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Jakub Kicinski
8619e429d6 Merge branch 'ipv6-allow-for-nexthop-device-mismatch-with-onlink'
Ido Schimmel says:

====================
ipv6: Allow for nexthop device mismatch with "onlink"

This patchset aligns IPv6 with IPv4 with respect to the "onlink" keyword
and allows IPv6 routes to be configured with a gateway address that is
resolved out of a different interface than the one specified.

Patches #1-#3 are small preparations in the existing "onlink" selftest.

Patch #4 is the actual change. See the commit message for detailed
description and motivation.

Patch #5 adds test cases for both address families, to make sure that
this use case does not regress.
====================

Link: https://patch.msgid.link/20260111120813.159799-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:57:38 -08:00
Ido Schimmel
f8f9ee9d8b selftests: fib-onlink: Add test cases for nexthop device mismatch
Add test cases that verify that when the "onlink" keyword is specified,
both address families (with and without VRF) accept routes with a
gateway address that is reachable via a different interface than the one
specified.

Output without "ipv6: Allow for nexthop device mismatch with "onlink"":

 # ./fib-onlink-tests.sh | grep mismatch
 TEST: nexthop device mismatch                             [ OK ]
 TEST: nexthop device mismatch                             [ OK ]
 TEST: nexthop device mismatch                             [FAIL]
 TEST: nexthop device mismatch                             [FAIL]

Output with "ipv6: Allow for nexthop device mismatch with "onlink"":

 # ./fib-onlink-tests.sh | grep mismatch
 TEST: nexthop device mismatch                             [ OK ]
 TEST: nexthop device mismatch                             [ OK ]
 TEST: nexthop device mismatch                             [ OK ]
 TEST: nexthop device mismatch                             [ OK ]

That is, the IPv4 tests were always passing, but the IPv6 ones only pass
after the specified patch.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260111120813.159799-6-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:57:35 -08:00
Ido Schimmel
b853b94e84 ipv6: Allow for nexthop device mismatch with "onlink"
IPv4 allows for a nexthop device mismatch when the "onlink" keyword is
specified:

 # ip link add name dummy1 up type dummy
 # ip address add 192.0.2.1/24 dev dummy1
 # ip link add name dummy2 up type dummy
 # ip route add 198.51.100.0/24 nexthop via 192.0.2.2 dev dummy2
 Error: Nexthop has invalid gateway.
 # ip route add 198.51.100.0/24 nexthop via 192.0.2.2 dev dummy2 onlink
 # echo $?
 0

This seems to be consistent with the description of "onlink" in the
ip-route man page: "Pretend that the nexthop is directly attached to
this link, even if it does not match any interface prefix".

On the other hand, IPv6 rejects a nexthop device mismatch, even when
"onlink" is specified:

 # ip link add name dummy1 up type dummy
 # ip address add 2001:db8:1::1/64 dev dummy1
 # ip link add name dummy2 up type dummy
 # ip route add 2001:db8:10::/64 nexthop via 2001:db8:1::2 dev dummy2
 RTNETLINK answers: No route to host
 # ip route add 2001:db8:10::/64 nexthop via 2001:db8:1::2 dev dummy2 onlink
 Error: Nexthop has invalid gateway or device mismatch.

This is intentional according to commit fc1e64e109 ("net/ipv6: Add
support for onlink flag") which added IPv6 "onlink" support and states
that "any unicast gateway is allowed as long as the gateway is not a
local address and if it resolves it must match the given device".

The condition was later relaxed in commit 4ed591c8ab ("net/ipv6: Allow
onlink routes to have a device mismatch if it is the default route") to
allow for a nexthop device mismatch if the gateway address is resolved
via the default route:

 # ip link add name dummy1 up type dummy
 # ip route add ::/0 dev dummy1
 # ip link add name dummy2 up type dummy
 # ip route add 2001:db8:10::/64 nexthop via 2001:db8:1::2 dev dummy2
 RTNETLINK answers: No route to host
 # ip route add 2001:db8:10::/64 nexthop via 2001:db8:1::2 dev dummy2 onlink
 # echo $?
 0

While the decision to forbid a nexthop device mismatch in IPv6 seems to
be intentional, it is unclear why it was made. Especially when it
differs from IPv4 and seems to go against the intended behavior of
"onlink".

Therefore, relax the condition further and allow for a nexthop device
mismatch when "onlink" is specified:

 # ip link add name dummy1 up type dummy
 # ip address add 2001:db8:1::1/64 dev dummy1
 # ip link add name dummy2 up type dummy
 # ip route add 2001:db8:10::/64 nexthop via 2001:db8:1::2 dev dummy2 onlink
 # echo $?
 0

The motivating use case is the fact that FRR would like to be able to
configure overlay routes of the following form:

 # ip route add <host-Z> vrf <VRF> encap ip id <ID> src <VTEP-A> dst <VTEP-Z> via <VTEP-Z> dev vxlan0 onlink

Where vxlan0 is in the default VRF in which "VTEP-Z" is reachable via
one of the underlay routes (e.g., via swpX). Without this patch, the
above only works with IPv4, but not with IPv6.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260111120813.159799-5-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:57:34 -08:00
Ido Schimmel
9bf8345fb3 selftests: fib-onlink: Add a test case for IPv4 multicast gateway
A multicast gateway address should be rejected when "onlink" is
specified, but it is only tested as part of the IPv6 tests. Add an
equivalent IPv4 test.

