[PATCH v2 21/27] tools/libxc+libxl+xl: Save v2 streams

[Andrew Cooper <andrew.cooper3@citrix.com>]

This is a complicated set of changes which must be done together for
bisectability.

 * libxl-save-helper is updated to unconditionally use libxc migration v2.
 * libxl compatibility workarounds in libxc are disabled for save operations.
 * libxl__stream_write_start() is logically spliced into the event location
   where libxl__xc_domain_save() used to reside.
 * xl is updated to indicate that the stream is now v2

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
---
 tools/libxc/Makefile             |    2 --
 tools/libxl/libxl.h              |    2 ++
 tools/libxl/libxl_dom.c          |   46 +++++++++-----------------------------
 tools/libxl/libxl_save_helper.c  |    2 +-
 tools/libxl/libxl_stream_write.c |   35 +++++++++++++++++++++++++++--
 tools/libxl/xl_cmdimpl.c         |    1 +
 6 files changed, 47 insertions(+), 41 deletions(-)

diff --git a/tools/libxc/Makefile b/tools/libxc/Makefile
index 2cd0b1a..1aec848 100644
--- a/tools/libxc/Makefile
+++ b/tools/libxc/Makefile
@@ -64,8 +64,6 @@ GUEST_SRCS-$(CONFIG_X86) += xc_sr_save_x86_hvm.c
 GUEST_SRCS-y += xc_sr_restore.c
 GUEST_SRCS-y += xc_sr_save.c
 GUEST_SRCS-y += xc_offline_page.c xc_compression.c
-xc_sr_save_x86_hvm.o: CFLAGS += -DXG_LIBXL_HVM_COMPAT
-xc_sr_save_x86_hvm.opic: CFLAGS += -DXG_LIBXL_HVM_COMPAT
 else
 GUEST_SRCS-y += xc_nomigrate.c
 endif
diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
index e64a606..4f24e5f 100644
--- a/tools/libxl/libxl.h
+++ b/tools/libxl/libxl.h
@@ -812,6 +812,8 @@
  *
  * If this is defined, then the libxl_domain_create_restore() interface takes
  * a "stream_version" parameter and supports a value of 2.
+ *
+ * libxl_domain_suspend() will produce a v2 stream.
  */
 #define LIBXL_HAVE_STREAM_V2 1
 
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index 8642192..de05124 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -1153,6 +1153,8 @@ int libxl__toolstack_restore(uint32_t domid, const uint8_t *ptr,
 
 /*==================== Domain suspend (save) ====================*/
 
+static void stream_done(libxl__egc *egc,
+                        libxl__stream_write_state *sws, int rc);
 static void domain_suspend_done(libxl__egc *egc,
                         libxl__domain_suspend_state *dss, int rc);
 static void domain_suspend_callback_common_done(libxl__egc *egc,
@@ -2117,50 +2119,22 @@ void libxl__domain_suspend(libxl__egc *egc, libxl__domain_suspend_state *dss)
     callbacks->switch_qemu_logdirty = libxl__domain_suspend_common_switch_qemu_logdirty;
     dss->shs.callbacks.save.toolstack_save = libxl__toolstack_save;
 
-    libxl__xc_domain_save(egc, dss);
+    dss->sws.fd = dss->fd;
+    dss->sws.ao = dss->ao;
+    dss->sws.completion_callback = stream_done;
+
+    libxl__stream_write_start(egc, &dss->sws);
     return;
 
