From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: [PATCH] Test case of emulating multibyte NOP Date: Thu, 6 Jun 2013 10:28:25 +0300 Message-ID: <20130606072825.GV4725@redhat.com> References: <1370448172-22960-1-git-send-email-yzt356@gmail.com> <20130605161352.GI4725@redhat.com> <20130606054032.GM4725@redhat.com> <20130606070237.GT4725@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: kvm , Paolo Bonzini To: =?utf-8?B?5p2O5pil5aWHIDxBcnRodXIgQ2h1bnFpIExpPg==?= Return-path: Received: from mx1.redhat.com ([209.132.183.28]:18824 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754872Ab3FFH22 convert rfc822-to-8bit (ORCPT ); Thu, 6 Jun 2013 03:28:28 -0400 Content-Disposition: inline In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On Thu, Jun 06, 2013 at 03:22:59PM +0800, =E6=9D=8E=E6=98=A5=E5=A5=87 <= Arthur Chunqi Li> wrote: > On Thu, Jun 6, 2013 at 3:17 PM, =E6=9D=8E=E6=98=A5=E5=A5=87 wrote: > > On Thu, Jun 6, 2013 at 3:02 PM, Gleb Natapov wrot= e: > >> On Thu, Jun 06, 2013 at 02:49:14PM +0800, =E6=9D=8E=E6=98=A5=E5=A5= =87 wrote: > >>> On Thu, Jun 6, 2013 at 1:40 PM, Gleb Natapov wr= ote: > >>> > On Thu, Jun 06, 2013 at 12:28:16AM +0800, =E6=9D=8E=E6=98=A5=E5= =A5=87 wrote: > >>> >> On Thu, Jun 6, 2013 at 12:13 AM, Gleb Natapov wrote: > >>> >> > This time the email is perfect :) > >>> >> > > >>> >> > On Thu, Jun 06, 2013 at 12:02:52AM +0800, Arthur Chunqi Li w= rote: > >>> >> >> 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 bo= oting RHEL5.9 64-bit. > >>> >> >> > >>> >> >> Signed-off-by: Arthur Chunqi Li > >>> >> >> --- > >>> >> >> 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 =3D=3D 0 && (fcw & 0x103f) =3D= =3D 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 no= p > >>> >> >> + MK_INSN(nopl3, ".byte 0x0f, 0x1f, 0x00\n\r"); // 3 by= tes 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. Yo= u can > >>> >> > disassemble realmode.elf in 16bit node (objdump -z -d -mi808= 6 > >>> >> > x86/realmode.elf) and check yourself. Lets not complicate th= ings 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 sa= me as > >>> >> https://bugzilla.redhat.com/show_bug.cgi?id=3D967652 > >>> >> > >>> > 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 co= mmit > >>> another patch? > >>> > >> Yes, all others will have to go into emulator.c. > > You mean I need also add another test for nopl5~nop9 in emulator.c > > with the "trick" emulator mode? > > I will commit a modified one for realmode.c since some other works > > should be done in emulator.c. > Since we need to place some relevant codes in emulator.c, why don't w= e > place all the tests in emulator.c? >=20 We can place those 4 in both. I do not always run all tests so it is nice to cover as much as possible in both. -- Gleb.