From 8129ee164267dc030b8e1d541ee3643c0b9f2fa1 Mon Sep 17 00:00:00 2001 From: Frank Pavlic Date: Fri, 6 Jan 2006 00:19:20 -0800 Subject: [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 Signed-off-by: Martin Schwidefsky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/s390/cio/chsc.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/s390/cio/chsc.h') diff --git a/drivers/s390/cio/chsc.h b/drivers/s390/cio/chsc.h index be20da49d14..69450134bec 100644 --- a/drivers/s390/cio/chsc.h +++ b/drivers/s390/cio/chsc.h @@ -43,7 +43,9 @@ struct css_general_char { 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)); -- cgit v1.2.3