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doc: re-organize and consolidate ACRN kernel parameters documentation
A few changes to the documents that describe kernel command-line parameters relevant to ACRN (SOS and UOS): - Merge two documents into one (with sections) - Move to the "User Guides" (from the "Developer Guides") - Update order in the list to make it consistent across sections - Add missing parameters to the overview list Signed-off-by: Geoffroy Van Cutsem <geoffroy.vancutsem@intel.com>
This commit is contained in:
Geoffroy Van Cutsem
David Kinder
parent
1da23415a9
commit
4cfd952413
@ -1,249 +0,0 @@
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.. _GVT-g-kernel-options:
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GVT-g (AcrnGT) Kernel Options
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#############################
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AcrnGT supports flexible configurations so customers can configure
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AcrnGT easily, according to their requirements. This document introduces
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the kernel command line options that are related to AcrnGT.
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i915.enable_gvt
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***************
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This option enables support for Intel GVT-g graphics virtualization
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support in the host. By default, it's not enabled, so we need to add
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``i915.enable_gvt=1`` in the SOS kernel command line. This is a Service
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OS only parameter, and cannot be enabled in the User OS.
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i915.enable_pvmmio
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******************
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We introduce the feature named **Para-Virtualized MMIO** (PVMMIO)
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to improve graphics performance of the GVT-g guest.
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This feature batches sequential MMIO writes into a
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shared buffer between the Service OS and User OS, and then submits a
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para-virtualized command to notify to GVT-g in Service OS. This
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effectively reduces the trap numbers of MMIO operations and improves
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overall graphics performance.
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The ``i915.enable_pvmmio`` option controls
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the optimization levels of the PVMMIO feature: each bit represents a
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sub-feature of the optimization. By default, all
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sub-features of PVMMIO are enabled. They can also be selectively
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enabled or disabled..
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The PVMMIO optimization levels are:
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* PVMMIO_ELSP_SUBMIT = 0x1 - Batch submission of the guest graphics
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workloads
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* PVMMIO_PLANE_UPDATE = 0x2 - Batch plane register update operations
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* PVMMIO_PLANE_WM_UPDATE = 0x4 - Batch watermark registers update operations
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* PVMMIO_MASTER_IRQ = 0x8 - Batch IRQ related registers
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* PVMMIO_PPGTT_UPDATE = 0x10 - Use PVMMIO method to update the PPGTT table
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of guest.
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.. note:: This parameter works in both the Service OS and User OS, but
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changes to one will affect the other. For example, if either SOS or UOS
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disables the PVMMIO_PPGTT_UPDATE feature, this optimization will be
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disabled for both.
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i915.gvt_workload_priority
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**************************
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AcrnGT supports **Prioritized Rendering** as described in the
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:ref:`GVT-g-prioritized-rendering` high-level design. This
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configuration option controls the priority level of GVT-g guests.
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Priority levels range from -1023 to 1023.
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The default priority is zero, the same priority as the Service OS. If
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the level is less than zero, the guest's priority will be lower than the
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Service OS, so graphics preemption will work and the prioritized
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rendering feature will be enabled. If the level is greater than zero,
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UOS graphics workloads will preempt most of the SOS graphics workloads,
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except for display updating related workloads that use a default highest
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priority (1023).
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Currently, all UOSes share the same priority.
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This is a Service OS only parameters, and does
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not work in the User OS.
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.. _i915-enable-initial-modeset:
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i915.enable_initial_modeset
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***************************
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At time, kernel graphics must be initialized with a valid display
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configuration with full display pipeline programming in place before the
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user space is initialized and without a fbdev & fb console.
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When ``i915.enable_initial_modeset=1``, the FBDEV of i915 will not be
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initialized, so users would not be able to see the fb console on screen.
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If there is no graphics UI running by default, users will see black
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screens displayed.
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When ``i915.enable_initial_modeset=0`` in SOS, the plane restriction
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(also known as plane-based domain ownership) feature will be disabled.
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(See the next section and :ref:`plane_restriction` in the ACRN GVT-g
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High Level Design for more information about this feature.)
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In the current configuration, we will set
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``i915.enable_initial_modeset=1`` in SOS and
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``i915.enable_initial_modeset=0`` in UOS.
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This parameter is not used on UEFI platforms.
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.. _i915-avail-planes-owners:
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i915.avail_planes_per_pipe and i915.domain_plane_owners
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*******************************************************
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Both Service OS and User OS are provided a set of HW planes where they
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can display their contents. Since each domain provides its content,
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there is no need for any extra composition to be done through SOS.
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``i915.avail_planes_per_pipe`` and ``i915.domain_plane_owners`` work
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together to provide the plane restriction (or plan-based domain
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ownership) feature.
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i915.domain_plane_owners
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========================
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On Intel's display
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hardware, each pipeline contains several planes, which are blended
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together by their Z-order and rendered to the display monitors. In
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AcrnGT, we can control each planes' ownership so that the domains can
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display contents on the planes they own.
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The ``i915.domain_plane_owners`` parameter controls the ownership of all
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the planes in the system, as shown in :numref:`i915-planes-pipes`. Each
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4-bit nibble identifies the domain id owner for that plane and a group
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of 4 nibbles represents a pipe. This is a Service OS only configuration
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and cannot be modified at runtime. Domain ID 0x0 is for the Service OS,
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the User OS use domain IDs from 0x1 to 0xF.
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.. figure:: images/i915-image1.png
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:width: 900px
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:align: center
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:name: i915-planes-pipes
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i915.domain_plane_owners
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For example, if we set ``i915.domain_plane_owners=0x010001101110``, the
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plane ownership will be as shown in :numref:`i915-planes-example1` - SOS
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(green) owns plane 1A, 1B, 4B, 1C, and 2C, and UOS #1 owns plane 2A, 3A,
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4A, 2B, 3B and 3C.
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.. figure:: images/i915-image2.png
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:width: 900px
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:align: center
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:name: i915-planes-example1
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i915.domain_plane_owners example
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Some other examples:
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* i915.domain_plane_owners=0x022211110000 - SOS (0x0) owns planes on pipe A;
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UOS #1 (0x1) owns all planes on pipe B; and UOS #2 (0x2) owns all
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planes on pipe C (since, in the representation in
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:numref:`i915-planes-pipes` above, there are only 3 planes attached to
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pipe C).
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* i915.domain_plane_owners=0x000001110000 - SOS owns all planes on pipe A
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and pipe C; UOS #1 owns plane 1, 2 and 3 on pipe B. Plane 4 on pipe B
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is owned by the SOS so that if it wants to display notice message, it
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can display on top of the UOS.
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i915.avail_planes_per_pipe
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==========================
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Option ``i915.avail_planes_per_pipe`` is a bitmask (shown in
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:numref:`i915-avail-planes`) that tells the i915
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driver which planes are available and can be exposed to the compositor.
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This is a parameter that must to be set in each domain. If
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``i915.avail_planes_per_pipe=0``, the plane restriction feature is disabled.
