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().
  ...

1 files changed, 294 insertions, 0 deletions

diff --git a/Documentation/virt/kvm/locking.rst b/Documentation/virt/kvm/locking.rst
new file mode 100644
index 000000000..a0146793d
--- /dev/null
+++ b/Documentation/virt/kvm/locking.rst
@@ -0,0 +1,294 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=================
+KVM Lock Overview
+=================
+
+1. Acquisition Orders
+---------------------
+
+The acquisition orders for mutexes are as follows:
+
+- kvm->lock is taken outside vcpu->mutex
+
+- kvm->lock is taken outside kvm->slots_lock and kvm->irq_lock
+
+- kvm->slots_lock is taken outside kvm->irq_lock, though acquiring
+  them together is quite rare.
+
+- kvm->mn_active_invalidate_count ensures that pairs of
+  invalidate_range_start() and invalidate_range_end() callbacks
+  use the same memslots array.  kvm->slots_lock and kvm->slots_arch_lock
+  are taken on the waiting side in install_new_memslots, so MMU notifiers
+  must not take either kvm->slots_lock or kvm->slots_arch_lock.
+
+For SRCU:
+
+- ``synchronize_srcu(&kvm->srcu)`` is called inside critical sections
+  for kvm->lock, vcpu->mutex and kvm->slots_lock.  These locks _cannot_
+  be taken inside a kvm->srcu read-side critical section; that is, the
+  following is broken::
+
+      srcu_read_lock(&kvm->srcu);
+      mutex_lock(&kvm->slots_lock);
+
+- kvm->slots_arch_lock instead is released before the call to
+  ``synchronize_srcu()``.  It _can_ therefore be taken inside a
+  kvm->srcu read-side critical section, for example while processing
+  a vmexit.
+
+On x86:
+
+- vcpu->mutex is taken outside kvm->arch.hyperv.hv_lock and kvm->arch.xen.xen_lock
+
+- kvm->arch.mmu_lock is an rwlock.  kvm->arch.tdp_mmu_pages_lock and
+  kvm->arch.mmu_unsync_pages_lock are taken inside kvm->arch.mmu_lock, and
+  cannot be taken without already holding kvm->arch.mmu_lock (typically with
+  ``read_lock`` for the TDP MMU, thus the need for additional spinlocks).
+
+Everything else is a leaf: no other lock is taken inside the critical
+sections.
+
+2. Exception
+------------
+
+Fast page fault:
+
+Fast page fault is the fast path which fixes the guest page fault out of
+the mmu-lock on x86. Currently, the page fault can be fast in one of the
+following two cases:
+
+1. Access Tracking: The SPTE is not present, but it is marked for access
+   tracking. That means we need to restore the saved R/X bits. This is
+   described in more detail later below.
+
+2. Write-Protection: The SPTE is present and the fault is caused by
+   write-protect. That means we just need to change the W bit of the spte.
+
+What we use to avoid all the race is the Host-writable bit and MMU-writable bit
+on the spte:
+
+- Host-writable means the gfn is writable in the host kernel page tables and in
+  its KVM memslot.
+- MMU-writable means the gfn is writable in the guest's mmu and it is not
+  write-protected by shadow page write-protection.
+
+On fast page fault path, we will use cmpxchg to atomically set the spte W
+bit if spte.HOST_WRITEABLE = 1 and spte.WRITE_PROTECT = 1, to restore the saved
+R/X bits if for an access-traced spte, or both. This is safe because whenever
+changing these bits can be detected by cmpxchg.
