diff options
author | 2023-02-21 18:24:12 -0800 | |
---|---|---|
committer | 2023-02-21 18:24:12 -0800 | |
commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /Documentation/gpu/vkms.rst | |
download | linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip |
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski:
"Core:
- Add dedicated kmem_cache for typical/small skb->head, avoid having
to access struct page at kfree time, and improve memory use.
- Introduce sysctl to set default RPS configuration for new netdevs.
- Define Netlink protocol specification format which can be used to
describe messages used by each family and auto-generate parsers.
Add tools for generating kernel data structures and uAPI headers.
- Expose all net/core sysctls inside netns.
- Remove 4s sleep in netpoll if carrier is instantly detected on
boot.
- Add configurable limit of MDB entries per port, and port-vlan.
- Continue populating drop reasons throughout the stack.
- Retire a handful of legacy Qdiscs and classifiers.
Protocols:
- Support IPv4 big TCP (TSO frames larger than 64kB).
- Add IP_LOCAL_PORT_RANGE socket option, to control local port range
on socket by socket basis.
- Track and report in procfs number of MPTCP sockets used.
- Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
manager.
- IPv6: don't check net.ipv6.route.max_size and rely on garbage
collection to free memory (similarly to IPv4).
- Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).
- ICMP: add per-rate limit counters.
- Add support for user scanning requests in ieee802154.
- Remove static WEP support.
- Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
reporting.
- WiFi 7 EHT channel puncturing support (client & AP).
BPF:
- Add a rbtree data structure following the "next-gen data structure"
precedent set by recently added linked list, that is, by using
kfunc + kptr instead of adding a new BPF map type.
- Expose XDP hints via kfuncs with initial support for RX hash and
timestamp metadata.
- Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
better support decap on GRE tunnel devices not operating in collect
metadata.
- Improve x86 JIT's codegen for PROBE_MEM runtime error checks.
- Remove the need for trace_printk_lock for bpf_trace_printk and
bpf_trace_vprintk helpers.
- Extend libbpf's bpf_tracing.h support for tracing arguments of
kprobes/uprobes and syscall as a special case.
- Significantly reduce the search time for module symbols by
livepatch and BPF.
- Enable cpumasks to be used as kptrs, which is useful for tracing
programs tracking which tasks end up running on which CPUs in
different time intervals.
- Add support for BPF trampoline on s390x and riscv64.
- Add capability to export the XDP features supported by the NIC.
- Add __bpf_kfunc tag for marking kernel functions as kfuncs.
- Add cgroup.memory=nobpf kernel parameter option to disable BPF
memory accounting for container environments.
Netfilter:
- Remove the CLUSTERIP target. It has been marked as obsolete for
years, and we still have WARN splats wrt races of the out-of-band
/proc interface installed by this target.
- Add 'destroy' commands to nf_tables. They are identical to the
existing 'delete' commands, but do not return an error if the
referenced object (set, chain, rule...) did not exist.
Driver API:
- Improve cpumask_local_spread() locality to help NICs set the right
IRQ affinity on AMD platforms.
- Separate C22 and C45 MDIO bus transactions more clearly.
- Introduce new DCB table to control DSCP rewrite on egress.
- Support configuration of Physical Layer Collision Avoidance (PLCA)
Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
shared medium Ethernet.
- Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
preemption of low priority frames by high priority frames.
- Add support for controlling MACSec offload using netlink SET.
- Rework devlink instance refcounts to allow registration and
de-registration under the instance lock. Split the code into
multiple files, drop some of the unnecessarily granular locks and
factor out common parts of netlink operation handling.
- Add TX frame aggregation parameters (for USB drivers).
- Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
messages with notifications for debug.
- Allow offloading of UDP NEW connections via act_ct.
- Add support for per action HW stats in TC.
- Support hardware miss to TC action (continue processing in SW from
a specific point in the action chain).
- Warn if old Wireless Extension user space interface is used with
modern cfg80211/mac80211 drivers. Do not support Wireless
Extensions for Wi-Fi 7 devices at all. Everyone should switch to
using nl80211 interface instead.
- Improve the CAN bit timing configuration. Use extack to return
error messages directly to user space, update the SJW handling,
including the definition of a new default value that will benefit
CAN-FD controllers, by increasing their oscillator tolerance.