 # ./fib-onlink-tests.sh -v
 [...]
 COMMAND: ip ro add table 254 169.254.101.12/32 via 233.252.0.1 dev veth1 onlink
 Error: Nexthop has invalid gateway.

 TEST: Invalid gw - multicast address                      [ OK ]
 [...]
 COMMAND: ip ro add table 1101 169.254.102.12/32 via 233.252.0.1 dev veth5 onlink
 Error: Nexthop has invalid gateway.

 TEST: Invalid gw - multicast address, VRF                 [ OK ]
 [...]
 Tests passed:  37
 Tests failed:   0

Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260111120813.159799-4-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:57:34 -08:00
Ido Schimmel
0a3419f4ba selftests: fib-onlink: Remove "wrong nexthop device" IPv6 tests
The command in the test fails as expected because IPv6 forbids a nexthop
device mismatch:

 # ./fib-onlink-tests.sh -v
 [...]
 COMMAND: ip -6 ro add table 1101 2001:db8:102::103/128 via 2001:db8:701::64 dev veth5 onlink
 Error: Nexthop has invalid gateway or device mismatch.

 TEST: Gateway resolves to wrong nexthop device - VRF      [ OK ]
 [...]

Where:

 # ip route get 2001:db8:701::64 vrf lisa
 2001:db8:701::64 dev veth7 table 1101 proto kernel src 2001:db8:701::1 metric 256 pref medium

This is in contrast to IPv4 where a nexthop device mismatch is allowed
when "onlink" is specified:

 # ip route get 169.254.7.2 vrf lisa
 169.254.7.2 dev veth7 table 1101 src 169.254.7.1 uid 0
 # ip ro add table 1101 169.254.102.103/32 via 169.254.7.2 dev veth5 onlink
 # echo $?
 0

Remove these tests in preparation for aligning IPv6 with IPv4 and
allowing nexthop device mismatch when "onlink" is specified.

A subsequent patch will add tests that verify that both address families
allow a nexthop device mismatch with "onlink".

Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260111120813.159799-3-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:57:34 -08:00
Ido Schimmel
e5566f6b1d selftests: fib-onlink: Remove "wrong nexthop device" IPv4 tests
According to the test description, these tests fail because of a wrong
nexthop device:

 # ./fib-onlink-tests.sh -v
 [...]
 COMMAND: ip ro add table 254 169.254.101.102/32 via 169.254.3.1 dev veth1 onlink
 Error: Nexthop has invalid gateway.

 TEST: Gateway resolves to wrong nexthop device            [ OK ]
 COMMAND: ip ro add table 1101 169.254.102.103/32 via 169.254.7.1 dev veth5 onlink
 Error: Nexthop has invalid gateway.

 TEST: Gateway resolves to wrong nexthop device - VRF      [ OK ]
 [...]

But this is incorrect. They fail because the gateway addresses are local
addresses:

 # ip -4 address show
 [...]
 28: veth3@if27: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link-netns peer_ns-Urqh3o
     inet 169.254.3.1/24 scope global veth3
 [...]
 32: veth7@if31: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master lisa state UP group default qlen 1000 link-netns peer_ns-Urqh3o
     inet 169.254.7.1/24 scope global veth7

Therefore, using a local address that matches the nexthop device fails
as well:

 # ip ro add table 254 169.254.101.102/32 via 169.254.3.1 dev veth3 onlink
 Error: Nexthop has invalid gateway.

Using a gateway address with a "wrong" nexthop device is actually valid
and allowed:

 # ip route get 169.254.1.2
 169.254.1.2 dev veth1 src 169.254.1.1 uid 0
 # ip ro add table 254 169.254.101.102/32 via 169.254.1.2 dev veth3 onlink
 # echo $?
 0

Remove these tests given that their output is confusing and that the
scenario that they are testing is already covered by other tests.

A subsequent patch will add tests for the nexthop device mismatch
scenario.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260111120813.159799-2-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:57:34 -08:00
Jakub Kicinski
75fe2b7adc Merge branch 'net-phy-introduce-phy-ports-representation'
Maxime Chevallier says:

====================
net: phy: Introduce PHY ports representation

A few important notes:

 - This is only a first phase. It instantiates the port, and leverage
   that to make the MAC <-> PHY <-> SFP usecase simpler.

 - Next phase will deal with controlling the port state, as well as the
   netlink uAPI for that.

 - The end-goal is to enable support for complex port MUX. This
   preliminary work focuses on PHY-driven ports, but this will be
   extended to support muxing at the MII level (Multi-phy, or compo PHY
   + SFP as found on Turris Omnia for example).

 - The naming is definitely not set in stone. I named that "phy_port",
   but this may convey the false sense that this is phylib-specific.
   Even the word "port" is not that great, as it already has several
   different meanings in the net world (switch port, devlink port,
   etc.). I used the term "connector" in the binding.