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.. figure:: images/i915-image3.png
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:width: 600px
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:align: center
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:name: i915-avail-planes
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i915.avail_planes_per_pipe
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For example, if we set ``i915.avail_planes_per_pipe=0x030901`` in SOS
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and ``i915.avail_planes_per_pipe=0x04060E`` in UOS, the planes will be as
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shown in :numref:`i915-avail-planes-example1` and
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:numref:`i915-avail-planes-example1`:
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.. figure:: images/i915-image4.png
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:width: 500px
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:align: center
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:name: i915-avail-planes-example1
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SOS i915.avail_planes_per_pipe
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.. figure:: images/i915-image5.png
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:width: 500px
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:align: center
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:name: i915-avail-planes-example2
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UOS i915.avail_planes_per_pipe
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``i915.avail_planes_per_pipe`` controls the view of planes from i915 drivers
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inside of every domain, and ``i915.domain_plane_owners`` is the global
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arbiter controlling which domain can present its content onto the
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real hardware. Generally, they are aligned. For example, we can set
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``i915.domain_plane_owners= 0x011111110000``,
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``i915.avail_planes_per_pipe=0x00000F`` in SOS, and
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``i915.avail_planes_per_pipe=0x070F00`` in domain 1, so every domain will
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only flip on the planes they owns.
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However, we don't force alignment: ``avail_planes_per_pipe`` might
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not be aligned with the
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setting of ``domain_plane_owners``. Consider this example:
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``i915.domain_plane_owners=0x011111110000``,
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``i915.avail_planes_per_pipe=0x01010F`` in SOS and
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``i915.avail_planes_per_pipe=0x070F00`` in domain 1.
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With this configuration, SOS will be able to render on plane 1B and
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plane 1C, however, the content of plane 1B and plane 1C will not be
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flipped onto the real hardware.
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i915.domain_scaler_owner
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************************
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On each Intel GPU display pipeline, there are several plane scalers
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to zoom in/out the planes. For example, if a 720p video is played
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full-screen on a 1080p display monitor, the kernel driver will use a
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scaler to zoom in the video plane to a 1080p image and present it onto a
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display pipeline. (Refer to "Intel Open Source Graphics PRM Vol 7:
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display" for the details.)
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On Broxton platforms, Pipe A and Pipe B each
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have two plane scalers, and Pipe C has one plane scaler. To support the
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plane scaling in AcrnGT guest OS, we introduced the parameter
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``i915.domain_scaler_owner``, to assign a specific scaler to the target
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guest OS.
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As with the parameter ``i915.domain_plane_owners``, each nibble of
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``i915.domain_scaler_owner`` represents the domain id that owns the scaler;
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every nibble (4 bits) represents a scaler and every group of 2 nibbles
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represents a pipe. This is a Service OS only configuration and cannot be
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modified at runtime. Domain ID 0x0 is for the Service OS, the User OS
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use domain IDs from 0x1 to 0xF.
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For example, if we set ``i915.domain_scaler_owner=0x021100``, the SOS
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owns scaler 1A, 2A; UOS #1 owns scaler 1B, 2B; and UOS #2 owns scaler
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1C.
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i915.enable_hangcheck
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*********************
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This parameter enable detection of a GPU hang. When enabled, the i915
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will start a timer to check if the workload is completed in a specific
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time. If not, i915 will treat it as a GPU hang and trigger a GPU reset.
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In AcrnGT, the workload in SOS and UOS can be set to different
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priorities. If SOS is assigned a higher priority than the UOS, the UOS's
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workload might not be able to run on the HW on time. This may lead to
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the guest i915 triggering a hangcheck and lead to a guest GPU reset.
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This reset is unnecessary so we use ``i915.enable_hangcheck=0`` to
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disable this timeout check and prevent guest from triggering unnecessary
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GPU resets.
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@ -8,9 +8,7 @@ Developer Guides
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hld/index
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hld/index
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primer
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primer
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kernel-parameters
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GVT-g-porting
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GVT-g-porting
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GVT-g-kernel-options
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trusty
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trusty
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l1tf
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l1tf
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VBSK-analysis
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VBSK-analysis
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@ -1,382 +0,0 @@
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.. _kernel-parameters:
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ACRN Kernel Parameters
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######################
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ACRN supports flexible configurations so customers can configure SOS and
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UOS behavior easily, and according to their requirements. This document
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introduces kernel command line options used to configure and boot VMs.
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.. list-table::
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:header-rows: 1
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:widths: 10,10,50,30
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* - Parameter
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- Used in SOS or UOS
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- Description
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- Usage example
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* - module_blacklist
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- SOS
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- A comma-separated list of modules that should not be loaded.
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Useful to debug or work
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around issues related to specific modules.
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- ::
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module_blacklist=dwc3_pci
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* - no_timer_check
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- SOS,UOS
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- Disables the code which tests for broken timer IRQ sources.
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- ::
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no_timer_check
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* - console
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- SOS,UOS
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- Output console device and options.
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``tty<n>``
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Use the virtual console device <n>.
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``ttyS<n>[,options]``
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Use the specified serial port and options. Default options are
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``9600n8`` meaning 9600 baud, no parity, 8 bits. Options are of the form *bbbbpnf*,
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where:
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| *bbbb* is baud rate, for example 9600;
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| *p* is parity, one of ``n``, ``o``, or ``e`` (for none, odd, or even),
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| *n* is number of bits (typically 8),
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| *f* is flow control (``r`` for RTS, or left blank)
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``hvc<n>``
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Use the hypervisor console device <n>. (This is for both Xen and
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PowerPC hypervisors.)
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- ::
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console=tty0
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console=ttyS0
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console=hvc0
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* - loglevel
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- SOS
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- All Kernel messages with a loglevel less than the console loglevel will
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be printed to the console. The loglevel can also be changed with
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``klogd`` or other programs. The loglevels are defined as follows:
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.. list-table::
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:header-rows: 1
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* - loglevel value
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- Definition
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* - 0 (KERN_EMERG)
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- system is unusable
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* - 1 (KERN_ALERT)
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- action must be taken immediately
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* - 2 (KERN_CRIT)
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- critical conditions
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* - 3 (KERN_ERR)
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- error conditions
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* - 4 (KERN_WARNING)
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- warning conditions
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* - 5 (KERN_NOTICE)
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- normal but significant condition
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* - 6 (KERN_INFO)
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- informational
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* - 7 (KERN_DEBUG)
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- debug-level messages
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- ::
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loglevel=7
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* - ignore_loglevel
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- UOS
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- Ignoring loglevel setting will print **all**
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kernel messages to the console. Useful for debugging.
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We also add it as printk module parameter, so users
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could change it dynamically, usually by changing
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``/sys/module/printk/parameters/ignore_loglevel``.
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- ::
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ignore_loglevel
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|
||||||
* - log_buf_len
|
|
||||||
- UOS
|
|
||||||
- Sets the size of the printk ring buffer,
|
|
||||||
in bytes. n must be a power of two and greater
|
|
||||||
than the minimal size. The minimal size is defined
|
|
||||||
by LOG_BUF_SHIFT kernel config parameter. There is
|
|
||||||
also CONFIG_LOG_CPU_MAX_BUF_SHIFT config parameter
|
|
||||||
that allows to increase the default size depending on
|
|
||||||
the number of CPUs. See init/Kconfig for more details."
|
|
||||||
- ::
|
|
||||||
|
|
||||||
log_buf_len=16M
|
|
||||||
|
|
||||||
* - consoleblank
|
|
||||||
- SOS,UOS
|
|
||||||
- The console blank (screen saver) timeout in
|
|
||||||
seconds. Defaults to 600 (10 minutes). A value of 0
|
|
||||||
disables the blank timer.
|
|
||||||
- ::
|
|
||||||
|
|
||||||
consoleblank=0
|
|
||||||
|
|
||||||
* - rootwait
|
|
||||||
- SOS,UOS
|
|
||||||
- Wait (indefinitely) for root device to show up.
