Merge branch 'xseg-refactor'

xseg/.gitignore

@@ -9,3 +9,8 @@
 *.o.cmd
 .*.ko.cmd
 *.ko
+*.pyc
+config.mk
+*tmp_versions*
+*Module*
+*modules*

xseg/Makefile

-.PHONY: clean
+# Copyright 2012 GRNET S.A. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or
+# without modification, are permitted provided that the following
+# conditions are met:
+#
+#   1. Redistributions of source code must retain the above
+#      copyright notice, this list of conditions and the following
+#      disclaimer.
+#   2. Redistributions in binary form must reproduce the above
+#      copyright notice, this list of conditions and the following
+#      disclaimer in the documentation and/or other materials
+#      provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
+# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
+# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+# The views and conclusions contained in the software and
+# documentation are those of the authors and should not be
+# interpreted as representing official policies, either expressed
+# or implied, of GRNET S.A.
+#
 
-XSEG_HOME=$(shell pwd)
-export XSEG_HOME
+.PHONY: default clean target-list distclean
 
-include config.mk
-include base.mk
+TARGET=default
+include ./base.mk
 
-default:
-	for f in $(MAKEDIRS); do \
-		make -C $$f || break; \
-		echo "-------------------------------------------------------------------"; \
-		echo " "; \
-	done
+FILES="base.mk"
+FILES+="config.env"
+FILES+="envsetup"
+FILES+="Makefile"
+FILES+="launch"
 
-clean:
-	for f in $(MAKEDIRS); do \
-		make -C $$f clean || break; \
-		echo " "; \
-	done
 
+XSEG_BUILD_TARGETS=$(patsubst %,build-%,$(XSEG_DIRS))
+XSEG_CLEAN_TARGETS=$(patsubst %,clean-%,$(XSEG_DIRS))
+XSEG_INSTALL_TARGETS=$(patsubst %,install-%,$(XSEG_DIRS))
+XSEG_INSTALLSRC_TARGETS=$(patsubst %,install-src-%,$(XSEG_DIRS))
+
+default: targets
+
+target-list:
+	@echo $(XSEG_DOMAIN_TARGETS)
+
+targets: $(XSEG_BUILD_TARGETS)
+
+clean: $(XSEG_CLEAN_TARGETS)
+	rm $(CONFIG)
+
+install: $(XSEG_INSTALL_TARGETS)
+
+install-src: $(XSEG_INSTALLSRC_TARGETS) $(XSEG_INSTALLSRC_DIRS)
+	install -d $(DESTDIR)$(srcdir)/lib
+	install -d $(DESTDIR)$(srcdir)/lib/user
+	install -d $(DESTDIR)$(srcdir)/lib/kernel
+	install -d $(DESTDIR)$(srcdir)/
+	install -o 0 -g 0 -m 755 -t $(DESTDIR)$(srcdir) envsetup
+	install -o 0 -g 0 -m 755 -t $(DESTDIR)$(srcdir) launch
+	install -o 0 -g 0 -m 644 -t $(DESTDIR)$(srcdir) config.env
+	install -o 0 -g 0 -m 644 -t $(DESTDIR)$(srcdir) Makefile
+	install -o 0 -g 0 -m 644 -t $(DESTDIR)$(srcdir) base.mk
+
+#	@for f in $(FILES); do \
+#		install -o 0 -g 0 -m 644 -t $(DESTDIR)$(srcdir) $$f ; \
+#	done
+
+
+.PHONY: $(XSEG_BUILD_TARGETS)
+$(XSEG_BUILD_TARGETS):
+	@echo "" ;
+	@echo "=== $@ ===";
+	@make -C $(@:build-%=%) default || exit 1;
+	@echo "" ;
+
+.PHONY: $(XSEG_INSTALL_TARGETS)
+$(XSEG_INSTALL_TARGETS):
+	@echo "" ;
+	@echo "=== $@ ===";
+	@make -C $(@:install-%=%) install || true;
+	@echo "" ;
+
+.PHONY: $(XSEG_INSTALLSRC_TARGETS)
+$(XSEG_INSTALLSRC_TARGETS):
+	@echo "" ;
+	@echo "=== $@ ===";
+	@make -C $(@:install-src-%=%) install-src || true;
+	@echo "" ;
+
+.PHONY: $(XSEG_CLEAN_TARGETS)
+$(XSEG_CLEAN_TARGETS):
+	@echo "" ;
+	@echo "=== $@ ===";
+	@make -C $(@:clean-%=%) clean || true;
+	@echo "" ;
+
+distclean: $(XSEG_CLEAN_TARGETS)
+	rm -f lib/user/*.so* lib/user/*.a
+	rm -f lib/kernel/*.ko
+	rm -f $(XSEG_HOME)/config.mk