New hardware / drivers:
- Ethernet:
- nVidia BlueField-3 support (control traffic driver)
- Ethernet support for imx93 SoCs
- Motorcomm yt8531 gigabit Ethernet PHY
- onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
- Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
- Amlogic gxl MDIO mux
- WiFi:
- RealTek RTL8188EU (rtl8xxxu)
- Qualcomm Wi-Fi 7 devices (ath12k)
- CAN:
- Renesas R-Car V4H
Drivers:
- Bluetooth:
- Set Per Platform Antenna Gain (PPAG) for Intel controllers.
- Ethernet NICs:
- Intel (1G, igc):
- support TSN / Qbv / packet scheduling features of i226 model
- Intel (100G, ice):
- use GNSS subsystem instead of TTY
- multi-buffer XDP support
- extend support for GPIO pins to E823 devices
- nVidia/Mellanox:
- update the shared buffer configuration on PFC commands
- implement PTP adjphase function for HW offset control
- TC support for Geneve and GRE with VF tunnel offload
- more efficient crypto key management method
- multi-port eswitch support
- Netronome/Corigine:
- add DCB IEEE support
- support IPsec offloading for NFP3800
- Freescale/NXP (enetc):
- support XDP_REDIRECT for XDP non-linear buffers
- improve reconfig, avoid link flap and waiting for idle
- support MAC Merge layer
- Other NICs:
- sfc/ef100: add basic devlink support for ef100
- ionic: rx_push mode operation (writing descriptors via MMIO)
- bnxt: use the auxiliary bus abstraction for RDMA
- r8169: disable ASPM and reset bus in case of tx timeout
- cpsw: support QSGMII mode for J721e CPSW9G
- cpts: support pulse-per-second output
- ngbe: add an mdio bus driver
- usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
- r8152: handle devices with FW with NCM support
- amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
- virtio-net: support multi buffer XDP
- virtio/vsock: replace virtio_vsock_pkt with sk_buff
- tsnep: XDP support
- Ethernet high-speed switches:
- nVidia/Mellanox (mlxsw):
- add support for latency TLV (in FW control messages)
- Microchip (sparx5):
- separate explicit and implicit traffic forwarding rules, make
the implicit rules always active
- add support for egress DSCP rewrite
- IS0 VCAP support (Ingress Classification)
- IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
etc.)
- ES2 VCAP support (Egress Access Control)
- support for Per-Stream Filtering and Policing (802.1Q,
8.6.5.1)
- Ethernet embedded switches:
- Marvell (mv88e6xxx):
- add MAB (port auth) offload support
- enable PTP receive for mv88e6390
- NXP (ocelot):
- support MAC Merge layer
- support for the the vsc7512 internal copper phys
- Microchip:
- lan9303: convert to PHYLINK
- lan966x: support TC flower filter statistics
- lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
- lan937x: support Credit Based Shaper configuration
- ksz9477: support Energy Efficient Ethernet
- other:
- qca8k: convert to regmap read/write API, use bulk operations
- rswitch: Improve TX timestamp accuracy
- Intel WiFi (iwlwifi):
- EHT (Wi-Fi 7) rate reporting
- STEP equalizer support: transfer some STEP (connection to radio
on platforms with integrated wifi) related parameters from the
BIOS to the firmware.
- Qualcomm 802.11ax WiFi (ath11k):
- IPQ5018 support
- Fine Timing Measurement (FTM) responder role support
- channel 177 support
- MediaTek WiFi (mt76):
- per-PHY LED support
- mt7996: EHT (Wi-Fi 7) support
- Wireless Ethernet Dispatch (WED) reset support
- switch to using page pool allocator
- RealTek WiFi (rtw89):
- support new version of Bluetooth co-existance
- Mobile:
- rmnet: support TX aggregation"
* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
page_pool: add a comment explaining the fragment counter usage
net: ethtool: fix __ethtool_dev_mm_supported() implementation
ethtool: pse-pd: Fix double word in comments
xsk: add linux/vmalloc.h to xsk.c
sefltests: netdevsim: wait for devlink instance after netns removal
selftest: fib_tests: Always cleanup before exit
net/mlx5e: Align IPsec ASO result memory to be as required by hardware
net/mlx5e: TC, Set CT miss to the specific ct action instance
net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
net/mlx5: Refactor tc miss handling to a single function
net/mlx5: Kconfig: Make tc offload depend on tc skb extension
net/sched: flower: Support hardware miss to tc action
net/sched: flower: Move filter handle initialization earlier
net/sched: cls_api: Support hardware miss to tc action
net/sched: Rename user cookie and act cookie
sfc: fix builds without CONFIG_RTC_LIB
sfc: clean up some inconsistent indentings
net/mlx4_en: Introduce flexible array to silence overflow warning
net: lan966x: Fix possible deadlock inside PTP
net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
...
