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, 384 insertions, 0 deletions

diff --git a/include/trace/events/xdp.h b/include/trace/events/xdp.h
new file mode 100644
index 000000000..18c0ac514
--- /dev/null
+++ b/include/trace/events/xdp.h
@@ -0,0 +1,384 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM xdp
+
+#if !defined(_TRACE_XDP_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_XDP_H
+
+#include <linux/netdevice.h>
+#include <linux/filter.h>
+#include <linux/tracepoint.h>
+#include <linux/bpf.h>
+#include <net/xdp.h>
+
+#define __XDP_ACT_MAP(FN)	\
+	FN(ABORTED)		\
+	FN(DROP)		\
+	FN(PASS)		\
+	FN(TX)			\
+	FN(REDIRECT)
+
+#define __XDP_ACT_TP_FN(x)	\
+	TRACE_DEFINE_ENUM(XDP_##x);
+#define __XDP_ACT_SYM_FN(x)	\
+	{ XDP_##x, #x },
+#define __XDP_ACT_SYM_TAB	\
+	__XDP_ACT_MAP(__XDP_ACT_SYM_FN) { -1, NULL }
+__XDP_ACT_MAP(__XDP_ACT_TP_FN)
+
+TRACE_EVENT(xdp_exception,
+
+	TP_PROTO(const struct net_device *dev,
+		 const struct bpf_prog *xdp, u32 act),
+
+	TP_ARGS(dev, xdp, act),
+
+	TP_STRUCT__entry(
+		__field(int, prog_id)
+		__field(u32, act)
+		__field(int, ifindex)
+	),
+
+	TP_fast_assign(
+		__entry->prog_id	= xdp->aux->id;
+		__entry->act		= act;
+		__entry->ifindex	= dev->ifindex;
+	),
+
+	TP_printk("prog_id=%d action=%s ifindex=%d",
+		  __entry->prog_id,
+		  __print_symbolic(__entry->act, __XDP_ACT_SYM_TAB),
+		  __entry->ifindex)
+);
+
+TRACE_EVENT(xdp_bulk_tx,
+
+	TP_PROTO(const struct net_device *dev,
+		 int sent, int drops, int err),
+
+	TP_ARGS(dev, sent, drops, err),
+
+	TP_STRUCT__entry(
+		__field(int, ifindex)
+		__field(u32, act)
+		__field(int, drops)
+		__field(int, sent)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__entry->ifindex	= dev->ifindex;
+		__entry->act		= XDP_TX;
+		__entry->drops		= drops;
+		__entry->sent		= sent;
+		__entry->err		= err;
+	),
+
+	TP_printk("ifindex=%d action=%s sent=%d drops=%d err=%d",
+		  __entry->ifindex,
+		  __print_symbolic(__entry->act, __XDP_ACT_SYM_TAB),
+		  __entry->sent, __entry->drops, __entry->err)
+);
+
+#ifndef __DEVMAP_OBJ_TYPE
+#define __DEVMAP_OBJ_TYPE
+struct _bpf_dtab_netdev {
+	struct net_device *dev;
+};
+#endif /* __DEVMAP_OBJ_TYPE */
+
+DECLARE_EVENT_CLASS(xdp_redirect_template,
+
+	TP_PROTO(const struct net_device *dev,
+		 const struct bpf_prog *xdp,
+		 const void *tgt, int err,
+		 enum bpf_map_type map_type,
+		 u32 map_id, u32 index),
+
+	TP_ARGS(dev, xdp, tgt, err, map_type, map_id, index),
+
+	TP_STRUCT__entry(
+		__field(int, prog_id)
+		__field(u32, act)
+		__field(int, ifindex)
+		__field(int, err)
+		__field(int, to_ifindex)
+		__field(u32, map_id)
+		__field(int, map_index)
+	),
+
+	TP_fast_assign(
+		u32 ifindex = 0, map_index = index;
+
+		if (map_type == BPF_MAP_TYPE_DEVMAP || map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
+			/* Just leave to_ifindex to 0 if do broadcast redirect,
+			 * as tgt will be NULL.