|
|
||||||
Useful for devices that are detected asynchronously
|
|
||||||
(e.g. USB and MMC devices).
|
|
||||||
- ::
|
|
||||||
|
|
||||||
rootwait
|
|
||||||
|
|
||||||
* - root
|
|
||||||
- SOS,UOS
|
|
||||||
- Define the root filesystem
|
|
||||||
|
|
||||||
``/dev/<disk_name><decimal>``
|
|
||||||
represents the device number of the partition - device
|
|
||||||
number of disk plus the partition number
|
|
||||||
|
|
||||||
``/dev/<disk_name>p<decimal>``
|
|
||||||
same as above, this form is used when disk name of
|
|
||||||
the partitioned disk ends with a digit. To separate
|
|
||||||
disk name and partition slot, a 'p' is inserted.
|
|
||||||
|
|
||||||
``PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF``
|
|
||||||
representing the unique id of a partition if the
|
|
||||||
partition table provides it. The UUID may be either
|
|
||||||
an EFI/GPT UUID, or refer to an MSDOS
|
|
||||||
partition using the format SSSSSSSS-PP, where SSSSSSSS is a
|
|
||||||
zero-filled hexadecimal representation of the 32-bit
|
|
||||||
"NT disk signature", and PP is a zero-filled hexadecimal
|
|
||||||
representation of the 1-based partition number.
|
|
||||||
- ::
|
|
||||||
|
|
||||||
root=/dev/mmcblk0p1
|
|
||||||
root=/dev/vda2
|
|
||||||
root=PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF
|
|
||||||
|
|
||||||
* - rw
|
|
||||||
- SOS,UOS
|
|
||||||
- Mount root device read-write on boot
|
|
||||||
- ::
|
|
||||||
|
|
||||||
rw
|
|
||||||
|
|
||||||
* - tsc
|
|
||||||
- UOS
|
|
||||||
- Disable clocksource stability checks for TSC.
|
|
||||||
|
|
||||||
Format: <string>, where the only supported value is:
|
|
||||||
|
|
||||||
``reliable``:
|
|
||||||
Mark TSC clocksource as reliable, and disables clocksource
|
|
||||||
verification at runtime, and the stability checks done at bootup.
|
|
||||||
Used to enable high-resolution timer mode on older hardware, and in
|
|
||||||
virtualized environments.
|
|
||||||
- ::
|
|
||||||
|
|
||||||
tsc=reliable
|
|
||||||
|
|
||||||
* - cma
|
|
||||||
- SOS
|
|
||||||
- Sets the size of the kernel global memory area for
|
|
||||||
contiguous memory allocations, and optionally the
|
|
||||||
placement constraint by the physical address range of
|
|
||||||
memory allocations. A value of 0 disables CMA
|
|
||||||
altogether. For more information, see
|
|
||||||
``include/linux/dma-contiguous``.
|
|
||||||
- ::
|
|
||||||
|
|
||||||
cma=64M@0
|
|
||||||
|
|
||||||
* - hvlog
|
|
||||||
- SOS
|
|
||||||
- Reserve memory for the ACRN hypervisor log. The reserved space should not
|
|
||||||
overlap any other blocks (e.g. hypervisor's reserved space).
|
|
||||||
- ::
|
|
||||||
|
|
||||||
hvlog=2M@0x6de00000
|
|
||||||
|
|
||||||
* - memmap
|
|
||||||
- SOS
|
|
||||||
- ::
|
|
||||||
|
|
||||||
memmap=0x400000$0x6da00000
|
|
||||||
|
|
||||||
- Mark specific memory as reserved.
|
|
||||||
|
|
||||||
``memmap=nn[KMG]$ss[KMG]``
|
|
||||||
Region of memory to be reserved is from ``ss`` to ``ss+nn``,
|
|
||||||
using ``K``, ``M``, and ``G`` representing Kilobytes, Megabytes, and
|
|
||||||
Gigabytes, respectively.
|
|
||||||
|
|
||||||
* - ramoops.mem_address
|
|
||||||
ramoops.mem_size
|
|
||||||
ramoops.console_size
|
|
||||||
- SOS
|
|
||||||
- Ramoops is an oops/panic logger that writes its logs to RAM
|
|
||||||
before the system crashes. Ramoops uses a predefined memory area
|
|
||||||
to store the dump. See `Linux Kernel Ramoops oops/panic logger
|
|
||||||
<https://www.kernel.org/doc/html/v4.19/admin-guide/ramoops.html#ramoops-oops-panic-logger>`_
|
|
||||||
for details.
|
|
||||||
- ::
|
|
||||||
|
|
||||||
ramoops.mem_address=0x6da00000
|
|
||||||
ramoops.mem_size=0x400000
|
|
||||||
ramoops.console_size=0x200000
|
|
||||||
|
|
||||||
|
|
||||||
* - reboot_panic
|
|
||||||
- SOS
|
|
||||||
- Reboot in case of panic
|
|
||||||
|
|
||||||
The comma-delimited parameters are:
|
|
||||||
|
|
||||||
reboot_mode:
|
|
||||||
``w`` (warm), ``s`` (soft), ``c`` (cold), or ``g`` (gpio)
|
|
||||||
|
|
||||||
reboot_type:
|
|
||||||
``b`` (bios), ``a`` (acpi), ``k`` (kbd), ``t`` (triple), ``e`` (efi),
|
|
||||||
or ``p`` (pci)
|
|
||||||
|
|
||||||
reboot_cpu:
|
|
||||||
``s###`` (smp, and processor number to be used for rebooting)
|
|
||||||
|
|
||||||
reboot_force:
|
|
||||||
``f`` (force), or not specified.
|
|
||||||
- ::
|
|
||||||
|
|
||||||
reboot_panic=p,w
|
|
||||||
|
|
||||||
* - maxcpus
|
|
||||||
- UOS
|
|
||||||
- Maximum number of processors that an SMP kernel
|
|
||||||
will bring up during bootup.
|
|
||||||
|
|
||||||
``maxcpus=n`` where n >= 0 limits
|
|
||||||
the kernel to bring up ``n`` processors during system bootup.
|
|
||||||
Giving n=0 is a special case, equivalent to ``nosmp``,which
|
|
||||||
also disables the I/O APIC.
|
|
||||||
|
|
||||||
After bootup, you can bring up additional plugged CPUs by executing
|
|
||||||
|
|
||||||
``echo 1 > /sys/devices/system/cpu/cpuX/online``
|
|
||||||
- ::
|
|
||||||
|
|
||||||
maxcpus=1
|
|
||||||
|
|
||||||
* - nohpet
|
|
||||||
- UOS
|
|
||||||
- Don't use the HPET timer
|
|
||||||
- ::
|
|
||||||
|
|
||||||
nohpet
|
|
||||||
|
|
||||||
* - intel_iommu
|
|
||||||
- UOS
|
|
||||||
- Intel IOMMU driver (DMAR) option
|
|
||||||
|
|
||||||
``on``:
|
|
||||||
Enable intel iommu driver.
|
|
||||||
|
|
||||||
``off``:
|
|
||||||
Disable intel iommu driver.
|
|
||||||
|
|
||||||
``igfx_off``:
|
|
||||||
By default, gfx is mapped as normal device. If a gfx
|
|
||||||
device has a dedicated DMAR unit, the DMAR unit is
|
|
||||||
bypassed by not enabling DMAR with this option. In
|
|
||||||
this case, gfx device will use physical address for DMA.