xseg/base.mk

-# Default setup for subdirectory Makefiles.
+# Copyright 2012 GRNET S.A. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or
+# without modification, are permitted provided that the following
+# conditions are met:
+#
+#   1. Redistributions of source code must retain the above
+#      copyright notice, this list of conditions and the following
+#      disclaimer.
+#   2. Redistributions in binary form must reproduce the above
+#      copyright notice, this list of conditions and the following
+#      disclaimer in the documentation and/or other materials
+#      provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
+# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
+# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+# The views and conclusions contained in the software and
+# documentation are those of the authors and should not be
+# interpreted as representing official policies, either expressed
+# or implied, of GRNET S.A.
+#
 
-CC=gcc
+# Setup for xseg Makefiles.
+
+ifndef TARGET
+TARGET:=$(shell basename $(shell pwd))
+endif
+
+export CC=gcc
 ifndef MOPTS
-MOPTS=
+export MOPTS=
 endif
 ifndef COPTS
-COPTS=-O2 -g -finline-functions $(MOPTS) $(DEBUG)
+export COPTS=-O2 -g -finline-functions $(MOPTS) $(DEBUG)
 endif
 ifndef CSTD
-CSTD=-std=gnu99 -pedantic
+export CSTD=-std=gnu99 -pedantic
 endif
+
+
+bindir=/usr/bin/
+libdir=/usr/lib/
+pythondir=/usr/lib/python2.7/
+moduledir=/lib/modules/`uname -r`/extra/
+srcdir=/usr/src/archipelago-kernel-dkms-VERSION/
+ganetidir=/usr/share/ganeti/extstorage/vlmc/
+
 INC=-I$(BASE)
-CFLAGS=-Wall $(INC) $(COPTS) $(CSTD)
+INC+=-I$(BASE)/peers/$(TARGET)
+INC+=-I$(BASE)/sys/$(TARGET)
+INC+=-I$(BASE)/drivers/$(TARGET)
+export INC
+
+export LIB=$(BASE)/lib/$(TARGET)
+export CFLAGS=-Wall $(COPTS) $(CSTD)
+
+#ifeq (,$(XSEG_HOME))
+#export XSEG_HOME=$(shell ${XSEG_HOME})
+#endif
+
+ifeq (,$(XSEG_HOME))
+export XSEG_HOME=$(CURDIR)
+endif
 
+CONFIG=./config.mk
+
+#default:
+
+#.PHONY: clean-config
+
+#clean: clean-config
+
+#clean-config:
+#	rm -f $(CONFIG)
+
+ifndef BASE
+exists=$(shell [ -f "$(CONFIG)" ] && echo exists)
+ifeq (exists,$(exists))
+include $(CONFIG)
+else
+$(shell $(XSEG_HOME)/envsetup show | sed -e 's/"//g' > "$(CONFIG)")
+include $(CONFIG)
+endif
+
+ifeq (,$(XSEG_DOMAIN_TARGETS))
+export XSEG_DOMAIN_TARGETS=$(shell $(XSEG_HOME)/tools/xseg-domain-targets | sed -e 's/^[^=]*=//;s/"//g')
+endif
+export BASE=$(XSEG_HOME)
+endif

xseg/config.env

+# Host configuration
+XSEG_MOPTS="-march=core2"
+
+# Order is significant due to dependencies
+# (e.g. 'peers' should be last).
+XSEG_DIRS="tools xtypes xseg sys drivers peers"
+#XSEG_DOMAIN_DIRS="util_libs sys drivers peers"

xseg/config.mk

-# Host configuration
-
-MOPTS=-march=core2
-
-# Order is significant due to dependencies.
-# 'peers' should be last.
-MAKEDIRS=xq drivers xseg peers sys
-

xseg/doc/components.rst

+Archipelagos Components
+=======================
+
+This document intends to document the various components of Archipelagos, the
+storage infrastructure behind the Cydlades IaaS cloud software.
+
+xq
+**
+Fixed-size (power of 2, up to 2^32), double-ended, circular queue of xserial
+(unsigned int) elements, which guarantees safe concurrent access (with built-in
+locking).
+
+xq is used to safely index and/or split a shared buffer.
+
+xseg
+****
+The backbone of Archipelagos.
+
+The xseg API (and its implementation) provides access to shared memory segments,
+residing either in userspace (posix segments) or in kernel space (segdev
+segments), to both user- and kernel-space 'processes/threads' (known as peers,
+in the xseg API).
+
+The shared memory segments (referred to as plainly segments in the xseg API) are
+formed by a pool of requests (xseg requests), and multiple endpoints (xseg
+ports), on which the xseg peers bind. 
+
+The xseg API defines certain operations that can be performed on a segment
+(malloc / allocate / map / etc), and ceration operations that can performed by
+peers (signal / wait_for_signal / prepare_wait / cancel_wait etc).

xseg/doc/flow.txt

+Intented audience
+=================
+
+People who want to tinker with xseg internals, and need a quick-n-dirty intro
+to the basics behind its operation.
+
+Terminology / API
+*****************
+
+Client, server, peer, xsegbd, vlmc, map, request, segment, signal, wait...
+
+Basic flow
+**********
+
+The initiator/client... then...
+
+ * Load the modules, mknod, create segment
+	- insmod lib/kernel/xseg.ko
+	- insmod lib/kernel/segdev.ko
+	- mknod /dev/segdev c 60 0
+	- insmod lib/kernel/xseg_segdev.ko
+	- insmod lib/kernel/xseg_posix.ko
+	- ./peer/users/xseg segdev:xsegbd:16:4096:64:1024:12 create
+	- insmod lib/kernel/xsegbd.ko
+
+ * Verify that the segment was created successfully:
+ 	- ./peer/users/xseg segdev:xsegbd reportall
+
+ * Allocate request for vlmcd:
+ 	- ./peer/users/xseg segdev:xsegbd 0:1 alloc_requests 1024
+
+ * Run vlmcd/mapperd/filed:
+ 	- ./peer/users/filed /srv/archip/images -p 9 -g segdev:xsegbd
+	- ./peer/users/mapperd[.py] -p 10 -g segdev:xsegbd
+	- ./peer/users/vlmcd -p 0 -g segdev:xsegbd -b 9 -m 10
+
+ * Create/List/Map/Unmap/Remove a volume:
+ 	- vlmc create test -s 4096
+	- vlmc list
+ 	- echo "test 1:0:1024" > /sys/bus/xsegbd/add
+	(vlmc map test might work as long as vlmcd runs on port 0, and port 1-2-n, where n the no of volumes mapped are free)
+	- vlmc showmapped
+	- echo 0 > /sys/bus/xsegbd/remove (or vlmc unmap /dev/xsegbd0)
+	- vlmc rm test

xseg/drivers/Makefile

-.PHONY: all clean xseg lib
+.PHONY: install-src
 
-BASE=..
+include $(XSEG_HOME)/base.mk
 
-include $(BASE)/config.mk
-include $(BASE)/base.mk
+FILES="Makefile"
+FILES+=$(shell ls *.h)
 
-DRIVERS=xseg_posix xseg_xsegdev
-DRVOBJS=$(DRIVERS:=.o)
-DRVSOS=$(DRIVERS:=.so)
+SUBDIR:=$(subst $(XSEG_HOME)/,,$(CURDIR))
+XSEG_CLEAN_TARGETS=$(patsubst %,clean-%,$(XSEG_DOMAIN_TARGETS))
+XSEG_INSTALL_TARGETS=$(patsubst %,install-%,$(XSEG_DOMAIN_TARGETS))
+XSEG_INSTALLSRC_TARGETS=$(patsubst %,install-src-%,$(XSEG_DOMAIN_TARGETS))
 
-all: xseg $(DRIVERS:=.so) lib
 
-$(BASE)/sys/xseg_user.o:
-	make -C $(BASE)/sys xseg_user.o
+default: $(XSEG_DOMAIN_TARGETS)
 
-xseg_posix.o: xseg_posix.c $(BASE)/xseg/xseg.h
-	$(CC) $(CFLAGS) -fPIC -c -o $@ $<
+install: $(XSEG_INSTALL_TARGETS)
 
-xseg_posix.so: xseg_posix.o $(BASE)/sys/xseg_user.o
-	$(CC) -shared -o $@ $< $(BASE)/sys/xseg_user.o 
+clean: $(XSEG_CLEAN_TARGETS)
 
-xseg_xsegdev.o: xseg_xsegdev.c $(BASE)/xseg/xseg.h
-	$(CC) $(CFLAGS) -I$(BASE)/sys -fPIC -c -o $@ $<
+.PHONY: $(XSEG_DOMAIN_TARGETS)
+$(XSEG_DOMAIN_TARGETS):
+	@echo " ";
+	@echo "=== $@ in $(SUBDIR) ===";
+	@echo " ";
+	@make -C $@ TARGET=$@ default || exit 1;
+	@echo " ";
 