A bit of history on that work :

The end goal that I personnaly want to achieve is :

            + PHY - RJ45
            |
 MAC - MUX -+ PHY - RJ45

After many discussions here on netdev@, but also at netdevconf[1] and
LPC[2], there appears to be several analoguous designs that exist out
there.

[1] : https://netdevconf.info/0x17/sessions/talk/improving-multi-phy-and-multi-port-interfaces.html
[2] : https://lpc.events/event/18/contributions/1964/ (video isn't the
right one)

Take the MAchiatobin, it has 2 interfaces that looks like this :

 MAC - PHY -+ RJ45
            |
	    + SFP - Whatever the module does

Now, looking at the Turris Omnia, we have :

 MAC - MUX -+ PHY - RJ45
            |
	    + SFP - Whatever the module does

We can find more example of this kind of designs, the common part is
that we expose multiple front-facing media ports. This is what this
current work aims at supporting. As of right now, it does'nt add any
support for muxing, but this will come later on.

This first phase focuses on phy-driven ports only, but there are already
quite some challenges already. For one, we can't really autodetect how
many ports are sitting behind a PHY. That's why this series introduces a
new binding. Describing ports in DT should however be a last-resort
thing when we need to clear some ambiguity about the PHY media-side.

The only use-cases that we have today for multi-port PHYs are combo PHYs
that drive both a Copper port and an SFP (the Macchiatobin case). This
in itself is challenging and this series only addresses part of this
support, by registering a phy_port for the PHY <-> SFP connection. The
SFP module should in the end be considered as a port as well, but that's
not yet the case.

However, because now PHYs can register phy_ports for every media-side
interface they have, they can register the capabilities of their ports,
which allows making the PHY-driver SFP case much more generic.
====================

Link: https://patch.msgid.link/20260108080041.553250-1-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:52:38 -08:00
Maxime Chevallier
62518b5b3d Documentation: networking: Document the phy_port infrastructure
This documentation aims at describing the main goal of the phy_port
infrastructure.

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260108080041.553250-15-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:52:36 -08:00
Maxime Chevallier
bad869b5e4 net: phy: Only rely on phy_port for PHY-driven SFP
Now that all PHY drivers that support downstream SFP have been converted
to phy_port serdes handling, we can make the generic PHY SFP handling
mandatory, thus making all phylib sfp helpers static.

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260108080041.553250-14-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:52:35 -08:00
Maxime Chevallier
154bc3b66c net: phy: qca807x: Support SFP through phy_port interface
QCA8072/8075 may be used as combo-port PHYs, with Serdes (100/1000BaseX)
 and Copper interfaces. The PHY has the ability to read the configuration
it's in.  If the configuration indicates the PHY is in combo mode, allow
registering up to 2 ports.

Register a dedicated set of port ops to handle the serdes port, and rely
on generic phylib SFP support for the SFP handling.

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260108080041.553250-13-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:52:35 -08:00
Maxime Chevallier
4e26a284b9 net: phy: at803x: Support SFP through phy_port interface
Convert the at803x driver to use the generic phylib SFP handling, via a
dedicated .attach_port() callback, populating the supported interfaces.

As these devices are limited to 1000BaseX, a workaround is used to also
support, in a very limited way, copper modules. This is done by
supporting SGMII but limiting it to 1G full duplex (in which case it's
somewhat compatible with 1000BaseX).

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260108080041.553250-12-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:52:35 -08:00
Maxime Chevallier
35d1a5464b net: phy: marvell10g: Support SFP through phy_port
Convert the Marvell10G driver to use the generic SFP handling, through a
dedicated .attach_port() handler to populate the port's supported
interfaces.

As the 88x3310 supports multiple MDI, the .attach_port() logic handles
both SFP attach with 10GBaseR support, and support for the "regular"
port that usually is a BaseT port.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260108080041.553250-11-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:52:35 -08:00
Maxime Chevallier
1384e13838 net: phy: marvell: Support SFP through phy_port interface
Convert the Marvell driver (especially the 88e1512 driver) to use the
phy_port interface to handle SFPs. This means registering a
.attach_port() handler to detect when a serdes line interface is used
(most likely, and SFP module).

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260108080041.553250-10-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:52:35 -08:00
Maxime Chevallier
ea317f077a net: phy: marvell-88x2222: Support SFP through phy_port interface
The 88x2222 PHY from Marvell only supports serialised modes as its
line-facing interfaces. Convert that driver to the generic phylib SFP
handling.

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260108080041.553250-9-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:52:35 -08:00
Maxime Chevallier
d7c6082f7e net: phy: Introduce generic SFP handling for PHY drivers
There are currently 4 PHY drivers that can drive downstream SFPs:
marvell.c, marvell10g.c, at803x.c and marvell-88x2222.c. Most of the
logic is boilerplate, either calling into generic phylib helpers (for
SFP PHY attach, bus attach, etc.) or performing the same tasks with a
bit of validation :
 - Getting the module's expected interface mode
 - Making sure the PHY supports it
 - Optionaly perform some configuration to make sure the PHY outputs
   the right mode

This can be made more generic by leveraging the phy_port, and its
configure_mii() callback which allows setting a port's interfaces when
the port is a serdes.

