From: Frank Pavlic Date: Fri, 6 Jan 2006 08:19:20 +0000 (-0800) Subject: [PATCH] s390: qdio V=V pass-through X-Git-Tag: v2.6.16-rc1~936^2~110 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8129ee164267dc030b8e1d541ee3643c0b9f2fa1;p=pandora-kernel.git [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 --- Reading git-diff-tree failed