[[PageOutline]]

 = virtio-gpu =
 * [https://virgil3d.github.io/ Virgil 3D GPU project by virgil3d]

 * [https://www.phoronix.com/scan.php?page=news_item&px=Virt-Manager-1.4-Released Virt-Manager 1.4 Exposes The New OpenGL Options - Phoronix]
 * [https://www.kraxel.org/blog/2016/09/using-virtio-gpu-with-libvirt-and-spice/ Using virtio-gpu with libvirt and spice | kraxel's news]

 == QXL vs virtio-vga ==
 * 結論から言うと、SPICEが未対応のためvirt-manager下では3D accelerationを有効にできない
  * https://wiki.archlinux.org/index.php/QEMU#virtio {{{virtio-vga}}} / {{{virtio-gpu}}} is a paravirtual 3D graphics driver based on [https://virgil3d.github.io/ virgl].
  > As of September 2016, support for the spice protocol is under development and can be tested installing the development release of spice (>= 0.13.2).

 * H/W: wiki:TipAndDoc/Hardware#ASUSH97M-PLUS
 * S/W
  * ArchLinux 4.7.6-1
  * qemu 2.7.0-2
  * seabios 1.9.3-1
  * libvirt 2.3.0-1
  * spice 0.12.8-1
  * virt-manager 1.4.0-2

 === QXL ===
 * mitty@guest:~$ lspci
{{{
00:02.0 VGA compatible controller: Red Hat, Inc. QXL paravirtual graphic card (rev 04)
}}}
 * mitty@guest:~$ dmesg | grep drm
{{{
[    1.057734] [drm] Initialized drm 1.1.0 20060810
[    1.110306] [drm] Device Version 0.0
[    1.110308] [drm] Compression level 0 log level 0
[    1.110309] [drm] Currently using mode #0, list at 0x488
[    1.110309] [drm] 12286 io pages at offset 0x1000000
[    1.110310] [drm] 16777216 byte draw area at offset 0x0
[    1.110310] [drm] RAM header offset: 0x3ffe000
[    1.110311] [drm] rom modes offset 0x488 for 128 modes
[    1.110364] [drm] qxl: 16M of VRAM memory size
[    1.110364] [drm] qxl: 63M of IO pages memory ready (VRAM domain)
[    1.110365] [drm] qxl: 64M of Surface memory size
[    1.112882] [drm] main mem slot 1 [f4000000,3ffe000]
[    1.112884] [drm] surface mem slot 2 [f8000000,4000000]
[    1.113677] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[    1.113679] [drm] No driver support for vblank timestamp query.
[    1.113891] [drm] fb mappable at 0xF4000000, size 3145728
[    1.113891] [drm] fb: depth 24, pitch 4096, width 1024, height 768
[    1.113892] fb: switching to qxldrmfb from VESA VGA
[    1.115537] fbcon: qxldrmfb (fb0) is primary device
[    1.116425] [drm:qxl_enc_commit [qxl]] *ERROR* head number too large or missing monitors config: ffffc90000748000, 0
[    1.118767] qxl 0000:00:02.0: fb0: qxldrmfb frame buffer device
[    1.136842] [drm] Initialized qxl 0.1.0 20120117 for 0000:00:02.0 on minor 0
}}}

 * minecraftは一応動いた[[br]][[Image(QXL-minecraft.png,33%)]]
  * 仮想CPU 4コア、メモリ4GBでCPU負荷50%程度、35fps(minecraftの3D設定はなるべく低負荷に設定)

 === virtio-vga (no 3D) ===
 * mitty@guest:~$ lspci
{{{
00:02.0 VGA compatible controller: Red Hat, Inc Virtio GPU (rev 01)
}}}
 * mitty@guest:~$ dmesg | grep drm
{{{
[    0.690401] [drm] Initialized drm 1.1.0 20060810
[    0.714409] [drm] pci: virtio-vga detected
[    0.714412] fb: switching to virtiodrmfb from VESA VGA
[    0.714786] [drm] virgl 3d acceleration not available
[    0.715117] [drm] virtio vbuffers: 80 bufs, 192B each, 15kB total.
[    0.715164] [drm] number of scanouts: 1
[    0.715177] [drm] number of cap sets: 0
[    0.717593] virtio_gpu virtio0: fb0: virtiodrmfb frame buffer device
[    0.726158] [drm] Initialized virtio_gpu 0.0.1 0 on minor 0
}}}

 * 3Dが有効にならない場合、QXLとほぼ変わらない[[br]][[Image(virgil_no3d-minecraft.png,33%)]]
  * 仮想CPU 4コア、メモリ4GBでCPU負荷50%程度、33fps(minecraftの3D設定はなるべく低負荷に設定)

 ==== errors ====
 * [https://www.kraxel.org/blog/2015/10/virtio-gpu-and-libvirt/ virtio-gpu and libvirt | kraxel's news] こちらを参考に、virsh editで直接編集してみたが、起動に失敗する

 1. mitty@host:~$ diff -u virgil.orig.xml virgil.gl.xml
{{{#!diff
--- virgil.orig.xml     2016-10-08 20:47:22.762150999 +0900
+++ virgil.gl.xml       2016-10-08 20:49:14.199368411 +0900
@@ -87,6 +87,7 @@
     <graphics type='spice' autoport='yes' listen='0.0.0.0'>
       <listen type='address' address='0.0.0.0'/>
       <image compression='off'/>
+      <gl enable='yes'/>
     </graphics>
     <sound model='ich6'>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
}}}
  * mitty@host:~$ virsh start virgil
{{{
error: Failed to start domain virgil
error: unsupported configuration: This QEMU doesn't support spice OpenGL
}}}
 2. mitty@host:~$ diff -u virgil.orig.xml virgil.gl.xml
{{{#!diff
--- virgil.orig.xml     2016-10-08 20:47:22.762150999 +0900
+++ virgil.gl.xml       2016-10-09 00:12:45.044761666 +0900
@@ -1,4 +1,4 @@
-<domain type='kvm'>
+<domain type='kvm' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>
   <name>virgil</name>
   <uuid>afd14745-a9f3-44ea-b2da-e2eefabea22b</uuid>
   <memory unit='KiB'>4194304</memory>
@@ -84,10 +84,7 @@
     </channel>
     <input type='mouse' bus='ps2'/>
     <input type='keyboard' bus='ps2'/>
-    <graphics type='spice' autoport='yes' listen='0.0.0.0'>
-      <listen type='address' address='0.0.0.0'/>
-      <image compression='off'/>
-    </graphics>
+    <graphics type='sdl' display=':0' xauth='/home/mitty/.Xauthority'/>
     <sound model='ich6'>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
     </sound>
@@ -105,5 +102,11 @@
       <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/>
     </memballoon>
   </devices>
+  <qemu:commandline>
+    <qemu:arg value='-set'/>
+    <qemu:arg value='device.video0.driver=virtio-vga'/>
+    <qemu:arg value='-display'/>
+    <qemu:arg value='gtk,gl=on'/>
+  </qemu:commandline>
 </domain>
}}}
  * mitty@host:~$ virsh start virgil
{{{
error: Failed to start domain virgil
error: internal error: process exited while connecting to monitor: Unable to init server: Could not connect: Connection refused
2016-10-08T15:12:30.027297Z qemu-system-x86_64: OpenGL is not supported by the display
}}}
  * ホスト上でXを動かせば良さそう