Introduce a generic PHY SFP support. If a driver doesn't probe the SFP
bus itself, but an SFP phandle is found in devicetree/firmware, then the
generic PHY SFP support will be used, relying on port ops.

PHY driver need to :
 - Register a .attach_port() callback
 - When a serdes port is registered to the PHY, drivers must set
   port->interfaces to the set of PHY_INTERFACE_MODE the port can output
 - If the port has limitations regarding speed, duplex and aneg, the
   port can also fine-tune the final linkmodes that can be supported
 - The port may register a set of ops, including .configure_mii(), that
   will be called at module_insert time to adjust the interface based on
   the module detected.

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260108080041.553250-8-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:52:34 -08:00
Maxime Chevallier
07f3ca9e09 net: phy: Create a phy_port for PHY-driven SFPs
Some PHY devices may be used as media-converters to drive SFP ports (for
example, to allow using SFP when the SoC can only output RGMII). This is
already supported to some extend by allowing PHY drivers to registers
themselves as being SFP upstream.

However, the logic to drive the SFP can actually be split to a per-port
control logic, allowing support for multi-port PHYs, or PHYs that can
either drive SFPs or Copper.

To that extent, create a phy_port when registering an SFP bus onto a
PHY. This port is considered a "serdes" port, in that it can feed data
to another entity on the link. The PHY driver needs to specify the
various PHY_INTERFACE_MODE_XXX that this port supports.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260108080041.553250-7-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:52:34 -08:00
Maxime Chevallier
ffb8587363 dt-bindings: net: dp83822: Deprecate ti,fiber-mode
The newly added ethernet-connector binding allows describing an Ethernet
connector with greater precision, and in a more generic manner, than
ti,fiber-mode. Deprecate this property.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260108080041.553250-6-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:52:34 -08:00
Maxime Chevallier
333c29a27f net: phy: dp83822: Add support for phy_port representation
With the phy_port representation introduced, we can use .attach_port to
populate the port information based on either the straps or the
ti,fiber-mode property. This allows simplifying the probe function and
allow users to override the strapping configuration.

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260108080041.553250-5-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:52:34 -08:00
Maxime Chevallier
589e934d27 net: phy: Introduce PHY ports representation
Ethernet provides a wide variety of layer 1 protocols and standards for
data transmission. The front-facing ports of an interface have their own
complexity and configurability.

Introduce a representation of these front-facing ports. The current code
is minimalistic and only support ports controlled by PHY devices, but
the plan is to extend that to SFP as well as raw Ethernet MACs that
don't use PHY devices.

This minimal port representation allows describing the media and number
of pairs of a BaseT port. From that information, we can derive the
linkmodes usable on the port, which can be used to limit the
capabilities of an interface.

For now, the port pairs and medium is derived from devicetree, defined
by the PHY driver, or populated with default values (as we assume that
all PHYs expose at least one port).

The typical example is 100M ethernet. 100BaseTX works using only 2
pairs on a Cat 5 cables. However, in the situation where a 10/100/1000
capable PHY is wired to its RJ45 port through 2 pairs only, we have no
way of detecting that. The "max-speed" DT property can be used, but a
more accurate representation can be used :

mdi {
	connector-0 {
		media = "BaseT";
		pairs = <2>;
	};
};

From that information, we can derive the max speed reachable on the
port.

Another benefit of having that is to avoid vendor-specific DT properties
(micrel,fiber-mode or ti,fiber-mode).

This basic representation is meant to be expanded, by the introduction
of port ops, userspace listing of ports, and support for multi-port
devices.

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20260108080041.553250-4-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:52:34 -08:00
Maxime Chevallier
3f25ff7409 net: ethtool: Introduce ETHTOOL_LINK_MEDIUM_* values
In an effort to have a better representation of Ethernet ports,
introduce enumeration values representing the various ethernet Mediums.

This is part of the 802.3 naming convention, for example :

1000 Base T 4
 |    |   | |
 |    |   | \_ pairs (4)
 |    |   \___ Medium (T == Twisted Copper Pairs)
 |    \_______ Baseband transmission
 \____________ Speed

 Other example :

10000 Base K X 4
           | | \_ lanes (4)
           | \___ encoding (BaseX is 8b/10b while BaseR is 66b/64b)
           \_____ Medium (K is backplane ethernet)

In the case of representing a physical port, only the medium and number
of pairs should be relevant. One exception would be 1000BaseX, which is
currently also used as a medium in what appears to be any of 1000BaseSX,
1000BaseCX, 1000BaseLX, 1000BaseEX, 1000BaseBX10 and some other.

This was reflected in the mediums associated with the 1000BaseX linkmode.

These mediums are set in the net/ethtool/common.c lookup table that
maintains a list of all linkmodes with their number of pairs, medium,
encoding, speed and duplex.

