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>

4 files changed, 371 insertions, 0 deletions

diff --git a/include/net/phonet/gprs.h b/include/net/phonet/gprs.h
new file mode 100644
index 000000000..6b7f57b2f
--- /dev/null
+++ b/include/net/phonet/gprs.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * File: pep_gprs.h
+ *
+ * GPRS over Phonet pipe end point socket
+ *
+ * Copyright (C) 2008 Nokia Corporation.
+ *
+ * Author: Rémi Denis-Courmont
+ */
+
+#ifndef NET_PHONET_GPRS_H
+#define NET_PHONET_GPRS_H
+
+struct sock;
+struct sk_buff;
+
+int pep_writeable(struct sock *sk);
+int pep_write(struct sock *sk, struct sk_buff *skb);
+struct sk_buff *pep_read(struct sock *sk);
+
+int gprs_attach(struct sock *sk);
+void gprs_detach(struct sock *sk);
+
+#endif
diff --git a/include/net/phonet/pep.h b/include/net/phonet/pep.h
new file mode 100644
index 000000000..645dddf5c
--- /dev/null
+++ b/include/net/phonet/pep.h
@@ -0,0 +1,159 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * File: pep.h
+ *
+ * Phonet Pipe End Point sockets definitions
+ *
+ * Copyright (C) 2008 Nokia Corporation.
+ */
+
+#ifndef NET_PHONET_PEP_H
+#define NET_PHONET_PEP_H
+
+#include <linux/skbuff.h>
+#include <net/phonet/phonet.h>
+
+struct pep_sock {
+	struct pn_sock		pn_sk;
+
+	/* XXX: union-ify listening vs connected stuff ? */
+	/* Listening socket stuff: */
+	struct hlist_head	hlist;
+
+	/* Connected socket stuff: */
+	struct sock		*listener;
+	struct sk_buff_head	ctrlreq_queue;
+#define PNPIPE_CTRLREQ_MAX	10
+	atomic_t		tx_credits;
+	int			ifindex;
+	u16			peer_type;	/* peer type/subtype */
+	u8			pipe_handle;
+
+	u8			rx_credits;
+	u8			rx_fc;	/* RX flow control */
+	u8			tx_fc;	/* TX flow control */
+	u8			init_enable;	/* auto-enable at creation */
+	u8			aligned;
+};
+
+static inline struct pep_sock *pep_sk(struct sock *sk)
+{
+	return (struct pep_sock *)sk;
+}
+
+extern const struct proto_ops phonet_stream_ops;
+
+/* Pipe protocol definitions */
+struct pnpipehdr {
+	u8			utid; /* transaction ID */
+	u8			message_id;
+	u8			pipe_handle;
+	union {
+		u8		state_after_connect;	/* connect request */
+		u8		state_after_reset;	/* reset request */
+		u8		error_code;		/* any response */
+		u8		pep_type;		/* status indication */
+		u8		data0;			/* anything else */
+	};
+	u8			data[];
+};
+#define other_pep_type		data[0]
+
+static inline struct pnpipehdr *pnp_hdr(struct sk_buff *skb)
+{
+	return (struct pnpipehdr *)skb_transport_header(skb);
+}
+
+#define MAX_PNPIPE_HEADER (MAX_PHONET_HEADER + 4)
+
+enum {
+	PNS_PIPE_CREATE_REQ = 0x00,
+	PNS_PIPE_CREATE_RESP,
+	PNS_PIPE_REMOVE_REQ,
+	PNS_PIPE_REMOVE_RESP,
+
+	PNS_PIPE_DATA = 0x20,
+	PNS_PIPE_ALIGNED_DATA,
+
+	PNS_PEP_CONNECT_REQ = 0x40,
+	PNS_PEP_CONNECT_RESP,
+	PNS_PEP_DISCONNECT_REQ,
+	PNS_PEP_DISCONNECT_RESP,
+	PNS_PEP_RESET_REQ,
+	PNS_PEP_RESET_RESP,
+	PNS_PEP_ENABLE_REQ,
+	PNS_PEP_ENABLE_RESP,
+	PNS_PEP_CTRL_REQ,
+	PNS_PEP_CTRL_RESP,
+	PNS_PEP_DISABLE_REQ = 0x4C,
+	PNS_PEP_DISABLE_RESP,
+
+	PNS_PEP_STATUS_IND = 0x60,
+	PNS_PIPE_CREATED_IND,
+	PNS_PIPE_RESET_IND = 0x63,
+	PNS_PIPE_ENABLED_IND,
+	PNS_PIPE_REDIRECTED_IND,
+	PNS_PIPE_DISABLED_IND = 0x66,
+};
+
+#define PN_PIPE_INVALID_HANDLE	0xff
