Ytsphinx.addnodesdocument)}( rawsourcechildren]( translations LanguagesNode)}(hhh](h pending_xref)}(hhh]docutils.nodesTextChinese (Simplified)}parenthsba attributes}(ids]classes]names]dupnames]backrefs] refdomainstdreftypedoc reftarget/translations/zh_CN/gpu/vkmsmodnameN classnameN refexplicitutagnamehhh ubh)}(hhh]hChinese (Traditional)}hh2sbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget/translations/zh_TW/gpu/vkmsmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hItalian}hhFsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget/translations/it_IT/gpu/vkmsmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hJapanese}hhZsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget/translations/ja_JP/gpu/vkmsmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hKorean}hhnsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget/translations/ko_KR/gpu/vkmsmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hSpanish}hhsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget/translations/sp_SP/gpu/vkmsmodnameN classnameN refexplicituh1hhh ubeh}(h]h ]h"]h$]h&]current_languageEnglishuh1h hh _documenthsourceNlineNubhtarget)}(h .. _vkms:h]h}(h]h ]h"]h$]h&]refidvkmsuh1hhKhhhhh6/var/lib/git/docbuild/linux/Documentation/gpu/vkms.rstubhsection)}(hhh](htitle)}(h#drm/vkms Virtual Kernel Modesettingh]h#drm/vkms Virtual Kernel Modesetting}(hhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhhhhhKubh paragraph)}(hVKMS is a software-only model of a KMS driver that is useful for testing and for running X (or similar) on headless machines. VKMS aims to enable a virtual display with no need of a hardware display capability, releasing the GPU in DRM API tests.h]hVKMS is a software-only model of a KMS driver that is useful for testing and for running X (or similar) on headless machines. VKMS aims to enable a virtual display with no need of a hardware display capability, releasing the GPU in DRM API tests.}(hhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhW/var/lib/git/docbuild/linux/Documentation/gpu/vkms:7: ./drivers/gpu/drm/vkms/vkms_drv.chKhhhhubh)}(hhh](h)}(hSetuph]hSetup}(hhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhhhhhK ubh)}(h6The VKMS driver can be setup with the following steps:h]h6The VKMS driver can be setup with the following steps:}(hhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK hhhhubh)}(h!To check if VKMS is loaded, run::h]h To check if VKMS is loaded, run:}(hhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhhhhubh literal_block)}(hlsmod | grep vkmsh]hlsmod | grep vkms}hjsbah}(h]h ]h"]h$]h&] xml:spacepreserveuh1jhhhKhhhhubh)}(hThis should list the VKMS driver. If no output is obtained, then you need to enable and/or load the VKMS driver. Ensure that the VKMS driver has been set as a loadable module in your kernel config file. Do::h]hThis should list the VKMS driver. If no output is obtained, then you need to enable and/or load the VKMS driver. Ensure that the VKMS driver has been set as a loadable module in your kernel config file. Do:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhhhhubj)}(h[make nconfig Go to `Device Drivers> Graphics support` Enable `Virtual KMS (EXPERIMENTAL)`h]h[make nconfig Go to `Device Drivers> Graphics support` Enable `Virtual KMS (EXPERIMENTAL)`}hj#sbah}(h]h ]h"]h$]h&]jjuh1jhhhKhhhhubh)}(h]Compile and build the kernel for the changes to get reflected. Now, to load the driver, use::h]h\Compile and build the kernel for the changes to get reflected. Now, to load the driver, use:}(hj1hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhhhhubj)}(hsudo modprobe vkmsh]hsudo modprobe vkms}hj?sbah}(h]h ]h"]h$]h&]jjuh1jhhhK!hhhhubh)}(hOn running the lsmod command now, the VKMS driver will appear listed. You can also observe the driver being loaded in the dmesg logs.h]hOn running the lsmod command now, the VKMS driver will appear listed. You can also observe the driver being loaded in the dmesg logs.