Sheng Yang wrote: > On Saturday 24 November 2007 07:23:20 Neo Jia wrote: > >> hi, >> >> I happened to get a "emulation fail" when running the following command: >> >> System environment: Intel Core 2 Duo (E6600) x86_64 Fedora 8 >> (2.6.23.1-49.fc8). >> >> qemu-img create -f qcow debian-testing.img 10G >> >> sudo qemu-system-x86_64 -cdrom >> /home/cjia/download/debian-testing-i386-netinst.iso -hda >> debian-testing.img -boot d -m 1024 >> >> Everything works fine until it prompts me that the installation is >> complete and need reboot. >> >> >>> sudo qemu-system-x86_64 -cdrom >>> /home/cjia/download/debian-testing-i386-netinst.iso -hda >>> debian-testing.img -boot d -m 1024 >>> >> exception 13 (0) >> rax 0000000000000100 rbx 0000000000000100 rcx 000000000000ffff rdx >> 0000000000000600 >> rsi 0000000000000000 rdi 0000000000000000 rsp 0000000000000000 rbp >> 0000000000000000 >> r8 0000000000000000 r9 0000000000000000 r10 0000000000000000 r11 >> 0000000000000000 >> r12 0000000000000000 r13 0000000000000000 r14 0000000000000000 r15 >> 0000000000000000 >> rip 0000000000010000 rflags 00033003 >> cs f000 (000f0000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0) >> ds 0000 (00000000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0) >> es 0000 (00000000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0) >> ss 0000 (00000000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0) >> fs 0000 (00000000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0) >> gs 0000 (00000000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0) >> tr 0080 (40c00000/00002088 p 1 dpl 0 db 0 s 0 type b l 0 g 0 avl 0) >> ldt 0000 (00000000/0000ffff p 1 dpl 0 db 0 s 0 type 2 l 0 g 0 avl 0) >> gdt 0/ffff >> idt 0/ffff >> cr0 60000010 cr2 0 cr3 0 cr4 0 cr8 0 efer 0 >> code: 00 00 00 00 ea 5b e0 00 f0 31 30 2f 32 38 2f 30 37 00 fc f5 --> >> fc 0f 01 15 92 a0 31 00 b8 18 00 00 00 8e d8 8e c0 8e e0 8e e8 31 c0 >> bf 00 30 39 00 b9 7c >> Aborted >> >> ---> dmesg: >> >> kvm: emulating exchange as write >> emulation failed but !mmio_needed? rip 10000 fc 0f 01 15 // I >> searched through the source code but not find a place to generate "but >> !mmio_needed?" string ... >> > >
That's been removed some time ago (and replaced by another string). See 054b1369679fb97582fc77f25a700d4290ff3e89. > It due to one instruction haven't been emulated: 0xfc(one byte instruction). > Look it up in SDM Vol.2B's opcode map, you can find that's "CLD". And look at > what is CLD in SDM Vol.2, you will find "CLD - Clear direction flag". So we > miss this in x86_emulate.c. > > >> The version of kvm I used for kvm module is >> "694401697ccd822bb08019731c3ee1bb34323d8e" and the kvm-userspace is >> "a57b838b49bc4e4e7439b18d0323385d53e41c7f". >> // Not sure if this is the right way to show the version I am using. >> If not, please correct me, this is the first time I am using git... >> > > Yeah, that's the right ones. :) > > >> Anyway, I really want to get some comments about how to trace this >> problem and would be very glad to dig into it! >> > > Here is the chance! Add this instruction to our x86 emulator. You can take > the > implement of "sti" and "cli" as a reference. While adding the instrucion is helpful, something else has gone wrong here. cs:ip == f000:10000. You can see the far jump at f000:fff0 (opcode ea) -- kvm just skipped over it somehow. Ah, it's been fixed already: see c408e4e8d9045d53c1d82c622a5756febd051ef9. I need to backport it to 2.6.23. -- Any sufficiently difficult bug is indistinguishable from a feature. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