+#define PN_PEP_TYPE_COMMON	0x00
+
+/* Phonet pipe status indication */
+enum {
+	PN_PEP_IND_FLOW_CONTROL,
+	PN_PEP_IND_ID_MCFC_GRANT_CREDITS,
+};
+
+/* Phonet pipe error codes */
+enum {
+	PN_PIPE_NO_ERROR,
+	PN_PIPE_ERR_INVALID_PARAM,
+	PN_PIPE_ERR_INVALID_HANDLE,
+	PN_PIPE_ERR_INVALID_CTRL_ID,
+	PN_PIPE_ERR_NOT_ALLOWED,
+	PN_PIPE_ERR_PEP_IN_USE,
+	PN_PIPE_ERR_OVERLOAD,
+	PN_PIPE_ERR_DEV_DISCONNECTED,
+	PN_PIPE_ERR_TIMEOUT,
+	PN_PIPE_ERR_ALL_PIPES_IN_USE,
+	PN_PIPE_ERR_GENERAL,
+	PN_PIPE_ERR_NOT_SUPPORTED,
+};
+
+/* Phonet pipe states */
+enum {
+	PN_PIPE_DISABLE,
+	PN_PIPE_ENABLE,
+};
+
+/* Phonet pipe sub-block types */
+enum {
+	PN_PIPE_SB_CREATE_REQ_PEP_SUB_TYPE,
+	PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE,
+	PN_PIPE_SB_REDIRECT_REQ_PEP_SUB_TYPE,
+	PN_PIPE_SB_NEGOTIATED_FC,
+	PN_PIPE_SB_REQUIRED_FC_TX,
+	PN_PIPE_SB_PREFERRED_FC_RX,
+	PN_PIPE_SB_ALIGNED_DATA,
+};
+
+/* Phonet pipe flow control models */
+enum {
+	PN_NO_FLOW_CONTROL,
+	PN_LEGACY_FLOW_CONTROL,
+	PN_ONE_CREDIT_FLOW_CONTROL,
+	PN_MULTI_CREDIT_FLOW_CONTROL,
+	PN_MAX_FLOW_CONTROL,
+};
+
+#define pn_flow_safe(fc) ((fc) >> 1)
+
+/* Phonet pipe flow control states */
+enum {
+	PEP_IND_EMPTY,
+	PEP_IND_BUSY,
+	PEP_IND_READY,
+};
+
+#endif
diff --git a/include/net/phonet/phonet.h b/include/net/phonet/phonet.h
new file mode 100644
index 000000000..cf5ecae4a
--- /dev/null
+++ b/include/net/phonet/phonet.h
@@ -0,0 +1,133 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * File: af_phonet.h
+ *
+ * Phonet sockets kernel definitions
+ *
+ * Copyright (C) 2008 Nokia Corporation.
+ */
+
+#ifndef AF_PHONET_H
+#define AF_PHONET_H
+
+#include <linux/phonet.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+
+/*
+ * The lower layers may not require more space, ever. Make sure it's
+ * enough.
+ */
+#define MAX_PHONET_HEADER	(8 + MAX_HEADER)
+
+/*
+ * Every Phonet* socket has this structure first in its
+ * protocol-specific structure under name c.
+ */
+struct pn_sock {
+	struct sock	sk;
+	u16		sobject;
+	u16		dobject;
+	u8		resource;
+};
+
+static inline struct pn_sock *pn_sk(struct sock *sk)
+{
+	return (struct pn_sock *)sk;
+}
+
+extern const struct proto_ops phonet_dgram_ops;
+
+void pn_sock_init(void);
+struct sock *pn_find_sock_by_sa(struct net *net, const struct sockaddr_pn *sa);
+void pn_deliver_sock_broadcast(struct net *net, struct sk_buff *skb);
+void phonet_get_local_port_range(int *min, int *max);
+int pn_sock_hash(struct sock *sk);
+void pn_sock_unhash(struct sock *sk);
+int pn_sock_get_port(struct sock *sk, unsigned short sport);
+
+struct sock *pn_find_sock_by_res(struct net *net, u8 res);
+int pn_sock_bind_res(struct sock *sock, u8 res);
+int pn_sock_unbind_res(struct sock *sk, u8 res);
+void pn_sock_unbind_all_res(struct sock *sk);
+
+int pn_skb_send(struct sock *sk, struct sk_buff *skb,
+		const struct sockaddr_pn *target);
+
+static inline struct phonethdr *pn_hdr(struct sk_buff *skb)
+{
+	return (struct phonethdr *)skb_network_header(skb);
+}
+
+static inline struct phonetmsg *pn_msg(struct sk_buff *skb)
+{
+	return (struct phonetmsg *)skb_transport_header(skb);
+}
+
+/*
+ * Get the other party's sockaddr from received skb. The skb begins
+ * with a Phonet header.
