KVM: SEV: Do cache maintenance on the source VM during intra-host migrationgrafted

Manually perform cache maintenance on the source VM during intra-host
migration to ensure no stale data is left in CPU caches after the VM is
destroyed.  Because the source VM is "converted" to a non-SEV VM, KVM's
memory reclaim flows won't trigger cache maintenance, e.g. when all guest
memory is reclaimed in response to detaching from the mmu_notifier.

Note, relying on the destination VM to do cache maintenance isn't an option
as KVM doesn't require identical guest memory configurations, i.e. the
source VM may have access to memory that the destination VM does not.
Enforcing equivalent memory configurations is infeasible, as it would
require a *deep* comparison of memslots, e.g. to verify that not only are
the memslot identical, but what the memslots point at is also identical.

Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration")
Cc: stable@vger.kernel.org
Reported-by: Stefan Teodorescu <fane@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260923163721.1584779-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 556 insertions, 0 deletions

diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
new file mode 100644
index 000000000..bfc06d171
--- /dev/null
+++ b/net/ipv4/proc.c
@@ -0,0 +1,556 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		This file implements the various access functions for the
+ *		PROC file system.  It is mainly used for debugging and
+ *		statistics.
+ *
+ * Authors:	Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *		Gerald J. Heim, <heim@peanuts.informatik.uni-tuebingen.de>
+ *		Fred Baumgarten, <dc6iq@insu1.etec.uni-karlsruhe.de>
+ *		Erik Schoenfelder, <schoenfr@ibr.cs.tu-bs.de>
+ *
+ * Fixes:
+ *		Alan Cox	:	UDP sockets show the rxqueue/txqueue
+ *					using hint flag for the netinfo.
+ *	Pauline Middelink	:	identd support
+ *		Alan Cox	:	Make /proc safer.
+ *	Erik Schoenfelder	:	/proc/net/snmp
+ *		Alan Cox	:	Handle dead sockets properly.
+ *	Gerhard Koerting	:	Show both timers
+ *		Alan Cox	:	Allow inode to be NULL (kernel socket)
+ *	Andi Kleen		:	Add support for open_requests and
+ *					split functions for more readibility.
+ *	Andi Kleen		:	Add support for /proc/net/netstat
+ *	Arnaldo C. Melo		:	Convert to seq_file
+ */
+#include <linux/types.h>
+#include <net/net_namespace.h>
+#include <net/icmp.h>
+#include <net/protocol.h>
+#include <net/tcp.h>
+#include <net/mptcp.h>
+#include <net/proto_memory.h>
+#include <net/udp.h>
+#include <linux/bottom_half.h>
+#include <linux/inetdevice.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/export.h>
+#include <net/sock.h>
+#include <net/raw.h>
+
+#define TCPUDP_MIB_MAX MAX_T(u32, UDP_MIB_MAX, TCP_MIB_MAX)
+
+/*
+ *	Report socket allocation statistics [mea@utu.fi]
+ */
+static int sockstat_seq_show(struct seq_file *seq, void *v)
+{
+	struct net *net = seq->private;
+	int orphans, sockets;
+