-xseg_xsegdev.so: xseg_xsegdev.o $(BASE)/sys/xseg_user.o
-	$(CC) -shared -o $@ $< $(BASE)/sys/xseg_user.o 
+.PHONY: $(XSEG_INSTALL_TARGETS)
+$(XSEG_INSTALL_TARGETS):
+	@echo " ";
+	@echo "=== $@ in $(SUBDIR)===";
+	@echo " ";
+	@make -C $(@:install-%=%) TARGET=$@ install || true;
+	@echo " ";
+
+
+.PHONY: $(XSEG_INSTALLSRC_TARGETS)
+$(XSEG_INSTALLSRC_TARGETS):
+	@echo " ";
+	@echo "=== $@ in $(SUBDIR)===";
+	@echo " ";
+	@make -C $(@:install-src-%=%) TARGET=$@ install-src || true;
+	@echo " ";
+
+.PHONY: $(XSEG_CLEAN_TARGETS)
+$(XSEG_CLEAN_TARGETS):
+	@echo " ";
+	@echo "=== $@ in $(SUBDIR)===";
+	@echo " ";
+	@make -C $(@:clean-%=%) TARGET=$@ clean || true;
+	@echo " ";
+
+
+
+install-src: $(XSEG_INSTALLSRC_TARGETS)
+	@install -d $(DESTDIR)$(srcdir)$(SUBDIR) ;
+	@for f in $(FILES) ; do \
+		install -o 0 -g 0 -m 644 -t $(DESTDIR)$(srcdir)$(SUBDIR) $$f ; \
+	done
 
-lib:
-	cp -vaf $(DRVSOS) ../lib
-clean:
-	rm -f $(DRVOBJS) $(DRVSOS)

xseg/drivers/kernel/Makefile

+# Copyright 2012 GRNET S.A. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or
+# without modification, are permitted provided that the following
+# conditions are met:
+#
+#   1. Redistributions of source code must retain the above
+#      copyright notice, this list of conditions and the following
+#      disclaimer.
+#   2. Redistributions in binary form must reproduce the above
+#      copyright notice, this list of conditions and the following
+#      disclaimer in the documentation and/or other materials
+#      provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
+# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
+# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+# The views and conclusions contained in the software and
+# documentation are those of the authors and should not be
+# interpreted as representing official policies, either expressed
+# or implied, of GRNET S.A.
+#
+
+.PHONY: default all clean install install-src
+
+include $(XSEG_HOME)/base.mk
+
+ifeq (,$(KVER))
+KVER := $(shell uname -r)
+endif
+
+KDIR := /lib/modules/$(KVER)/build
+PWD := $(shell pwd)
+EXTRA_CFLAGS += -g -I$(BASE) -I$(BASE)/sys/kernel
+LIBDIR=$(BASE)/lib/kernel
+
+obj-m += xseg_segdev.o
+obj-m += xseg_posix.o
+obj-m += xseg_pthread.o
+
+FILES="Makefile"
+#FILES+=$(shell ls *.h)
+FILES+=$(shell ls *.c)
+
+SUBDIR:=$(subst $(XSEG_HOME),,$(CURDIR))
+
+default: all
+
+$(BASE)/sys/kernel/Module.symvers:
+	$(MAKE) -C $(BASE)/sys/kernel TARGET=kernel default
+
+all: $(BASE)/sys/kernel/Module.symvers
+	cp -vaf $< .
+	$(MAKE) -C $(KDIR) SUBDIRS=$(PWD) V=$(V) modules
+	cp -vaf xseg_pthread.ko xseg_segdev.ko xseg_posix.ko $(LIBDIR)
+
+install:
+	install -d $(DESTDIR)$(moduledir)
+	install -o 0 -g 0 -m 644 -t $(DESTDIR)$(moduledir) xseg_segdev.ko
+	install -o 0 -g 0 -m 644 -t $(DESTDIR)$(moduledir) xseg_posix.ko
+	install -o 0 -g 0 -m 644 -t $(DESTDIR)$(moduledir) xseg_pthread.ko
+
+install-src:
+	install -d $(DESTDIR)$(srcdir)$(SUBDIR) ;
+	@for f in $(FILES) ; do \
+		install -o 0 -g 0 -m 644 -t $(DESTDIR)$(srcdir)$(SUBDIR) $$f ; \
+	done
+
+
+clean:
+	rm -f Module.symvers
+	make -C /lib/modules/$(KVER)/build M=$(PWD) V=$(V) clean