+ */
+static inline
+void pn_skb_get_src_sockaddr(struct sk_buff *skb, struct sockaddr_pn *sa)
+{
+	struct phonethdr *ph = pn_hdr(skb);
+	u16 obj = pn_object(ph->pn_sdev, ph->pn_sobj);
+
+	sa->spn_family = AF_PHONET;
+	pn_sockaddr_set_object(sa, obj);
+	pn_sockaddr_set_resource(sa, ph->pn_res);
+	memset(sa->spn_zero, 0, sizeof(sa->spn_zero));
+}
+
+static inline
+void pn_skb_get_dst_sockaddr(struct sk_buff *skb, struct sockaddr_pn *sa)
+{
+	struct phonethdr *ph = pn_hdr(skb);
+	u16 obj = pn_object(ph->pn_rdev, ph->pn_robj);
+
+	sa->spn_family = AF_PHONET;
+	pn_sockaddr_set_object(sa, obj);
+	pn_sockaddr_set_resource(sa, ph->pn_res);
+	memset(sa->spn_zero, 0, sizeof(sa->spn_zero));
+}
+
+/* Protocols in Phonet protocol family. */
+struct phonet_protocol {
+	const struct proto_ops	*ops;
+	struct proto		*prot;
+	int			sock_type;
+};
+
+int phonet_proto_register(unsigned int protocol,
+		const struct phonet_protocol *pp);
+void phonet_proto_unregister(unsigned int protocol,
+		const struct phonet_protocol *pp);
+
+int phonet_sysctl_init(void);
+void phonet_sysctl_exit(void);
+int isi_register(void);
+void isi_unregister(void);
+
+static inline bool sk_is_phonet(struct sock *sk)
+{
+	return sk->sk_family == PF_PHONET;
+}
+
+static inline int phonet_sk_ioctl(struct sock *sk, unsigned int cmd,
+				  void __user *arg)
+{
+	int karg;
+
+	switch (cmd) {
+	case SIOCPNADDRESOURCE:
+	case SIOCPNDELRESOURCE:
+		if (get_user(karg, (int __user *)arg))
+			return -EFAULT;
+
+		return sk->sk_prot->ioctl(sk, cmd, &karg);
+	}
+	/* A positive return value means that the ioctl was not processed */
+	return 1;
+}
+#endif
diff --git a/include/net/phonet/pn_dev.h b/include/net/phonet/pn_dev.h
new file mode 100644
index 000000000..37a3e8353
--- /dev/null
+++ b/include/net/phonet/pn_dev.h
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * File: pn_dev.h
+ *
+ * Phonet network device
+ *
+ * Copyright (C) 2008 Nokia Corporation.
+ */
+
+#ifndef PN_DEV_H
+#define PN_DEV_H
+
+#include <linux/list.h>
+#include <linux/spinlock.h>
+
+struct net;
+
+struct phonet_device_list {
+	struct list_head list;
+	spinlock_t lock;
+};
+
+struct phonet_device_list *phonet_device_list(struct net *net);
+
+struct phonet_device {
+	struct list_head list;
+	struct net_device *netdev;
+	DECLARE_BITMAP(addrs, 64);
+	struct rcu_head	rcu;
+};
+
+int phonet_device_init(void);
+void phonet_device_exit(void);
+int phonet_netlink_register(void);
+struct net_device *phonet_device_get(struct net *net);
+
+int phonet_address_add(struct net_device *dev, u8 addr);
+int phonet_address_del(struct net_device *dev, u8 addr);
+u8 phonet_address_get(struct net_device *dev, u8 addr);
+int phonet_address_lookup(struct net *net, u8 addr);
+void phonet_address_notify(struct net *net, int event, u32 ifindex, u8 addr);
+
+int phonet_route_add(struct net_device *dev, u8 daddr);
+int phonet_route_del(struct net_device *dev, u8 daddr);
+void rtm_phonet_notify(struct net *net, int event, u32 ifindex, u8 dst);
+struct net_device *phonet_route_get_rcu(struct net *net, u8 daddr);
+struct net_device *phonet_route_output(struct net *net, u8 daddr);
+
+#define PN_NO_ADDR	0xff
+
+extern const struct seq_operations pn_sock_seq_ops;
+extern const struct seq_operations pn_res_seq_ops;
+
+#endif