[libvirt RFC v2 08/11] qemu: wire up saveimage code with the multifd helper

[Claudio Fontana <cfontana@xxxxxxx>]

Signed-off-by: Claudio Fontana <cfontana@xxxxxxx>
---
 src/qemu/qemu_saveimage.c | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

diff --git a/src/qemu/qemu_saveimage.c b/src/qemu/qemu_saveimage.c
index 6a65d72fb3..bb23788a5e 100644
--- a/src/qemu/qemu_saveimage.c
+++ b/src/qemu/qemu_saveimage.c
@@ -17,6 +17,7 @@
  */
 
 #include <config.h>
+#include <configmake.h>
 
 #include "qemu_saveimage.h"
 #include "qemu_domain.h"
@@ -412,7 +413,8 @@ static int qemuSaveImageCloseMultiFd(virQEMUSaveFd *multiFd, int nconn, virDomai
 
 static virQEMUSaveFd *
 qemuSaveImageCreateMultiFd(virQEMUDriver *driver, virDomainObj *vm,
-                           const char *path, uid_t user, gid_t group,
+                           virCommand *cmd, const char *path,
+                           uid_t user, gid_t group,
                            int nconn, unsigned int flags)
 {
     virQEMUSaveFd *multiFd = g_new0(virQEMUSaveFd, nconn);
@@ -426,6 +428,8 @@ qemuSaveImageCreateMultiFd(virQEMUDriver *driver, virDomainObj *vm,
             virQEMUSaveFdFini(m, vm, -1);
             goto error;
         }
+        virCommandAddArgFormat(cmd, "%d", m->fd);
+        virCommandPassFD(cmd, m->fd, 0);
     }
     return multiFd;
 
@@ -463,8 +467,30 @@ qemuSaveImageCreate(virQEMUDriver *driver,
         goto cleanup;
 
     if (flags & VIR_DOMAIN_SAVE_PARALLEL) {
+        g_autoptr(virCommand) cmd = NULL;
+        g_autofree char *helper_path = NULL;
+        qemuDomainObjPrivate *priv = vm->privateData;
+        g_autofree char *sun_path = g_strdup_printf("%s/save-multifd.sock", priv->libDir);
+        char buf[1];
+        int helper_out = -1;
+        if (!(helper_path = virFileFindResource("libvirt_multifd_helper",
+                                                abs_top_builddir "/src",
+                                                LIBEXECDIR)))
+            goto cleanup;
+        cmd = virCommandNewArgList(helper_path, sun_path, NULL);
+        virCommandAddArgFormat(cmd, "%d", nconn);
+        virCommandAddArgFormat(cmd, "%d", saveFd.fd);
+        virCommandPassFD(cmd, saveFd.fd, 0);
+        virCommandSetOutputFD(cmd, &helper_out); /* should create pipe automagically */
+
         /* Perform parallel multifd migration to files (main fd + channels) */
-        if (!(multiFd = qemuSaveImageCreateMultiFd(driver, vm, saveFd.path, cfg->user, cfg->group, nconn, flags)))
+        if (!(multiFd = qemuSaveImageCreateMultiFd(driver, vm, cmd, saveFd.path, cfg->user, cfg->group, nconn, flags)))
+            goto cleanup;
+        if (virCommandRunAsync(cmd, NULL) < 0)
+            goto cleanup;
+        if (saferead(helper_out, &buf, 1) != 1 || buf[0] != 'R')
+            goto cleanup;
+        if (chown(sun_path, cfg->user, cfg->group) < 0)
             goto cleanup;
         /* still using single fd migration for now */
         if (qemuMigrationSrcToFile(driver, vm, saveFd.fd, compressor, asyncJob) < 0)
-- 
2.34.1