<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/Documentation/admin-guide/sysctl/net.rst, branch v7.2-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'net-next-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next</title>
<updated>2026-06-17T07:17:00+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-06-17T07:17:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b85966adbf5de0668a815c6e3527f87e0c387fb4'/>
<id>b85966adbf5de0668a815c6e3527f87e0c387fb4</id>
<content type='text'>
Pull networking updates from Jakub Kicinski:
 "Core &amp; protocols:

   - Work on removing rtnl_lock protection throughout the stack
     continues. In this chapter:
       - don't use rtnl_lock for IPv6 multicast routing configuration
       - don't take rtnl_lock in ethtool for modern drivers
       - prepare Qdisc dump callbacks for rtnl_lock removal

   - Support dumping just ifindex + name of all interfaces, under RCU.
     It's a common operation for Netlink CLI tools (when translating
     names to ifindexes) and previously required full rtnl_lock.

   - Support dumping qdiscs and page pools for a specific netdev. Even
     tho user space wants a dump of all netdevs, most of the time, the
     OOO programming model results in repeating the dump for each
     netdev. Which, in absence of a cache, leads to a O(n^2) behavior.

   - Flush nexthops once on multi-nexthop removal (e.g. when device goes
     down), another O(n^2) -&gt; O(n) improvement.

   - Rehash locally generated traffic to a different nexthop on
     retransmit timeout.

   - Honor oif when choosing nexthop for locally generated IPv6 traffic.

   - Convert TCP Auth Option to crypto library, and drop non-RFC algos.

   - Increase subflow limits in MPTCP to 64 and endpoint limit to 256.

   - Support MPTCP signaling of IPv6 address + port (ADD_ADDR). We need
     to selectively skip reporting of the standard TCP Timestamp option,
     because they won't fit into the header space together (12 + 30 &gt;
     40).

   - Support using bridge neighbor suppression, Duplicate Address
     Detection, Gratuitous ARP and unsolicited NA forwarding - in EVPN
     deployments, e.g. VXLAN fabrics (IPv4 and IPv6).

   - Improve link state reporting for upper netdevs (e.g. macvlan) over
     tunnel devices (again, mostly for EVPN deployments).

   - Support binding GENEVE tunnels to a local address.

   - Speed up UDP tunnel destruction (remove one synchronize_rcu()).

   - Support exponential field encoding in multicast (IGMPv3 and MLDv2).

   - Support attaching PSP crypto offload to containers (veth, netkit).

   - Add a new IPSec Netlink message XFRM_MSG_MIGRATE_STATE that allows
     migrating individual IPsec SAs independently of their policies.

     The existing XFRM_MSG_MIGRATE is tightly coupled to policy+SA
     migration, lacks SPI for unique SA identification, and cannot
     express reqid changes or migrate Transport mode selectors.

     The new interface identifies the SA via SPI and mark, supports
     reqid changes, address family changes, encap removal, and uses an
     atomic create+install flow under x-&gt;lock to prevent SN/IV reuse
     during AEAD SA migration.

   - Implement GRO/GSO support for PPPoE.

   - Convert sockopt callbacks in a number of protocols to iov_iter.

  Cross-tree stuff:

   - Remove support for Crypto TFM cloning (unblocked after the TCP Auth
     Option rework). This feature regressed performance for all crypto
     API users, since it changed crypto transformation objects into
     reference-counted objects.

   - Add FCrypt-PCBC implementation to rxrpc and remove it from the
     global crypto API as obsolete and insecure.

  Wireless:

   - Major rework of station bandwidth handling, fixing issues with
     lower capability than AP.

   - Cleanups for EMLSR spec issues (drafts differed).

   - More Neighbor Awareness Networking (Wi-Fi Aware) work (multicast,
     schedule improvements, multi-station etc.)

   - Some Ultra High Reliability (UHR) / IEEE 802.11bn (D1.4) work
     (e.g. non-primary channel access, UHR DBE support).

   - Fine Timing Measurement ranging (i.e. distance measurement) APIs.

  Netfilter:

   - Use per-rule hash initval in nf_conncount. This avoids unnecessary
     lock contention with short keys (e.g. conntrack zones) in different
     namespaces.

   - Various safety improvements, both in packet parsing and object
     lifetimes. Notably add refcounts to conntrack timeout policy.

  Deletions:

   - Remove TLS + sockmap integration. TLS wants to pin user pages to
     avoid a copy, and sockmap wants to write to the input stream. More
     work on this integration is clearly needed, and we can't find any
     users (original author admitted that they never deployed it).

   - Remove support for TLS offload with TCP Offload Engine (the far
     more common opportunistic offload is retained). The locking looks
     unfixable (driver sleeps under TCP spin locks) and people from the
     vendor that added this are AWOL.

   - Remove more ATM code, trying to leave behind only what PPPoATM
     needs, AAL5 and br2684 with permanent circuits.

   - Remove AppleTalk. Let it join hamradio in our out of tree protocol
     graveyard, I mean, repository.

   - Disable 32-bit x_tables compatibility (32bit binaries on 64bit
     kernel) interface in user namespaces. To be deleted completely,
     soon.

   - Remove 5/10 MHz support from cfg80211/mac80211.