}(hjMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK#hhhhubh)}(hThe VKMS driver has optional features to simulate different kinds of hardware, which are exposed as module options. You can use the `modinfo` command to see the module options for vkms::h](hThe VKMS driver has optional features to simulate different kinds of hardware, which are exposed as module options. You can use the }(hj[hhhNhNubhtitle_reference)}(h `modinfo`h]hmodinfo}(hjehhhNhNubah}(h]h ]h"]h$]h&]uh1jchj[ubh, command to see the module options for vkms:}(hj[hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhK&hhhhubj)}(h modinfo vkmsh]h modinfo vkms}hj}sbah}(h]h ]h"]h$]h&]jjuh1jhhhK*hhhhubh)}(hModule options are helpful when testing, and enabling modules can be done while loading vkms. For example, to load vkms with cursor enabled, use::h]hModule options are helpful when testing, and enabling modules can be done while loading vkms. For example, to load vkms with cursor enabled, use:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK,hhhhubj)}(h"sudo modprobe vkms enable_cursor=1h]h"sudo modprobe vkms enable_cursor=1}hjsbah}(h]h ]h"]h$]h&]jjuh1jhhhK0hhhhubh)}(hTo disable the driver, use ::h]hTo disable the driver, use}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK2hhhhubj)}(hsudo modprobe -r vkmsh]hsudo modprobe -r vkms}hjsbah}(h]h ]h"]h$]h&]jjuh1jhhhK4hhhhubeh}(h]setupah ]h"]setupah$]h&]uh1hhhhhhhhK ubh)}(hhh](h)}(hTesting With IGTh]hTesting With IGT}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjhhhhhK7ubh)}(hThe IGT GPU Tools is a test suite used specifically for debugging and development of the DRM drivers. The IGT Tools can be installed from `here `_ .h](hThe IGT GPU Tools is a test suite used specifically for debugging and development of the DRM drivers. The IGT Tools can be installed from }(hjhhhNhNubh reference)}(h:`here `_h]hhere}(hjhhhNhNubah}(h]h ]h"]h$]h&]namehererefuri0https://gitlab.freedesktop.org/drm/igt-gpu-toolsuh1jhjubh)}(h3 h]h}(h]hereah ]h"]hereah$]h&]refurijuh1h referencedKhjubh .}(hjhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhK9hjhhubh)}(hlThe tests need to be run without a compositor, so you need to switch to text only mode. You can do this by::h]hkThe tests need to be run without a compositor, so you need to switch to text only mode. You can do this by:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK>hjhhubj)}(h(sudo systemctl isolate multi-user.targeth]h(sudo systemctl isolate multi-user.target}hjsbah}(h]h ]h"]h$]h&]jjuh1jhhhKAhjhhubh)}(h!To return to graphical mode, do::h]h To return to graphical mode, do:}(hj,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKChjhhubj)}(h'sudo systemctl isolate graphical.targeth]h'sudo systemctl isolate graphical.target}hj:sbah}(h]h ]h"]h$]h&]jjuh1jhhhKEhjhhubh)}(hXOnce you are in text only mode, you can run tests using the --device switch or IGT_DEVICE variable to specify the device filter for the driver we want to test. IGT_DEVICE can also be used with the run-test.sh script to run the tests for a specific driver::h]hOnce you are in text only mode, you can run tests using the --device switch or IGT_DEVICE variable to specify the device filter for the driver we want to test. IGT_DEVICE can also be used with the run-test.sh script to run the tests for a specific driver:}(hjHhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKGhjhhubj)}(hsudo ./build/tests/ --device "sys:/sys/devices/platform/vkms" sudo IGT_DEVICE="sys:/sys/devices/platform/vkms" ./build/tests/ sudo IGT_DEVICE="sys:/sys/devices/platform/vkms" ./scripts/run-tests.sh -t h]hsudo ./build/tests/ --device "sys:/sys/devices/platform/vkms" sudo IGT_DEVICE="sys:/sys/devices/platform/vkms" ./build/tests/ sudo IGT_DEVICE="sys:/sys/devices/platform/vkms" ./scripts/run-tests.sh -t }hjVsbah}(h]h ]h"]h$]h&]jjuh1jhhhKLhjhhubh)}(hdFor example, to test the functionality of the writeback library, we can run the kms_writeback test::h]hcFor example, to test the functionality of the writeback library, we can run the kms_writeback test:}(hjdhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKPhjhhubj)}(hsudo ./build/tests/kms_writeback --device "sys:/sys/devices/platform/vkms" sudo IGT_DEVICE="sys:/sys/devices/platform/vkms" ./build/tests/kms_writeback sudo IGT_DEVICE="sys:/sys/devices/platform/vkms" ./scripts/run-tests.sh -t