[xen master] xenstored: rebind event channels after live update in stubdom

[patchbot@xxxxxxx]

commit 75c7d6a6c6d459214b7b48737c1fa244160238e7
Author:     Juergen Gross <jgross@xxxxxxxx>
AuthorDate: Thu Jul 31 09:45:40 2025 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu Jul 31 09:45:40 2025 +0200

    xenstored: rebind event channels after live update in stubdom
    
    After performing a live update in stubdom environment some information
    about inter-domain event channels is lost. In order to set this
    information again, call xenevtchn_bind() from new_domain() in the
    restore case.
    
    Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
    Reviewed-by: Jason Andryuk <jason.andryuk@xxxxxxx>
---
 tools/xenstored/core.c   | 1 -
 tools/xenstored/core.h   | 3 +++
 tools/xenstored/domain.c | 8 ++++++--
 tools/xenstored/minios.c | 5 +++++
 tools/xenstored/posix.c  | 5 +++++
 5 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/tools/xenstored/core.c b/tools/xenstored/core.c
index 3022efdce1..e3e8607592 100644
--- a/tools/xenstored/core.c
+++ b/tools/xenstored/core.c
@@ -49,7 +49,6 @@
 #include "control.h"
 #include "lu.h"
 
-extern xenevtchn_handle *xce_handle; /* in domain.c */
 static int xce_pollfd_idx = -1;
 struct pollfd *poll_fds;
 static unsigned int current_array_size;
diff --git a/tools/xenstored/core.h b/tools/xenstored/core.h
index bef24a688c..3f7426fbe3 100644
--- a/tools/xenstored/core.h
+++ b/tools/xenstored/core.h
@@ -394,6 +394,8 @@ static inline bool domain_is_unprivileged(const struct 
connection *conn)
        return conn && domid_is_unprivileged(conn->id);
 }
 
+extern xenevtchn_handle *xce_handle; /* in domain.c */
+
 /* Return the event channel used by xenbus. */
 evtchn_port_t get_xenbus_evtchn(void);
 void early_init(bool live_update, bool dofork, const char *pidfile);
@@ -407,6 +409,7 @@ int get_socket_fd(void);
 void set_socket_fd(int fd);
 
 xenevtchn_handle *evtchn_fdopen(int fd);
+int evtchn_rebind(int port);
 
 #ifdef __MINIOS__
 void mount_9pfs(void);
diff --git a/tools/xenstored/domain.c b/tools/xenstored/domain.c
index 7f8f04dc78..34bf7f9c82 100644
--- a/tools/xenstored/domain.c
+++ b/tools/xenstored/domain.c
@@ -862,9 +862,13 @@ static int new_domain(struct domain *domain, int port, 
bool restore)
 
        wrl_domain_new(domain);
 
-       if (restore)
+       if (restore) {
+               if (evtchn_rebind(port)) {
+                       errno = ENOMEM;
+                       return errno;
+               }
                domain->port = port;
-       else {
+       } else {
                /* Tell kernel we're interested in this event. */
                rc = xenevtchn_bind_interdomain(xce_handle, domain->domid,
                                                port);
diff --git a/tools/xenstored/minios.c b/tools/xenstored/minios.c
index aa1f03fd6b..ec5faebaf3 100644
--- a/tools/xenstored/minios.c
+++ b/tools/xenstored/minios.c
@@ -90,6 +90,11 @@ xenevtchn_handle *evtchn_fdopen(int fd)
        return xenevtchn_open(NULL, XENEVTCHN_NO_CLOEXEC);
 }
 
+int evtchn_rebind(int port)
+{
+       return xenevtchn_bind(xce_handle, port);
+}
+
 static void mount_thread(void *p)
 {
        xenbus_event_queue events = NULL;
diff --git a/tools/xenstored/posix.c b/tools/xenstored/posix.c
index ebdec82215..97561701ae 100644
--- a/tools/xenstored/posix.c
+++ b/tools/xenstored/posix.c
@@ -413,6 +413,11 @@ xenevtchn_handle *evtchn_fdopen(int fd)
        return xenevtchn_fdopen(NULL, fd, 0);
 }
 
+int evtchn_rebind(int port)
+{
+       return 0;
+}
+
 const char *xenstore_rundir(void)
 {
        return xenstore_daemon_rundir();
--
generated by git-patchbot for /home/xen/git/xen.git#master