  out:
     domain_suspend_done(egc, dss, rc);
 }
 
-void libxl__xc_domain_save_done(libxl__egc *egc, void *dss_void,
-                                int rc, int retval, int errnoval)
+static void stream_done(libxl__egc *egc,
+                        libxl__stream_write_state *sws, int rc)
 {
-    libxl__domain_suspend_state *dss = dss_void;
-    STATE_AO_GC(dss->ao);
-
-    /* Convenience aliases */
-    const libxl_domain_type type = dss->type;
-
-    if (rc)
-        goto out;
-
-    if (retval) {
-        LOGEV(ERROR, errnoval, "saving domain: %s",
-                         dss->guest_responded ?
-                         "domain responded to suspend request" :
-                         "domain did not respond to suspend request");
-        if ( !dss->guest_responded )
-            rc = ERROR_GUEST_TIMEDOUT;
-        else if (dss->rc)
-            rc = dss->rc;
-        else
-            rc = ERROR_FAIL;
-        goto out;
-    }
-
-    if (type == LIBXL_DOMAIN_TYPE_HVM) {
-        rc = libxl__domain_suspend_device_model(gc, dss);
-        if (rc) goto out;
+    libxl__domain_suspend_state *dss = CONTAINER_OF(sws, *dss, sws);
 
-        libxl__domain_save_device_model(egc, dss, domain_suspend_done);
-        return;
-    }
-
-    rc = 0;
-
-out:
     domain_suspend_done(egc, dss, rc);
 }
 
diff --git a/tools/libxl/libxl_save_helper.c b/tools/libxl/libxl_save_helper.c
index efbe2eb..f196786 100644
--- a/tools/libxl/libxl_save_helper.c
+++ b/tools/libxl/libxl_save_helper.c
@@ -286,7 +286,7 @@ int main(int argc, char **argv)
         startup("save");
         setup_signals(save_signal_handler);
 
-        r = xc_domain_save(xch, io_fd, dom, max_iters, max_factor, flags,
+        r = xc_domain_save2(xch, io_fd, dom, max_iters, max_factor, flags,
                            &helper_save_callbacks, hvm);
         complete(r);
 
diff --git a/tools/libxl/libxl_stream_write.c b/tools/libxl/libxl_stream_write.c
index bf568ad..331173f 100644
--- a/tools/libxl/libxl_stream_write.c
+++ b/tools/libxl/libxl_stream_write.c
@@ -276,8 +276,39 @@ static void libxc_header_done(libxl__egc *egc,
     libxl__xc_domain_save(egc, dss);
 }
 
-static void __attribute__((unused))
-write_toolstack_record(libxl__egc *egc,
+void libxl__xc_domain_save_done(libxl__egc *egc, void *dss_void,
+                                int rc, int retval, int errnoval)
+{
+    libxl__domain_suspend_state *dss = dss_void;
+    libxl__stream_write_state *stream = &dss->sws;
+    STATE_AO_GC(dss->ao);
+
+    if (rc)
+        goto err;
+
+    if (retval) {
+        LOGEV(ERROR, errnoval, "saving domain: %s",
+                         dss->guest_responded ?
+                         "domain responded to suspend request" :
+                         "domain did not respond to suspend request");
+        if ( !dss->guest_responded )
+            rc = ERROR_GUEST_TIMEDOUT;
+        else if (dss->rc)
+            rc = dss->rc;
+        else
+            rc = ERROR_FAIL;
+        goto err;
+    }
+
+    write_toolstack_record(egc, stream);
+    return;
+
+ err:
+    assert(rc);
+    check_stream_finished(egc, stream, rc, "save/restore helper");
+}
+
+static void write_toolstack_record(libxl__egc *egc,
                                    libxl__stream_write_state *stream)
 {
     libxl__domain_suspend_state *dss = CONTAINER_OF(stream, *dss, sws);
diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index 71a22b8..13e154d 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -3922,6 +3922,7 @@ static void save_domain_core_writeconfig(int fd, const char *source,
     memset(&hdr, 0, sizeof(hdr));
     memcpy(hdr.magic, savefileheader_magic, sizeof(hdr.magic));
     hdr.byteorder = SAVEFILE_BYTEORDER_VALUE;
+    hdr.mandatory_flags = XL_MANDATORY_FLAG_STREAMv2;
 
     optdata_begin= 0;
 
-- 
1.7.10.4