  Drivers:

   - Software:
       - Support DEVMEM/DMABUF Tx over NETMEM_TX_NO_DMA devices (netkit)
       - bonding: add knob to strictly follow 802.3ad for link state

   - New drivers:
       - Alibaba Elastic Ethernet Adaptor (cloud vNIC).
       - NXP NETC switch within i.MX94.

   - DPLL:
       - Add operational state to pins (implement in zl3073x).
       - Add generic DPLL type, for daisy-chaining DPLLs (implement in ice).

   - Ethernet high-speed NICs:
       - Huawei (hinic3):
           - enhance tc flow offload support with queue selection,
             tunnels
       - nVidia/Mellanox:
           - avoid over-copying payload to the skb's linear part (up to
             60% win for LRO on slow CPUs like ARM64 V2)
           - expose more per-queue stats over the standard API
           - support additional, unprivileged PFs in the DPU
             configuration
           - support Socket Direct (multi-PF) with switchdev offloads
           - add a pool / frag allocator for DMA mapped buffers for
             control objects, save memory on systems with 64kB page size
           - take advantage of the ability to dynamically change RSS
             table size, even when table is configured by the user
           - increase the max RSS table size for even traffic
             distribution

   - Ethernet NICs:
       - Marvell/Aquantia:
           - AQC113 PTP support
       - Realtek USB (r8152):
           - support 10Gbit Link Speeds and Energy-Efficient Ethernet
             (EEE)
           - support firmware loaded (for RTL8157/RTL8159)
           - support for the RTL8159
       - Intel (ixgbe):
           - support Energy-Efficient Ethernet (EEE) on E610 devices

   - Ethernet switches:
       - Airoha:
           - support multiple netdevs on a single GDM block / port
       - Marvell (mv88e6xxx):
           - support SERDES of mv88e6321
       - Microchip (ksz8/9):
           - rework the driver callbacks to remove one indirection layer
       - Motorcomm (yt921x):
           - support port rate policing
           - support TBF qdisc offload
           - support ACL/flower offload
       - nVidia/Mellanox:
           - expose per-PG rx_discards
       - Realtek:
           - rtl8365mb: bridge offloading and VLAN support

   - Ethernet PHYs:
       - Airoha:
           - support Airoha AN8801R Gigabit PHYs.
       - Micrel:
           - implement 3 low-loss cable tunables
       - Realtek:
           - support MDI swapping for RTL8226-CG
           - support MDIO for RTL931x
       - Qualcomm:
           - at803x: Rx and Tx clock management for IPQ5018 PHY
       - Motorcomm:
           - support YT8522 100M RMII PHY
           - set drive strength in YT8531s RGMII
       - TI:
           - dp83822: add optional external PHY clock

   - Bluetooth:
       - hci_sync: add support for HCI_LE_Set_Host_Feature [v2]
       - SMP: use AES-CMAC library API
       - Intel:
           - support Product level reset
           - support smart trigger dump
       - Mediatek:
           - add event filter to filter specific event
       - Realtek:
           - fix RTL8761B/BU broken LE extended scan

   - WiFi:
       - Broadcom (b43):
           - new support for a 11n device
       - MediaTek (mt76):
           - support mt7927
           - mt792x: broken usb transport detection
           - mt7921: regulatory improvements
       - Qualcomm (ath9k):
           - GPIO interface improvements
       - Qualcomm (ath12k):
           - WDS support
           - replace dynamic memory allocation in WMI Rx path
           - thermal throttling/cooling device support
           - 6 GHz incumbent interference detection
           - channel 177 in 5 GHz
       - Realtek (rt89):
           - RTL8922AU support
           - USB 3 mode switch for performance
           - better monitor radiotap support
           - RTL8922DE preparations"

* tag 'net-next-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1778 commits)
  ipv4: fib_rule: Move fib4_rules_exit() to -&gt;exit().
  net: serialize netif_running() check in enqueue_to_backlog()
  net: skmsg: preserve sg.copy across SG transforms
  appletalk: move the protocol out of tree
  appletalk: stop storing per-interface state in struct net_device
  selftests/bpf: test that TLS crypto is rejected on a sockmap socket
  selftests/bpf: drop the unused kTLS program from test_sockmap
  selftests/bpf: remove sockmap + ktls tests
  tls: remove dead sockmap (psock) handling from the SW path
  tls: reject the combination of TLS and sockmap
  atm: remove orphaned uAPI for deleted drivers, protocols and SVCs
  atm: remove unused ATM PHY operations
  atm: remove the unused pre_send and send_bh device operations
  atm: remove the unused change_qos device operation
  atm: remove SVC socket support and the signaling daemon interface
  atm: remove the local ATM (NSAP) address registry
  atm: remove dead SONET PHY ioctls
  atm: remove the unused send_oam / push_oam callbacks
  atm: remove AAL3/4 transport support
  net: dsa: sja1105: fix lastused timestamp in flower stats
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking updates from Jakub Kicinski:
 "Core &amp; protocols:

   - Work on removing rtnl_lock protection throughout the stack
     continues. In this chapter:
       - don't use rtnl_lock for IPv6 multicast routing configuration
       - don't take rtnl_lock in ethtool for modern drivers
       - prepare Qdisc dump callbacks for rtnl_lock removal

   - Support dumping just ifindex + name of all interfaces, under RCU.
     It's a common operation for Netlink CLI tools (when translating
     names to ifindexes) and previously required full rtnl_lock.