+	orphans = tcp_orphan_count_sum();
+	sockets = proto_sockets_allocated_sum_positive(&tcp_prot);
+
+	socket_seq_show(seq);
+	seq_printf(seq, "TCP: inuse %d orphan %d tw %d alloc %d mem %ld\n",
+		   sock_prot_inuse_get(net, &tcp_prot), orphans,
+		   refcount_read(&net->ipv4.tcp_death_row.tw_refcount) - 1,
+		   sockets, proto_memory_allocated(&tcp_prot));
+	seq_printf(seq, "UDP: inuse %d mem %ld\n",
+		   sock_prot_inuse_get(net, &udp_prot),
+		   proto_memory_allocated(&udp_prot));
+	seq_printf(seq, "RAW: inuse %d\n",
+		   sock_prot_inuse_get(net, &raw_prot));
+	seq_printf(seq,  "FRAG: inuse %u memory %lu\n",
+		   atomic_read(&net->ipv4.fqdir->rhashtable.nelems),
+		   frag_mem_limit(net->ipv4.fqdir));
+	return 0;
+}
+
+/* snmp items */
+static const struct snmp_mib snmp4_ipstats_list[] = {
+	SNMP_MIB_ITEM("InReceives", IPSTATS_MIB_INPKTS),
+	SNMP_MIB_ITEM("InHdrErrors", IPSTATS_MIB_INHDRERRORS),
+	SNMP_MIB_ITEM("InAddrErrors", IPSTATS_MIB_INADDRERRORS),
+	SNMP_MIB_ITEM("ForwDatagrams", IPSTATS_MIB_OUTFORWDATAGRAMS),
+	SNMP_MIB_ITEM("InUnknownProtos", IPSTATS_MIB_INUNKNOWNPROTOS),
+	SNMP_MIB_ITEM("InDiscards", IPSTATS_MIB_INDISCARDS),
+	SNMP_MIB_ITEM("InDelivers", IPSTATS_MIB_INDELIVERS),
+	SNMP_MIB_ITEM("OutRequests", IPSTATS_MIB_OUTREQUESTS),
+	SNMP_MIB_ITEM("OutDiscards", IPSTATS_MIB_OUTDISCARDS),
+	SNMP_MIB_ITEM("OutNoRoutes", IPSTATS_MIB_OUTNOROUTES),
+	SNMP_MIB_ITEM("ReasmTimeout", IPSTATS_MIB_REASMTIMEOUT),
+	SNMP_MIB_ITEM("ReasmReqds", IPSTATS_MIB_REASMREQDS),
+	SNMP_MIB_ITEM("ReasmOKs", IPSTATS_MIB_REASMOKS),
+	SNMP_MIB_ITEM("ReasmFails", IPSTATS_MIB_REASMFAILS),
+	SNMP_MIB_ITEM("FragOKs", IPSTATS_MIB_FRAGOKS),
+	SNMP_MIB_ITEM("FragFails", IPSTATS_MIB_FRAGFAILS),
+	SNMP_MIB_ITEM("FragCreates", IPSTATS_MIB_FRAGCREATES),
+	SNMP_MIB_ITEM("OutTransmits", IPSTATS_MIB_OUTPKTS),
+};
+
+/* Following items are displayed in /proc/net/netstat */
+static const struct snmp_mib snmp4_ipextstats_list[] = {
+	SNMP_MIB_ITEM("InNoRoutes", IPSTATS_MIB_INNOROUTES),
+	SNMP_MIB_ITEM("InTruncatedPkts", IPSTATS_MIB_INTRUNCATEDPKTS),
+	SNMP_MIB_ITEM("InMcastPkts", IPSTATS_MIB_INMCASTPKTS),
+	SNMP_MIB_ITEM("OutMcastPkts", IPSTATS_MIB_OUTMCASTPKTS),
+	SNMP_MIB_ITEM("InBcastPkts", IPSTATS_MIB_INBCASTPKTS),
+	SNMP_MIB_ITEM("OutBcastPkts", IPSTATS_MIB_OUTBCASTPKTS),
+	SNMP_MIB_ITEM("InOctets", IPSTATS_MIB_INOCTETS),
+	SNMP_MIB_ITEM("OutOctets", IPSTATS_MIB_OUTOCTETS),
+	SNMP_MIB_ITEM("InMcastOctets", IPSTATS_MIB_INMCASTOCTETS),
+	SNMP_MIB_ITEM("OutMcastOctets", IPSTATS_MIB_OUTMCASTOCTETS),
+	SNMP_MIB_ITEM("InBcastOctets", IPSTATS_MIB_INBCASTOCTETS),
+	SNMP_MIB_ITEM("OutBcastOctets", IPSTATS_MIB_OUTBCASTOCTETS),
+	/* Non RFC4293 fields */
+	SNMP_MIB_ITEM("InCsumErrors", IPSTATS_MIB_CSUMERRORS),
+	SNMP_MIB_ITEM("InNoECTPkts", IPSTATS_MIB_NOECTPKTS),
+	SNMP_MIB_ITEM("InECT1Pkts", IPSTATS_MIB_ECT1PKTS),
+	SNMP_MIB_ITEM("InECT0Pkts", IPSTATS_MIB_ECT0PKTS),
+	SNMP_MIB_ITEM("InCEPkts", IPSTATS_MIB_CEPKTS),
+	SNMP_MIB_ITEM("ReasmOverlaps", IPSTATS_MIB_REASM_OVERLAPS),
+};
+
+static const struct {
+	const char *name;
+	int index;
+} icmpmibmap[] = {
+	{ "DestUnreachs", ICMP_DEST_UNREACH },
+	{ "TimeExcds", ICMP_TIME_EXCEEDED },
+	{ "ParmProbs", ICMP_PARAMETERPROB },
+	{ "SrcQuenchs", ICMP_SOURCE_QUENCH },
+	{ "Redirects", ICMP_REDIRECT },
+	{ "Echos", ICMP_ECHO },
+	{ "EchoReps", ICMP_ECHOREPLY },
+	{ "Timestamps", ICMP_TIMESTAMP },
+	{ "TimestampReps", ICMP_TIMESTAMPREPLY },
+	{ "AddrMasks", ICMP_ADDRESS },
+	{ "AddrMaskReps", ICMP_ADDRESSREPLY },
+	{ NULL, 0 }
+};
+
+
+static const struct snmp_mib snmp4_tcp_list[] = {
+	SNMP_MIB_ITEM("RtoAlgorithm", TCP_MIB_RTOALGORITHM),
+	SNMP_MIB_ITEM("RtoMin", TCP_MIB_RTOMIN),
+	SNMP_MIB_ITEM("RtoMax", TCP_MIB_RTOMAX),
+	SNMP_MIB_ITEM("MaxConn", TCP_MIB_MAXCONN),
+	SNMP_MIB_ITEM("ActiveOpens", TCP_MIB_ACTIVEOPENS),
+	SNMP_MIB_ITEM("PassiveOpens", TCP_MIB_PASSIVEOPENS),
+	SNMP_MIB_ITEM("AttemptFails", TCP_MIB_ATTEMPTFAILS),
+	SNMP_MIB_ITEM("EstabResets", TCP_MIB_ESTABRESETS),
+	SNMP_MIB_ITEM("CurrEstab", TCP_MIB_CURRESTAB),
+	SNMP_MIB_ITEM("InSegs", TCP_MIB_INSEGS),
+	SNMP_MIB_ITEM("OutSegs", TCP_MIB_OUTSEGS),
+	SNMP_MIB_ITEM("RetransSegs", TCP_MIB_RETRANSSEGS),
+	SNMP_MIB_ITEM("InErrs", TCP_MIB_INERRS),
+	SNMP_MIB_ITEM("OutRsts", TCP_MIB_OUTRSTS),
+	SNMP_MIB_ITEM("InCsumErrors", TCP_MIB_CSUMERRORS),
+};
+
+static const struct snmp_mib snmp4_udp_list[] = {
+	SNMP_MIB_ITEM("InDatagrams", UDP_MIB_INDATAGRAMS),
+	SNMP_MIB_ITEM("NoPorts", UDP_MIB_NOPORTS),
+	SNMP_MIB_ITEM("InErrors", UDP_MIB_INERRORS),
+	SNMP_MIB_ITEM("OutDatagrams", UDP_MIB_OUTDATAGRAMS),
+	SNMP_MIB_ITEM("RcvbufErrors", UDP_MIB_RCVBUFERRORS),
+	SNMP_MIB_ITEM("SndbufErrors", UDP_MIB_SNDBUFERRORS),
+	SNMP_MIB_ITEM("InCsumErrors", UDP_MIB_CSUMERRORS),
+	SNMP_MIB_ITEM("IgnoredMulti", UDP_MIB_IGNOREDMULTI),
+	SNMP_MIB_ITEM("MemErrors", UDP_MIB_MEMERRORS),
+};
+
+static const struct snmp_mib snmp4_net_list[] = {
+	SNMP_MIB_ITEM("SyncookiesSent", LINUX_MIB_SYNCOOKIESSENT),
+	SNMP_MIB_ITEM("SyncookiesRecv", LINUX_MIB_SYNCOOKIESRECV),
+	SNMP_MIB_ITEM("SyncookiesFailed", LINUX_MIB_SYNCOOKIESFAILED),
+	SNMP_MIB_ITEM("EmbryonicRsts", LINUX_MIB_EMBRYONICRSTS),
+	SNMP_MIB_ITEM("PruneCalled", LINUX_MIB_PRUNECALLED),
+	SNMP_MIB_ITEM("RcvPruned", LINUX_MIB_RCVPRUNED),
+	SNMP_MIB_ITEM("OfoPruned", LINUX_MIB_OFOPRUNED),
+	SNMP_MIB_ITEM("OutOfWindowIcmps", LINUX_MIB_OUTOFWINDOWICMPS),
+	SNMP_MIB_ITEM("LockDroppedIcmps", LINUX_MIB_LOCKDROPPEDICMPS),
+	SNMP_MIB_ITEM("ArpFilter", LINUX_MIB_ARPFILTER),
+	SNMP_MIB_ITEM("TW", LINUX_MIB_TIMEWAITED),
+	SNMP_MIB_ITEM("TWRecycled", LINUX_MIB_TIMEWAITRECYCLED),
+	SNMP_MIB_ITEM("TWKilled", LINUX_MIB_TIMEWAITKILLED),
+	SNMP_MIB_ITEM("PAWSActive", LINUX_MIB_PAWSACTIVEREJECTED),
+	SNMP_MIB_ITEM("PAWSEstab", LINUX_MIB_PAWSESTABREJECTED),
+	SNMP_MIB_ITEM("BeyondWindow", LINUX_MIB_BEYOND_WINDOW),
+	SNMP_MIB_ITEM("TSEcrRejected", LINUX_MIB_TSECRREJECTED),
+	SNMP_MIB_ITEM("PAWSOldAck", LINUX_MIB_PAWS_OLD_ACK),