One notable exception to this is 100BaseT Ethernet. It emcompasses 100BaseTX,
which is a 2-pairs protocol but also 100BaseT4, that will also work on 4-pairs
cables. As we don't make a disctinction between these,  the lookup table
contains 2 sets of pair numbers, indicating the min number of pairs for a
protocol to work and the "nominal" number of pairs as well.

Another set of exceptions are linkmodes such 100000baseLR4_ER4, where
the same link mode seems to represent 100GBaseLR4 and 100GBaseER4. The
macro __DEFINE_LINK_MODE_PARAMS_MEDIUMS is here used to populate the
.mediums bitfield with all appropriate mediums.

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20260108080041.553250-3-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:52:34 -08:00
Maxime Chevallier
fb7a8d0786 dt-bindings: net: Introduce the ethernet-connector description
The ability to describe the physical ports of Ethernet devices is useful
to describe multi-port devices, as well as to remove any ambiguity with
regard to the nature of the port.

Moreover, describing ports allows for a better description of features
that are tied to connectors, such as PoE through the PSE-PD devices.

Introduce a binding to allow describing the ports, for now with 2
attributes :

 - The number of pairs, which is a quite generic property that allows
   differentating between multiple similar technologies such as BaseT1
   and "regular" BaseT (which usually means BaseT4).

 - The media that can be used on that port, such as BaseT for Twisted
   Copper, BaseC for coax copper, BaseS/L for Fiber, BaseK for backplane
   ethernet, etc. This allows defining the nature of the port, and
   therefore avoids the need for vendor-specific properties such as
   "micrel,fiber-mode" or "ti,fiber-mode".

The port description lives in its own file, as it is intended in the
future to allow describing the ports for phy-less devices.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20260108080041.553250-2-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 18:52:33 -08:00
Pavel Begunkov
d1de61db15 io_uring/zcrx: document area chunking parameter
struct io_uring_zcrx_ifq_reg::rx_buf_len is used as a hint specifying
the kernel what buffer size it should use. Document the API and
limitations.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
2026-01-14 02:13:37 +00:00
Pavel Begunkov
a32bb32d01 selftests: iou-zcrx: test large chunk sizes
Add a test using large chunks for zcrx memory area.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
2026-01-14 02:13:37 +00:00
Pavel Begunkov
f96e1b3577 eth: bnxt: support qcfg provided rx page size
Implement support for qcfg provided rx page sizes. For that, implement
the ndo_default_qcfg callback and validate the config on restart. Also,
use the current config's value in bnxt_init_ring_struct to retain the
correct size across resets.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
2026-01-14 02:13:37 +00:00
Jakub Kicinski
c55bf90a21 eth: bnxt: adjust the fill level of agg queues with larger buffers
The driver tries to provision more agg buffers than header buffers
since multiple agg segments can reuse the same header. The calculation
/ heuristic tries to provide enough pages for 65k of data for each header
(or 4 frags per header if the result is too big). This calculation is
currently global to the adapter. If we increase the buffer sizes 8x
we don't want 8x the amount of memory sitting on the rings.
Luckily we don't have to fill the rings completely, adjust
the fill level dynamically in case particular queue has buffers
larger than the global size.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[pavel: rebase on top of agg_size_fac]
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
2026-01-14 02:13:37 +00:00
Pavel Begunkov
f57efb32aa eth: bnxt: store rx buffer size per queue
Instead of using a constant buffer length, allow configuring the size
for each queue separately. There is no way to change the length yet, and
it'll be passed from memory providers in a later patch.

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
2026-01-14 02:13:37 +00:00
Pavel Begunkov
c0b709bf43 net: pass queue rx page size from memory provider
Allow memory providers to configure rx queues with a custom receive
page size. It's passed in struct pp_memory_provider_params, which is
copied into the queue, so it's preserved across queue restarts. Then,
it's propagated to the driver in a new queue config parameter.

Drivers should explicitly opt into using it by setting
QCFG_RX_PAGE_SIZE, in which case they should implement ndo_default_qcfg,
validate the size on queue restart and honour the current config in case
of a reset.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
2026-01-14 02:13:36 +00:00
Pavel Begunkov
efcb9a4d32 net: add bare bone queue configs
We'll need to pass extra parameters when allocating a queue for memory
providers. Define a new structure for queue configurations, and pass it
to qapi callbacks. It's empty for now, actual parameters will be added
in following patches.

Configurations should persist across resets, and for that they're
default-initialised on device registration and stored in struct
netdev_rx_queue. We also add a new qapi callback for defaulting a given
config. It must be implemented if a driver wants to use queue configs
and is optional otherwise.

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
2026-01-14 02:13:36 +00:00
Jakub Kicinski
92d76cf96d net: reduce indent of struct netdev_queue_mgmt_ops members
Trivial change, reduce the indent. I think the original is copied
from real NDOs. It's unnecessarily deep, makes passing struct args
problematic.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
2026-01-14 02:13:36 +00:00
Pavel Begunkov
7073bb4b69 net: memzero mp params when closing a queue
Instead of resetting memory provider parameters one by one in
__net_mp_{open,close}_rxq, memzero the entire structure. It'll be used
to extend the structure.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
2026-01-14 02:13:36 +00:00
Jakub Kicinski
8d48d92eab Merge branch 'selftests-drv-net-gro-enable-hw-gro-and-lro-testing'
Jakub Kicinski says:

====================
selftests: drv-net: gro: enable HW GRO and LRO testing

Add support for running our existing GRO test against HW GRO
and LRO implementation. The first 3 patches are just ksft lib
nice-to-haves, and patch 4 cleans up the existing gro Python.