   - Support dumping qdiscs and page pools for a specific netdev. Even
     tho user space wants a dump of all netdevs, most of the time, the
     OOO programming model results in repeating the dump for each
     netdev. Which, in absence of a cache, leads to a O(n^2) behavior.

   - Flush nexthops once on multi-nexthop removal (e.g. when device goes
     down), another O(n^2) -&gt; O(n) improvement.

   - Rehash locally generated traffic to a different nexthop on
     retransmit timeout.

   - Honor oif when choosing nexthop for locally generated IPv6 traffic.

   - Convert TCP Auth Option to crypto library, and drop non-RFC algos.

   - Increase subflow limits in MPTCP to 64 and endpoint limit to 256.

   - Support MPTCP signaling of IPv6 address + port (ADD_ADDR). We need
     to selectively skip reporting of the standard TCP Timestamp option,
     because they won't fit into the header space together (12 + 30 &gt;
     40).

   - Support using bridge neighbor suppression, Duplicate Address
     Detection, Gratuitous ARP and unsolicited NA forwarding - in EVPN
     deployments, e.g. VXLAN fabrics (IPv4 and IPv6).

   - Improve link state reporting for upper netdevs (e.g. macvlan) over
     tunnel devices (again, mostly for EVPN deployments).

   - Support binding GENEVE tunnels to a local address.

   - Speed up UDP tunnel destruction (remove one synchronize_rcu()).

   - Support exponential field encoding in multicast (IGMPv3 and MLDv2).

   - Support attaching PSP crypto offload to containers (veth, netkit).

   - Add a new IPSec Netlink message XFRM_MSG_MIGRATE_STATE that allows
     migrating individual IPsec SAs independently of their policies.

     The existing XFRM_MSG_MIGRATE is tightly coupled to policy+SA
     migration, lacks SPI for unique SA identification, and cannot
     express reqid changes or migrate Transport mode selectors.

     The new interface identifies the SA via SPI and mark, supports
     reqid changes, address family changes, encap removal, and uses an
     atomic create+install flow under x-&gt;lock to prevent SN/IV reuse
     during AEAD SA migration.

   - Implement GRO/GSO support for PPPoE.

   - Convert sockopt callbacks in a number of protocols to iov_iter.

  Cross-tree stuff:

   - Remove support for Crypto TFM cloning (unblocked after the TCP Auth
     Option rework). This feature regressed performance for all crypto
     API users, since it changed crypto transformation objects into
     reference-counted objects.

   - Add FCrypt-PCBC implementation to rxrpc and remove it from the
     global crypto API as obsolete and insecure.

  Wireless:

   - Major rework of station bandwidth handling, fixing issues with
     lower capability than AP.

   - Cleanups for EMLSR spec issues (drafts differed).

   - More Neighbor Awareness Networking (Wi-Fi Aware) work (multicast,
     schedule improvements, multi-station etc.)

   - Some Ultra High Reliability (UHR) / IEEE 802.11bn (D1.4) work
     (e.g. non-primary channel access, UHR DBE support).

   - Fine Timing Measurement ranging (i.e. distance measurement) APIs.

  Netfilter:

   - Use per-rule hash initval in nf_conncount. This avoids unnecessary
     lock contention with short keys (e.g. conntrack zones) in different
     namespaces.

   - Various safety improvements, both in packet parsing and object
     lifetimes. Notably add refcounts to conntrack timeout policy.

  Deletions:

   - Remove TLS + sockmap integration. TLS wants to pin user pages to
     avoid a copy, and sockmap wants to write to the input stream. More
     work on this integration is clearly needed, and we can't find any
     users (original author admitted that they never deployed it).

   - Remove support for TLS offload with TCP Offload Engine (the far
     more common opportunistic offload is retained). The locking looks
     unfixable (driver sleeps under TCP spin locks) and people from the
     vendor that added this are AWOL.

   - Remove more ATM code, trying to leave behind only what PPPoATM
     needs, AAL5 and br2684 with permanent circuits.

   - Remove AppleTalk. Let it join hamradio in our out of tree protocol
     graveyard, I mean, repository.

   - Disable 32-bit x_tables compatibility (32bit binaries on 64bit
     kernel) interface in user namespaces. To be deleted completely,
     soon.

   - Remove 5/10 MHz support from cfg80211/mac80211.

  Drivers:

   - Software:
       - Support DEVMEM/DMABUF Tx over NETMEM_TX_NO_DMA devices (netkit)
       - bonding: add knob to strictly follow 802.3ad for link state

   - New drivers:
       - Alibaba Elastic Ethernet Adaptor (cloud vNIC).
       - NXP NETC switch within i.MX94.

   - DPLL:
       - Add operational state to pins (implement in zl3073x).
       - Add generic DPLL type, for daisy-chaining DPLLs (implement in ice).