|
|
||||||
- ::
|
|
||||||
|
|
||||||
intel_iommu=off
|
|
||||||
|
|
||||||
|
|
||||||
Intel GVT-g Parameters
|
|
||||||
**********************
|
|
||||||
|
|
||||||
.. list-table::
|
|
||||||
:header-rows: 1
|
|
||||||
:widths: 10,10,50,30
|
|
||||||
|
|
||||||
* - Parameter
|
|
||||||
- Used in SOS or UOS
|
|
||||||
- Description
|
|
||||||
- Usage example
|
|
||||||
|
|
||||||
* - i915.nuclear_pageflip
|
|
||||||
- SOS,UOS
|
|
||||||
- Force enable atomic functionality on platforms that don't have full support yet.
|
|
||||||
- ::
|
|
||||||
|
|
||||||
i915.nuclear_pageflip=1
|
|
||||||
|
|
||||||
* - i915.enable_initial_modeset
|
|
||||||
- SOS
|
|
||||||
- On MRB, value must be ``1``. On NUC or UP2 boards, value must be
|
|
||||||
``0``. See :ref:`i915-enable-initial-modeset`.
|
|
||||||
- ::
|
|
||||||
|
|
||||||
i915.enable_initial_modeset=1
|
|
||||||
i915.enable_initial_modeset=0
|
|
||||||
|
|
||||||
* - i915.avail_planes_per_pipe
|
|
||||||
- SOS
|
|
||||||
- See :ref:`i915-avail-planes-owners`.
|
|
||||||
- ::
|
|
||||||
|
|
||||||
i915.avail_planes_per_pipe=0x01010F
|
|
||||||
|
|
||||||
* - i915.domain_plane_owners
|
|
||||||
- SOS
|
|
||||||
- See :ref:`i915-avail-planes-owners`.
|
|
||||||
- ::
|
|
||||||
|
|
||||||
i915.domain_plane_owners=0x011111110000
|
|
||||||
|
|
||||||
* - i915.enable_gvt
|
|
||||||
- SOS
|
|
||||||
- Enable Intel GVT-g graphics virtualization support in the host
|
|
||||||
- ::
|
|
||||||
|
|
||||||
i915.enable_gvt=1
|
|
||||||
|
|
||||||
* - i915.enable_guc
|
|
||||||
- SOS
|
|
||||||
- Enable GuC load for HuC load.
|
|
||||||
- ::
|
|
||||||
|
|
||||||
i915.enable_guc=0x02
|
|
||||||
|
|
||||||
* - i915.avail_planes_per_pipe
|
|
||||||
- UOS
|
|
||||||
- See :ref:`i915-avail-planes-owners`.
|
|
||||||
- ::
|
|
||||||
|
|
||||||
i915.avail_planes_per_pipe=0x070F00
|
|
||||||
|
|
||||||
* - i915.enable_guc
|
|
||||||
- UOS
|
|
||||||
- Disable GuC
|
|
||||||
- ::
|
|
||||||
|
|
||||||
i915.enable_guc=0
|
|
||||||
|
|
||||||
* - i915.enable_hangcheck
|
|
||||||
- UOS
|
|
||||||
- Disable check GPU activity for detecting hangs.
|
|
||||||
- ::
|
|
||||||
|
|
||||||
i915.enable_hangcheck=0
|
|
||||||
|
|
||||||
* - i915.enable_fbc
|
|
||||||
- UOS
|
|
||||||
- Enable frame buffer compression for power savings
|
|
||||||
- ::
|
|
||||||
|
|
||||||
i915.enable_fbc=1
|
|
||||||
|
Before Width: | Height: | Size: 10 KiB After Width: | Height: | Size: 10 KiB |
|
Before Width: | Height: | Size: 37 KiB After Width: | Height: | Size: 37 KiB |
|
Before Width: | Height: | Size: 7.3 KiB After Width: | Height: | Size: 7.3 KiB |
|
Before Width: | Height: | Size: 13 KiB After Width: | Height: | Size: 13 KiB |
|
Before Width: | Height: | Size: 13 KiB After Width: | Height: | Size: 13 KiB |
663
doc/user-guides/kernel-parameters.rst
Normal file
663
doc/user-guides/kernel-parameters.rst
Normal file
@ -0,0 +1,663 @@
|
|||||||
|
.. _kernel-parameters:
|
||||||
|
|
||||||
|
ACRN Kernel Parameters
|
||||||
|
######################
|
||||||
|
|
||||||
|
Generic kernel parameters
|
||||||
|
*************************
|
||||||
|
|
||||||
|
A number of kernel parameters control the behaviour of ACRN-based systems. Some
|
||||||
|
are applicable to the Service OS (SOS) kernel, others to the User OS (UOS)
|
||||||
|
kernel, and some are applicable to both.
|
||||||
|
|
||||||
|
This section focusses on generic parameters from the Linux kernel which are
|
||||||
|
relevant for configuring or debugging ACRN-based systems.
|
||||||
|
|
||||||
|
.. list-table::
|
||||||
|
:header-rows: 1
|
||||||
|
:widths: 10,10,50,30
|
||||||
|
|
||||||
|
* - Parameter
|
||||||
|
- Used in SOS or UOS
|
||||||
|
- Description
|
||||||
|
- Usage example
|
||||||
|
|
||||||
|
* - module_blacklist
|
||||||
|
- SOS
|
||||||
|
- A comma-separated list of modules that should not be loaded.
|
||||||
|
Useful to debug or work
|
||||||
|
around issues related to specific modules.
|
||||||
|
- ::
|
||||||
|
|
||||||
|
module_blacklist=dwc3_pci
|
||||||
|
|
||||||
|
* - no_timer_check
|
||||||
|
- SOS,UOS
|
||||||
|
- Disables the code which tests for broken timer IRQ sources.
|
||||||
|
- ::
|
||||||
|
|
||||||
|
no_timer_check
|
||||||
|
|
||||||
|
* - console
|
||||||
|
- SOS,UOS
|
||||||
|
- Output console device and options.
|
||||||
|
|
||||||
|
``tty<n>``
|
||||||
|
Use the virtual console device <n>.
|
||||||
|
|
||||||
|
``ttyS<n>[,options]``
|
||||||
|
Use the specified serial port and options. Default options are
|
||||||
|
``9600n8`` meaning 9600 baud, no parity, 8 bits. Options are of the form *bbbbpnf*,
|
||||||
|
where:
|
||||||
|
|
||||||
|
| *bbbb* is baud rate, for example 9600;
|
||||||
|
| *p* is parity, one of ``n``, ``o``, or ``e`` (for none, odd, or even),
|
||||||
|
| *n* is number of bits (typically 8),
|
||||||
|
| *f* is flow control (``r`` for RTS, or left blank)
|
||||||
|
|
||||||
|
``hvc<n>``
|
||||||
|
Use the hypervisor console device <n>. (This is for both Xen and
|
||||||
|
PowerPC hypervisors.)
