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<p class="MsoNormal"><span style="color:black;mso-fareast-language:EN-US">Nipur,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:black;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:black;mso-fareast-language:EN-US">Your best bet is to file a Feature Request in the Red Hat Bugzilla:
<a href="https://bugzilla.redhat.com/">https://bugzilla.redhat.com/</a>. You will want to file it against RHEL 7 and tag it as kernel. If/when Red Hat implements it in the kernel source, it will be compiled for CentOS 7.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:black;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:black;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:black;mso-fareast-language:EN-US">Greg<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:black;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US">From:</span></b><span lang="EN-US"> CentOS-devel <centos-devel-bounces@centos.org>
<b>On Behalf Of </b>Priya, Nupur<br>
<b>Sent:</b> February 25, 2019 11:19 PM<br>
<b>To:</b> centos-devel@centos.org<br>
<b>Cc:</b> Singh, Alok <Alok.Singh@harman.com>; Bhutani, Sudhanshu <Sudhanshu.Bhutani@Harman.com><br>
<b>Subject:</b> [CentOS-devel] Need a knob to disable all spectre/meltdown fixes<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span lang="EN-US" style="font-size:10.5pt;font-family:"Arial",sans-serif;color:#333333;background:white">Hi there,</span><span lang="EN-US" style="font-size:10.5pt;font-family:"Arial",sans-serif;color:#333333"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.5pt;font-family:"Arial",sans-serif;color:#333333;background:white">I would like to implement a command , to be able to disable all variants(or at least the ones causing performance impact). As per
the RH article: </span><span lang="EN-US"><a href="https://access.redhat.com/articles/3311301," title="Follow link"><span style="font-size:10.5pt;font-family:"Arial",sans-serif;color:#3B73AF;background:white;text-decoration:none">https://access.redhat.com/articles/3311301,</span></a></span><span lang="EN-US" style="font-size:10.5pt;font-family:"Arial",sans-serif;color:#333333;background:white"> we
would be able to only disable spectre variant 2 and 3(pti). <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.5pt;font-family:"Arial",sans-serif;color:#333333"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.5pt;font-family:"Arial",sans-serif;color:#333333;background:white">I need an option to disable variant 1, 3a and 4 as well. Some of the recent articles suggest that options like no_spectre_v1, no_spectre_v2
and spec_store_bypass_disable parameters are available in latest versions of kernel(4.15 and above). </span><span lang="EN-US" style="font-size:10.5pt;font-family:"Arial",sans-serif;color:#333333"><br>
<br>
</span><span lang="EN-US"><a href="https://www.zdnet.com/article/linux-kernel-gets-another-option-to-disable-spectre-mitigations/" title="Follow link"><span style="font-size:10.5pt;font-family:"Arial",sans-serif;color:#3B73AF;background:white;text-decoration:none">https://www.zdnet.com/article/linux-kernel-gets-another-option-to-disable-spectre-mitigations/</span></a></span><span lang="EN-US" style="font-size:10.5pt;font-family:"Arial",sans-serif;color:#333333;background:white"> </span><span lang="EN-US" style="font-size:10.5pt;font-family:"Arial",sans-serif;color:#333333"><br>
</span><span lang="EN-US"><a href="https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html?highlight=kernel%20parameters" title="Follow link"><span style="font-size:10.5pt;font-family:"Arial",sans-serif;color:#3B73AF;background:white;text-decoration:none">https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html?highlight=kernel%20parameters</span></a></span><span lang="EN-US" style="font-size:10.5pt;font-family:"Arial",sans-serif;color:#333333;background:white"> </span><span lang="EN-US" style="font-size:10.5pt;font-family:"Arial",sans-serif;color:#333333"><br>
<br>
<span style="background:white">Can this be made available in our Centos 7 kernels? Or is there any plan for RH to implement the same in any future release?<o:p></o:p></span></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Regards,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Nupur<o:p></o:p></span></p>
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