<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:SimSun;
panose-1:2 1 6 0 3 1 1 1 1 1;}
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:"\@SimSun";
panose-1:2 1 6 0 3 1 1 1 1 1;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:#0563C1;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:#954F72;
text-decoration:underline;}
p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph
{mso-style-priority:34;
margin-top:0in;
margin-right:0in;
margin-bottom:0in;
margin-left:.5in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
span.EmailStyle18
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.EmailStyle19
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-US" link="#0563C1" vlink="#954F72">
<div class="WordSection1">
<p class="MsoNormal"><span style="color:#1F497D">+</span> <span style="color:#1F497D">
intel-gvt-dev@lists.freedesktop.org<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<div style="border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt">
<div>
<div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><a name="_____replyseparator"></a><b>From:</b> Zhang, Tina <br>
<b>Sent:</b> Thursday, April 26, 2018 1:54 PM<br>
<b>To:</b> 'Alex Williamson' <alex.williamson@redhat.com><br>
<b>Cc:</b> Lv, Zhiyuan <zhiyuan.lv@intel.com>; Yuan, Hang <hang.yuan@intel.com>; Tian, Kevin <kevin.tian@intel.com>; Wang, Zhenyu Z <zhenyu.z.wang@intel.com>; Wang, Zhi A <zhi.a.wang@intel.com>; Zhang, Xiong Y <xiong.y.zhang@intel.com>; Du, Changbin <changbin.du@intel.com><br>
<b>Subject:</b> Discussion about x-igd-opregion<o:p></o:p></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Hi Alex,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">These days, more and more people are asking if it’s possible to let GVT-g support dma-buf feature with OVMF. As we know that, simply enabling the BDSM fw_cfg entry in OVMF cannot solve the whole problem, as we are still basing on “x-igd-opregion=on”
which is an experimental option. So, we’d like to use this thread to discuss the issue and find a solution for it.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Background:<o:p></o:p></p>
<p class="MsoNormal">The problem is in GVT-g, Windows guest needs opregion to touch display registers, which is key to GVT-g dma-buf display feature based on VFIO. This opregion is provided by an QEMU experimental option called “x-igd-opregion=on”, which was
introduced due to some interesting display usages for IGD UPT mode. But the UPT mode isn’t invented to be used with display. That’s why this opinion is called experimental x-option.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">So, Alex, we saw that you have some comments about this issue before: “The feature cannot be considered supportable in libvirt until opregion support is either enabled automatically or enabled through a non-experimental option”. Could you
elaborate more on these two opinions?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">We’d like to propose a solution to solve this issue between QEMU/VFIO and GVT-g. After all, as you know, it’s not reasonable to let OVMF support opregion only for IGD UPT mode, as the legacy mode is missing and the UPT mode isn’t defined
to work with the help of a firmware.<o:p></o:p></p>
<p class="MsoNormal">Thanks.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Reference:<o:p></o:p></p>
<p class="MsoNormal"><a href="https://bugzilla.tianocore.org/show_bug.cgi?id=935">https://bugzilla.tianocore.org/show_bug.cgi?id=935</a><o:p></o:p></p>
<p class="MsoNormal"><a href="http://vfio.blogspot.com/2016/07/intel-graphics-assignment.html">http://vfio.blogspot.com/2016/07/intel-graphics-assignment.html</a><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">BR,<o:p></o:p></p>
<p class="MsoNormal">Tina<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
</div>
</body>
</html>