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doc: remove PTM tutorial for now 

PTM feature postponed to v2.6 so remove documentation about enabling
this feature.

Signed-off-by: David B. Kinder <david.b.kinder@intel.com>
This commit is contained in:
David B. Kinder 2021-06-24 18:35:58 -07:00 committed by David Kinder
parent 8d2f158d26
commit b82b8073a9
3 changed files with 1 additions and 89 deletions
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1
doc/develop.rst
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@ -77,7 +77,6 @@ Enable ACRN Features
tutorials/acrn-secure-boot-with-efi-stub
tutorials/pre-launched-rt
tutorials/enable_ivshmem
tutorials/enable_ptm
Debug
*****

3
doc/release_notes/release_notes_2.5.rst
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@ -134,10 +134,9 @@ to the ACRN documentation around configuration, options, and parameters:
* :ref:`acrn-dm_parameters`
* :ref:`kernel-parameters`
Some new capabilities are documented here:
New capabilities are documented here:
* :ref:`nested_virt`
* :ref:`enable-ptm`
We've also made edits throughout the documentation to improve clarity,
formatting, and presentation throughout the ACRN documentation:

86
doc/tutorials/enable_ptm.rst
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@ -1,86 +0,0 @@
.. _enable-ptm:
Enable PCIe Precision Time Management
#####################################
The PCI Express (PCIe) specification defines a Precision Time Measurement (PTM)
mechanism that lets you coordinate and synchronize events across multiple PCI
components within the same system with very fine time precision.
ACRN adds PCIe root port emulation in the hypervisor to support the PTM feature
and emulates a simple PTM hierarchy. ACRN enables PTM in a Guest VM if the user
sets the ``enable_ptm`` option when passing through a device to a post-launched
VM and :ref:`vm.PTM` is enabled in the scenario configuration. When you enable
PTM, the passthrough device is connected to a virtual root port instead of the host
bridge as it normally would.
Here is an example launch script that configures a supported Ethernet card for
passthrough and enables PTM on it:
.. code-block:: bash
:emphasize-lines: 9-11,17
declare -A passthru_vpid
declare -A passthru_bdf
passthru_vpid=(
["ethptm"]="8086 15f2"
)
passthru_bdf=(
["ethptm"]="0000:aa:00.0"
)
echo ${passthru_vpid["ethptm"]} > /sys/bus/pci/drivers/pci-stub/new_id
echo ${passthru_bdf["ethptm"]} > /sys/bus/pci/devices/${passthru_bdf["ethptm"]}/driver/unbind
echo ${passthru_bdf["ethptm"]} > /sys/bus/pci/drivers/pci-stub/bind
acrn-dm -A -m $mem_size -s 0:0,hostbridge \
-s 3,virtio-blk,uos-test.img \
-s 4,virtio-net,tap0 \
-s 5,virtio-console,@stdio:stdio_port \
-s 6,passthru,a9/00/0,enable_ptm \
--ovmf /usr/share/acrn/bios/OVMF.fd
.. important:: By default, the :ref:`vm.PTM` option is disabled in ACRN VMs. Use the
:ref:`ACRN configuration tool <acrn_configuration_tool>` to enable PTM
in the scenario XML file that configures the Guest VM.
Here is the bus hierarchy in the Guest VM (as shown by the ``lspci`` command)::
lspci -tv
-[0000:00]-+-00.0 Network Appliance Corporation Device 1275
+-03.0 Red Hat, Inc. Virtio block device
+-04.0 Red Hat, Inc. Virtio network device
+-05.0 Red Hat, Inc. Virtio console
\-06.0-[01]----00.0 Intel Corporation Device 15f2
(Instead of ``Device 15f2`` you might see ``Ethernet Controller I225LM``.)
You can also verify that PTM was enabled by using ``dmesg`` in the guest VM::
dmesg | grep -i ptm
[ 1.555284] pci_ptm_init: 00:00.00, ispcie=1, type=0x4
[ 1.555356] Cannot find PTM ext cap.
[ 1.561311] pci_ptm_init: 00:03.00, ispcie=0, type=0x0
[ 1.567146] pci_ptm_init: 00:04.00, ispcie=0, type=0x0
[ 1.572983] pci_ptm_init: 00:05.00, ispcie=0, type=0x0
[ 1.718038] pci_ptm_init: 00:06.00, ispcie=1, type=0x4
[ 1.722034] ptm is ptm_root.
[ 1.723033] Condition-2: ptm is enabled.
[ 1.723052] pci 0000:00:06.0: PTM enabled (root), 4ns granularity
[ 1.766438] pci_ptm_init: a9:00.00, ispcie=1, type=0x0
[ 5.715000] igc_probe enable ptm.
[ 5.715068] pci_enable_ptm: a9:00.00, ispcie=1, type=0x0
[ 5.715294] ptm is enabled on endpoint device.
[ 5.715371] igc 0000:a9:00.0: PTM enabled, 4ns granularity
PTM Implementation Notes
************************
To simplify the implementation, the virtual root port only supports the most
basic PCIe configuration and operation, in addition to PTM capabilities.
To use PTM in a virtualized environment, you may want to first verify that PTM
is supported by the device and is enabled on the bare metal machine and in the
Guest VM kernel (e.g., ``CONFIG_PCIE_PTM=y`` option is set in the Linux kernel).
You can find more details about the PTM implementation in the
:ref:`ACRN HLD PCIe PTM documentation <PCIe PTM implementation>`.