[PATCH] s390: qdio V=V pass-through
New feature V=V qdio pass-through.
QDIO and HiperSockets processing in z/VM V=V guest environments (as well as
V=R with z/VM running in LPAR mode) requires shadowing of all QDIO
architecture queue elements. Especially the shadowing of SBALs and SLSBs
structures in the hypervisor, and the need to issue SIGA SYNC operations to
observe state changes, eventually causes significant CPU processing overhead
in the hypervisor.
The QDIO pass-through support for V=V guests avoids the shadowing of SBALs and
SLSBs. This significantly reduces the hypervisor overhead for QDIO based I/O.
Signed-off-by: Frank Pavlic <pavlic@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/s390/cio/chsc.h b/drivers/s390/cio/chsc.h
index be20da4..6945013 100644
--- a/drivers/s390/cio/chsc.h
+++ b/drivers/s390/cio/chsc.h
@@ -43,7 +43,9 @@
u32 ext_mb : 1; /* bit 48 */
u32 : 7;
u32 aif_tdd : 1; /* bit 56 */
- u32 : 10;
+ u32 : 1;
+ u32 qebsm : 1; /* bit 58 */
+ u32 : 8;
u32 aif_osa : 1; /* bit 67 */
u32 : 28;
}__attribute__((packed));