KVM: Don't pre-reserve xarray entries when storing empty/NULL attributesgrafted

Skip the xarray reservation loop when clearing all memory attributes, as
storing NULL only erases the entry and never needs to allocate, so no
reservation (and no cleanup of a failed one) is required in that case.

Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: David Ballesteros <davimaba.v@proton.me>
Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com
[sean: split to separate patch]
Signed-off-by: Sean Christopherson <seanjc@google.com>

1 files changed, 134 insertions, 0 deletions

diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst
new file mode 100644
index 000000000..44a422ad3
--- /dev/null
+++ b/Documentation/networking/index.rst
@@ -0,0 +1,134 @@
+Networking
+==========
+
+Refer to :ref:`netdev-FAQ` for a guide on netdev development process specifics.
+
+Contents:
+
+.. toctree::
+   :maxdepth: 2
+
+   af_xdp
+   bareudp
+   batman-adv
+   can
+   can_ucan_protocol
+   device_drivers/index
+   diagnostic/index
+   dsa/index
+   devlink/index
+   ethtool-netlink
+   ieee802154
+   iso15765-2
+   j1939
+   kapi
+   msg_zerocopy
+   failover
+   net_dim
+   net_failover
+   page_pool
+   phy
+   sfp-phylink
+   alias
+   bridge
+   snmp_counter
+   checksum-offloads
+   segmentation-offloads
+   scaling
+   tls
+   tls-offload
+   tls-handshake
+   nfc
+   6lowpan
+   arcnet-hardware
+   arcnet
+   atm
+   bonding
+   cdc_mbim
+   dctcp
+   devmem
+   dns_resolver
+   driver
+   eql
+   fib_trie
+   filter
+   generic-hdlc
+   generic_netlink
+   ../netlink/specs/index
+   gen_stats
+   gtp
+   ila
+   ioam6-sysctl
+   iou-zcrx
+   ip_dynaddr
+   ipsec
+   ip-sysctl
+   ipv6
+   ipvlan
+   ipvs-sysctl
+   kcm
+   l2tp
+   lapb-module
+   mac80211-injection
+   mctp
+   mpls-sysctl
+   mptcp
+   mptcp-sysctl
+   multiqueue
+   multi-pf-netdev
+   napi
+   net_cachelines/index
+   netconsole
+   netdev-features
+   netdevices
+   netfilter-sysctl
+   netif-msg
+   netmem
+   nexthop-group-resilient
+   nf_conntrack-sysctl
+   nf_flowtable
+   oa-tc6-framework
+   openvswitch
+   operstates
+   packet_mmap
+   phonet
+   phy-link-topology
+   phy-port
+   pktgen
+   plip
+   ppp_generic
+   proc_net_tcp
+   pse-pd/index
+   psp
+   radiotap-headers
+   rds
+   regulatory
+   representors
+   rxrpc
+   sctp
+   secid
+   seg6-sysctl
+   skbuff
+   smc-sysctl
+   sriov
+   statistics
+   strparser
+   switchdev
+   sysfs-tagging
+   tc-actions-env-rules
+   tc-queue-filters
+   tcp_ao
+   tcp-thin
+   team
+   timestamping
+   tipc
+   tproxy
+   tuntap
+   udplite
+   vrf
+   vxlan
+   x25
+   x25-iface
+   xfrm/index
+   xdp-rx-metadata
+   xsk-tx-metadata