+
+But we need carefully check these cases:
+
+1) The mapping from gfn to pfn
+
+The mapping from gfn to pfn may be changed since we can only ensure the pfn
+is not changed during cmpxchg. This is a ABA problem, for example, below case
+will happen:
+
++------------------------------------------------------------------------+
+| At the beginning::                                                     |
+|                                                                        |
+|	gpte = gfn1                                                      |
+|	gfn1 is mapped to pfn1 on host                                   |
+|	spte is the shadow page table entry corresponding with gpte and  |
+|	spte = pfn1                                                      |
++------------------------------------------------------------------------+
+| On fast page fault path:                                               |
++------------------------------------+-----------------------------------+
+| CPU 0:                             | CPU 1:                            |
++------------------------------------+-----------------------------------+
+| ::                                 |                                   |
+|                                    |                                   |
+|   old_spte = *spte;                |                                   |
++------------------------------------+-----------------------------------+
+|                                    | pfn1 is swapped out::             |
+|                                    |                                   |
+|                                    |    spte = 0;                      |
+|                                    |                                   |
+|                                    | pfn1 is re-alloced for gfn2.      |
+|                                    |                                   |
+|                                    | gpte is changed to point to       |
+|                                    | gfn2 by the guest::               |
+|                                    |                                   |
+|                                    |    spte = pfn1;                   |
++------------------------------------+-----------------------------------+
+| ::                                                                     |
+|                                                                        |
+|   if (cmpxchg(spte, old_spte, old_spte+W)                              |
+|	mark_page_dirty(vcpu->kvm, gfn1)                                 |
+|            OOPS!!!                                                     |
++------------------------------------------------------------------------+
+
+We dirty-log for gfn1, that means gfn2 is lost in dirty-bitmap.
+
+For direct sp, we can easily avoid it since the spte of direct sp is fixed
+to gfn.  For indirect sp, we disabled fast page fault for simplicity.
+
+A solution for indirect sp could be to pin the gfn, for example via
+kvm_vcpu_gfn_to_pfn_atomic, before the cmpxchg.  After the pinning:
+
+- We have held the refcount of pfn that means the pfn can not be freed and
+  be reused for another gfn.
+- The pfn is writable and therefore it cannot be shared between different gfns
+  by KSM.
+
+Then, we can ensure the dirty bitmaps is correctly set for a gfn.
+
+2) Dirty bit tracking
+
+In the origin code, the spte can be fast updated (non-atomically) if the
+spte is read-only and the Accessed bit has already been set since the
+Accessed bit and Dirty bit can not be lost.
+
+But it is not true after fast page fault since the spte can be marked
+writable between reading spte and updating spte. Like below case:
+
++------------------------------------------------------------------------+
+| At the beginning::                                                     |
+|                                                                        |
+|	spte.W = 0                                                       |
+|	spte.Accessed = 1                                                |
++------------------------------------+-----------------------------------+
+| CPU 0:                             | CPU 1:                            |
++------------------------------------+-----------------------------------+
+| In mmu_spte_clear_track_bits()::   |                                   |
+|                                    |                                   |
+|  old_spte = *spte;                 |                                   |
+|                                    |                                   |
+|                                    |                                   |
+|  /* 'if' condition is satisfied. */|                                   |
+|  if (old_spte.Accessed == 1 &&     |                                   |
+|       old_spte.W == 0)             |                                   |
+|     spte = 0ull;                   |                                   |
++------------------------------------+-----------------------------------+
+|                                    | on fast page fault path::         |
+|                                    |                                   |
+|                                    |    spte.W = 1                     |
+|                                    |                                   |
+|                                    | memory write on the spte::        |
+|                                    |                                   |
+|                                    |    spte.Dirty = 1                 |
++------------------------------------+-----------------------------------+
+|  ::                                |                                   |
+|                                    |                                   |
+|   else                             |                                   |
+|     old_spte = xchg(spte, 0ull)    |                                   |
+|   if (old_spte.Accessed == 1)      |                                   |
+|     kvm_set_pfn_accessed(spte.pfn);|                                   |
+|   if (old_spte.Dirty == 1)         |                                   |
+|     kvm_set_pfn_dirty(spte.pfn);   |                                   |
+|     OOPS!!!                        |                                   |
++------------------------------------+-----------------------------------+
+
+The Dirty bit is lost in this case.
+
+In order to avoid this kind of issue, we always treat the spte as "volatile"
+if it can be updated out of mmu-lock, see spte_has_volatile_bits(), it means,
+the spte is always atomically updated in this case.
+
+3) flush tlbs due to spte updated
+
+If the spte is updated from writable to readonly, we should flush all TLBs,
+otherwise rmap_write_protect will find a read-only spte, even though the
+writable spte might be cached on a CPU's TLB.