|
||||||
|
- ::
|
||||||
|
|
||||||
|
console=tty0
|
||||||
|
console=ttyS0
|
||||||
|
console=hvc0
|
||||||
|
|
||||||
|
* - loglevel
|
||||||
|
- SOS
|
||||||
|
- All Kernel messages with a loglevel less than the console loglevel will
|
||||||
|
be printed to the console. The loglevel can also be changed with
|
||||||
|
``klogd`` or other programs. The loglevels are defined as follows:
|
||||||
|
|
||||||
|
.. list-table::
|
||||||
|
:header-rows: 1
|
||||||
|
|
||||||
|
* - loglevel value
|
||||||
|
- Definition
|
||||||
|
* - 0 (KERN_EMERG)
|
||||||
|
- system is unusable
|
||||||
|
* - 1 (KERN_ALERT)
|
||||||
|
- action must be taken immediately
|
||||||
|
* - 2 (KERN_CRIT)
|
||||||
|
- critical conditions
|
||||||
|
* - 3 (KERN_ERR)
|
||||||
|
- error conditions
|
||||||
|
* - 4 (KERN_WARNING)
|
||||||
|
- warning conditions
|
||||||
|
* - 5 (KERN_NOTICE)
|
||||||
|
- normal but significant condition
|
||||||
|
* - 6 (KERN_INFO)
|
||||||
|
- informational
|
||||||
|
* - 7 (KERN_DEBUG)
|
||||||
|
- debug-level messages
|
||||||
|
- ::
|
||||||
|
|
||||||
|
loglevel=7
|
||||||
|
|
||||||
|
* - ignore_loglevel
|
||||||
|
- UOS
|
||||||
|
- Ignoring loglevel setting will print **all**
|
||||||
|
kernel messages to the console. Useful for debugging.
|
||||||
|
We also add it as printk module parameter, so users
|
||||||
|
could change it dynamically, usually by changing
|
||||||
|
``/sys/module/printk/parameters/ignore_loglevel``.
|
||||||
|
- ::
|
||||||
|
|
||||||
|
ignore_loglevel
|
||||||
|
|
||||||
|
|
||||||
|
* - log_buf_len
|
||||||
|
- UOS
|
||||||
|
- Sets the size of the printk ring buffer,
|
||||||
|
in bytes. n must be a power of two and greater
|
||||||
|
than the minimal size. The minimal size is defined
|
||||||
|
by LOG_BUF_SHIFT kernel config parameter. There is
|
||||||
|
also CONFIG_LOG_CPU_MAX_BUF_SHIFT config parameter
|
||||||
|
that allows to increase the default size depending on
|
||||||
|
the number of CPUs. See init/Kconfig for more details."
|
||||||
|
- ::
|
||||||
|
|
||||||
|
log_buf_len=16M
|
||||||
|
|
||||||
|
* - consoleblank
|
||||||
|
- SOS,UOS
|
||||||
|
- The console blank (screen saver) timeout in
|
||||||
|
seconds. Defaults to 600 (10 minutes). A value of 0
|
||||||
|
disables the blank timer.
|
||||||
|
- ::
|
||||||
|
|
||||||
|
consoleblank=0
|
||||||
|
|
||||||
|
* - rootwait
|
||||||
|
- SOS,UOS
|
||||||
|
- Wait (indefinitely) for root device to show up.
|
||||||
|
Useful for devices that are detected asynchronously
|
||||||
|
(e.g. USB and MMC devices).
|
||||||
|
- ::
|
||||||
|
|
||||||
|
rootwait
|
||||||
|
|
||||||
|
* - root
|
||||||
|
- SOS,UOS
|
||||||
|
- Define the root filesystem
|
||||||
|
|
||||||
|
``/dev/<disk_name><decimal>``
|
||||||
|
represents the device number of the partition - device
|
||||||
|
number of disk plus the partition number
|
||||||
|
|
||||||
|
``/dev/<disk_name>p<decimal>``
|
||||||
|
same as above, this form is used when disk name of
|
||||||
|
the partitioned disk ends with a digit. To separate
|
||||||
|
disk name and partition slot, a 'p' is inserted.
|
||||||
|
|
||||||
|
``PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF``
|
||||||
|
representing the unique id of a partition if the
|
||||||
|
partition table provides it. The UUID may be either
|
||||||
|
an EFI/GPT UUID, or refer to an MSDOS
|
||||||
|
partition using the format SSSSSSSS-PP, where SSSSSSSS is a
|
||||||
|
zero-filled hexadecimal representation of the 32-bit
|
||||||
|
"NT disk signature", and PP is a zero-filled hexadecimal
|
||||||
|
representation of the 1-based partition number.
|
||||||
|
- ::
|
||||||
|
|
||||||
|
root=/dev/mmcblk0p1
|
||||||
|
root=/dev/vda2
|
||||||
|
root=PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF
|
||||||
|
|
||||||
|
* - rw
|
||||||
|
- SOS,UOS
|
||||||
|
- Mount root device read-write on boot
|
||||||
|
- ::
|
||||||
|
|
||||||
|
rw
|
||||||
|
|
||||||
|
* - tsc
|
||||||
|
- UOS
|
||||||
|
- Disable clocksource stability checks for TSC.
|
||||||
|
|
||||||
|
Format: <string>, where the only supported value is:
|
||||||
|
|
||||||
|
``reliable``:
|
||||||
|
Mark TSC clocksource as reliable, and disables clocksource
|
||||||
|
verification at runtime, and the stability checks done at bootup.
|
||||||
|
Used to enable high-resolution timer mode on older hardware, and in
|
||||||
|
virtualized environments.
|
||||||
|
- ::
|
||||||
|
|
||||||
|
tsc=reliable
|
||||||
|
|
||||||
|
* - cma
|
||||||
|
- SOS
|
||||||
|
- Sets the size of the kernel global memory area for
|
||||||
|
contiguous memory allocations, and optionally the
|
||||||
|
placement constraint by the physical address range of
|
||||||
|
memory allocations. A value of 0 disables CMA
|
||||||
|
altogether. For more information, see
|
||||||
|
``include/linux/dma-contiguous``.
|
||||||
|
- ::
|
||||||
|
|
||||||
|
cma=64M@0
|
||||||
|
|
||||||
|
* - hvlog
|
||||||
|
- SOS
|
||||||
|
- Reserve memory for the ACRN hypervisor log. The reserved space should not
|
||||||
|
overlap any other blocks (e.g. hypervisor's reserved space).
|
||||||
|
- ::
|
||||||
|
|
||||||
|
hvlog=2M@0x6de00000
|
||||||
|
|
||||||
|
* - memmap
|
||||||
|
- SOS
|
||||||
|
- ::
|
||||||
|
|
||||||
|
memmap=0x400000$0x6da00000
|
||||||
|
|
||||||
|
- Mark specific memory as reserved.
|
||||||
|
|
||||||
|
``memmap=nn[KMG]$ss[KMG]``
|
||||||
|
Region of memory to be reserved is from ``ss`` to ``ss+nn``,
|
||||||
|
using ``K``, ``M``, and ``G`` representing Kilobytes, Megabytes, and
|
||||||
|
Gigabytes, respectively.
|
||||||
|
|
||||||
|
* - ramoops.mem_address
|
||||||
|
ramoops.mem_size
|
||||||
|
ramoops.console_size
|
||||||
|
- SOS
|
||||||
|
- Ramoops is an oops/panic logger that writes its logs to RAM
|
||||||
|
before the system crashes. Ramoops uses a predefined memory area
|
||||||
|
to store the dump. See `Linux Kernel Ramoops oops/panic logger
|
||||||
|
<https://www.kernel.org/doc/html/v4.19/admin-guide/ramoops.html#ramoops-oops-panic-logger>`_
|
||||||
|
for details.
