doc: remove enable ptm tutorial
Enabling PTM requires some additional engineering work, so we're removing these instructions for now. Signed-off-by: David B. Kinder <david.b.kinder@intel.com>
This commit is contained in:
David B. Kinder
David Kinder
parent
bd57475854
commit
ce8d69333a
|
|
@ -89,7 +89,6 @@ Advanced Features
|
|||
tutorials/acrn-secure-boot-with-efi-stub
|
||||
tutorials/pre-launched-rt
|
||||
tutorials/enable_ivshmem
|
||||
tutorials/enable_ptm
|
||||
|
||||
Debug
|
||||
*****
|
||||
|
|
|
|||
|
|
@ -104,7 +104,6 @@ formatting, and presentation:
|
|||
* :ref:`virtio-net`
|
||||
* :ref:`acrn_on_qemu`
|
||||
* :ref:`cpu_sharing`
|
||||
* :ref:`enable-ptm`
|
||||
* :ref:`nested_virt`
|
||||
* :ref:`setup_openstack_libvirt`
|
||||
* :ref:`using_hybrid_mode_on_nuc`
|
||||
|
|
|
|||
|
|
@ -1,88 +0,0 @@
|
|||
.. _enable-ptm:
|
||||
|
||||
Enable PCIe Precision Time Management in a User VM
|
||||
##################################################
|
||||
|
||||
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 User 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.
|
||||
|
||||
Before you can enable PTM in a User VM, PTM must be enabled in the Service VM.
|
||||
You should verify this by using ``dmesg`` in a Service VM terminal::
|
||||
|
||||
dmesg | grep -i ptm
|
||||
[ 3.072144] pci 0000:00:06.0: PTM enabled (root), 4ns granularity
|
||||
[ 3.101591] pci 0000:00:1a.0: PTM enabled (root), 4ns granularity
|
||||
[ 3.103434] pci 0000:00:1c.0: PTM enabled (root), 4ns granularity
|
||||
[ 5.089042] igc 0000:04:00.0: PTM enabled, 4ns granularity
|
||||
[ 88.103910] acrn_dm: <PTM>: opt=enable_ptm.
|
||||
[ 88.217266] acrn_dm: <PTM>-get_ptm_reg_value: device [4:0.0]: ptm pos=0x1f0, ptm reg val=0x401.
|
||||
[ 88.217566] acrn_dm: <PTM>-get_ptm_reg_value: device [0:1c.0]: ptm pos=0x150, ptm reg val=0x416.
|
||||
[ 88.217743] acrn_dm: <PTM>-get_ptm_reg_value: device [0:1c.0]: ptm pos=0x150, ptm reg val=0x3.
|
||||
|
||||
|
||||
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:a9:00.0"
|
||||
)
|
||||
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 User 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 verify that PTM was enabled by using ``dmesg`` in the User VM::
|
||||
|
||||
dmesg | grep -i ptm
|
||||
[ 0.774547] pci 0000:00:05.0: PTM enabled (root), 4ns granularity
|
||||
[ 2.478440] igc 0000:01:00.0: 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>`.
|
||||
Loading…
Reference in New Issue