+
+As mentioned before, the spte can be updated to writable out of mmu-lock on
+fast page fault path, in order to easily audit the path, we see if TLBs need
+be flushed caused by this reason in mmu_spte_update() since this is a common
+function to update spte (present -> present).
+
+Since the spte is "volatile" if it can be updated out of mmu-lock, we always
+atomically update the spte, the race caused by fast page fault can be avoided,
+See the comments in spte_has_volatile_bits() and mmu_spte_update().
+
+Lockless Access Tracking:
+
+This is used for Intel CPUs that are using EPT but do not support the EPT A/D
+bits. In this case, PTEs are tagged as A/D disabled (using ignored bits), and
+when the KVM MMU notifier is called to track accesses to a page (via
+kvm_mmu_notifier_clear_flush_young), it marks the PTE not-present in hardware
+by clearing the RWX bits in the PTE and storing the original R & X bits in more
+unused/ignored bits. When the VM tries to access the page later on, a fault is
+generated and the fast page fault mechanism described above is used to
+atomically restore the PTE to a Present state. The W bit is not saved when the
+PTE is marked for access tracking and during restoration to the Present state,
+the W bit is set depending on whether or not it was a write access. If it
+wasn't, then the W bit will remain clear until a write access happens, at which
+time it will be set using the Dirty tracking mechanism described above.
+
+3. Reference
+------------
+
+``kvm_lock``
+^^^^^^^^^^^^
+
+:Type:		mutex
+:Arch:		any
+:Protects:	- vm_list
+
+``kvm_count_lock``
+^^^^^^^^^^^^^^^^^^
+
+:Type:		raw_spinlock_t
+:Arch:		any
+:Protects:	- hardware virtualization enable/disable
+:Comment:	'raw' because hardware enabling/disabling must be atomic /wrt
+		migration.
+
+``kvm->mn_invalidate_lock``
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+:Type:          spinlock_t
+:Arch:          any
+:Protects:      mn_active_invalidate_count, mn_memslots_update_rcuwait
+
+``kvm_arch::tsc_write_lock``
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+:Type:		raw_spinlock_t
+:Arch:		x86
+:Protects:	- kvm_arch::{last_tsc_write,last_tsc_nsec,last_tsc_offset}
+		- tsc offset in vmcb
+:Comment:	'raw' because updating the tsc offsets must not be preempted.
+
+``kvm->mmu_lock``
+^^^^^^^^^^^^^^^^^
+:Type:		spinlock_t or rwlock_t
+:Arch:		any
+:Protects:	-shadow page/shadow tlb entry
+:Comment:	it is a spinlock since it is used in mmu notifier.
+
+``kvm->srcu``
+^^^^^^^^^^^^^
+:Type:		srcu lock
+:Arch:		any
+:Protects:	- kvm->memslots
+		- kvm->buses
+:Comment:	The srcu read lock must be held while accessing memslots (e.g.
+		when using gfn_to_* functions) and while accessing in-kernel
+		MMIO/PIO address->device structure mapping (kvm->buses).
+		The srcu index can be stored in kvm_vcpu->srcu_idx per vcpu
+		if it is needed by multiple functions.
+
+``kvm->slots_arch_lock``
+^^^^^^^^^^^^^^^^^^^^^^^^
+:Type:          mutex
+:Arch:          any (only needed on x86 though)
+:Protects:      any arch-specific fields of memslots that have to be modified
+                in a ``kvm->srcu`` read-side critical section.
+:Comment:       must be held before reading the pointer to the current memslots,
+                until after all changes to the memslots are complete
+
+``wakeup_vcpus_on_cpu_lock``
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+:Type:		spinlock_t
+:Arch:		x86
+:Protects:	wakeup_vcpus_on_cpu
+:Comment:	This is a per-CPU lock and it is used for VT-d posted-interrupts.
+		When VT-d posted-interrupts is supported and the VM has assigned
+		devices, we put the blocked vCPU on the list blocked_vcpu_on_cpu
+		protected by blocked_vcpu_on_cpu_lock, when VT-d hardware issues
+		wakeup notification event since external interrupts from the
+		assigned devices happens, we will find the vCPU on the list to
+		wakeup.