Hi, I currently see some regressions on Microsoft operating systems. 1) Windows XP bugchecks since commit: commit 7f0b7141b4c7deab51efd8ee1e83eab2d9b7a9ea Author: Richard Henderson Date: Mon Jul 6 17:29:59 2015 +0100 target-i386: Perform set/reset_inhibit_irq inline With helpers that can be reused for other things. Signed-off-by: Richard Henderson I'm starting QEMU with -cpu pentium2. Attached patch can be applied on master to work-around the problem. Another work-around is to start with -enable-kvm. 2) Windows 95 bugchecks since commit: commit d6a2914984c89fa0a3125b9842e0cbf68de79a3d Author: Richard Henderson Date: Thu Dec 17 11:19:19 2015 -0800 target-i386: Use gen_lea_v_seg in gen_lea_modrm Centralize handling of segment bases. Signed-off-by: Richard Henderson Message-Id: <1450379966-28198-4-git-send-email-rth@twiddle.net> Signed-off-by: Paolo Bonzini (with 88c73d16ad1b6c22a2ab082064d0d521f756296a and 4987783400667147ada01a5bdcce53f11b822888 cherry-picked) I'm starting QEMU with -cpu pentium. I've not searched for a work-around. 3) MS-DOS 6 freezes when loading himem.sys since commit: commit 1906b2af7c2345037d9b2fdf484b457b5acd09d1 Author: Richard Henderson Date: Thu Jul 2 13:59:21 2015 +0100 target-i386: Rearrange processing of 0F 01 Rather than nesting tests of OP, MOD, and RM, decode them all at once with a switch. Fixes incorrect decoding of AMD Pacifica extensions (aka vmrun et al) via op==2 path. Signed-off-by: Richard Henderson I'm starting QEMU with -cpu 486. It works on master if I add -enable-kvm Hervé