block: Support Archipelago as a QEMU block backend

VM Image on Archipelago volume is specified like this:

file.driver=archipelago,file.volume=<volumename>[,file.mport=<mapperd_port>[,
file.vport=<vlmcd_port>][,file.segment=<segment_name>]]

'archipelago' is the protocol.

'mport' is the port number on which mapperd is listening. This is optional
and if not specified, QEMU will make Archipelago to use the default port.

'vport' is the port number on which vlmcd is listening. This is optional
and if not specified, QEMU will make Archipelago to use the default port.

'segment' is the name of the shared memory segment Archipelago stack is using.
This is optional and if not specified, QEMU will make Archipelago to use the
default value, 'archipelago'.

Examples:

file.driver=archipelago,file.volume=my_vm_volume
file.driver=archipelago,file.volume=my_vm_volume,file.mport=123
file.driver=archipelago,file.volume=my_vm_volume,file.mport=123,
file.vport=1234
file.driver=archipelago,file.volume=my_vm_volume,file.mport=123,
file.vport=1234,file.segment=my_segment

Signed-off-by: Chrysostomos Nanakos <cnanakos@grnet.gr>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

MAINTAINERS

@@ -1000,3 +1000,9 @@ SSH
 M: Richard W.M. Jones <rjones@redhat.com>
 S: Supported
 F: block/ssh.c
+
+ARCHIPELAGO
+M: Chrysostomos Nanakos <cnanakos@grnet.gr>
+M: Chrysostomos Nanakos <chris@include.gr>
+S: Maintained
+F: block/archipelago.c

block/Makefile.objs

@@ -17,6 +17,7 @@ block-obj-$(CONFIG_LIBNFS) += nfs.o
 block-obj-$(CONFIG_CURL) += curl.o
 block-obj-$(CONFIG_RBD) += rbd.o
 block-obj-$(CONFIG_GLUSTERFS) += gluster.o
+block-obj-$(CONFIG_ARCHIPELAGO) += archipelago.o
 block-obj-$(CONFIG_LIBSSH2) += ssh.o
 endif
 
@@ -35,5 +36,6 @@ gluster.o-cflags   := $(GLUSTERFS_CFLAGS)
 gluster.o-libs     := $(GLUSTERFS_LIBS)
 ssh.o-cflags       := $(LIBSSH2_CFLAGS)
 ssh.o-libs         := $(LIBSSH2_LIBS)
+archipelago.o-libs := $(ARCHIPELAGO_LIBS)
 qcow.o-libs        := -lz
 linux-aio.o-libs   := -laio

configure

@@ -326,6 +326,7 @@ seccomp=""
 glusterfs=""
 glusterfs_discard="no"
 glusterfs_zerofill="no"
+archipelago=""
 virtio_blk_data_plane=""
 gtk=""
 gtkabi=""
@@ -1087,6 +1088,10 @@ for opt do
   ;;
   --enable-glusterfs) glusterfs="yes"
   ;;
+  --disable-archipelago) archipelago="no"
+  ;;
+  --enable-archipelago) archipelago="yes"
+  ;;
   --disable-virtio-blk-data-plane) virtio_blk_data_plane="no"
   ;;
   --enable-virtio-blk-data-plane) virtio_blk_data_plane="yes"
@@ -1382,6 +1387,8 @@ Advanced options (experts only):
   --enable-coroutine-pool  enable coroutine freelist (better performance)
   --enable-glusterfs       enable GlusterFS backend
   --disable-glusterfs      disable GlusterFS backend
+  --enable-archipelago     enable Archipelago backend
+  --disable-archipelago    disable Archipelago backend
   --enable-gcov            enable test coverage analysis with gcov
   --gcov=GCOV              use specified gcov [$gcov_tool]
   --disable-tpm            disable TPM support
@@ -3071,6 +3078,33 @@ EOF
   fi
 fi
 
+
+##########################################
+# archipelago probe
+if test "$archipelago" != "no" ; then
+    cat > $TMPC <<EOF
+#include <stdio.h>
+#include <xseg/xseg.h>
+#include <xseg/protocol.h>
+int main(void) {
+    xseg_initialize();
+    return 0;
+}
+EOF
+    archipelago_libs=-lxseg
+    if compile_prog "" "$archipelago_libs"; then
+        archipelago="yes"
+        libs_tools="$archipelago_libs $libs_tools"
+        libs_softmmu="$archipelago_libs $libs_softmmu"
+    else
+      if test "$archipelago" = "yes" ; then
+        feature_not_found "Archipelago backend support" "Install libxseg devel"
+      fi
+      archipelago="no"
+    fi
+fi
+
+
 ##########################################
 # glusterfs probe
 if test "$glusterfs" != "no" ; then
@@ -4252,6 +4286,7 @@ echo "seccomp support   $seccomp"
 echo "coroutine backend $coroutine"
 echo "coroutine pool    $coroutine_pool"
 echo "GlusterFS support $glusterfs"
+echo "Archipelago support $archipelago"
 echo "virtio-blk-data-plane $virtio_blk_data_plane"
 echo "gcov              $gcov_tool"
 echo "gcov enabled      $gcov"
@@ -4690,6 +4725,11 @@ if test "$glusterfs_zerofill" = "yes" ; then
   echo "CONFIG_GLUSTERFS_ZEROFILL=y" >> $config_host_mak
 fi
 
+if test "$archipelago" = "yes" ; then
+  echo "CONFIG_ARCHIPELAGO=m" >> $config_host_mak
+  echo "ARCHIPELAGO_LIBS=$archipelago_libs" >> $config_host_mak
+fi
+
 if test "$libssh2" = "yes" ; then
   echo "CONFIG_LIBSSH2=m" >> $config_host_mak
   echo "LIBSSH2_CFLAGS=$libssh2_cflags" >> $config_host_mak