Patches 5 and 6 are of most practical interest. The support
reconfiguring the NIC to disable SW GRO and enable HW GRO and LRO.
Additionally last patch breaks up the existing GRO cases to
track HW compliance at finer granularity.
====================

Link: https://patch.msgid.link/20260113000740.255360-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 17:54:03 -08:00
Jakub Kicinski
fe074aaa53 selftests: drv-net: gro: break out all individual test cases
GRO test groups the cases into categories, e.g. "tcp" case
checks coalescing in presence of:
 - packets with bad csum,
 - sequence number mismatch,
 - timestamp option value mismatch,
 - different TCP options.

Since we now have TAP support grouping the cases like that
lowers our reporting granularity. This matters even more for
NICs performing HW GRO and LRO since it appears that most
implementation have _some_ bugs. Flagging the whole group
of tests as failed prevents us from catching regressions
in the things that work today.

Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260113000740.255360-7-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 17:54:01 -08:00
Jakub Kicinski
d3b35898de selftests: drv-net: gro: run the test against HW GRO and LRO
Run the test against HW GRO and LRO. NICs I have pass the base cases.
Interestingly all are happy to build GROs larger than 64k.

Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260113000740.255360-6-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 17:54:01 -08:00
Jakub Kicinski
8171f6a76b selftests: drv-net: gro: improve feature config
We'll need to do a lot more feature handling to test HW-GRO and LRO.
Clean up the feature handling for SW GRO a bit to let the next commit
focus on the new test cases, only.

Make sure HW GRO-like features are not enabled for the SW tests.
Be more careful about changing features as "nothing changed"
situations may result in non-zero error code from ethtool.

Don't disable TSO on the local interface (receiver) when running over
netdevsim, we just want GSO to break up the segments on the sender.

Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260113000740.255360-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 17:54:01 -08:00
Jakub Kicinski
d131da6d72 selftests: drv-net: gro: use cmd print
Now that cmd() can be printed directly remove the old formatting.

Before:

  # fragmented ip6 doesn't coalesce:
  # Expected {200 100 100 }, Total 3 packets
  # Received {200 100 }, Total 2 packets.
  # /root/ksft-net-drv/drivers/net/gro: incorrect number of packets

Now:

  # CMD: drivers/net/gro --ipv6 --dmac 9e:[...]
  #   EXIT: 1
  #   STDOUT: fragmented ip6 doesn't coalesce:
  #   STDERR: Expected {200 100 100 }, Total 3 packets
  #           Received {200 100 }, Total 2 packets.
  #           /root/ksft-net-drv/drivers/net/gro: incorrect number of packets

Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://patch.msgid.link/20260113000740.255360-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 17:54:00 -08:00
Jakub Kicinski
ce0f92dc73 selftests: net: py: teach cmd() how to print itself
Teach cmd() how to print itself, to make debug prints easier.
Example output (leading # due to ksft_pr()):

  # CMD: /root/ksft-net-drv/drivers/net/gro
  #   EXIT: 1
  #   STDOUT: ipv6 with ext header does coalesce:
  #   STDERR: Expected {200 }, Total 1 packets
  #           Received {100 [!=200]100 [!=0]}, Total 2 packets.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://patch.msgid.link/20260113000740.255360-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 17:54:00 -08:00
Jakub Kicinski
b324192e36 selftests: net: py: teach ksft_pr() multi-line safety
Make printing multi-line logs easier by automatically prefixing
each line in ksft_pr(). Make use of this when formatting exceptions.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://patch.msgid.link/20260113000740.255360-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 17:54:00 -08:00
Bobby Eshleman
69cb6ca52d tools/net/ynl: suppress jobserver warning in ynltool version detection
When building ynltool with parallel make (-jN), a warning is emitted:

  make[1]: warning: jobserver unavailable: using -j1.
  Add '+' to parent make rule.

The warning trips up local runs of NIPA's ingest_mdir.py, which
correctly fails on make warnings.

This occurs because SRC_VERSION uses $(shell make ...) to make
kernelversion. The $(shell) function inherits make's MAKEFLAGS env var
which specifies "--jobserver-auth=R,W" pointing to file descriptors that
the invoked make sub-shell does not have access to.

Observed with:

$ make --version | head -1
GNU Make 4.3

Instead of suppressing MAKEFLAGS and foregoing all future MAKEFLAGS
(some of which may be desirable, such as variable overrides) or
introducing a new make target, we instead just ignore the warning by
piping stderr to /dev/null. If 'make kernelversion' fails, the ' || echo
"unknown"' phrase will catch the failure.

