Gentlemen, attached one-liner passes through IO port 0xed accesses of HVM guests. Applying this patch improves guest boot performance of affected Linux kernels by about 0.5 to 1.0 seconds measured from GRUB to login. Port 0x80 is already passed-through. Writes to port 0x80 are traditionally used as IO delay. Recent Linux kernel versions can be configured to use port 0xed instead (CONFIG_IO_DELAY_0XED=y). Ubuntu 8.04 and later kernels are configured to use port 0xed. In Linux IO delay is implemented by (in|out)[bwl]_p. From a first glance at Linux it looks like the only relevant usage of delayed IO is in drivers/video/console/vgacon.c. Affected is VGA console initialization and font setup. Output / scrolling is not affected. Signed-off-by: Thomas Friebel <thomas.friebel@amd.com> ----to satisfy European Law for business letters: Advanced Micro Devices GmbH Karl-Hammerschmidt-Str. 34, 85609 Dornach b. Muenchen Geschaeftsfuehrer: Jochen Polster; Thomas M. McCoy; Giuliano Meroni Sitz: Dornach, Gemeinde Aschheim, Landkreis Muenchen Registergericht Muenchen, HRB Nr. 43632 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel