Re: [PATCH] tune-core2: use n270 instead of core2duo

From: Andre McCurdy <armccurdy@gmail.com>
To: Martin Jansa <martin.jansa@gmail.com>
Cc: Patches and discussions about the oe-core layer
	<openembedded-core@lists.openembedded.org>
Subject: Re: [PATCH] tune-core2: use n270 instead of core2duo
Date: Thu, 13 Sep 2018 15:50:29 -0700	[thread overview]
Message-ID: <CAJ86T=WukCufiTWU-p8L2cCA4DsnCxC-iPp+Ed-7nWviEAYjRQ@mail.gmail.com> (raw)
In-Reply-To: <CA+chaQePowpbWZi_k-iJKdUn+ocPZC_0T4VBArs82DSuO0iJkw@mail.gmail.com>

On Thu, Sep 13, 2018 at 3:16 PM, Martin Jansa <martin.jansa@gmail.com> wrote:
> Is this different issue than what was discussed in:
> https://www.mail-archive.com/openembedded-core@lists.openembedded.org/msg109516.html
>
> The message is slightly different (might be changed in newer qemu used now),
> but the issue I had before was that features of selected -cpu and host cpu
> didn't match and qemu failed with:
> qemu-system-x86_64: warning: host doesn't support requested feature:
> CPUID.01H:EDX.ss [bit 27]
> when some features were missing and kvm was used.
>
> If it's the same root cause, then it's not a bug in qemu.

Thanks. Looks like it could be the same issue - if qemu is running
with KVM on a host which isn't natively compatible with the full
core2duo feature set.

From the Yocto bug these warnings are coming from the nightly builds:

  https://bugzilla.yoctoproject.org/show_bug.cgi?id=12916

Has something changed recently? Have the nightly builds moved onto an
AMD machine?

> On Thu, Sep 13, 2018 at 11:33 PM Andre McCurdy <armccurdy@gmail.com> wrote:
>>
>> On Thu, Sep 13, 2018 at 12:25 AM, Anuj Mittal <anuj.mittal@intel.com>
>> wrote:
>> > Fixes warnings in builds using core2-32 tune:
>> >
>> > warning: TCG doesn't support requested feature:
>> > CPUID.80000001H:EDX.syscall [bit 11]
>> > warning: TCG doesn't support requested feature: CPUID.80000001H:EDX.lm
>> > [bit 29]
>> >
>> > when executing postinsts using qemu-i386.
>> >
>> > i386 target doesn't enable CPUID_EXT2_SYSCALL and CPUID_EXT2_LM [1]
>> > while cpu choice of core2duo that we use for core2-32 TUNE does [2].
>> > Use n270 cpu instead to use with qemu which supports SSSE3 and doesn't
>> > have these bits enabled [3].
>> >
>> > [1] https://github.com/qemu/qemu/blob/master/target/i386/cpu.c#L739
>> > [2] https://github.com/qemu/qemu/blob/master/target/i386/cpu.c#L1439
>> > [3] https://github.com/qemu/qemu/blob/master/target/i386/cpu.c#L1603
>> >
>> > Fixes [YOCTO #12916]
>>
>> Is this working around a bug in qemu?
>>
>> > Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>> ---
>> >  meta/conf/machine/include/tune-core2.inc | 2 +-
>> >  1 file changed, 1 insertion(+), 1 deletion(-)
>> >
>> > diff --git a/meta/conf/machine/include/tune-core2.inc
>> > b/meta/conf/machine/include/tune-core2.inc
>> > index c686bb4682..ddde719bde 100644
>> > --- a/meta/conf/machine/include/tune-core2.inc
>> > +++ b/meta/conf/machine/include/tune-core2.inc
>> > @@ -21,7 +21,7 @@ TUNE_FEATURES_tune-core2-32 =
>> > "${TUNE_FEATURES_tune-x86} core2"
>> >  BASE_LIB_tune-core2-32 = "lib"
>> >  TUNE_PKGARCH_tune-core2-32 = "core2-32"
>> >  PACKAGE_EXTRA_ARCHS_tune-core2-32 = "${PACKAGE_EXTRA_ARCHS_tune-i686}
>> > core2-32"
>> > -QEMU_EXTRAOPTIONS_core2-32 = " -cpu core2duo"
>> > +QEMU_EXTRAOPTIONS_core2-32 = " -cpu n270"
>> >
>> >  AVAILTUNES += "core2-64"
>> >  TUNE_FEATURES_tune-core2-64 = "${TUNE_FEATURES_tune-x86-64} core2"
>> > --
>> > 2.17.1
>> >
>> > --
>> > _______________________________________________
>> > Openembedded-core mailing list
>> > Openembedded-core@lists.openembedded.org
>> > http://lists.openembedded.org/mailman/listinfo/openembedded-core
>> --
>> _______________________________________________
>> Openembedded-core mailing list
>> Openembedded-core@lists.openembedded.org
>> http://lists.openembedded.org/mailman/listinfo/openembedded-core