Before:
	NIPA ingest_mdir.py:

	ynl
	 Full series FAIL   (1)
	   Generated files up to date; build has 1 warnings/errors; no diff in
	   generated;

After:
	NIPA ingest_mdir.py:

	Series level tests:
	 ynl                             OKAY

Validated output:
	$ ./ynltool/ynltool --version
	ynltool 6.19.0-rc4

Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
Link: https://patch.msgid.link/20260112-ynl-make-fix-v1-1-c399e76925ad@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 17:51:51 -08:00
Jakub Kicinski
9d405911a5 Merge branch 'mlx5-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mellanox/linux
Tariq Toukan says:

====================
mlx5-next updates 2026-01-13

* 'mlx5-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mellanox/linux:
  net/mlx5: Add IFC bits for extended ETS rate limit bandwidth value
  net/mlx5: Add support for querying bond speed
  net/mlx5: Handle port and vport speed change events in MPESW
  net/mlx5: Propagate LAG effective max_tx_speed to vports
  net/mlx5: Add max_tx_speed and its CAP bit to IFC
====================

Link: https://patch.msgid.link/1768299471-1603093-1-git-send-email-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-13 17:46:19 -08:00
Sean Christopherson
d6c20d19f7 KVM: SVM: Assert that Hyper-V's HV_SVM_EXITCODE_ENL == SVM_EXIT_SW
Add a build-time assertiont that Hyper-V's "enlightened" exit code is that,
same as the AMD-defined "Reserved for Host" exit code, mostly to help
readers connect the dots and understand why synthesizing a software-defined
exit code is safe/ok.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://patch.msgid.link/20251230211347.4099600-9-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-13 17:37:03 -08:00
Sean Christopherson
1e3dddafec KVM: SVM: Harden exit_code against being used in Spectre-like attacks
Explicitly clamp the exit code used to index KVM's exit handlers to guard
against Spectre-like attacks, mainly to provide consistency between VMX
and SVM (VMX was given the same treatment by commit c926f2f723 ("KVM:
x86: Protect exit_reason from being used in Spectre-v1/L1TF attacks").

For normal VMs, it's _extremely_ unlikely the exit code could be used to
exploit a speculation vulnerability, as the exit code is set by hardware
and unexpected/unknown exit codes should be quite well bounded (as is/was
the case with VMX).  But with SEV-ES+, the exit code is guest-controlled
as it comes from the GHCB, not from hardware, i.e. an attack from the
guest is at least somewhat plausible.

Irrespective of SEV-ES+, hardening KVM is easy and inexpensive, and such
an attack is theoretically possible.

Link: https://patch.msgid.link/20251230211347.4099600-8-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-13 17:37:03 -08:00
Sean Christopherson
a08ca6691f KVM: SVM: Limit incorrect check on SVM_EXIT_ERR to running as a VM
Limit KVM's incorrect check for VMXEXIT_INVALID, a.k.a. SVM_EXIT_ERR, to
running as a VM, as detected by X86_FEATURE_HYPERVISOR.  The exit_code and
all failure codes, e.g. VMXEXIT_INVALID, are 64-bit values, and so checking
only bits 31:0 could result in false positives when running on non-broken
hardware, e.g. in the extremely unlikely scenario exit code 0xffffffffull
is ever generated by hardware.

Keep the 32-bit check to play nice with running on broken KVM (for years,
KVM has not set bits 63:32 when synthesizing nested SVM VM-Exits).

Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230211347.4099600-7-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-13 17:37:03 -08:00
Sean Christopherson
d7507a94a0 KVM: SVM: Treat exit_code as an unsigned 64-bit value through all of KVM
Fix KVM's long-standing buggy handling of SVM's exit_code as a 32-bit
value.  Per the APM and Xen commit d1bd157fbc ("Big merge the HVM
full-virtualisation abstractions.") (which is arguably more trustworthy
than KVM), offset 0x70 is a single 64-bit value:

  070h 63:0 EXITCODE

Track exit_code as a single u64 to prevent reintroducing bugs where KVM
neglects to correctly set bits 63:32.

Fixes: 6aa8b732ca ("[PATCH] kvm: userspace interface")
Cc: Jim Mattson <jmattson@google.com>
Cc: Yosry Ahmed <yosry.ahmed@linux.dev>
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230211347.4099600-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-13 17:37:03 -08:00
Sean Christopherson
405fce694b KVM: SVM: Filter out 64-bit exit codes when invoking exit handlers on bare metal
Explicitly filter out 64-bit exit codes when invoking exit handlers, as
svm_exit_handlers[] will never be sized with entries that use bits 63:32.

Processing the non-failing exit code as a 32-bit value will allow tracking
exit_code as a single 64-bit value (which it is, architecturally).  This
will also allow hardening KVM against Spectre-like attacks without needing
to do silly things to avoid build failures on 32-bit kernels
(array_index_nospec() rightly asserts that the index fits in an "unsigned
long").

