Not for upstream: Some notes about kexec in a ballooned guest

Signed-off-by: Olaf Hering <olaf@aepfle.de>
drm/cirrus: bind also to qemu-xen-traditional

qemu as used by xend/xm toolstack uses a different subvendor id.
Bind the drm driver also to this emulated card.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
xen-blkfront: remove type check from blkfront_setup_discard

In its initial implementation a check for "type" was added, but only phy
and file are handled. This breaks advertised discard support for other
type values such as qdisk.

Fix and simplify this function: If the backend advertises discard
support it is supposed to implement it properly, so enable
feature_discard unconditionally. If the backend advertises the need for
a certain granularity and alignment then propagate both properties to
the blocklayer. The discard-secure property is a boolean, update the code
to reflect that.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
xen blkif.h: fix comment typo in discard-alignment

Add the missing 'n' to discard-alignment

Signed-off-by: Olaf Hering <olaf@aepfle.de>
xen/blkback: disable discard feature if requested by toolstack

Newer toolstacks may provide a boolean property "discard-enable" in the
backend node. Its purpose is to disable discard for file backed storage
to avoid fragmentation. Recognize this setting also for physical
storage.  If that property exists and is false, do not advertise
"feature-discard" to the frontend.

Signed-off-by: Olaf Hering <olaf@aepfle.de>