xseg/drivers/kernel/xseg_posix.c

+/*
+ * Copyright (C) 2012 GRNET S.A.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+/* xseg_posix.c
+ * kernel driver for posix peers
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/timer.h>
+#include <linux/types.h>
+#include <linux/vmalloc.h>
+#include <linux/genhd.h>
+#include <linux/blkdev.h>
+#include <linux/bio.h>
+#include <linux/device.h>
+#include <linux/completion.h>
+
+#include <xseg/xseg.h>
+#include <sys/kernel/segdev.h>
+#include <sys/util.h>
+#include <drivers/xseg_posix.h>
+
+MODULE_DESCRIPTION("xseg_posix");
+MODULE_AUTHOR("XSEG");
+MODULE_LICENSE("GPL");
+
+static int posix_remote_signal_init(void)
+{
+	return 0;
+}
+
+static void posix_remote_signal_quit(void)
+{
+	return;
+}
+
+static int posix_local_signal_init(struct xseg *xseg, xport portno)
+{
+	return -1;
+}
+
+static void posix_local_signal_quit(struct xseg *xseg, xport portno)
+{
+	return;
+}
+
+static int posix_prepare_wait(struct xseg *xseg, uint32_t portno)
+{
+	return -1;
+}
+
+static int posix_cancel_wait(struct xseg *xseg, uint32_t portno)
+{
+	return -1;
+}
+
+static int posix_wait_signal(struct xseg *xseg, uint32_t timeout)
+{
+	return -1;
+}
+
+static int posix_signal(struct xseg *xseg, uint32_t portno)
+{
+	struct pid *pid;
+	struct task_struct *task;
+	int ret = -ENOENT;
+	uint64_t p;
+	struct xseg_port *port = xseg_get_port(xseg, portno);
+	if (!port) 
+		return -1;
+
+	struct posix_signal_desc *psd = xseg_get_signal_desc(xseg, port);
+	if (!psd)
+		return -1;
+
+	rcu_read_lock();
+	/* XXX Security: xseg peers can kill anyone */
+	p = * (volatile uint64_t *) &psd->waitcue;
+	if (!p) {
+		ret = 0;
+		goto out;
+	}
+
+	pid = find_vpid((pid_t)p);
+	if (!pid)
+		goto out;
+	task = pid_task(pid, PIDTYPE_PID);
+	if (!task)
+		goto out;
+
+	ret = send_sig(SIGIO, task, 1);
+out:
+	rcu_read_unlock();
+	return ret;
+}
+
+static void *posix_malloc(uint64_t size)
+{
+	return NULL;
+}
+
+static void *posix_realloc(void *mem, uint64_t size)
+{
+	return NULL;
+}
+
+static void posix_mfree(void *mem) { }
+
+int posix_init_signal_desc(struct xseg *xseg, void *sd)
+{
+	return -1;
+}
+
+void posix_quit_signal_desc(struct xseg *xseg, void *sd)
+{
+	return;
+}
+
+void * posix_alloc_data(struct xseg *xseg)
+{
+	return NULL;
+}
+
+void posix_free_data(struct xseg *xseg, void *data)
+{
+	return;
+}
+
+void *posix_alloc_signal_desc(struct xseg *xseg, void *data)
+{
+	return NULL;
+}
+
+void posix_free_signal_desc(struct xseg *xseg, void *data, void *sd)
+{
+	return;
+}
+
+static struct xseg_peer xseg_peer_posix = {
+	/* xseg signal operations */
+	{
+		.init_signal_desc   = posix_init_signal_desc,
+		.quit_signal_desc   = posix_quit_signal_desc,
+		.alloc_data         = posix_alloc_data,
+		.free_data          = posix_free_data,
+		.alloc_signal_desc  = posix_alloc_signal_desc,
+		.free_signal_desc   = posix_free_signal_desc,
+		.local_signal_init  = posix_local_signal_init,
+		.local_signal_quit  = posix_local_signal_quit,
+		.remote_signal_init = posix_remote_signal_init,
+		.remote_signal_quit = posix_remote_signal_quit,
+		.prepare_wait	    = posix_prepare_wait,
+		.cancel_wait = posix_cancel_wait,
+		.prepare_wait = posix_prepare_wait,
+		.wait_signal = posix_wait_signal,
+		.signal = posix_signal,
+		.malloc = posix_malloc,
+		.realloc = posix_realloc,
+		.mfree = posix_mfree
+	},
+	/* name */
+	"posix"
+};
+
+static int posix_init(void)
+{
+	int r;
+