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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">You need to use “drmModeAddFB2WithModifiers()” instead of “drmModeAddFB()” in case your framebuffer needs to use fourcc codes as pixel format specifiers.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Thanks.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">BR,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Tina<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><a name="_____replyseparator"></a><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> intel-gvt-dev [mailto:intel-gvt-dev-bounces@lists.freedesktop.org]
<b>On Behalf Of </b>Charles Frey<br>
<b>Sent:</b> Thursday, May 10, 2018 12:00 AM<br>
<b>To:</b> intel-gvt-dev@lists.freedesktop.org<br>
<b>Subject:</b> [Help] Dma-buf local display<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Arial",sans-serif;color:black">Hi,<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Arial",sans-serif;color:black">I'm trying to achieve local display of my guest dma-bufs without using a Qemu UI. My goal is to be able to directly display the framebuffers on a local display
without necessiting an X server and Qemu UI such as GTK or spice.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Arial",sans-serif;color:black">Following the tutorial on </span><span class="object"><span style="font-family:"Arial",sans-serif;color:#005A95"><a href="https://01.org/igvt-g/blogs/wangbo85/2018/sharing-guest-framebuffer-host" target="_blank"><span style="color:#005A95;text-decoration:none">https://01.org/igvt-g/blogs/wangbo85/2018/sharing-guest-framebuffer-host</span></a></span></span><span style="font-family:"Arial",sans-serif;color:black">,
I'm using the drm KMS API to get a framebuffer from a dma-buf FD, but can't get any display on my screen.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Arial",sans-serif;color:black">The way I'm implementing this is the following : <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Arial",sans-serif;color:black">from qemu/hw/vfio/display.c, function vfio_display_get_dmabuf(), I get the following dma-buf FD and send it to a Unix socket that my DRM program listens to.<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Arial",sans-serif;color:black"> <o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Arial",sans-serif;color:black">fd = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_GET_GFX_DMABUF, &plane.dmabuf_id);<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Arial",sans-serif;color:black">Then in my application, I get the corresponding handle with drmPrimeFDToHandle(dri_drm, fd, &device->handle), where dri_drm is the /dev/dri/card0 FD and device
the struct representing it.<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Arial",sans-serif;color:black">No error on this and I get a handle.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Arial",sans-serif;color:black">drmPrimeFDToHandle(dri_drm, fd, &device->handle);<o:p></o:p></span></p>
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</span><span style="font-family:"Arial",sans-serif;color:black"><o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Courier New";color:black">When I try adding a framebuffer with drmModeAddFB() though, I get an error (-22, invalid argument).</span><span style="font-family:"Arial",sans-serif;color:black"><o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Courier New";color:black">The error is self explanatory as it is but I can't get to find which one is invalid, my height, width are correct. Is there a step I am missing?<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Courier New";color:black"><br>
<br>
</span><span style="font-family:"Arial",sans-serif;color:black"><o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Courier New";color:black">Thanks for your time.</span><span style="font-family:"Arial",sans-serif;color:black"><o:p></o:p></span></p>
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