kms_writebackh]hsudo ./build/tests/kms_writeback --device "sys:/sys/devices/platform/vkms" sudo IGT_DEVICE="sys:/sys/devices/platform/vkms" ./build/tests/kms_writeback sudo IGT_DEVICE="sys:/sys/devices/platform/vkms" ./scripts/run-tests.sh -t kms_writeback}hjrsbah}(h]h ]h"]h$]h&]jjuh1jhhhKShjhhubh)}(hEYou can also run subtests if you do not want to run the entire test::h]hDYou can also run subtests if you do not want to run the entire test:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKWhjhhubj)}(hsudo ./build/tests/kms_flip --run-subtest basic-plain-flip --device "sys:/sys/devices/platform/vkms" sudo IGT_DEVICE="sys:/sys/devices/platform/vkms" ./build/tests/kms_flip --run-subtest basic-plain-fliph]hsudo ./build/tests/kms_flip --run-subtest basic-plain-flip --device "sys:/sys/devices/platform/vkms" sudo IGT_DEVICE="sys:/sys/devices/platform/vkms" ./build/tests/kms_flip --run-subtest basic-plain-flip}hjsbah}(h]h ]h"]h$]h&]jjuh1jhhhKYhjhhubeh}(h]testing-with-igtah ]h"]testing with igtah$]h&]uh1hhhhhhhhK7ubh)}(hhh](h)}(hTesting With KUnith]hTesting With KUnit}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjhhhhhK]ubh)}(hKUnit (Kernel unit testing framework) provides a common framework for unit tests within the Linux kernel. More information in ../dev-tools/kunit/index.rst .h]hKUnit (Kernel unit testing framework) provides a common framework for unit tests within the Linux kernel. More information in ../dev-tools/kunit/index.rst .}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK_hjhhubh)}(hTo run the VKMS KUnit tests::h]hTo run the VKMS KUnit tests:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKchjhhubj)}(hItools/testing/kunit/kunit.py run --kunitconfig=drivers/gpu/drm/vkms/testsh]hItools/testing/kunit/kunit.py run --kunitconfig=drivers/gpu/drm/vkms/tests}hjsbah}(h]h ]h"]h$]h&]jjuh1jhhhKehjhhubeh}(h]testing-with-kunitah ]h"]testing with kunitah$]h&]uh1hhhhhhhhK]ubh)}(hhh](h)}(hTODOh]hTODO}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjhhhhhKhubh)}(hbIf you want to do any of the items listed below, please share your interest with VKMS maintainers.h]hbIf you want to do any of the items listed below, please share your interest with VKMS maintainers.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKjhjhhubh)}(hhh](h)}(hIGT better supporth]hIGT better support}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhjhhhhhKnubh)}(h Debugging:h]h Debugging:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKphjhhubh bullet_list)}(hhh]h list_item)}(hHkms_plane: some test cases are failing due to timeout on capturing CRC; h]h)}(hGkms_plane: some test cases are failing due to timeout on capturing CRC;h]hGkms_plane: some test cases are failing due to timeout on capturing CRC;}(hj0hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKrhj,ubah}(h]h ]h"]h$]h&]uh1j*hj'hhhhhNubah}(h]h ]h"]h$]h&]bullet-uh1j%hhhKrhjhhubh)}(h$Virtual hardware (vblank-less) mode:h]h$Virtual hardware (vblank-less) mode:}(hjLhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKthjhhubj&)}(hhh]j+)}(hXVKMS already has support for vblanks simulated via hrtimers, which can be tested with kms_flip test; in some way, we can say that VKMS already mimics the real hardware vblank. However, we also have virtual hardware that does not support vblank interrupt and completes page_flip events right away; in this case, compositor developers may end up creating a busy loop on virtual hardware. It would be useful to support Virtual Hardware behavior in VKMS because this can help compositor developers to test their features in multiple scenarios. h]h)}(hXVKMS already has support for vblanks simulated via hrtimers, which can be tested with kms_flip test; in some way, we can say that VKMS already mimics the real hardware vblank. However, we also have virtual hardware that does not support vblank interrupt and completes page_flip events right away; in this case, compositor developers may end up creating a busy loop on virtual hardware. It would be useful to support Virtual Hardware behavior in VKMS because this can help compositor developers to test their features in multiple scenarios.h]hXVKMS already has support for vblanks simulated via hrtimers, which can be tested with kms_flip test; in some way, we can say that VKMS already mimics the real hardware vblank. However, we also have virtual hardware that does not support vblank interrupt and completes page_flip events right away; in this case, compositor developers may end up creating a busy loop on virtual hardware. It would be useful to support Virtual Hardware behavior in VKMS because this can help compositor developers to test their features in multiple scenarios.