+	SNMP_MIB_ITEM("PAWSTimewait", LINUX_MIB_PAWS_TW_REJECTED),
+	SNMP_MIB_ITEM("DelayedACKs", LINUX_MIB_DELAYEDACKS),
+	SNMP_MIB_ITEM("DelayedACKLocked", LINUX_MIB_DELAYEDACKLOCKED),
+	SNMP_MIB_ITEM("DelayedACKLost", LINUX_MIB_DELAYEDACKLOST),
+	SNMP_MIB_ITEM("ListenOverflows", LINUX_MIB_LISTENOVERFLOWS),
+	SNMP_MIB_ITEM("ListenDrops", LINUX_MIB_LISTENDROPS),
+	SNMP_MIB_ITEM("TCPHPHits", LINUX_MIB_TCPHPHITS),
+	SNMP_MIB_ITEM("TCPPureAcks", LINUX_MIB_TCPPUREACKS),
+	SNMP_MIB_ITEM("TCPHPAcks", LINUX_MIB_TCPHPACKS),
+	SNMP_MIB_ITEM("TCPRenoRecovery", LINUX_MIB_TCPRENORECOVERY),
+	SNMP_MIB_ITEM("TCPSackRecovery", LINUX_MIB_TCPSACKRECOVERY),
+	SNMP_MIB_ITEM("TCPSACKReneging", LINUX_MIB_TCPSACKRENEGING),
+	SNMP_MIB_ITEM("TCPSACKReorder", LINUX_MIB_TCPSACKREORDER),
+	SNMP_MIB_ITEM("TCPRenoReorder", LINUX_MIB_TCPRENOREORDER),
+	SNMP_MIB_ITEM("TCPTSReorder", LINUX_MIB_TCPTSREORDER),
+	SNMP_MIB_ITEM("TCPFullUndo", LINUX_MIB_TCPFULLUNDO),
+	SNMP_MIB_ITEM("TCPPartialUndo", LINUX_MIB_TCPPARTIALUNDO),
+	SNMP_MIB_ITEM("TCPDSACKUndo", LINUX_MIB_TCPDSACKUNDO),
+	SNMP_MIB_ITEM("TCPLossUndo", LINUX_MIB_TCPLOSSUNDO),
+	SNMP_MIB_ITEM("TCPLostRetransmit", LINUX_MIB_TCPLOSTRETRANSMIT),
+	SNMP_MIB_ITEM("TCPRenoFailures", LINUX_MIB_TCPRENOFAILURES),
+	SNMP_MIB_ITEM("TCPSackFailures", LINUX_MIB_TCPSACKFAILURES),
+	SNMP_MIB_ITEM("TCPLossFailures", LINUX_MIB_TCPLOSSFAILURES),
+	SNMP_MIB_ITEM("TCPFastRetrans", LINUX_MIB_TCPFASTRETRANS),
+	SNMP_MIB_ITEM("TCPSlowStartRetrans", LINUX_MIB_TCPSLOWSTARTRETRANS),
+	SNMP_MIB_ITEM("TCPTimeouts", LINUX_MIB_TCPTIMEOUTS),
+	SNMP_MIB_ITEM("TCPLossProbes", LINUX_MIB_TCPLOSSPROBES),
+	SNMP_MIB_ITEM("TCPLossProbeRecovery", LINUX_MIB_TCPLOSSPROBERECOVERY),
+	SNMP_MIB_ITEM("TCPRenoRecoveryFail", LINUX_MIB_TCPRENORECOVERYFAIL),
+	SNMP_MIB_ITEM("TCPSackRecoveryFail", LINUX_MIB_TCPSACKRECOVERYFAIL),
+	SNMP_MIB_ITEM("TCPRcvCollapsed", LINUX_MIB_TCPRCVCOLLAPSED),
+	SNMP_MIB_ITEM("TCPBacklogCoalesce", LINUX_MIB_TCPBACKLOGCOALESCE),
+	SNMP_MIB_ITEM("TCPDSACKOldSent", LINUX_MIB_TCPDSACKOLDSENT),
+	SNMP_MIB_ITEM("TCPDSACKOfoSent", LINUX_MIB_TCPDSACKOFOSENT),
+	SNMP_MIB_ITEM("TCPDSACKRecv", LINUX_MIB_TCPDSACKRECV),
+	SNMP_MIB_ITEM("TCPDSACKOfoRecv", LINUX_MIB_TCPDSACKOFORECV),
+	SNMP_MIB_ITEM("TCPAbortOnData", LINUX_MIB_TCPABORTONDATA),
+	SNMP_MIB_ITEM("TCPAbortOnClose", LINUX_MIB_TCPABORTONCLOSE),
+	SNMP_MIB_ITEM("TCPAbortOnMemory", LINUX_MIB_TCPABORTONMEMORY),
+	SNMP_MIB_ITEM("TCPAbortOnTimeout", LINUX_MIB_TCPABORTONTIMEOUT),
+	SNMP_MIB_ITEM("TCPAbortOnLinger", LINUX_MIB_TCPABORTONLINGER),
+	SNMP_MIB_ITEM("TCPAbortFailed", LINUX_MIB_TCPABORTFAILED),
+	SNMP_MIB_ITEM("TCPMemoryPressures", LINUX_MIB_TCPMEMORYPRESSURES),
+	SNMP_MIB_ITEM("TCPMemoryPressuresChrono", LINUX_MIB_TCPMEMORYPRESSURESCHRONO),
+	SNMP_MIB_ITEM("TCPSACKDiscard", LINUX_MIB_TCPSACKDISCARD),
+	SNMP_MIB_ITEM("TCPDSACKIgnoredOld", LINUX_MIB_TCPDSACKIGNOREDOLD),
+	SNMP_MIB_ITEM("TCPDSACKIgnoredNoUndo", LINUX_MIB_TCPDSACKIGNOREDNOUNDO),