   - Ethernet high-speed NICs:
       - Huawei (hinic3):
           - enhance tc flow offload support with queue selection,
             tunnels
       - nVidia/Mellanox:
           - avoid over-copying payload to the skb's linear part (up to
             60% win for LRO on slow CPUs like ARM64 V2)
           - expose more per-queue stats over the standard API
           - support additional, unprivileged PFs in the DPU
             configuration
           - support Socket Direct (multi-PF) with switchdev offloads
           - add a pool / frag allocator for DMA mapped buffers for
             control objects, save memory on systems with 64kB page size
           - take advantage of the ability to dynamically change RSS
             table size, even when table is configured by the user
           - increase the max RSS table size for even traffic
             distribution

   - Ethernet NICs:
       - Marvell/Aquantia:
           - AQC113 PTP support
       - Realtek USB (r8152):
           - support 10Gbit Link Speeds and Energy-Efficient Ethernet
             (EEE)
           - support firmware loaded (for RTL8157/RTL8159)
           - support for the RTL8159
       - Intel (ixgbe):
           - support Energy-Efficient Ethernet (EEE) on E610 devices

   - Ethernet switches:
       - Airoha:
           - support multiple netdevs on a single GDM block / port
       - Marvell (mv88e6xxx):
           - support SERDES of mv88e6321
       - Microchip (ksz8/9):
           - rework the driver callbacks to remove one indirection layer
       - Motorcomm (yt921x):
           - support port rate policing
           - support TBF qdisc offload
           - support ACL/flower offload
       - nVidia/Mellanox:
           - expose per-PG rx_discards
       - Realtek:
           - rtl8365mb: bridge offloading and VLAN support

   - Ethernet PHYs:
       - Airoha:
           - support Airoha AN8801R Gigabit PHYs.
       - Micrel:
           - implement 3 low-loss cable tunables
       - Realtek:
           - support MDI swapping for RTL8226-CG
           - support MDIO for RTL931x
       - Qualcomm:
           - at803x: Rx and Tx clock management for IPQ5018 PHY
       - Motorcomm:
           - support YT8522 100M RMII PHY
           - set drive strength in YT8531s RGMII
       - TI:
           - dp83822: add optional external PHY clock

   - Bluetooth:
       - hci_sync: add support for HCI_LE_Set_Host_Feature [v2]
       - SMP: use AES-CMAC library API
       - Intel:
           - support Product level reset
           - support smart trigger dump
       - Mediatek:
           - add event filter to filter specific event
       - Realtek:
           - fix RTL8761B/BU broken LE extended scan

   - WiFi:
       - Broadcom (b43):
           - new support for a 11n device
       - MediaTek (mt76):
           - support mt7927
           - mt792x: broken usb transport detection
           - mt7921: regulatory improvements
       - Qualcomm (ath9k):
           - GPIO interface improvements
       - Qualcomm (ath12k):
           - WDS support
           - replace dynamic memory allocation in WMI Rx path
           - thermal throttling/cooling device support
           - 6 GHz incumbent interference detection
           - channel 177 in 5 GHz
       - Realtek (rt89):
           - RTL8922AU support
           - USB 3 mode switch for performance
           - better monitor radiotap support
           - RTL8922DE preparations"

* tag 'net-next-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1778 commits)
  ipv4: fib_rule: Move fib4_rules_exit() to -&gt;exit().
  net: serialize netif_running() check in enqueue_to_backlog()
  net: skmsg: preserve sg.copy across SG transforms
  appletalk: move the protocol out of tree
  appletalk: stop storing per-interface state in struct net_device
  selftests/bpf: test that TLS crypto is rejected on a sockmap socket
  selftests/bpf: drop the unused kTLS program from test_sockmap
  selftests/bpf: remove sockmap + ktls tests
  tls: remove dead sockmap (psock) handling from the SW path
  tls: reject the combination of TLS and sockmap
  atm: remove orphaned uAPI for deleted drivers, protocols and SVCs
  atm: remove unused ATM PHY operations
  atm: remove the unused pre_send and send_bh device operations
  atm: remove the unused change_qos device operation
  atm: remove SVC socket support and the signaling daemon interface
  atm: remove the local ATM (NSAP) address registry
  atm: remove dead SONET PHY ioctls
  atm: remove the unused send_oam / push_oam callbacks
  atm: remove AAL3/4 transport support
  net: dsa: sja1105: fix lastused timestamp in flower stats
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>appletalk: move the protocol out of tree</title>
<updated>2026-06-16T21:37:06+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2026-06-15T22:29:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8a398a0c189ead8bbce98f5be70b8ea0e30b21f8'/>
<id>8a398a0c189ead8bbce98f5be70b8ea0e30b21f8</id>
<content type='text'>
AppleTalk has been removed in MacOS X 10.6 (Snow Leopard), in 2009,
according to Wikipedia. We recently got a burst of AI generated
fixes to this protocol which nobody is reviewing.

Let AppleTalk follow AX.25 and hamradio out of the Linux tree.
We we will maintain the code at: github.com/linux-netdev/mod-orphan
for anyone interested in playing with it.

Retain the uAPI for now. No strong reason, simply because I suspect
keeping it will be less controversial.

Acked-by: Stephen Hemminger &lt;stephen@networkplumber.org&gt;
Link: https://patch.msgid.link/20260615222935.947233-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
AppleTalk has been removed in MacOS X 10.6 (Snow Leopard), in 2009,
according to Wikipedia. We recently got a burst of AI generated
fixes to this protocol which nobody is reviewing.

Let AppleTalk follow AX.25 and hamradio out of the Linux tree.
We we will maintain the code at: github.com/linux-netdev/mod-orphan
for anyone interested in playing with it.