|
||||||
|
- ::
|
||||||
|
|
||||||
|
ramoops.mem_address=0x6da00000
|
||||||
|
ramoops.mem_size=0x400000
|
||||||
|
ramoops.console_size=0x200000
|
||||||
|
|
||||||
|
|
||||||
|
* - reboot_panic
|
||||||
|
- SOS
|
||||||
|
- Reboot in case of panic
|
||||||
|
|
||||||
|
The comma-delimited parameters are:
|
||||||
|
|
||||||
|
reboot_mode:
|
||||||
|
``w`` (warm), ``s`` (soft), ``c`` (cold), or ``g`` (gpio)
|
||||||
|
|
||||||
|
reboot_type:
|
||||||
|
``b`` (bios), ``a`` (acpi), ``k`` (kbd), ``t`` (triple), ``e`` (efi),
|
||||||
|
or ``p`` (pci)
|
||||||
|
|
||||||
|
reboot_cpu:
|
||||||
|
``s###`` (smp, and processor number to be used for rebooting)
|
||||||
|
|
||||||
|
reboot_force:
|
||||||
|
``f`` (force), or not specified.
|
||||||
|
- ::
|
||||||
|
|
||||||
|
reboot_panic=p,w
|
||||||
|
|
||||||
|
* - maxcpus
|
||||||
|
- UOS
|
||||||
|
- Maximum number of processors that an SMP kernel
|
||||||
|
will bring up during bootup.
|
||||||
|
|
||||||
|
``maxcpus=n`` where n >= 0 limits
|
||||||
|
the kernel to bring up ``n`` processors during system bootup.
|
||||||
|
Giving n=0 is a special case, equivalent to ``nosmp``,which
|
||||||
|
also disables the I/O APIC.
|
||||||
|
|
||||||
|
After bootup, you can bring up additional plugged CPUs by executing
|
||||||
|
|
||||||
|
``echo 1 > /sys/devices/system/cpu/cpuX/online``
|
||||||
|
- ::
|
||||||
|
|
||||||
|
maxcpus=1
|
||||||
|
|
||||||
|
* - nohpet
|
||||||
|
- UOS
|
||||||
|
- Don't use the HPET timer
|
||||||
|
- ::
|
||||||
|
|
||||||
|
nohpet
|
||||||
|
|
||||||
|
* - intel_iommu
|
||||||
|
- UOS
|
||||||
|
- Intel IOMMU driver (DMAR) option
|
||||||
|
|
||||||
|
``on``:
|
||||||
|
Enable intel iommu driver.
|
||||||
|
|
||||||
|
``off``:
|
||||||
|
Disable intel iommu driver.
|
||||||
|
|
||||||
|
``igfx_off``:
|
||||||
|
By default, gfx is mapped as normal device. If a gfx
|
||||||
|
device has a dedicated DMAR unit, the DMAR unit is
|
||||||
|
bypassed by not enabling DMAR with this option. In
|
||||||
|
this case, gfx device will use physical address for DMA.
|
||||||
|
- ::
|
||||||
|
|
||||||
|
intel_iommu=off
|
||||||
|
|
||||||
|
|
||||||
|
`Intel GVT-g`_ (AcrnGT) Parameters
|
||||||
|
**********************************
|
||||||
|
|
||||||
|
This table gives an overview of all the `Intel GVT-g`_ parameters that are
|
||||||
|
available to tweak the behaviour of the graphics sharing (`Intel GVT-g`_, aka
|
||||||
|
AcrnGT) capabilities in ACRN. `GVT-g-kernel-options`_ has more details on a
|
||||||
|
few select parameters.
|
||||||
|
|
||||||
|
.. list-table::
|
||||||
|
:header-rows: 1
|
||||||
|
:widths: 10,10,50,30
|
||||||
|
|
||||||
|
* - Parameter
|
||||||
|
- Used in SOS or UOS
|
||||||
|
- Description
|
||||||
|
- Usage example
|
||||||
|
|
||||||
|
* - i915.enable_gvt
|
||||||
|
- SOS
|
||||||
|
- Enable Intel GVT-g graphics virtualization support in the host
|
||||||
|
- ::
|
||||||
|
|
||||||
|
i915.enable_gvt=1
|
||||||
|
|
||||||
|
* - i915.enable_pvmmio
|
||||||
|
- SOS, UOS
|
||||||
|
- Control Para-Virtualized MMIO (PVMMIO). It batches sequential MMIO writes
|
||||||
|
into a shared buffer between the SOS and UOS
|
||||||
|
- ::
|
||||||
|
|
||||||
|
i915.enable_pvmmio=0x1F
|
||||||
|
|
||||||
|
* - i915.gvt_workload_priority
|
||||||
|
- SOS
|
||||||
|
- Define the priority level of UOS graphics workloads
|
||||||
|
- ::
|
||||||
|
|
||||||
|
i915.gvt_workload_priority=1
|
||||||
|
|
||||||
|
* - i915.enable_initial_modeset
|
||||||
|
- SOS
|
||||||
|
- On MRB, value must be ``1``. On NUC or UP2 boards, value must be
|
||||||
|
``0``. See :ref:`i915-enable-initial-modeset`.
|
||||||
|
- ::
|
||||||
|
|
||||||
|
i915.enable_initial_modeset=1
|
||||||
|
i915.enable_initial_modeset=0
|
||||||
|
|
||||||
|
* - i915.nuclear_pageflip
|
||||||
|
- SOS,UOS
|
||||||
|
- Force enable atomic functionality on platforms that don't have full support yet.
|
||||||
|
- ::
|
||||||
|
|
||||||
|
i915.nuclear_pageflip=1
|
||||||
|
|
||||||
|
* - i915.avail_planes_per_pipe
|
||||||
|
- SOS
|
||||||
|
- See :ref:`i915-avail-planes-owners`.
|
||||||
|
- ::
|
||||||
|
|
||||||
|
i915.avail_planes_per_pipe=0x01010F
|
||||||
|
|
||||||
|
* - i915.domain_plane_owners
|
||||||
|
- SOS
|
||||||
|
- See :ref:`i915-avail-planes-owners`.
|
||||||
|
- ::
|
||||||
|
|
||||||
|
i915.domain_plane_owners=0x011111110000
|
||||||
|
|
||||||
|
* - i915.domain_scaler_owner
|
||||||
|
- SOS
|
||||||
|
- See `i915.domain_scaler_owner`_
|
||||||
|
- ::
|
||||||
|
|
||||||
|
i915.domain_scaler_owner=0x021100
|
||||||
|
|
||||||
|
* - i915.enable_guc
|
||||||
|
- SOS
|
||||||
|
- Enable GuC load for HuC load.
|
||||||
|
- ::
|
||||||
|
|
||||||
|
i915.enable_guc=0x02
|
||||||
|
|
||||||
|
* - i915.avail_planes_per_pipe
|
||||||
|
- UOS
|
||||||
|
- See :ref:`i915-avail-planes-owners`.
|
||||||
|
- ::
|
||||||
|
|
||||||
|
i915.avail_planes_per_pipe=0x070F00
|
||||||
|
|
||||||
|
* - i915.enable_guc
|
||||||
|
- UOS
|
||||||
|
- Disable GuC
|
||||||
|
- ::
|
||||||
|
|
||||||
|
i915.enable_guc=0
|
||||||
|
|
||||||
|
* - i915.enable_hangcheck
|
||||||
|
- UOS
|
||||||
|
- Disable check GPU activity for detecting hangs.
