On Thu, Jun 6, 2013 at 1:40 PM, Gleb Natapov <gleb@xxxxxxxxxx> wrote:
> On Thu, Jun 06, 2013 at 12:28:16AM +0800, 李春奇 <Arthur Chunqi Li> wrote:
>> On Thu, Jun 6, 2013 at 12:13 AM, Gleb Natapov <gleb@xxxxxxxxxx> wrote:
>> > This time the email is perfect :)
>> >
>> > On Thu, Jun 06, 2013 at 12:02:52AM +0800, Arthur Chunqi Li wrote:
>> >> Add multibyte NOP test case to kvm-unit-tests. This version adds test cases into x86/realmode.c. This can test one of bugs when booting RHEL5.9 64-bit.
>> >>
>> >> Signed-off-by: Arthur Chunqi Li <yzt356@xxxxxxxxx>
>> >> ---
>> >> x86/realmode.c | 24 ++++++++++++++++++++++++
>> >> 1 file changed, 24 insertions(+)
>> >>
>> >> diff --git a/x86/realmode.c b/x86/realmode.c
>> >> index 981be08..e103ca6 100644
>> >> --- a/x86/realmode.c
>> >> +++ b/x86/realmode.c
>> >> @@ -1504,6 +1504,29 @@ static void test_fninit(void)
>> >> report("fninit", 0, fsw == 0 && (fcw & 0x103f) == 0x003f);
>> >> }
>> >>
>> >> +static void test_nopl(void)
>> >> +{
>> >> + MK_INSN(nopl1, ".byte 0x90\n\r"); // 1 byte nop
>> >> + MK_INSN(nopl2, ".byte 0x66, 0x90\n\r"); // 2 bytes nop
>> >> + MK_INSN(nopl3, ".byte 0x0f, 0x1f, 0x00\n\r"); // 3 bytes nop
>> >> + MK_INSN(nopl4, ".byte 0x0f, 0x1f, 0x40, 0x00\n\r"); // 4 bytes nop
>> > But all nops below that are not supported in 16 bit mode. You can
>> > disassemble realmode.elf in 16bit node (objdump -z -d -mi8086
>> > x86/realmode.elf) and check yourself. Lets not complicate things for now
>> > and test only those that are easy to test.
>> Yes. But what if a 7-bytes nop runs in 16bit mode? Just the same as
>> https://bugzilla.redhat.com/show_bug.cgi?id=967652
>>
> It cannot. In 16 bit mode it is decoded as two instructions:
> 0f 1f 80 00 00 nopw 0x0(%bx,%si)
> 00 00 add %al,(%bx,%si)
>
OK, I will just test the first four nop instructions. Should I commit
another patch?
Arthur.
>> DR6=00000000ffff0ff0 DR7=0000000000000400
>> EFER=0000000000000500
>> Code=00 00 e9 50 ff ff ff 00 00 00 00 85 d2 74 20 45 31 c0 31 c9 <0f>
>> 1f 80 00 00 00 00 0f b6 04 31 41 83 c0 01 88 04 39 48 83 c1 01 41 39
>> d0 75 ec 48 89 f8
>>
>> The error code is "0f 1f 80 00 00 00 00", which is a 7-bytes nop. Will
>> the emulator runs well in that case when booting RHEL5.9 64-bit?
>>
>> Arthur
>>
>>
>> >
>> >> + MK_INSN(nopl5, ".byte 0x0f, 0x1f, 0x44, 0x00, 0x00\n\r"); // 5 bytes nop
>> >> + MK_INSN(nopl6, ".byte 0x66, 0x0f, 0x1f, 0x44, 0x00, 0x00\n\r"); // 6 bytes nop
>> >> + MK_INSN(nopl7, ".byte 0x0f, 0x1f, 0x80, 0x00, 0x00, 0x00, 0x00\n\r"); // 7 bytes nop
>> >> + MK_INSN(nopl8, ".byte 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00\n\r"); // 8 bytes nop
>> >> + MK_INSN(nopl9, ".byte 0x66, 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00\n\r"); // 9 bytes nop
>> >> + exec_in_big_real_mode(&insn_nopl1);
>> >> + exec_in_big_real_mode(&insn_nopl2);
>> >> + exec_in_big_real_mode(&insn_nopl3);
>> >> + exec_in_big_real_mode(&insn_nopl4);
>> >> + exec_in_big_real_mode(&insn_nopl5);
>> >> + exec_in_big_real_mode(&insn_nopl6);
>> >> + exec_in_big_real_mode(&insn_nopl7);
>> >> + exec_in_big_real_mode(&insn_nopl8);
>> >> + exec_in_big_real_mode(&insn_nopl9);
>> >> + report("nopl", 0, 1);
>> >> +}
>> >> +
>> >> void realmode_start(void)
>> >> {
>> >> test_null();
>> >> @@ -1548,6 +1571,7 @@ void realmode_start(void)
>> >> test_xlat();
>> >> test_salc();
>> >> test_fninit();
>> >> + test_nopl();
>> >>
>> >> exit(0);
>> >> }
>> >> --
>> >> 1.7.9.5
>> >
>> > --
>> > Gleb.
>
> --
> Gleb.
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