-vss.dll is required. To build it from COM IDL (.idl),
VisualC++, MIDL and stdole2.tlb in Windows SDK are required. This patch also
adds pre-compiled .tlb file in the repository in order to enable
cross-compile qemu-ga.exe for Windows with VSS support.
"requester.cpp" provides the VSS requester to kick the VSS snapshot process.
Qemu-ga.exe works without the DLL, although fsfreeze features are disabled.
These functions are only supported in Windows 2003 or later. In older
systems, fsfreeze features are disabled.
In several versions of Windows which don't support attribute
VSS_VOLSNAP_ATTR_NO_AUTORECOVERY, DoSnapshotSet fails with error
VSS_E_OBJECT_NOT_FOUND. In this patch, we just ignore this error.
To solve this fundamentally, we need a framework to handle mount writable
snapshot on guests, which is required by VSS auto-recovery feature
(cleanup phase after a snapshot is taken).
Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
This patch will fix the following linking failed:
LINK qemu-ga
gcc: error: qga/../qapi-generated/qga-qapi-types.o: No such file or directory
gcc: error: qga/../qapi-generated/qga-qapi-visit.o: No such file or directory
gcc: error: qga/../qapi-generated/qga-qmp-marshal.o: No such file or directory
make: *** [qemu-ga] Error 1
Commit cdc976b040 changes the
dependencies of qemu-ga to depend "../qapi-generated/qga-qapi-types.o",
which will be expanded to "qga/../qapi-generated/qga-qapi-types.o" when
building qemu-ga.
In top-level Makefile, we defined a target "qapi-generated/qga-qapi-types.o"
which was not equal to "qga/../qapi-generated/qga-qapi-types" in the
Makefile world. So "No such file" error happened when qemu-ga was linking.
The easy approach to fix is to change the target name to
"qga/../qapi-generated/qga-qapi-types.o", but it is weird.
So, in order to solve it more graciously, I move those temporary
files(qga-qapi-*.{c,h}) qemu-ga depends on to qemu-ga/qapi-generated,
this makes dependencies more clearer.
Signed-off-by: Dunrong Huang <riegamaths@gmail.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
No reason to leave them out, and it will ensure that the dependencies
are picked up. Later we can perhaps move the files to another
directory to avoid ../ usage.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Tomoki Sekiyama
Paolo Bonzini
Dunrong Huang