Retain the uAPI for now. No strong reason, simply because I suspect
keeping it will be less controversial.

Acked-by: Stephen Hemminger &lt;stephen@networkplumber.org&gt;
Link: https://patch.msgid.link/20260615222935.947233-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>docs: sysctl/net: Remove ax25, netrom, rose entries</title>
<updated>2026-05-25T20:31:44+00:00</updated>
<author>
<name>Costa Shulyupin</name>
<email>costa.shul@redhat.com</email>
</author>
<published>2026-05-15T18:01:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d7391997ea9c93137bc855fd2b55392acbb7ef63'/>
<id>d7391997ea9c93137bc855fd2b55392acbb7ef63</id>
<content type='text'>
These networking subsystems were removed in commit dd8d4bc28ad7
("net: remove ax25 and amateur radio (hamradio) subsystem"),
but the sysctl directory table still listed them.

Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Costa Shulyupin &lt;costa.shul@redhat.com&gt;
Acked-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Signed-off-by: Jonathan Corbet &lt;corbet@lwn.net&gt;
Message-ID: &lt;20260515180200.1490926-1-costa.shul@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
These networking subsystems were removed in commit dd8d4bc28ad7
("net: remove ax25 and amateur radio (hamradio) subsystem"),
but the sysctl directory table still listed them.

Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Costa Shulyupin &lt;costa.shul@redhat.com&gt;
Acked-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Signed-off-by: Jonathan Corbet &lt;corbet@lwn.net&gt;
Message-ID: &lt;20260515180200.1490926-1-costa.shul@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>vsock: add G2H fallback for CIDs not owned by H2G transport</title>
<updated>2026-03-12T09:59:36+00:00</updated>
<author>
<name>Alexander Graf</name>
<email>graf@amazon.com</email>
</author>
<published>2026-03-04T23:00:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0de607dc4fd80ede3b2a35e8a72f99c7a0bbc321'/>
<id>0de607dc4fd80ede3b2a35e8a72f99c7a0bbc321</id>
<content type='text'>
When no H2G transport is loaded, vsock currently routes all CIDs to the
G2H transport (commit 65b422d9b61b ("vsock: forward all packets to the
host when no H2G is registered"). Extend that existing behavior: when
an H2G transport is loaded but does not claim a given CID, the
connection falls back to G2H in the same way.

This matters in environments like Nitro Enclaves, where an instance may
run nested VMs via vhost-vsock (H2G) while also needing to reach sibling
enclaves at higher CIDs through virtio-vsock-pci (G2H). With the old
code, any CID &gt; 2 was unconditionally routed to H2G when vhost was
loaded, making those enclaves unreachable without setting
VMADDR_FLAG_TO_HOST explicitly on every connect.

Requiring every application to set VMADDR_FLAG_TO_HOST creates friction:
tools like socat, iperf, and others would all need to learn about it.
The flag was introduced 6 years ago and I am still not aware of any tool
that supports it. Even if there was support, it would be cumbersome to
use. The most natural experience is a single CID address space where H2G
only wins for CIDs it actually owns, and everything else falls through to
G2H, extending the behavior that already exists when H2G is absent.

To give user space at least a hint that the kernel applied this logic,
automatically set the VMADDR_FLAG_TO_HOST on the remote address so it
can determine the path taken via getpeername().

Add a per-network namespace sysctl net.vsock.g2h_fallback (default 1).
At 0 it forces strict routing: H2G always wins for CID &gt; VMADDR_CID_HOST,
or ENODEV if H2G is not loaded.

Signed-off-by: Alexander Graf &lt;graf@amazon.com&gt;
Tested-by: syzbot@syzkaller.appspotmail.com
Reviewed-by: Stefano Garzarella &lt;sgarzare@redhat.com&gt;
Link: https://patch.msgid.link/20260304230027.59857-1-graf@amazon.com
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When no H2G transport is loaded, vsock currently routes all CIDs to the
G2H transport (commit 65b422d9b61b ("vsock: forward all packets to the
host when no H2G is registered"). Extend that existing behavior: when
an H2G transport is loaded but does not claim a given CID, the
connection falls back to G2H in the same way.

This matters in environments like Nitro Enclaves, where an instance may
run nested VMs via vhost-vsock (H2G) while also needing to reach sibling
enclaves at higher CIDs through virtio-vsock-pci (G2H). With the old
code, any CID &gt; 2 was unconditionally routed to H2G when vhost was
loaded, making those enclaves unreachable without setting
VMADDR_FLAG_TO_HOST explicitly on every connect.

Requiring every application to set VMADDR_FLAG_TO_HOST creates friction:
tools like socat, iperf, and others would all need to learn about it.
The flag was introduced 6 years ago and I am still not aware of any tool
that supports it. Even if there was support, it would be cumbersome to
use. The most natural experience is a single CID address space where H2G
only wins for CIDs it actually owns, and everything else falls through to
G2H, extending the behavior that already exists when H2G is absent.

To give user space at least a hint that the kernel applied this logic,
automatically set the VMADDR_FLAG_TO_HOST on the remote address so it
can determine the path taken via getpeername().