+			 */
+			if (tgt)
+				ifindex = ((struct _bpf_dtab_netdev *)tgt)->dev->ifindex;
+		} else if (map_type == BPF_MAP_TYPE_UNSPEC && map_id == INT_MAX) {
+			ifindex = index;
+			map_index = 0;
+		}
+
+		__entry->prog_id	= xdp->aux->id;
+		__entry->act		= XDP_REDIRECT;
+		__entry->ifindex	= dev->ifindex;
+		__entry->err		= err;
+		__entry->to_ifindex	= ifindex;
+		__entry->map_id		= map_id;
+		__entry->map_index	= map_index;
+	),
+
+	TP_printk("prog_id=%d action=%s ifindex=%d to_ifindex=%d err=%d"
+		  " map_id=%d map_index=%d",
+		  __entry->prog_id,
+		  __print_symbolic(__entry->act, __XDP_ACT_SYM_TAB),
+		  __entry->ifindex, __entry->to_ifindex,
+		  __entry->err, __entry->map_id, __entry->map_index)
+);
+
+DEFINE_EVENT(xdp_redirect_template, xdp_redirect,
+	TP_PROTO(const struct net_device *dev,
+		 const struct bpf_prog *xdp,
+		 const void *tgt, int err,
+		 enum bpf_map_type map_type,
+		 u32 map_id, u32 index),
+	TP_ARGS(dev, xdp, tgt, err, map_type, map_id, index)
+);
+
+DEFINE_EVENT(xdp_redirect_template, xdp_redirect_err,
+	TP_PROTO(const struct net_device *dev,
+		 const struct bpf_prog *xdp,
+		 const void *tgt, int err,
+		 enum bpf_map_type map_type,
+		 u32 map_id, u32 index),
+	TP_ARGS(dev, xdp, tgt, err, map_type, map_id, index)
+);
+
+#define _trace_xdp_redirect(dev, xdp, to)						\
+	 trace_xdp_redirect(dev, xdp, NULL, 0, BPF_MAP_TYPE_UNSPEC, INT_MAX, to)
+
+#define _trace_xdp_redirect_err(dev, xdp, to, err)					\
+	 trace_xdp_redirect_err(dev, xdp, NULL, err, BPF_MAP_TYPE_UNSPEC, INT_MAX, to)
+
+#define _trace_xdp_redirect_map(dev, xdp, to, map_type, map_id, index) \
+	 trace_xdp_redirect(dev, xdp, to, 0, map_type, map_id, index)
+
+#define _trace_xdp_redirect_map_err(dev, xdp, to, map_type, map_id, index, err) \
+	 trace_xdp_redirect_err(dev, xdp, to, err, map_type, map_id, index)
+
+#ifdef CONFIG_BPF_SYSCALL
+TRACE_EVENT(xdp_cpumap_kthread,
+
+	TP_PROTO(int map_id, unsigned int processed,  unsigned int drops,
+		 int sched, struct xdp_cpumap_stats *xdp_stats),
+
+	TP_ARGS(map_id, processed, drops, sched, xdp_stats),
+
+	TP_STRUCT__entry(
+		__field(int, map_id)
+		__field(u32, act)
+		__field(int, cpu)
+		__field(unsigned int, drops)
+		__field(unsigned int, processed)
+		__field(int, sched)
+		__field(unsigned int, xdp_pass)
+		__field(unsigned int, xdp_drop)
+		__field(unsigned int, xdp_redirect)
+	),
+
+	TP_fast_assign(
+		__entry->map_id		= map_id;
+		__entry->act		= XDP_REDIRECT;
+		__entry->cpu		= smp_processor_id();
+		__entry->drops		= drops;
+		__entry->processed	= processed;
+		__entry->sched	= sched;
+		__entry->xdp_pass	= xdp_stats->pass;
+		__entry->xdp_drop	= xdp_stats->drop;
+		__entry->xdp_redirect	= xdp_stats->redirect;
+	),
+
+	TP_printk("kthread"
+		  " cpu=%d map_id=%d action=%s"
+		  " processed=%u drops=%u"
+		  " sched=%d"
+		  " xdp_pass=%u xdp_drop=%u xdp_redirect=%u",
+		  __entry->cpu, __entry->map_id,
+		  __print_symbolic(__entry->act, __XDP_ACT_SYM_TAB),
+		  __entry->processed, __entry->drops,
+		  __entry->sched,
+		  __entry->xdp_pass, __entry->xdp_drop, __entry->xdp_redirect)
+);
+
+TRACE_EVENT(xdp_cpumap_enqueue,
+
+	TP_PROTO(int map_id, unsigned int processed,  unsigned int drops,
+		 int to_cpu),
+
+	TP_ARGS(map_id, processed, drops, to_cpu),
+
+	TP_STRUCT__entry(
+		__field(int, map_id)
+		__field(u32, act)
+		__field(int, cpu)
+		__field(unsigned int, drops)
+		__field(unsigned int, processed)
+		__field(int, to_cpu)
+	),
+
+	TP_fast_assign(
+		__entry->map_id		= map_id;
