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, 136 insertions, 0 deletions

diff --git a/include/net/dcbnl.h b/include/net/dcbnl.h
new file mode 100644
index 000000000..42207fc44
--- /dev/null
+++ b/include/net/dcbnl.h
@@ -0,0 +1,136 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2008, Intel Corporation.
+ *
+ * Author: Lucy Liu <lucy.liu@intel.com>
+ */
+
+#ifndef __NET_DCBNL_H__
+#define __NET_DCBNL_H__
+
+#include <linux/dcbnl.h>
+
+struct net_device;
+
+struct dcb_app_type {
+	int	ifindex;
+	struct dcb_app	  app;
+	struct list_head  list;
+	u8	dcbx;
+};
+
+u16 dcb_getrewr(struct net_device *dev, struct dcb_app *app);
+int dcb_setrewr(struct net_device *dev, struct dcb_app *app);
+int dcb_delrewr(struct net_device *dev, struct dcb_app *app);
+
+int dcb_setapp(struct net_device *, struct dcb_app *);
+u8 dcb_getapp(struct net_device *, struct dcb_app *);
+int dcb_ieee_setapp(struct net_device *, struct dcb_app *);
+int dcb_ieee_delapp(struct net_device *, struct dcb_app *);
+u8 dcb_ieee_getapp_mask(struct net_device *, struct dcb_app *);
+
+struct dcb_rewr_prio_pcp_map {
+	u16 map[IEEE_8021QAZ_MAX_TCS];
+};
+
+void dcb_getrewr_prio_pcp_mask_map(const struct net_device *dev,
+				   struct dcb_rewr_prio_pcp_map *p_map);
+
+struct dcb_ieee_app_prio_map {
+	u64 map[IEEE_8021QAZ_MAX_TCS];
+};
+void dcb_ieee_getapp_prio_dscp_mask_map(const struct net_device *dev,
+					struct dcb_ieee_app_prio_map *p_map);
+
+void dcb_getrewr_prio_dscp_mask_map(const struct net_device *dev,
+				    struct dcb_ieee_app_prio_map *p_map);
+
+struct dcb_ieee_app_dscp_map {
+	u8 map[64];
+};
+void dcb_ieee_getapp_dscp_prio_mask_map(const struct net_device *dev,
+					struct dcb_ieee_app_dscp_map *p_map);
+u8 dcb_ieee_getapp_default_prio_mask(const struct net_device *dev);
+
+int dcbnl_ieee_notify(struct net_device *dev, int event, int cmd,
+		      u32 seq, u32 pid);
+int dcbnl_cee_notify(struct net_device *dev, int event, int cmd,
+		     u32 seq, u32 pid);
+
+/*
+ * Ops struct for the netlink callbacks.  Used by DCB-enabled drivers through
+ * the netdevice struct.
+ */
+struct dcbnl_rtnl_ops {
+	/* IEEE 802.1Qaz std */
+	int (*ieee_getets) (struct net_device *, struct ieee_ets *);
+	int (*ieee_setets) (struct net_device *, struct ieee_ets *);
+	int (*ieee_getmaxrate) (struct net_device *, struct ieee_maxrate *);
+	int (*ieee_setmaxrate) (struct net_device *, struct ieee_maxrate *);
+	int (*ieee_getqcn) (struct net_device *, struct ieee_qcn *);
+	int (*ieee_setqcn) (struct net_device *, struct ieee_qcn *);
+	int (*ieee_getqcnstats) (struct net_device *, struct ieee_qcn_stats *);
+	int (*ieee_getpfc) (struct net_device *, struct ieee_pfc *);
+	int (*ieee_setpfc) (struct net_device *, struct ieee_pfc *);
+	int (*ieee_getapp) (struct net_device *, struct dcb_app *);
+	int (*ieee_setapp) (struct net_device *, struct dcb_app *);
+	int (*ieee_delapp) (struct net_device *, struct dcb_app *);
+	int (*ieee_peer_getets) (struct net_device *, struct ieee_ets *);
+	int (*ieee_peer_getpfc) (struct net_device *, struct ieee_pfc *);
+
+	/* CEE std */
+	u8   (*getstate)(struct net_device *);
+	u8   (*setstate)(struct net_device *, u8);
+	void (*getpermhwaddr)(struct net_device *, u8 *);
+	void (*setpgtccfgtx)(struct net_device *, int, u8, u8, u8, u8);
+	void (*setpgbwgcfgtx)(struct net_device *, int, u8);
+	void (*setpgtccfgrx)(struct net_device *, int, u8, u8, u8, u8);
+	void (*setpgbwgcfgrx)(struct net_device *, int, u8);
+	void (*getpgtccfgtx)(struct net_device *, int, u8 *, u8 *, u8 *, u8 *);
+	void (*getpgbwgcfgtx)(struct net_device *, int, u8 *);
+	void (*getpgtccfgrx)(struct net_device *, int, u8 *, u8 *, u8 *, u8 *);
+	void (*getpgbwgcfgrx)(struct net_device *, int, u8 *);
+	void (*setpfccfg)(struct net_device *, int, u8);
+	void (*getpfccfg)(struct net_device *, int, u8 *);
+	u8   (*setall)(struct net_device *);
+	u8   (*getcap)(struct net_device *, int, u8 *);
+	int  (*getnumtcs)(struct net_device *, int, u8 *);
+	int  (*setnumtcs)(struct net_device *, int, u8);
+	u8   (*getpfcstate)(struct net_device *);
+	void (*setpfcstate)(struct net_device *, u8);
+	void (*getbcncfg)(struct net_device *, int, u32 *);
+	void (*setbcncfg)(struct net_device *, int, u32);
+	void (*getbcnrp)(struct net_device *, int, u8 *);
+	void (*setbcnrp)(struct net_device *, int, u8);
+	int  (*setapp)(struct net_device *, u8, u16, u8);
+	int  (*getapp)(struct net_device *, u8, u16);
+	u8   (*getfeatcfg)(struct net_device *, int, u8 *);
+	u8   (*setfeatcfg)(struct net_device *, int, u8);
+
+	/* DCBX configuration */
+	u8   (*getdcbx)(struct net_device *);
+	u8   (*setdcbx)(struct net_device *, u8);
+
+	/* peer apps */
+	int (*peer_getappinfo)(struct net_device *, struct dcb_peer_app_info *,
+			       u16 *);
+	int (*peer_getapptable)(struct net_device *, struct dcb_app *);
+
+	/* CEE peer */
+	int (*cee_peer_getpg) (struct net_device *, struct cee_pg *);
+	int (*cee_peer_getpfc) (struct net_device *, struct cee_pfc *);
+
+	/* buffer settings */
+	int (*dcbnl_getbuffer)(struct net_device *, struct dcbnl_buffer *);
+	int (*dcbnl_setbuffer)(struct net_device *, struct dcbnl_buffer *);
+
+	/* apptrust */
+	int (*dcbnl_setapptrust)(struct net_device *, u8 *, int);
+	int (*dcbnl_getapptrust)(struct net_device *, u8 *, int *);
+
+	/* rewrite */
+	int (*dcbnl_setrewr)(struct net_device *dev, struct dcb_app *app);
+	int (*dcbnl_delrewr)(struct net_device *dev, struct dcb_app *app);
+};
+
+#endif /* __NET_DCBNL_H__ */