Add a per-network namespace sysctl net.vsock.g2h_fallback (default 1).
At 0 it forces strict routing: H2G always wins for CID &gt; VMADDR_CID_HOST,
or ENODEV if H2G is not loaded.

Signed-off-by: Alexander Graf &lt;graf@amazon.com&gt;
Tested-by: syzbot@syzkaller.appspotmail.com
Reviewed-by: Stefano Garzarella &lt;sgarzare@redhat.com&gt;
Link: https://patch.msgid.link/20260304230027.59857-1-graf@amazon.com
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>vsock: document write-once behavior of the child_ns_mode sysctl</title>
<updated>2026-02-26T10:10:03+00:00</updated>
<author>
<name>Bobby Eshleman</name>
<email>bobbyeshleman@meta.com</email>
</author>
<published>2026-02-23T22:38:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b6302e057fdc8f199ddae736ecdf45029f892e5c'/>
<id>b6302e057fdc8f199ddae736ecdf45029f892e5c</id>
<content type='text'>
Update the vsock child_ns_mode documentation to include the new
write-once semantics of setting child_ns_mode. The semantics are
implemented in a preceding patch in this series.

Signed-off-by: Bobby Eshleman &lt;bobbyeshleman@meta.com&gt;
Reviewed-by: Stefano Garzarella &lt;sgarzare@redhat.com&gt;
Link: https://patch.msgid.link/20260223-vsock-ns-write-once-v3-3-c0cde6959923@meta.com
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Update the vsock child_ns_mode documentation to include the new
write-once semantics of setting child_ns_mode. The semantics are
implemented in a preceding patch in this series.

Signed-off-by: Bobby Eshleman &lt;bobbyeshleman@meta.com&gt;
Reviewed-by: Stefano Garzarella &lt;sgarzare@redhat.com&gt;
Link: https://patch.msgid.link/20260223-vsock-ns-write-once-v3-3-c0cde6959923@meta.com
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>vsock: document namespace mode sysctls</title>
<updated>2026-02-18T01:20:21+00:00</updated>
<author>
<name>Stefano Garzarella</name>
<email>sgarzare@redhat.com</email>
</author>
<published>2026-02-16T16:31:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a07c33c6f2fc693bf9c67514fcc15d9d417f390d'/>
<id>a07c33c6f2fc693bf9c67514fcc15d9d417f390d</id>
<content type='text'>
Add documentation for the vsock per-namespace sysctls (`ns_mode` and
`child_ns_mode`) to Documentation/admin-guide/sysctl/net.rst.
These sysctls were introduced by commit eafb64f40ca4 ("vsock: add
netns to vsock core").

Document the two namespace modes (`global` and `local`), the
inheritance behavior of `child_ns_mode`, and the restriction preventing
local namespaces from setting `child_ns_mode` to `global`.

Signed-off-by: Stefano Garzarella &lt;sgarzare@redhat.com&gt;
Tested-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Acked-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Link: https://patch.msgid.link/20260216163147.236844-1-sgarzare@redhat.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add documentation for the vsock per-namespace sysctls (`ns_mode` and
`child_ns_mode`) to Documentation/admin-guide/sysctl/net.rst.
These sysctls were introduced by commit eafb64f40ca4 ("vsock: add
netns to vsock core").

Document the two namespace modes (`global` and `local`), the
inheritance behavior of `child_ns_mode`, and the restriction preventing
local namespaces from setting `child_ns_mode` to `global`.

Signed-off-by: Stefano Garzarella &lt;sgarzare@redhat.com&gt;
Tested-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Acked-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Link: https://patch.msgid.link/20260216163147.236844-1-sgarzare@redhat.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: expand NETDEV_RSS_KEY_LEN to 256 bytes</title>
<updated>2026-01-25T21:20:46+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2026-01-22T19:03:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=37b0ea8fef56ccc29bd5a07f235ac218f7f98379'/>
<id>37b0ea8fef56ccc29bd5a07f235ac218f7f98379</id>
<content type='text'>
NETDEV_RSS_KEY_LEN has been set to 52 bytes in 2014, until now.

Jakub suggested we bump the size to 128 bytes or more.

Some drivers (like idpf) were already working around the core limit.

Since this change might cause some issues in admin scripts,
bump it directly to 256 in one go.

tjbp26:~# cat /proc/sys/net/core/netdev_rss_key | wc -c
768

tjbp26:~# ethtool -x eth1
RX flow hash indirection table for eth1 with 32 RX ring(s):
...
RSS hash key:
fe:16:5b:2f:93:85:c2:c9:c1:ef:bd:60:c6:e0:2b:99:4d:bf:b7:14:c8:1e:8d:cb:31:17:51:da:55:eb:91:d9:9e:f9:89:9b:44:a1:dc:08:72:3a:b3:d6:31:86:9a:fe:02:3a:0d:eb:a1:7c:f5:a3:51:3b:08:56:c9:3f:71:69:01:ba:70:38
RSS hash function:
    toeplitz: on
    xor: off
    crc32: off

Suggested-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Link: https://lore.kernel.org/netdev/20260122075206.504ec591@kernel.org/
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Willem de Bruijn &lt;willemb@google.com&gt;
Link: https://patch.msgid.link/20260122190349.2771064-1-edumazet@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
NETDEV_RSS_KEY_LEN has been set to 52 bytes in 2014, until now.