Diffstat (limited to 'Documentation/gpu/vkms.rst')
-rw-r--r-- | Documentation/gpu/vkms.rst | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst new file mode 100644 index 000000000..49db221c0 --- /dev/null +++ b/Documentation/gpu/vkms.rst @@ -0,0 +1,200 @@ +.. _vkms: + +========================================== + drm/vkms Virtual Kernel Modesetting +========================================== + +.. kernel-doc:: drivers/gpu/drm/vkms/vkms_drv.c + :doc: vkms (Virtual Kernel Modesetting) + +Setup +===== + +The VKMS driver can be setup with the following steps: + +To check if VKMS is loaded, run:: + + lsmod | grep vkms + +This 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:: + + make nconfig + + Go to `Device Drivers> Graphics support` + + Enable `Virtual KMS (EXPERIMENTAL)` + +Compile and build the kernel for the changes to get reflected. +Now, to load the driver, use:: + + sudo modprobe vkms + +On running the lsmod command now, the VKMS driver will appear listed. +You can also observe the driver being loaded in the dmesg logs. + +The 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:: + + modinfo vkms + +Module options are helpful when testing, and enabling modules +can be done while loading vkms. For example, to load vkms with cursor enabled, +use:: + + sudo modprobe vkms enable_cursor=1 + +To disable the driver, use :: + + sudo modprobe -r vkms + +Testing With IGT +================ + +The 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 <https://gitlab.freedesktop.org/drm/igt-gpu-tools>`_ . + +The tests need to be run without a compositor, so you need to switch to text +only mode. You can do this by:: + + sudo systemctl isolate multi-user.target + +To return to graphical mode, do:: + + sudo systemctl isolate graphical.target + +Once 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:: + + sudo ./build/tests/<name of test> --device "sys:/sys/devices/platform/vkms" + sudo IGT_DEVICE="sys:/sys/devices/platform/vkms" ./build/tests/<name of test> + sudo IGT_DEVICE="sys:/sys/devices/platform/vkms" ./scripts/run-tests.sh -t <name of test> + +For example, to test the functionality of the writeback library, +we can run the kms_writeback test:: + + sudo ./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 + +You can also run subtests if you do not want to run the entire test:: + + sudo ./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 + +TODO +==== + +If you want to do any of the items listed below, please share your interest +with VKMS maintainers. + +IGT better support +------------------ + +Debugging: + +- kms_plane: some test cases are failing due to timeout on capturing CRC; + +Virtual hardware (vblank-less) mode: + +- VKMS 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. + +Add Plane Features +------------------ + +There's lots of plane features we could add support for: + +- ARGB format on primary plane: blend the primary plane into background with + translucent alpha. + +- Add background color KMS property[Good to get started]. + +- Full alpha blending on all planes. + +- Rotation, scaling. + +- Additional buffer formats, especially YUV formats for video like NV12. + Low/high bpp RGB formats would also be interesting. + +- Async updates (currently only possible on cursor plane using the legacy + cursor api). + +For 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. + +Runtime Configuration +--------------------- + +We want to be able to reconfigure vkms instance without having to reload the +module. Use/Test-cases: + +- Hotplug/hotremove connectors on the fly (to be able to test DP MST handling + of compositors). + +- Configure planes/crtcs/connectors (we'd need some code to have more than 1 of + them first). + +- Change output configuration: Plug/unplug screens, change EDID, allow changing + the refresh rate. + +The currently proposed solution is to expose vkms configuration through +configfs. All existing module options should be supported through configfs +too. + +Writeback support +----------------- + +- The 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] + +- Add support for cloned writeback outputs and related test cases using a + cloned output in the IGT kms_writeback. + +- As a v4l device. This is useful for debugging compositors on special vkms + configurations, so that developers see what's really going on. + +Output Features +--------------- + +- Variable 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. + +- Add support for link status, so that compositors can validate their runtime + fallbacks when e.g. a Display Port link goes bad. + +CRC API Improvements +-------------------- + +- Optimize CRC computation ``compute_crc()`` and plane blending ``blend()`` + +Atomic Check using eBPF +----------------------- + +Atomic 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. + +This needs a bunch of features (plane compositing, multiple outputs, ...) +enabled already to make sense. |