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, 95 insertions, 0 deletions

diff --git a/include/trace/events/mce.h b/include/trace/events/mce.h
new file mode 100644
index 000000000..c1c50df9e
--- /dev/null
+++ b/include/trace/events/mce.h
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM mce
+
+#if !defined(_TRACE_MCE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_MCE_H
+
+#include <linux/ktime.h>
+#include <linux/tracepoint.h>
+#include <asm/mce.h>
+
+/*
+ * MCE Event Record.
+ *
+ * Only very relevant and transient information which cannot be
+ * gathered from a system by any other means or which can only be
+ * acquired arduously should be added to this record.
+ */
+
+TRACE_EVENT(mce_record,
+
+	TP_PROTO(struct mce_hw_err *err),
+
+	TP_ARGS(err),
+
+	TP_STRUCT__entry(
+		__field(	u64,		mcgcap		)
+		__field(	u64,		mcgstatus	)
+		__field(	u64,		status		)
+		__field(	u64,		addr		)
+		__field(	u64,		misc		)
+		__field(	u64,		synd		)
+		__field(	u64,		ipid		)
+		__field(	u64,		ip		)
+		__field(	u64,		tsc		)
+		__field(	u64,		ppin		)
+		__field(	u64,		walltime	)
+		__field(	u32,		cpu		)
+		__field(	u32,		cpuid		)
+		__field(	u32,		apicid		)
+		__field(	u32,		socketid	)
+		__field(	u8,		cs		)
+		__field(	u8,		bank		)
+		__field(	u8,		cpuvendor	)
+		__field(	u32,		microcode	)
+		__dynamic_array(u8, v_data, sizeof(err->vendor))
+	),
+
+	TP_fast_assign(
+		__entry->mcgcap		= err->m.mcgcap;
+		__entry->mcgstatus	= err->m.mcgstatus;
+		__entry->status		= err->m.status;
+		__entry->addr		= err->m.addr;
+		__entry->misc		= err->m.misc;
+		__entry->synd		= err->m.synd;
+		__entry->ipid		= err->m.ipid;
+		__entry->ip		= err->m.ip;
+		__entry->tsc		= err->m.tsc;
+		__entry->ppin		= err->m.ppin;
+		__entry->walltime	= err->m.time;
+		__entry->cpu		= err->m.extcpu;
+		__entry->cpuid		= err->m.cpuid;
+		__entry->apicid		= err->m.apicid;
+		__entry->socketid	= err->m.socketid;
+		__entry->cs		= err->m.cs;
+		__entry->bank		= err->m.bank;
+		__entry->cpuvendor	= err->m.cpuvendor;
+		__entry->microcode	= err->m.microcode;
+		memcpy(__get_dynamic_array(v_data), &err->vendor, sizeof(err->vendor));
+	),
+
+	TP_printk("CPU: %d, MCGc/s: %llx/%llx, MC%d: %016llx, IPID: %016llx, ADDR: %016llx, MISC: %016llx, SYND: %016llx, RIP: %02x:<%016llx>, TSC: %llx, PPIN: %llx, vendor: %u, CPUID: %x, time: %llu, socket: %u, APIC: %x, microcode: %x, vendor data: %s",
+		__entry->cpu,
+		__entry->mcgcap, __entry->mcgstatus,
+		__entry->bank, __entry->status,
+		__entry->ipid,
+		__entry->addr,
+		__entry->misc,
+		__entry->synd,
+		__entry->cs, __entry->ip,
+		__entry->tsc,
+		__entry->ppin,
+		__entry->cpuvendor,
+		__entry->cpuid,
+		__entry->walltime,
+		__entry->socketid,
+		__entry->apicid,
+		__entry->microcode,
+		__print_dynamic_array(v_data, sizeof(u8)))
+);
+
+#endif /* _TRACE_MCE_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>