Jakub suggested we bump the size to 128 bytes or more.

Some drivers (like idpf) were already working around the core limit.

Since this change might cause some issues in admin scripts,
bump it directly to 256 in one go.

tjbp26:~# cat /proc/sys/net/core/netdev_rss_key | wc -c
768

tjbp26:~# ethtool -x eth1
RX flow hash indirection table for eth1 with 32 RX ring(s):
...
RSS hash key:
fe:16:5b:2f:93:85:c2:c9:c1:ef:bd:60:c6:e0:2b:99:4d:bf:b7:14:c8:1e:8d:cb:31:17:51:da:55:eb:91:d9:9e:f9:89:9b:44:a1:dc:08:72:3a:b3:d6:31:86:9a:fe:02:3a:0d:eb:a1:7c:f5:a3:51:3b:08:56:c9:3f:71:69:01:ba:70:38
RSS hash function:
    toeplitz: on
    xor: off
    crc32: off

Suggested-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Link: https://lore.kernel.org/netdev/20260122075206.504ec591@kernel.org/
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Willem de Bruijn &lt;willemb@google.com&gt;
Link: https://patch.msgid.link/20260122190349.2771064-1-edumazet@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: add net.core.qdisc_max_burst</title>
<updated>2026-01-13T09:12:11+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2026-01-07T10:41:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ffe4ccd359d006eba559cb1a3c6113144b7fb38c'/>
<id>ffe4ccd359d006eba559cb1a3c6113144b7fb38c</id>
<content type='text'>
In blamed commit, I added a check against the temporary queue
built in __dev_xmit_skb(). Idea was to drop packets early,
before any spinlock was acquired.

if (unlikely(defer_count &gt; READ_ONCE(q-&gt;limit))) {
	kfree_skb_reason(skb, SKB_DROP_REASON_QDISC_DROP);
	return NET_XMIT_DROP;
}

It turned out that HTB Qdisc has a zero q-&gt;limit.
HTB limits packets on a per-class basis.
Some of our tests became flaky.

Add a new sysctl : net.core.qdisc_max_burst to control
how many packets can be stored in the temporary lockless queue.

Also add a new QDISC_BURST_DROP drop reason to better diagnose
future issues.

Thanks Neal !

Fixes: 100dfa74cad9 ("net: dev_queue_xmit() llist adoption")
Reported-and-bisected-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Link: https://patch.msgid.link/20260107104159.3669285-1-edumazet@google.com
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In blamed commit, I added a check against the temporary queue
built in __dev_xmit_skb(). Idea was to drop packets early,
before any spinlock was acquired.

if (unlikely(defer_count &gt; READ_ONCE(q-&gt;limit))) {
	kfree_skb_reason(skb, SKB_DROP_REASON_QDISC_DROP);
	return NET_XMIT_DROP;
}

It turned out that HTB Qdisc has a zero q-&gt;limit.
HTB limits packets on a per-class basis.
Some of our tests became flaky.

Add a new sysctl : net.core.qdisc_max_burst to control
how many packets can be stored in the temporary lockless queue.

Also add a new QDISC_BURST_DROP drop reason to better diagnose
future issues.

Thanks Neal !

Fixes: 100dfa74cad9 ("net: dev_queue_xmit() llist adoption")
Reported-and-bisected-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Link: https://patch.msgid.link/20260107104159.3669285-1-edumazet@google.com
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>net: increase skb_defer_max default to 128</title>
<updated>2025-11-08T03:02:40+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2025-11-06T20:29:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b61785852ed0a0e7dc16b606157e4a0228cd76cf'/>
<id>b61785852ed0a0e7dc16b606157e4a0228cd76cf</id>
<content type='text'>
skb_defer_max value is very conservative, and can be increased
to avoid too many calls to kick_defer_list_purge().

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Reviewed-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Reviewed-by: Jason Xing &lt;kerneljasonxing@gmail.com&gt;
Link: https://patch.msgid.link/20251106202935.1776179-4-edumazet@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
skb_defer_max value is very conservative, and can be increased
to avoid too many calls to kick_defer_list_purge().

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Reviewed-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Reviewed-by: Jason Xing &lt;kerneljasonxing@gmail.com&gt;
Link: https://patch.msgid.link/20251106202935.1776179-4-edumazet@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: Introduce net.core.bypass_prot_mem sysctl.</title>
<updated>2025-10-16T19:04:47+00:00</updated>
<author>
<name>Kuniyuki Iwashima</name>
<email>kuniyu@google.com</email>
</author>
<published>2025-10-14T23:54:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b46ab63181ff973ddce44ebc9ac24b269d42f481'/>
<id>b46ab63181ff973ddce44ebc9ac24b269d42f481</id>
<content type='text'>
If a socket has sk-&gt;sk_bypass_prot_mem flagged, the socket opts out
of the global protocol memory accounting.

Let's control the flag by a new sysctl knob.

The flag is written once during socket(2) and is inherited to child
sockets.

Tested with a script that creates local socket pairs and send()s a
bunch of data without recv()ing.