+	SNMP_MIB_ITEM("TCPSpuriousRTOs", LINUX_MIB_TCPSPURIOUSRTOS),
+	SNMP_MIB_ITEM("TCPMD5NotFound", LINUX_MIB_TCPMD5NOTFOUND),
+	SNMP_MIB_ITEM("TCPMD5Unexpected", LINUX_MIB_TCPMD5UNEXPECTED),
+	SNMP_MIB_ITEM("TCPMD5Failure", LINUX_MIB_TCPMD5FAILURE),
+	SNMP_MIB_ITEM("TCPSackShifted", LINUX_MIB_SACKSHIFTED),
+	SNMP_MIB_ITEM("TCPSackMerged", LINUX_MIB_SACKMERGED),
+	SNMP_MIB_ITEM("TCPSackShiftFallback", LINUX_MIB_SACKSHIFTFALLBACK),
+	SNMP_MIB_ITEM("TCPBacklogDrop", LINUX_MIB_TCPBACKLOGDROP),
+	SNMP_MIB_ITEM("PFMemallocDrop", LINUX_MIB_PFMEMALLOCDROP),
+	SNMP_MIB_ITEM("TCPMinTTLDrop", LINUX_MIB_TCPMINTTLDROP),
+	SNMP_MIB_ITEM("TCPDeferAcceptDrop", LINUX_MIB_TCPDEFERACCEPTDROP),
+	SNMP_MIB_ITEM("IPReversePathFilter", LINUX_MIB_IPRPFILTER),
+	SNMP_MIB_ITEM("TCPTimeWaitOverflow", LINUX_MIB_TCPTIMEWAITOVERFLOW),
+	SNMP_MIB_ITEM("TCPReqQFullDoCookies", LINUX_MIB_TCPREQQFULLDOCOOKIES),
+	SNMP_MIB_ITEM("TCPReqQFullDrop", LINUX_MIB_TCPREQQFULLDROP),
+	SNMP_MIB_ITEM("TCPRetransFail", LINUX_MIB_TCPRETRANSFAIL),
+	SNMP_MIB_ITEM("TCPRcvCoalesce", LINUX_MIB_TCPRCVCOALESCE),
+	SNMP_MIB_ITEM("TCPOFOQueue", LINUX_MIB_TCPOFOQUEUE),
+	SNMP_MIB_ITEM("TCPOFODrop", LINUX_MIB_TCPOFODROP),
+	SNMP_MIB_ITEM("TCPOFOMerge", LINUX_MIB_TCPOFOMERGE),
+	SNMP_MIB_ITEM("TCPChallengeACK", LINUX_MIB_TCPCHALLENGEACK),
+	SNMP_MIB_ITEM("TCPSYNChallenge", LINUX_MIB_TCPSYNCHALLENGE),
+	SNMP_MIB_ITEM("TCPFastOpenActive", LINUX_MIB_TCPFASTOPENACTIVE),
+	SNMP_MIB_ITEM("TCPFastOpenActiveFail", LINUX_MIB_TCPFASTOPENACTIVEFAIL),
+	SNMP_MIB_ITEM("TCPFastOpenPassive", LINUX_MIB_TCPFASTOPENPASSIVE),
+	SNMP_MIB_ITEM("TCPFastOpenPassiveFail", LINUX_MIB_TCPFASTOPENPASSIVEFAIL),
+	SNMP_MIB_ITEM("TCPFastOpenListenOverflow", LINUX_MIB_TCPFASTOPENLISTENOVERFLOW),
+	SNMP_MIB_ITEM("TCPFastOpenCookieReqd", LINUX_MIB_TCPFASTOPENCOOKIEREQD),
+	SNMP_MIB_ITEM("TCPFastOpenBlackhole", LINUX_MIB_TCPFASTOPENBLACKHOLE),
+	SNMP_MIB_ITEM("TCPSpuriousRtxHostQueues", LINUX_MIB_TCPSPURIOUS_RTX_HOSTQUEUES),
+	SNMP_MIB_ITEM("BusyPollRxPackets", LINUX_MIB_BUSYPOLLRXPACKETS),
+	SNMP_MIB_ITEM("TCPAutoCorking", LINUX_MIB_TCPAUTOCORKING),
+	SNMP_MIB_ITEM("TCPFromZeroWindowAdv", LINUX_MIB_TCPFROMZEROWINDOWADV),
+	SNMP_MIB_ITEM("TCPToZeroWindowAdv", LINUX_MIB_TCPTOZEROWINDOWADV),
+	SNMP_MIB_ITEM("TCPWantZeroWindowAdv", LINUX_MIB_TCPWANTZEROWINDOWADV),
+	SNMP_MIB_ITEM("TCPSynRetrans", LINUX_MIB_TCPSYNRETRANS),
+	SNMP_MIB_ITEM("TCPOrigDataSent", LINUX_MIB_TCPORIGDATASENT),
+	SNMP_MIB_ITEM("TCPHystartTrainDetect", LINUX_MIB_TCPHYSTARTTRAINDETECT),
+	SNMP_MIB_ITEM("TCPHystartTrainCwnd", LINUX_MIB_TCPHYSTARTTRAINCWND),
+	SNMP_MIB_ITEM("TCPHystartDelayDetect", LINUX_MIB_TCPHYSTARTDELAYDETECT),
+	SNMP_MIB_ITEM("TCPHystartDelayCwnd", LINUX_MIB_TCPHYSTARTDELAYCWND),
+	SNMP_MIB_ITEM("TCPACKSkippedSynRecv", LINUX_MIB_TCPACKSKIPPEDSYNRECV),
+	SNMP_MIB_ITEM("TCPACKSkippedPAWS", LINUX_MIB_TCPACKSKIPPEDPAWS),
+	SNMP_MIB_ITEM("TCPACKSkippedSeq", LINUX_MIB_TCPACKSKIPPEDSEQ),