|
||||||
|
- ::
|
||||||
|
|
||||||
|
i915.enable_hangcheck=0
|
||||||
|
|
||||||
|
* - i915.enable_fbc
|
||||||
|
- UOS
|
||||||
|
- Enable frame buffer compression for power savings
|
||||||
|
- ::
|
||||||
|
|
||||||
|
i915.enable_fbc=1
|
||||||
|
|
||||||
|
.. _GVT-g-kernel-options:
|
||||||
|
|
||||||
|
GVT-g (AcrnGT) Kernel Options
|
||||||
|
*****************************
|
||||||
|
|
||||||
|
This section provides additional information and details on the kernel command
|
||||||
|
line options that are related to AcrnGT.
|
||||||
|
|
||||||
|
i915.enable_gvt
|
||||||
|
---------------
|
||||||
|
|
||||||
|
This option enables support for Intel GVT-g graphics virtualization
|
||||||
|
support in the host. By default, it's not enabled, so we need to add
|
||||||
|
``i915.enable_gvt=1`` in the SOS kernel command line. This is a Service
|
||||||
|
OS only parameter, and cannot be enabled in the User OS.
|
||||||
|
|
||||||
|
i915.enable_pvmmio
|
||||||
|
------------------
|
||||||
|
|
||||||
|
We introduce the feature named **Para-Virtualized MMIO** (PVMMIO)
|
||||||
|
to improve graphics performance of the GVT-g guest.
|
||||||
|
This feature batches sequential MMIO writes into a
|
||||||
|
shared buffer between the Service OS and User OS, and then submits a
|
||||||
|
para-virtualized command to notify to GVT-g in Service OS. This
|
||||||
|
effectively reduces the trap numbers of MMIO operations and improves
|
||||||
|
overall graphics performance.
|
||||||
|
|
||||||
|
The ``i915.enable_pvmmio`` option controls
|
||||||
|
the optimization levels of the PVMMIO feature: each bit represents a
|
||||||
|
sub-feature of the optimization. By default, all
|
||||||
|
sub-features of PVMMIO are enabled. They can also be selectively
|
||||||
|
enabled or disabled..
|
||||||
|
|
||||||
|
The PVMMIO optimization levels are:
|
||||||
|
|
||||||
|
* PVMMIO_ELSP_SUBMIT = 0x1 - Batch submission of the guest graphics
|
||||||
|
workloads
|
||||||
|
* PVMMIO_PLANE_UPDATE = 0x2 - Batch plane register update operations
|
||||||
|
* PVMMIO_PLANE_WM_UPDATE = 0x4 - Batch watermark registers update operations
|
||||||
|
* PVMMIO_MASTER_IRQ = 0x8 - Batch IRQ related registers
|
||||||
|
* PVMMIO_PPGTT_UPDATE = 0x10 - Use PVMMIO method to update the PPGTT table
|
||||||
|
of guest.
|
||||||
|
|
||||||
|
.. note:: This parameter works in both the Service OS and User OS, but
|
||||||
|
changes to one will affect the other. For example, if either SOS or UOS
|
||||||
|
disables the PVMMIO_PPGTT_UPDATE feature, this optimization will be
|
||||||
|
disabled for both.
|
||||||
|
|
||||||
|
i915.gvt_workload_priority
|
||||||
|
--------------------------
|
||||||
|
|
||||||
|
AcrnGT supports **Prioritized Rendering** as described in the
|
||||||
|
:ref:`GVT-g-prioritized-rendering` high-level design. This
|
||||||
|
configuration option controls the priority level of GVT-g guests.
|
||||||
|
Priority levels range from -1023 to 1023.
|
||||||
|
|
||||||
|
The default priority is zero, the same priority as the Service OS. If
|
||||||
|
the level is less than zero, the guest's priority will be lower than the
|
||||||
|
Service OS, so graphics preemption will work and the prioritized
|
||||||
|
rendering feature will be enabled. If the level is greater than zero,
|
||||||
|
UOS graphics workloads will preempt most of the SOS graphics workloads,
|
||||||
|
except for display updating related workloads that use a default highest
|
||||||
|
priority (1023).
|
||||||
|
|
||||||
|
Currently, all UOSes share the same priority.
|
||||||
|
This is a Service OS only parameters, and does
|
||||||
|
not work in the User OS.
|
||||||
|
|
||||||
|
.. _i915-enable-initial-modeset:
|
||||||
|
|
||||||
|
i915.enable_initial_modeset
|
||||||
|
---------------------------
|
||||||
|
|
||||||
|
At time, kernel graphics must be initialized with a valid display
|
||||||
|
configuration with full display pipeline programming in place before the
|
||||||
|
user space is initialized and without a fbdev & fb console.
|
||||||
|
|
||||||
|
When ``i915.enable_initial_modeset=1``, the FBDEV of i915 will not be
|
||||||
|
initialized, so users would not be able to see the fb console on screen.
|
||||||
|
If there is no graphics UI running by default, users will see black
|
||||||
|
screens displayed.
|
||||||
|
|
||||||
|
When ``i915.enable_initial_modeset=0`` in SOS, the plane restriction
|
||||||
|
(also known as plane-based domain ownership) feature will be disabled.
|
||||||
|
(See the next section and :ref:`plane_restriction` in the ACRN GVT-g
|
||||||
|
High Level Design for more information about this feature.)
|
||||||
|
|
||||||
|
In the current configuration, we will set
|
||||||
|
``i915.enable_initial_modeset=1`` in SOS and
|
||||||
|
``i915.enable_initial_modeset=0`` in UOS.
|
||||||
|
|
||||||
|
This parameter is not used on UEFI platforms.
|
||||||
|
|
||||||
|
.. _i915-avail-planes-owners:
|
||||||
|
|
||||||
|
i915.avail_planes_per_pipe and i915.domain_plane_owners
|
||||||
|
-------------------------------------------------------
|
||||||
|
|
||||||
|
Both Service OS and User OS are provided a set of HW planes where they
|
||||||
|
can display their contents. Since each domain provides its content,
|
||||||
|
there is no need for any extra composition to be done through SOS.
|
||||||
|
``i915.avail_planes_per_pipe`` and ``i915.domain_plane_owners`` work
|
||||||
|
together to provide the plane restriction (or plan-based domain
|
||||||
|
ownership) feature.
|
||||||
|
|
||||||
|
* i915.domain_plane_owners
|
||||||
|
|
||||||
|
On Intel's display hardware, each pipeline contains several planes, which are
|
||||||
|
blended
|
||||||
|
together by their Z-order and rendered to the display monitors. In
|
||||||
|
AcrnGT, we can control each planes' ownership so that the domains can
|
||||||
|
display contents on the planes they own.
|
||||||
|
|
||||||
|
The ``i915.domain_plane_owners`` parameter controls the ownership of all
|
||||||
|
the planes in the system, as shown in :numref:`i915-planes-pipes`. Each
|
||||||
|
4-bit nibble identifies the domain id owner for that plane and a group
|
||||||
|
of 4 nibbles represents a pipe. This is a Service OS only configuration
|
||||||
|
and cannot be modified at runtime. Domain ID 0x0 is for the Service OS,
|
||||||
|
the User OS use domain IDs from 0x1 to 0xF.
|
||||||
|
|
||||||
|
.. figure:: images/i915-image1.png
|
||||||
|
:width: 900px
|
||||||
|
:align: center
|
||||||
|
:name: i915-planes-pipes
|
||||||
|
|
||||||
|
i915.domain_plane_owners
|
||||||
|
|
||||||
|
For example, if we set ``i915.domain_plane_owners=0x010001101110``, the
|
||||||
|
plane ownership will be as shown in :numref:`i915-planes-example1` - SOS
|
||||||
|
(green) owns plane 1A, 1B, 4B, 1C, and 2C, and UOS #1 owns plane 2A, 3A,
|
||||||
|
4A, 2B, 3B and 3C.