}(hjahhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKvhj]ubah}(h]h ]h"]h$]h&]uh1j*hjZhhhhhNubah}(h]h ]h"]h$]h&]jJjKuh1j%hhhKvhjhhubeh}(h]igt-better-supportah ]h"]igt better supportah$]h&]uh1hhjhhhhhKnubh)}(hhh](h)}(hAdd Plane Featuresh]hAdd Plane Features}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjhhhhhKubh)}(h8There's lots of plane features we could add support for:h]h:There’s lots of plane features we could add support for:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjhhubj&)}(hhh](j+)}(h8Add background color KMS property[Good to get started]. h]h)}(h7Add background color KMS property[Good to get started].h]h7Add background color KMS property[Good to get started].}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j*hjhhhhhNubj+)}(h Scaling. h]h)}(hScaling.h]hScaling.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j*hjhhhhhNubj+)}(h`Additional buffer formats. Low/high bpp RGB formats would be interesting [Good to get started]. h]h)}(h_Additional buffer formats. Low/high bpp RGB formats would be interesting [Good to get started].h]h_Additional buffer formats. Low/high bpp RGB formats would be interesting [Good to get started].}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j*hjhhhhhNubj+)}(hUAsync updates (currently only possible on cursor plane using the legacy cursor api). h]h)}(hTAsync updates (currently only possible on cursor plane using the legacy cursor api).h]hTAsync updates (currently only possible on cursor plane using the legacy cursor api).}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j*hjhhhhhNubeh}(h]h ]h"]h$]h&]jJjKuh1j%hhhKhjhhubh)}(hFor all of these, we also want to review the igt test coverage and make sure all relevant igt testcases work on vkms. They are good options for internship project.h]hFor all of these, we also want to review the igt test coverage and make sure all relevant igt testcases work on vkms. They are good options for internship project.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjhhubeh}(h]add-plane-featuresah ]h"]add plane featuresah$]h&]uh1hhjhhhhhKubh)}(hhh](h)}(hRuntime Configurationh]hRuntime Configuration}(hj$hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj!hhhhhKubh)}(hdWe want to be able to reconfigure vkms instance without having to reload the module. Use/Test-cases:h]hdWe want to be able to reconfigure vkms instance without having to reload the module. Use/Test-cases:}(hj2hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj!hhubj&)}(hhh](j+)}(h]Hotplug/hotremove connectors on the fly (to be able to test DP MST handling of compositors). h]h)}(h\Hotplug/hotremove connectors on the fly (to be able to test DP MST handling of compositors).h]h\Hotplug/hotremove connectors on the fly (to be able to test DP MST handling of compositors).}(hjGhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjCubah}(h]h ]h"]h$]h&]uh1j*hj@hhhhhNubj+)}(h[Configure planes/crtcs/connectors (we'd need some code to have more than 1 of them first). h]h)}(hZConfigure planes/crtcs/connectors (we'd need some code to have more than 1 of them first).h]h\Configure planes/crtcs/connectors (we’d need some code to have more than 1 of them first).}(hj_hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj[ubah}(h]h ]h"]h$]h&]uh1j*hj@hhhhhNubj+)}(h`Change output configuration: Plug/unplug screens, change EDID, allow changing the refresh rate. h]h)}(h_Change output configuration: Plug/unplug screens, change EDID, allow changing the refresh rate.h]h_Change output configuration: Plug/unplug screens, change EDID, allow changing the refresh rate.