+	SNMP_MIB_ITEM("TCPACKSkippedFinWait2", LINUX_MIB_TCPACKSKIPPEDFINWAIT2),
+	SNMP_MIB_ITEM("TCPACKSkippedTimeWait", LINUX_MIB_TCPACKSKIPPEDTIMEWAIT),
+	SNMP_MIB_ITEM("TCPACKSkippedChallenge", LINUX_MIB_TCPACKSKIPPEDCHALLENGE),
+	SNMP_MIB_ITEM("TCPWinProbe", LINUX_MIB_TCPWINPROBE),
+	SNMP_MIB_ITEM("TCPKeepAlive", LINUX_MIB_TCPKEEPALIVE),
+	SNMP_MIB_ITEM("TCPMTUPFail", LINUX_MIB_TCPMTUPFAIL),
+	SNMP_MIB_ITEM("TCPMTUPSuccess", LINUX_MIB_TCPMTUPSUCCESS),
+	SNMP_MIB_ITEM("TCPDelivered", LINUX_MIB_TCPDELIVERED),
+	SNMP_MIB_ITEM("TCPDeliveredCE", LINUX_MIB_TCPDELIVEREDCE),
+	SNMP_MIB_ITEM("TCPAckCompressed", LINUX_MIB_TCPACKCOMPRESSED),
+	SNMP_MIB_ITEM("TCPZeroWindowDrop", LINUX_MIB_TCPZEROWINDOWDROP),
+	SNMP_MIB_ITEM("TCPRcvQDrop", LINUX_MIB_TCPRCVQDROP),
+	SNMP_MIB_ITEM("TCPWqueueTooBig", LINUX_MIB_TCPWQUEUETOOBIG),
+	SNMP_MIB_ITEM("TCPFastOpenPassiveAltKey", LINUX_MIB_TCPFASTOPENPASSIVEALTKEY),
+	SNMP_MIB_ITEM("TcpTimeoutRehash", LINUX_MIB_TCPTIMEOUTREHASH),
+	SNMP_MIB_ITEM("TcpDuplicateDataRehash", LINUX_MIB_TCPDUPLICATEDATAREHASH),
+	SNMP_MIB_ITEM("TCPDSACKRecvSegs", LINUX_MIB_TCPDSACKRECVSEGS),
+	SNMP_MIB_ITEM("TCPDSACKIgnoredDubious", LINUX_MIB_TCPDSACKIGNOREDDUBIOUS),
+	SNMP_MIB_ITEM("TCPMigrateReqSuccess", LINUX_MIB_TCPMIGRATEREQSUCCESS),
+	SNMP_MIB_ITEM("TCPMigrateReqFailure", LINUX_MIB_TCPMIGRATEREQFAILURE),
+	SNMP_MIB_ITEM("TCPPLBRehash", LINUX_MIB_TCPPLBREHASH),
+	SNMP_MIB_ITEM("TCPAORequired", LINUX_MIB_TCPAOREQUIRED),
+	SNMP_MIB_ITEM("TCPAOBad", LINUX_MIB_TCPAOBAD),
+	SNMP_MIB_ITEM("TCPAOKeyNotFound", LINUX_MIB_TCPAOKEYNOTFOUND),
+	SNMP_MIB_ITEM("TCPAOGood", LINUX_MIB_TCPAOGOOD),
+	SNMP_MIB_ITEM("TCPAODroppedIcmps", LINUX_MIB_TCPAODROPPEDICMPS),
+};
+
+static void icmpmsg_put_line(struct seq_file *seq, unsigned long *vals,
+			     unsigned short *type, int count)
+{
+	int j;
+
+	if (count) {
+		seq_puts(seq, "\nIcmpMsg:");
+		for (j = 0; j < count; ++j)
+			seq_printf(seq, " %sType%u",
+				type[j] & 0x100 ? "Out" : "In",
+				type[j] & 0xff);
+		seq_puts(seq, "\nIcmpMsg:");
+		for (j = 0; j < count; ++j)
+			seq_printf(seq, " %lu", vals[j]);
+	}
+}
+
+static void icmpmsg_put(struct seq_file *seq)
+{
+#define PERLINE	16
+
+	int i, count;
+	unsigned short type[PERLINE];
+	unsigned long vals[PERLINE], val;
+	struct net *net = seq->private;
+
+	count = 0;
+	for (i = 0; i < ICMPMSG_MIB_MAX; i++) {
+		val = atomic_long_read(&net->mib.icmpmsg_statistics->mibs[i]);
+		if (val) {
+			type[count] = i;
+			vals[count++] = val;
+		}
+		if (count == PERLINE) {
+			icmpmsg_put_line(seq, vals, type, count);
+			count = 0;
+		}
+	}
+	icmpmsg_put_line(seq, vals, type, count);
+
+#undef PERLINE
+}
+
+static void icmp_put(struct seq_file *seq)
+{
+	int i;
+	struct net *net = seq->private;
+	atomic_long_t *ptr = net->mib.icmpmsg_statistics->mibs;
+
+	seq_puts(seq, "\nIcmp: InMsgs InErrors InCsumErrors");
+	for (i = 0; icmpmibmap[i].name; i++)
+		seq_printf(seq, " In%s", icmpmibmap[i].name);
