[PATCH] tools/xenstored: fix live update

[Juergen Gross <jgross@xxxxxxxx>]

Commit e5b0a940557 ("tools/xenstored: Auto-introduce domains") broke
xenstored live update, as init_domains() will be skipped when live
update is detected to have happened. This will leave priv_domid and
store_domid set as invalid.

Fix that by calling init_domains() in live update case, too. In case
of live update skip introducing any found domains, as this will be done
when reading the live update state.

Fixes: e5b0a940557 ("tools/xenstored: Auto-introduce domains")
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
 tools/xenstored/core.c   |  3 ++-
 tools/xenstored/domain.c | 20 +++++++++++++-------
 tools/xenstored/domain.h |  2 +-
 3 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/tools/xenstored/core.c b/tools/xenstored/core.c
index 64c478a801..d509736c32 100644
--- a/tools/xenstored/core.c
+++ b/tools/xenstored/core.c
@@ -2763,7 +2763,7 @@ int main(int argc, char *argv[])
        /* Listen to hypervisor. */
        if (!live_update) {
                domain_init(-1);
-               init_domains();
+               init_domains(false);
        }
 
        /* redirect to /dev/null now we're ready to accept connections */
@@ -3109,6 +3109,7 @@ void read_state_global(const void *ctx, const void *state)
        set_socket_fd(glb->socket_fd);
 
        domain_init(glb->evtchn_fd);
+       init_domains(true);
 }
 
 static void add_buffered_data(struct buffered_data *bdata,
diff --git a/tools/xenstored/domain.c b/tools/xenstored/domain.c
index 10ac1c1a8f..e453b3061f 100644
--- a/tools/xenstored/domain.c
+++ b/tools/xenstored/domain.c
@@ -1344,7 +1344,7 @@ static bool init_domain(unsigned int domid)
 
        return true;
 }
-void init_domains(void)
+void init_domains(bool live_update)
 {
        unsigned int *domids = NULL;
        unsigned int nr_domids = 0;
@@ -1356,12 +1356,15 @@ void init_domains(void)
 
        while (!xenmanage_poll_changed_domain(xm_handle, &domid, &state, &caps,
                                              &unique_id)) {
-               nr_domids++;
-               domids = talloc_realloc(NULL, domids, unsigned int, nr_domids);
-               if (!domids)
-                       barf_perror("Failed to reallocate domids");
-
-               domids[nr_domids - 1] = domid;
+               if (!live_update) {
+                       nr_domids++;
+                       domids = talloc_realloc(NULL, domids,
+                                               unsigned int, nr_domids);
+                       if (!domids)
+                               barf_perror("Failed to reallocate domids");
+
+                       domids[nr_domids - 1] = domid;
+               }
 
                if (caps & XENMANAGE_GETDOMSTATE_CAP_CONTROL) {
                        /*
@@ -1397,6 +1400,9 @@ void init_domains(void)
        snprintf(store_domain_path, sizeof(store_domain_path),
                 "/local/domain/%u", store_domid);
 
+       if (live_update)
+               return;
+
        /*
         * Privileged domid must be first to setup structures for firing the
         * special watches.
diff --git a/tools/xenstored/domain.h b/tools/xenstored/domain.h
index 3b1fce74cf..28186ccac0 100644
--- a/tools/xenstored/domain.h
+++ b/tools/xenstored/domain.h
@@ -92,7 +92,7 @@ int do_set_feature(const void *ctx, struct connection *conn,
 
 void domain_early_init(void);
 void domain_init(int evtfd);
-void init_domains(void);
+void init_domains(bool live_update);
 void stubdom_init(bool live_update);
 void domain_deinit(void);
 void ignore_connection(struct connection *conn, unsigned int err);
-- 
2.53.0