Omit the check when running as a VM, as KVM has historically failed to set
bits 63:32 appropriately when synthesizing VM-Exits, i.e. KVM could get
false positives when running as a VM on an older, broken KVM/kernel.  From
a functional perspective, omitting the check is "fine", as any unwanted
collision between e.g. VMEXIT_INVALID and a 32-bit exit code will be
fatal to KVM-on-KVM regardless of what KVM-as-L1 does.

Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230211347.4099600-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-13 17:37:03 -08:00
Sean Christopherson
194c17bf5e KVM: SVM: Check for an unexpected VM-Exit after RETPOLINE "fast" handling
Check for an unexpected/unhandled VM-Exit after the manual RETPOLINE=y
handling.  The entire point of the RETPOLINE checks is to optimize for
common VM-Exits, i.e. checking for the rare case of an unsupported
VM-Exit is counter-productive.  This also aligns SVM and VMX exit handling.

No functional change intended.

Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230211347.4099600-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-13 17:37:03 -08:00
Sean Christopherson
2450c97745 KVM: SVM: Open code handling of unexpected exits in svm_invoke_exit_handler()
Fold svm_check_exit_valid() and svm_handle_invalid_exit() into their sole
caller, svm_invoke_exit_handler(), as having tiny single-use helpers makes
the code unncessarily difficult to follow.  This will also allow for
additional cleanups in svm_invoke_exit_handler().

No functional change intended.

Suggested-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Link: https://patch.msgid.link/20251230211347.4099600-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-13 17:37:03 -08:00
Sean Christopherson
217463aa32 KVM: SVM: Add a helper to detect VMRUN failures
Add a helper to detect VMRUN failures so that KVM can guard against its
own long-standing bug, where KVM neglects to set exitcode[63:32] when
synthesizing a nested VMFAIL_INVALID VM-Exit.  This will allow fixing
KVM's mess of treating exitcode as two separate 32-bit values without
breaking KVM-on-KVM when running on an older, unfixed KVM.

Cc: Jim Mattson <jmattson@google.com>
Cc: Yosry Ahmed <yosry.ahmed@linux.dev>
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230211347.4099600-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-13 17:37:03 -08:00
Jun Miao
de0dc71188 KVM: x86: align the code with kvm_x86_call()
The use of static_call_cond() is essentially the same as static_call() on
x86 (e.g. static_call() now handles a NULL pointer as a NOP), and then the
kvm_x86_call() is added to improve code readability and maintainability
for keeping consistent code style.

Fixes 8d032b683c ("KVM: TDX: create/destroy VM structure")

Link: https://lore.kernel.org/all/3916caa1dcd114301a49beafa5030eca396745c1.1679456900.git.jpoimboe@kernel.org/
Link: https://lore.kernel.org/r/20240507133103.15052-3-wei.w.wang@intel.com
Signed-off-by: Jun Miao <jun.miao@intel.com>
Link: https://patch.msgid.link/20260105065423.1870622-1-jun.miao@intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-13 17:36:44 -08:00
Sean Christopherson
ead63640d4 KVM: x86: Ignore -EBUSY when checking nested events from vcpu_block()
Ignore -EBUSY when checking nested events after exiting a blocking state
while L2 is active, as exiting to userspace will generate a spurious
userspace exit, usually with KVM_EXIT_UNKNOWN, and likely lead to the VM's
demise.  Continuing with the wakeup isn't perfect either, as *something*
has gone sideways if a vCPU is awakened in L2 with an injected event (or
worse, a nested run pending), but continuing on gives the VM a decent
chance of surviving without any major side effects.

As explained in the Fixes commits, it _should_ be impossible for a vCPU to
be put into a blocking state with an already-injected event (exception,
IRQ, or NMI).  Unfortunately, userspace can stuff MP_STATE and/or injected
events, and thus put the vCPU into what should be an impossible state.

Don't bother trying to preserve the WARN, e.g. with an anti-syzkaller
Kconfig, as WARNs can (hopefully) be added in paths where _KVM_ would be
violating x86 architecture, e.g. by WARNing if KVM attempts to inject an
exception or interrupt while the vCPU isn't running.

Cc: Alessandro Ratti <alessandro@0x65c.net>
Cc: stable@vger.kernel.org
Fixes: 26844fee6a ("KVM: x86: never write to memory from kvm_vcpu_check_block()")
Fixes: 45405155d8 ("KVM: x86: WARN if a vCPU gets a valid wakeup that KVM can't yet inject")
Link: https://syzkaller.appspot.com/text?tag=ReproC&x=10d4261a580000
Reported-by: syzbot+1522459a74d26b0ac33a@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/671bc7a7.050a0220.455e8.022a.GAE@google.com
Link: https://patch.msgid.link/20260109030657.994759-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-13 17:36:09 -08:00
Sean Christopherson
d23051f59a KVM: SVM: Tag sev_supported_vmsa_features as read-only after init
Tag sev_supported_vmsa_features with __ro_after_init as it's configured by
sev_hardware_setup() and never written after initial configuration (and if
it were, that'd be a blatant bug).

Opportunistically relocate the variable out of the module params area now
that sev_es_debug_swap_enabled is gone (which largely motivated its
original location).

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://patch.msgid.link/20260109033101.1005769-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-13 17:35:55 -08:00