Implement discard support for xen_disk. It makes use of the existing
discard code in qemu.
The discard support is enabled unconditionally. The tool stack may
provide a property "discard-enable" in the backend node to optionally
disable discard support. This is helpful in case the backing file was
intentionally created non-sparse to avoid fragmentation.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Many of these should be cleaned up with proper qdev-/QOM-ification.
Right now there are many catch-all headers in include/hw/ARCH depending
on cpu.h, and this makes it necessary to compile these files per-target.
However, fixing this does not belong in these patches.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>