+	seq_puts(seq, " OutMsgs OutErrors OutRateLimitGlobal OutRateLimitHost");
+	for (i = 0; icmpmibmap[i].name; i++)
+		seq_printf(seq, " Out%s", icmpmibmap[i].name);
+	seq_printf(seq, "\nIcmp: %lu %lu %lu",
+		snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_INMSGS),
+		snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_INERRORS),
+		snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_CSUMERRORS));
+	for (i = 0; icmpmibmap[i].name; i++)
+		seq_printf(seq, " %lu",
+			   atomic_long_read(ptr + icmpmibmap[i].index));
+	seq_printf(seq, " %lu %lu %lu %lu",
+		snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTMSGS),
+		snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTERRORS),
+		snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_RATELIMITGLOBAL),
+		snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_RATELIMITHOST));
+	for (i = 0; icmpmibmap[i].name; i++)
+		seq_printf(seq, " %lu",
+			   atomic_long_read(ptr + (icmpmibmap[i].index | 0x100)));
+}
+
+/*
+ *	Called from the PROCfs module. This outputs /proc/net/snmp.
+ */
+static int snmp_seq_show_ipstats(struct seq_file *seq, void *v)
+{
+	const int cnt = ARRAY_SIZE(snmp4_ipstats_list);
+	u64 buff64[ARRAY_SIZE(snmp4_ipstats_list)];
+	struct net *net = seq->private;
+	int i;
+
+	memset(buff64, 0, sizeof(buff64));
+
+	seq_puts(seq, "Ip: Forwarding DefaultTTL");
+	for (i = 0; i < cnt; i++)
+		seq_printf(seq, " %s", snmp4_ipstats_list[i].name);
+
+	seq_printf(seq, "\nIp: %d %d",
+		   IPV4_DEVCONF_ALL_RO(net, FORWARDING) ? 1 : 2,
+		   READ_ONCE(net->ipv4.sysctl_ip_default_ttl));
+
+	BUILD_BUG_ON(offsetof(struct ipstats_mib, mibs) != 0);
+	snmp_get_cpu_field64_batch_cnt(buff64, snmp4_ipstats_list, cnt,
+				       net->mib.ip_statistics,
+				       offsetof(struct ipstats_mib, syncp));
+	for (i = 0; i < cnt; i++)
+		seq_printf(seq, " %llu", buff64[i]);
+
+	return 0;
+}
+
+static int snmp_seq_show_tcp_udp(struct seq_file *seq, void *v)
+{
+	const int udp_cnt = ARRAY_SIZE(snmp4_udp_list);
+	const int tcp_cnt = ARRAY_SIZE(snmp4_tcp_list);
+	unsigned long buff[TCPUDP_MIB_MAX];
+	struct net *net = seq->private;
+	int i;
+
+	memset(buff, 0, tcp_cnt * sizeof(unsigned long));
+
+	seq_puts(seq, "\nTcp:");
+	for (i = 0; i < tcp_cnt; i++)
+		seq_printf(seq, " %s", snmp4_tcp_list[i].name);
+
+	seq_puts(seq, "\nTcp:");
+	snmp_get_cpu_field_batch_cnt(buff, snmp4_tcp_list,
+				     tcp_cnt,
+				     net->mib.tcp_statistics);
+	for (i = 0; i < tcp_cnt; i++) {
+		/* MaxConn field is signed, RFC 2012 */
+		if (snmp4_tcp_list[i].entry == TCP_MIB_MAXCONN)
+			seq_printf(seq, " %ld", buff[i]);
+		else
+			seq_printf(seq, " %lu", buff[i]);
+	}
+
+	memset(buff, 0, udp_cnt * sizeof(unsigned long));
+
+	snmp_get_cpu_field_batch_cnt(buff, snmp4_udp_list,
+				     udp_cnt,
+				     net->mib.udp_statistics);
+	seq_puts(seq, "\nUdp:");
+	for (i = 0; i < udp_cnt; i++)
+		seq_printf(seq, " %s", snmp4_udp_list[i].name);
+	seq_puts(seq, "\nUdp:");