+		__entry->act		= XDP_REDIRECT;
+		__entry->cpu		= smp_processor_id();
+		__entry->drops		= drops;
+		__entry->processed	= processed;
+		__entry->to_cpu		= to_cpu;
+	),
+
+	TP_printk("enqueue"
+		  " cpu=%d map_id=%d action=%s"
+		  " processed=%u drops=%u"
+		  " to_cpu=%d",
+		  __entry->cpu, __entry->map_id,
+		  __print_symbolic(__entry->act, __XDP_ACT_SYM_TAB),
+		  __entry->processed, __entry->drops,
+		  __entry->to_cpu)
+);
+
+TRACE_EVENT(xdp_devmap_xmit,
+
+	TP_PROTO(const struct net_device *from_dev,
+		 const struct net_device *to_dev,
+		 int sent, int drops, int err),
+
+	TP_ARGS(from_dev, to_dev, sent, drops, err),
+
+	TP_STRUCT__entry(
+		__field(int, from_ifindex)
+		__field(u32, act)
+		__field(int, to_ifindex)
+		__field(int, drops)
+		__field(int, sent)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__entry->from_ifindex	= from_dev->ifindex;
+		__entry->act		= XDP_REDIRECT;
+		__entry->to_ifindex	= to_dev->ifindex;
+		__entry->drops		= drops;
+		__entry->sent		= sent;
+		__entry->err		= err;
+	),
+
+	TP_printk("ndo_xdp_xmit"
+		  " from_ifindex=%d to_ifindex=%d action=%s"
+		  " sent=%d drops=%d"
+		  " err=%d",
+		  __entry->from_ifindex, __entry->to_ifindex,
+		  __print_symbolic(__entry->act, __XDP_ACT_SYM_TAB),
+		  __entry->sent, __entry->drops,
+		  __entry->err)
+);
+#endif /* CONFIG_BPF_SYSCALL */
+
+/* Expect users already include <net/xdp.h>, but not xdp_priv.h */
+#include <net/xdp_priv.h>
+
+#define __MEM_TYPE_MAP(FN)	\
+	FN(PAGE_SHARED)		\
+	FN(PAGE_ORDER0)		\
+	FN(PAGE_POOL)		\
+	FN(XSK_BUFF_POOL)
+
+#define __MEM_TYPE_TP_FN(x)	\
+	TRACE_DEFINE_ENUM(MEM_TYPE_##x);
+#define __MEM_TYPE_SYM_FN(x)	\
+	{ MEM_TYPE_##x, #x },
+#define __MEM_TYPE_SYM_TAB	\
+	__MEM_TYPE_MAP(__MEM_TYPE_SYM_FN) { -1, 0 }
+__MEM_TYPE_MAP(__MEM_TYPE_TP_FN)
+
+TRACE_EVENT(mem_disconnect,
+
+	TP_PROTO(const struct xdp_mem_allocator *xa),
+
+	TP_ARGS(xa),
+
+	TP_STRUCT__entry(
+		__field(const struct xdp_mem_allocator *,	xa)
+		__field(u32,		mem_id)
+		__field(u32,		mem_type)
+		__field(const void *,	allocator)
+	),
+
+	TP_fast_assign(
+		__entry->xa		= xa;
+		__entry->mem_id		= xa->mem.id;
+		__entry->mem_type	= xa->mem.type;
+		__entry->allocator	= xa->allocator;
+	),
+
+	TP_printk("mem_id=%d mem_type=%s allocator=%p",
+		  __entry->mem_id,
+		  __print_symbolic(__entry->mem_type, __MEM_TYPE_SYM_TAB),
+		  __entry->allocator
+	)
+);
+
+TRACE_EVENT(mem_connect,
+
+	TP_PROTO(const struct xdp_mem_allocator *xa,
+		 const struct xdp_rxq_info *rxq),
+
+	TP_ARGS(xa, rxq),
+
+	TP_STRUCT__entry(
+		__field(const struct xdp_mem_allocator *,	xa)
+		__field(u32,		mem_id)
+		__field(u32,		mem_type)
+		__field(const void *,	allocator)
+		__field(const struct xdp_rxq_info *,		rxq)
+		__field(int,		ifindex)
+	),
+
+	TP_fast_assign(
+		__entry->xa		= xa;
+		__entry->mem_id		= xa->mem.id;
+		__entry->mem_type	= xa->mem.type;
+		__entry->allocator	= xa->allocator;
+		__entry->rxq		= rxq;
+		__entry->ifindex	= rxq->dev->ifindex;
+	),
+
+	TP_printk("mem_id=%d mem_type=%s allocator=%p"
+		  " ifindex=%d",
+		  __entry->mem_id,
+		  __print_symbolic(__entry->mem_type, __MEM_TYPE_SYM_TAB),
+		  __entry->allocator,
+		  __entry->ifindex
+	)
+);
+
+TRACE_EVENT(bpf_xdp_link_attach_failed,
+
+	TP_PROTO(const char *msg),
+
+	TP_ARGS(msg),
+
+	TP_STRUCT__entry(
+		__string(msg, msg)
+	),
+
+	TP_fast_assign(
+		__assign_str(msg);
+	),
+
+	TP_printk("errmsg=%s", __get_str(msg))
+);
+
+#endif /* _TRACE_XDP_H */
+
+#include <trace/define_trace.h>