}(hjwhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjsubah}(h]h ]h"]h$]h&]uh1j*hj@hhhhhNubeh}(h]h ]h"]h$]h&]jJjKuh1j%hhhKhj!hhubh)}(hThe currently proposed solution is to expose vkms configuration through configfs. All existing module options should be supported through configfs too.h]hThe currently proposed solution is to expose vkms configuration through configfs. All existing module options should be supported through configfs too.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj!hhubeh}(h]runtime-configurationah ]h"]runtime configurationah$]h&]uh1hhjhhhhhKubh)}(hhh](h)}(hWriteback supporth]hWriteback support}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjhhhhhKubj&)}(hhh](j+)}(hThe writeback and CRC capture operations share the use of composer_enabled boolean to ensure vblanks. Probably, when these operations work together, composer_enabled needs to refcounting the composer state to proper work. [Good to get started] h]h)}(hThe writeback and CRC capture operations share the use of composer_enabled boolean to ensure vblanks. Probably, when these operations work together, composer_enabled needs to refcounting the composer state to proper work. [Good to get started]h]hThe writeback and CRC capture operations share the use of composer_enabled boolean to ensure vblanks. Probably, when these operations work together, composer_enabled needs to refcounting the composer state to proper work. [Good to get started]}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j*hjhhhhhNubj+)}(hpAdd support for cloned writeback outputs and related test cases using a cloned output in the IGT kms_writeback. h]h)}(hoAdd support for cloned writeback outputs and related test cases using a cloned output in the IGT kms_writeback.h]hoAdd support for cloned writeback outputs and related test cases using a cloned output in the IGT kms_writeback.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j*hjhhhhhNubj+)}(hAs a v4l device. This is useful for debugging compositors on special vkms configurations, so that developers see what's really going on. h]h)}(hAs a v4l device. This is useful for debugging compositors on special vkms configurations, so that developers see what's really going on.h]hAs a v4l device. This is useful for debugging compositors on special vkms configurations, so that developers see what’s really going on.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j*hjhhhhhNubeh}(h]h ]h"]h$]h&]jJjKuh1j%hhhKhjhhubeh}(h]writeback-supportah ]h"]writeback supportah$]h&]uh1hhjhhhhhKubh)}(hhh](h)}(hOutput Featuresh]hOutput Features}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjhhhhhKubj&)}(hhh](j+)}(hVariable refresh rate/freesync support. This probably needs prime buffer sharing support, so that we can use vgem fences to simulate rendering in testing. Also needs support to specify the EDID. h]h)}(hVariable refresh rate/freesync support. This probably needs prime buffer sharing support, so that we can use vgem fences to simulate rendering in testing. Also needs support to specify the EDID.h]hVariable refresh rate/freesync support. This probably needs prime buffer sharing support, so that we can use vgem fences to simulate rendering in testing. Also needs support to specify the EDID.}(hj)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj%ubah}(h]h ]h"]h$]h&]uh1j*hj"hhhhhNubj+)}(h~Add support for link status, so that compositors can validate their runtime fallbacks when e.g. a Display Port link goes bad. h]h)}(h}Add support for link status, so that compositors can validate their runtime fallbacks when e.g. a Display Port link goes bad.h]h}Add support for link status, so that compositors can validate their runtime fallbacks when e.g. a Display Port link goes bad.