|
||||||
|
|
||||||
|
.. figure:: images/i915-image2.png
|
||||||
|
:width: 900px
|
||||||
|
:align: center
|
||||||
|
:name: i915-planes-example1
|
||||||
|
|
||||||
|
i915.domain_plane_owners example
|
||||||
|
|
||||||
|
Some other examples:
|
||||||
|
|
||||||
|
* i915.domain_plane_owners=0x022211110000 - SOS (0x0) owns planes on pipe A;
|
||||||
|
UOS #1 (0x1) owns all planes on pipe B; and UOS #2 (0x2) owns all
|
||||||
|
planes on pipe C (since, in the representation in
|
||||||
|
:numref:`i915-planes-pipes` above, there are only 3 planes attached to
|
||||||
|
pipe C).
|
||||||
|
|
||||||
|
* i915.domain_plane_owners=0x000001110000 - SOS owns all planes on pipe A
|
||||||
|
and pipe C; UOS #1 owns plane 1, 2 and 3 on pipe B. Plane 4 on pipe B
|
||||||
|
is owned by the SOS so that if it wants to display notice message, it
|
||||||
|
can display on top of the UOS.
|
||||||
|
|
||||||
|
* i915.avail_planes_per_pipe
|
||||||
|
|
||||||
|
Option ``i915.avail_planes_per_pipe`` is a bitmask (shown in
|
||||||
|
:numref:`i915-avail-planes`) that tells the i915
|
||||||
|
driver which planes are available and can be exposed to the compositor.
|
||||||
|
This is a parameter that must to be set in each domain. If
|
||||||
|
``i915.avail_planes_per_pipe=0``, the plane restriction feature is disabled.
|
||||||
|
|
||||||
|
.. figure:: images/i915-image3.png
|
||||||
|
:width: 600px
|
||||||
|
:align: center
|
||||||
|
:name: i915-avail-planes
|
||||||
|
|
||||||
|
i915.avail_planes_per_pipe
|
||||||
|
|
||||||
|
For example, if we set ``i915.avail_planes_per_pipe=0x030901`` in SOS
|
||||||
|
and ``i915.avail_planes_per_pipe=0x04060E`` in UOS, the planes will be as
|
||||||
|
shown in :numref:`i915-avail-planes-example1` and
|
||||||
|
:numref:`i915-avail-planes-example1`:
|
||||||
|
|
||||||
|
.. figure:: images/i915-image4.png
|
||||||
|
:width: 500px
|
||||||
|
:align: center
|
||||||
|
:name: i915-avail-planes-example1
|
||||||
|
|
||||||
|
SOS i915.avail_planes_per_pipe
|
||||||
|
|
||||||
|
.. figure:: images/i915-image5.png
|
||||||
|
:width: 500px
|
||||||
|
:align: center
|
||||||
|
:name: i915-avail-planes-example2
|
||||||
|
|
||||||
|
UOS i915.avail_planes_per_pipe
|
||||||
|
|
||||||
|
``i915.avail_planes_per_pipe`` controls the view of planes from i915 drivers
|
||||||
|
inside of every domain, and ``i915.domain_plane_owners`` is the global
|
||||||
|
arbiter controlling which domain can present its content onto the
|
||||||
|
real hardware. Generally, they are aligned. For example, we can set
|
||||||
|
``i915.domain_plane_owners= 0x011111110000``,
|
||||||
|
``i915.avail_planes_per_pipe=0x00000F`` in SOS, and
|
||||||
|
``i915.avail_planes_per_pipe=0x070F00`` in domain 1, so every domain will
|
||||||
|
only flip on the planes they owns.
|
||||||
|
|
||||||
|
However, we don't force alignment: ``avail_planes_per_pipe`` might
|
||||||
|
not be aligned with the
|
||||||
|
setting of ``domain_plane_owners``. Consider this example:
|
||||||
|
``i915.domain_plane_owners=0x011111110000``,
|
||||||
|
``i915.avail_planes_per_pipe=0x01010F`` in SOS and
|
||||||
|
``i915.avail_planes_per_pipe=0x070F00`` in domain 1.
|
||||||
|
With this configuration, SOS will be able to render on plane 1B and
|
||||||
|
plane 1C, however, the content of plane 1B and plane 1C will not be
|
||||||
|
flipped onto the real hardware.
|
||||||
|
|
||||||
|
i915.domain_scaler_owner
|
||||||
|
========================
|
||||||
|
|
||||||
|
On each Intel GPU display pipeline, there are several plane scalers
|
||||||
|
to zoom in/out the planes. For example, if a 720p video is played
|
||||||
|
full-screen on a 1080p display monitor, the kernel driver will use a
|
||||||
|
scaler to zoom in the video plane to a 1080p image and present it onto a
|
||||||
|
display pipeline. (Refer to "Intel Open Source Graphics PRM Vol 7:
|
||||||
|
display" for the details.)
|
||||||
|
|
||||||
|
On Broxton platforms, Pipe A and Pipe B each
|
||||||
|
have two plane scalers, and Pipe C has one plane scaler. To support the
|
||||||
|
plane scaling in AcrnGT guest OS, we introduced the parameter
|
||||||
|
``i915.domain_scaler_owner``, to assign a specific scaler to the target
|
||||||
|
guest OS.
|
||||||
|
|
||||||
|
As with the parameter ``i915.domain_plane_owners``, each nibble of
|
||||||
|
``i915.domain_scaler_owner`` represents the domain id that owns the scaler;
|
||||||
|
every nibble (4 bits) represents a scaler and every group of 2 nibbles
|
||||||
|
represents a pipe. This is a Service OS only configuration and cannot be
|
||||||
|
modified at runtime. Domain ID 0x0 is for the Service OS, the User OS
|
||||||
|
use domain IDs from 0x1 to 0xF.
|
||||||
|
|
||||||
|
For example, if we set ``i915.domain_scaler_owner=0x021100``, the SOS
|
||||||
|
owns scaler 1A, 2A; UOS #1 owns scaler 1B, 2B; and UOS #2 owns scaler
|
||||||
|
1C.
|
||||||
|
|
||||||
|
i915.enable_hangcheck
|
||||||
|
=====================
|
||||||
|
|
||||||
|
This parameter enable detection of a GPU hang. When enabled, the i915
|
||||||
|
will start a timer to check if the workload is completed in a specific
|
||||||
|
time. If not, i915 will treat it as a GPU hang and trigger a GPU reset.
|
||||||
|
|
||||||
|
In AcrnGT, the workload in SOS and UOS can be set to different
|
||||||
|
priorities. If SOS is assigned a higher priority than the UOS, the UOS's
|
||||||
|
workload might not be able to run on the HW on time. This may lead to
|
||||||
|
the guest i915 triggering a hangcheck and lead to a guest GPU reset.
|
||||||
|
This reset is unnecessary so we use ``i915.enable_hangcheck=0`` to
|
||||||
|
disable this timeout check and prevent guest from triggering unnecessary
|
||||||
|
GPU resets.
|
||||||
|
|
||||||
|
.. _Intel GVT-g: https://www.collinsdictionary.com/dictionary/english/focusses
|
||||||
Loading…
Reference in New Issue
Block a user