s390x/css: realize css_create_sch
The S390 virtual css support already has a mechanism to create a
virtual subchannel and provide it to the guest. However, to
pass-through subchannels to a guest, we need to introduce a new
mechanism to create the subchannel according to the real device
information. Thus we reconstruct css_create_virtual_sch to a new
css_create_sch function to handle all these cases and do allocation
and initialization of the subchannel according to the device type
and machine configuration.
Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170517004813.58227-6-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
diff --git a/include/hw/s390x/css.h b/include/hw/s390x/css.h
index e59a115..60ff83e 100644
--- a/include/hw/s390x/css.h
+++ b/include/hw/s390x/css.h
@@ -192,16 +192,25 @@
/**
* Create a subchannel for the given bus id.
*
- * If @p bus_id is valid, verify that it uses the virtual channel
- * subsystem id and is not already in use, and find a free subchannel
- * id for it. If @p bus_id is not valid, find a free subchannel id and
- * device number across all subchannel sets. If either of the former
- * actions succeed, allocate a subchannel structure, initialise it
- * with the bus id, subchannel id and device number, register it with
- * the CSS and return it. Otherwise return NULL.
+ * If @p bus_id is valid, and @p squash_mcss is true, verify that it is
+ * not already in use in the default css, and find a free devno from the
+ * default css image for it.
+ * If @p bus_id is valid, and @p squash_mcss is false, verify that it is
+ * not already in use, and find a free devno for it.
+ * If @p bus_id is not valid, and if either @p squash_mcss or @p is_virtual
+ * is true, find a free subchannel id and device number across all
+ * subchannel sets from the default css image.
+ * If @p bus_id is not valid, and if both @p squash_mcss and @p is_virtual
+ * are false, find a non-full css image and find a free subchannel id and
+ * device number across all subchannel sets from it.
+ *
+ * If either of the former actions succeed, allocate a subchannel structure,
+ * initialise it with the bus id, subchannel id and device number, register
+ * it with the CSS and return it. Otherwise return NULL.
*
* The caller becomes owner of the returned subchannel structure and
* is responsible for unregistering and freeing it.
*/
-SubchDev *css_create_virtual_sch(CssDevId bus_id, Error **errp);
+SubchDev *css_create_sch(CssDevId bus_id, bool is_virtual, bool squash_mcss,
+ Error **errp);
#endif