}(hjAhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj=ubah}(h]h ]h"]h$]h&]uh1j*hj"hhhhhNubeh}(h]h ]h"]h$]h&]jJjKuh1j%hhhKhjhhubeh}(h]output-featuresah ]h"]output featuresah$]h&]uh1hhjhhhhhKubh)}(hhh](h)}(hCRC API Improvementsh]hCRC API Improvements}(hjfhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjchhhhhKubj&)}(hhh]j+)}(hJOptimize CRC computation ``compute_crc()`` and plane blending ``blend()`` h]h)}(hIOptimize CRC computation ``compute_crc()`` and plane blending ``blend()``h](hOptimize CRC computation }(hj{hhhNhNubhliteral)}(h``compute_crc()``h]h compute_crc()}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1jhj{ubh and plane blending }(hj{hhhNhNubj)}(h ``blend()``h]hblend()}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1jhj{ubeh}(h]h ]h"]h$]h&]uh1hhhhKhjwubah}(h]h ]h"]h$]h&]uh1j*hjthhhhhNubah}(h]h ]h"]h$]h&]jJjKuh1j%hhhKhjchhubeh}(h]crc-api-improvementsah ]h"]crc api improvementsah$]h&]uh1hhjhhhhhKubh)}(hhh](h)}(hAtomic Check using eBPFh]hAtomic Check using eBPF}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjhhhhhKubh)}(hXAtomic drivers have lots of restrictions which are not exposed to userspace in any explicit form through e.g. possible property values. Userspace can only inquiry about these limits through the atomic IOCTL, possibly using the TEST_ONLY flag. Trying to add configurable code for all these limits, to allow compositors to be tested against them, would be rather futile exercise. Instead we could add support for eBPF to validate any kind of atomic state, and implement a library of different restrictions.h]hXAtomic drivers have lots of restrictions which are not exposed to userspace in any explicit form through e.g. possible property values. Userspace can only inquiry about these limits through the atomic IOCTL, possibly using the TEST_ONLY flag. Trying to add configurable code for all these limits, to allow compositors to be tested against them, would be rather futile exercise. Instead we could add support for eBPF to validate any kind of atomic state, and implement a library of different restrictions.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjhhubh)}(hhThis needs a bunch of features (plane compositing, multiple outputs, ...) enabled already to make sense.h]hhThis needs a bunch of features (plane compositing, multiple outputs, ...) enabled already to make sense.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjhhubeh}(h]atomic-check-using-ebpfah ]h"]atomic check using ebpfah$]h&]uh1hhjhhhhhKubeh}(h]todoah ]h"]todoah$]h&]uh1hhhhhhhhKhubeh}(h](#drm-vkms-virtual-kernel-modesettingheh ]h"](#drm/vkms virtual kernel modesettingvkmseh$]h&]uh1hhhhhhhhKexpect_referenced_by_name}jhsexpect_referenced_by_id}hhsubeh}(h]h ]h"]h$]h&]sourcehuh1hcurrent_sourceN current_lineNsettingsdocutils.frontendValues)}(hN generatorN datestampN source_linkN source_urlN toc_backlinksentryfootnote_backlinksK sectnum_xformKstrip_commentsNstrip_elements_with_classesN strip_classesN report_levelK halt_levelKexit_status_levelKdebugNwarning_streamN tracebackinput_encoding utf-8-siginput_encoding_error_handlerstrictoutput_encodingutf-8output_encoding_error_handlerj,error_encodingutf-8error_encoding_error_handlerbackslashreplace language_codeenrecord_dependenciesNconfigN id_prefixhauto_id_prefixid dump_settingsNdump_internalsNdump_transformsNdump_pseudo_xmlNexpose_internalsNstrict_visitorN_disable_configN_sourceh _destinationN _config_files]7/var/lib/git/docbuild/linux/Documentation/docutils.confafile_insertion_enabled raw_enabledKline_length_limitM'pep_referencesN pep_base_urlhttps://peps.python.org/pep_file_url_templatepep-%04drfc_referencesN rfc_base_url&https://datatracker.ietf.org/doc/html/ tab_widthKtrim_footnote_reference_spacesyntax_highlightlong smart_quotessmartquotes_locales]character_level_inline_markupdoctitle_xform docinfo_xformKsectsubtitle_xform image_loadinglinkembed_stylesheetcloak_email_addressessection_self_linkenvNubreporterNindirect_targets]substitution_defs}substitution_names}refnames}refids}h]hasnameids}(jhjjjjjjjjjjjjjj}jjjjjj j`j]jjjju nametypes}(jjjjjjjjjjjj`jjuh}(hhjhjhjjjjjjjjj}jjjjj!j jj]jjjcjju footnote_refs} citation_refs} autofootnotes]autofootnote_refs]symbol_footnotes]symbol_footnote_refs] footnotes] citations]autofootnote_startKsymbol_footnote_startK id_counter collectionsCounter}Rparse_messages]transform_messages]hsystem_message)}(hhh]h)}(hhh]h*Hyperlink target "vkms" is not referenced.}hjsbah}(h]h ]h"]h$]h&]uh1hhjubah}(h]h ]h"]h$]h&]levelKtypeINFOsourcehlineKuh1juba transformerN include_log] decorationNhhub.