tools: Add kvm_stat man page

Converted from the Texinfo source in QEMU to asciidoc.  The a2x
incantation was provided by Janosch Frank.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

tools/kvm/kvm_stat/Makefile

+include ../../scripts/Makefile.include
+include ../../scripts/utilities.mak
 BINDIR=usr/bin
+MANDIR=usr/share/man
+MAN1DIR=$(MANDIR)/man1
 
-install:
-	mkdir -p $(INSTALL_ROOT)/$(BINDIR)
+MAN1=kvm_stat.1
+
+A2X=a2x
+a2x_path := $(call get-executable,$(A2X))
+
+all: man
+
+ifneq ($(findstring $(MAKEFLAGS),s),s)
+  ifneq ($(V),1)
+     QUIET_A2X = @echo '  A2X     '$@;
+  endif
+endif
+
+%.1: %.txt
+ifeq ($(a2x_path),)
+	$(error "You need to install asciidoc for man pages")
+else
+	$(QUIET_A2X)$(A2X) --doctype manpage --format manpage $<
+endif
+
+clean:
+	rm -f $(MAN1)
+
+man: $(MAN1)
+
+install-man: man
+	install -d -m 755 $(INSTALL_ROOT)/$(MAN1DIR)
+	install -m 644 kvm_stat.1 $(INSTALL_ROOT)/$(MAN1DIR)
+
+install-tools:
+	install -d -m 755 $(INSTALL_ROOT)/$(BINDIR)
 	install -m 755 -p "kvm_stat" "$(INSTALL_ROOT)/$(BINDIR)/$(TARGET)"
+
+install: install-tools install-man
+.PHONY: all clean man install-tools install-man install

tools/kvm/kvm_stat/kvm_stat.txt

+kvm_stat(1)
+===========
+
+NAME
+----
+kvm_stat - Report KVM kernel module event counters
+
+SYNOPSIS
+--------
+[verse]
+'kvm_stat' [OPTION]...
+
+DESCRIPTION
+-----------
+kvm_stat prints counts of KVM kernel module trace events.  These events signify
+state transitions such as guest mode entry and exit.
+
+This tool is useful for observing guest behavior from the host perspective.
+Often conclusions about performance or buggy behavior can be drawn from the
+output.
+
+The set of KVM kernel module trace events may be specific to the kernel version
+or architecture.  It is best to check the KVM kernel module source code for the
+meaning of events.
+
+Note that trace events are counted globally across all running guests.
+
+OPTIONS
+-------
+-1::
+--once::
+--batch::
+	run in batch mode for one second
+
+-l::
+--log::
+	run in logging mode (like vmstat)
+
+-t::
+--tracepoints::
+	retrieve statistics from tracepoints
+
+-d::
+--debugfs::
+	retrieve statistics from debugfs
+
+-f<fields>::
+--fields=<fields>::
+	fields to display (regex)
+
+-h::
+--help::
+	show help message
+
+SEE ALSO
+--------
+'perf'(1), 'trace-cmd'(1)
+
+AUTHOR
+------
+Stefan Hajnoczi <stefanha@redhat.com>