Setup:

  # mkdir /sys/fs/cgroup/test
  # echo $$ &gt;&gt; /sys/fs/cgroup/test/cgroup.procs
  # sysctl -q net.ipv4.tcp_mem="1000 1000 1000"
  # ulimit -n 524288

Without net.core.bypass_prot_mem, charged to tcp_mem &amp; memcg

  # python3 pressure.py &amp;
  # cat /sys/fs/cgroup/test/memory.stat | grep sock
  sock 22642688 &lt;-------------------------------------- charged to memcg
  # cat /proc/net/sockstat| grep TCP
  TCP: inuse 2006 orphan 0 tw 0 alloc 2008 mem 5376 &lt;-- charged to tcp_mem
  # ss -tn | head -n 5
  State Recv-Q Send-Q Local Address:Port  Peer Address:Port
  ESTAB 2000   0          127.0.0.1:34479    127.0.0.1:53188
  ESTAB 2000   0          127.0.0.1:34479    127.0.0.1:49972
  ESTAB 2000   0          127.0.0.1:34479    127.0.0.1:53868
  ESTAB 2000   0          127.0.0.1:34479    127.0.0.1:53554
  # nstat | grep Pressure || echo no pressure
  TcpExtTCPMemoryPressures        1                  0.0

With net.core.bypass_prot_mem=1, charged to memcg only:

  # sysctl -q net.core.bypass_prot_mem=1
  # python3 pressure.py &amp;
  # cat /sys/fs/cgroup/test/memory.stat | grep sock
  sock 2757468160 &lt;------------------------------------ charged to memcg
  # cat /proc/net/sockstat | grep TCP
  TCP: inuse 2006 orphan 0 tw 0 alloc 2008 mem 0 &lt;- NOT charged to tcp_mem
  # ss -tn | head -n 5
  State Recv-Q Send-Q  Local Address:Port  Peer Address:Port
  ESTAB 111000 0           127.0.0.1:36019    127.0.0.1:49026
  ESTAB 110000 0           127.0.0.1:36019    127.0.0.1:45630
  ESTAB 110000 0           127.0.0.1:36019    127.0.0.1:44870
  ESTAB 111000 0           127.0.0.1:36019    127.0.0.1:45274
  # nstat | grep Pressure || echo no pressure
  no pressure

Signed-off-by: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Reviewed-by: Shakeel Butt &lt;shakeel.butt@linux.dev&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Acked-by: Roman Gushchin &lt;roman.gushchin@linux.dev&gt;
Link: https://patch.msgid.link/20251014235604.3057003-4-kuniyu@google.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If a socket has sk-&gt;sk_bypass_prot_mem flagged, the socket opts out
of the global protocol memory accounting.

Let's control the flag by a new sysctl knob.

The flag is written once during socket(2) and is inherited to child
sockets.

Tested with a script that creates local socket pairs and send()s a
bunch of data without recv()ing.

Setup:

  # mkdir /sys/fs/cgroup/test
  # echo $$ &gt;&gt; /sys/fs/cgroup/test/cgroup.procs
  # sysctl -q net.ipv4.tcp_mem="1000 1000 1000"
  # ulimit -n 524288

Without net.core.bypass_prot_mem, charged to tcp_mem &amp; memcg

  # python3 pressure.py &amp;
  # cat /sys/fs/cgroup/test/memory.stat | grep sock
  sock 22642688 &lt;-------------------------------------- charged to memcg
  # cat /proc/net/sockstat| grep TCP
  TCP: inuse 2006 orphan 0 tw 0 alloc 2008 mem 5376 &lt;-- charged to tcp_mem
  # ss -tn | head -n 5
  State Recv-Q Send-Q Local Address:Port  Peer Address:Port
  ESTAB 2000   0          127.0.0.1:34479    127.0.0.1:53188
  ESTAB 2000   0          127.0.0.1:34479    127.0.0.1:49972
  ESTAB 2000   0          127.0.0.1:34479    127.0.0.1:53868
  ESTAB 2000   0          127.0.0.1:34479    127.0.0.1:53554
  # nstat | grep Pressure || echo no pressure
  TcpExtTCPMemoryPressures        1                  0.0

With net.core.bypass_prot_mem=1, charged to memcg only:

  # sysctl -q net.core.bypass_prot_mem=1
  # python3 pressure.py &amp;
  # cat /sys/fs/cgroup/test/memory.stat | grep sock
  sock 2757468160 &lt;------------------------------------ charged to memcg
  # cat /proc/net/sockstat | grep TCP
  TCP: inuse 2006 orphan 0 tw 0 alloc 2008 mem 0 &lt;- NOT charged to tcp_mem
  # ss -tn | head -n 5
  State Recv-Q Send-Q  Local Address:Port  Peer Address:Port
  ESTAB 111000 0           127.0.0.1:36019    127.0.0.1:49026
  ESTAB 110000 0           127.0.0.1:36019    127.0.0.1:45630
  ESTAB 110000 0           127.0.0.1:36019    127.0.0.1:44870
  ESTAB 111000 0           127.0.0.1:36019    127.0.0.1:45274
  # nstat | grep Pressure || echo no pressure
  no pressure

Signed-off-by: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Reviewed-by: Shakeel Butt &lt;shakeel.butt@linux.dev&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Acked-by: Roman Gushchin &lt;roman.gushchin@linux.dev&gt;
Link: https://patch.msgid.link/20251014235604.3057003-4-kuniyu@google.com
</pre>
</div>
</content>
</entry>
</feed>