+	for (i = 0; i < udp_cnt; i++)
+		seq_printf(seq, " %lu", buff[i]);
+
+	seq_putc(seq, '\n');
+	return 0;
+}
+
+static int snmp_seq_show(struct seq_file *seq, void *v)
+{
+	snmp_seq_show_ipstats(seq, v);
+
+	icmp_put(seq);	/* RFC 2011 compatibility */
+	icmpmsg_put(seq);
+
+	snmp_seq_show_tcp_udp(seq, v);
+
+	return 0;
+}
+
+/*
+ *	Output /proc/net/netstat
+ */
+static int netstat_seq_show(struct seq_file *seq, void *v)
+{
+	const int ip_cnt = ARRAY_SIZE(snmp4_ipextstats_list);
+	const int tcp_cnt = ARRAY_SIZE(snmp4_net_list);
+	struct net *net = seq->private;
+	unsigned long *buff;
+	int i;
+
+	seq_puts(seq, "TcpExt:");
+	for (i = 0; i < tcp_cnt; i++)
+		seq_printf(seq, " %s", snmp4_net_list[i].name);
+
+	seq_puts(seq, "\nTcpExt:");
+	buff = kzalloc(max(tcp_cnt * sizeof(long), ip_cnt * sizeof(u64)),
+		       GFP_KERNEL);
+	if (buff) {
+		snmp_get_cpu_field_batch_cnt(buff, snmp4_net_list, tcp_cnt,
+					     net->mib.net_statistics);
+		for (i = 0; i < tcp_cnt; i++)
+			seq_printf(seq, " %lu", buff[i]);
+	} else {
+		for (i = 0; i < tcp_cnt; i++)
+			seq_printf(seq, " %lu",
+				   snmp_fold_field(net->mib.net_statistics,
+						   snmp4_net_list[i].entry));
+	}
+	seq_puts(seq, "\nIpExt:");
+	for (i = 0; i < ip_cnt; i++)
+		seq_printf(seq, " %s", snmp4_ipextstats_list[i].name);
+
+	seq_puts(seq, "\nIpExt:");
+	if (buff) {
+		u64 *buff64 = (u64 *)buff;
+
+		memset(buff64, 0, ip_cnt * sizeof(u64));
+		snmp_get_cpu_field64_batch_cnt(buff64, snmp4_ipextstats_list, ip_cnt,
+					   net->mib.ip_statistics,
+					   offsetof(struct ipstats_mib, syncp));
+		for (i = 0; i < ip_cnt; i++)
+			seq_printf(seq, " %llu", buff64[i]);
+	} else {
+		for (i = 0; i < ip_cnt; i++)
+			seq_printf(seq, " %llu",
+				   snmp_fold_field64(net->mib.ip_statistics,
+						     snmp4_ipextstats_list[i].entry,
+						     offsetof(struct ipstats_mib, syncp)));
+	}
+	kfree(buff);
+	seq_putc(seq, '\n');
+	mptcp_seq_show(seq);
+	return 0;
+}
+
+static __net_init int ip_proc_init_net(struct net *net)
+{
+	if (!proc_create_net_single("sockstat", 0444, net->proc_net,
+			sockstat_seq_show, NULL))
+		goto out_sockstat;
+	if (!proc_create_net_single("netstat", 0444, net->proc_net,
+			netstat_seq_show, NULL))
+		goto out_netstat;
+	if (!proc_create_net_single("snmp", 0444, net->proc_net, snmp_seq_show,
+			NULL))
+		goto out_snmp;
+
+	return 0;
+
+out_snmp:
+	remove_proc_entry("netstat", net->proc_net);
+out_netstat:
+	remove_proc_entry("sockstat", net->proc_net);
+out_sockstat:
+	return -ENOMEM;
+}
+
+static __net_exit void ip_proc_exit_net(struct net *net)
+{
+	remove_proc_entry("snmp", net->proc_net);
+	remove_proc_entry("netstat", net->proc_net);
+	remove_proc_entry("sockstat", net->proc_net);
+}
+
+static __net_initdata struct pernet_operations ip_proc_ops = {
+	.init = ip_proc_init_net,
+	.exit = ip_proc_exit_net,
+};
+
+int __init ip_misc_proc_init(void)
+{
+	return register_pernet_subsys(&ip_proc_ops);
+}