From: Lennart Poettering <lennart@poettering.net>
Date: Thu, 15 May 2025 09:00:17 +0000 (+0200)
Subject: vmspawn: use VM leader PID not vmspawn PID to register machine
X-Git-Tag: v258-rc1~79^2~8
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6dc6e6459bb4dba7cd88c4f6688b1aea9159c9d2;p=thirdparty%2Fsystemd.git

vmspawn: use VM leader PID not vmspawn PID to register machine

Let's make vmspawn machine registration more like nspawn machine
registration, and register the payload, not vmspawn/nspawn itself.
---

diff --git a/src/vmspawn/vmspawn-register.c b/src/vmspawn/vmspawn-register.c
index ae7edd0fdbf..d9925f171dd 100644
--- a/src/vmspawn/vmspawn-register.c
+++ b/src/vmspawn/vmspawn-register.c
@@ -10,7 +10,9 @@
 #include "bus-error.h"
 #include "bus-locator.h"
 #include "errno-util.h"
+#include "json-util.h"
 #include "log.h"
+#include "pidref.h"
 #include "process-util.h"
 #include "socket-util.h"
 #include "string-util.h"
@@ -23,6 +25,7 @@ int register_machine(
                 const char *machine_name,
                 sd_id128_t uuid,
                 const char *service,
+                const PidRef *pidref,
                 const char *directory,
                 unsigned cid,
                 const char *address,
@@ -54,7 +57,7 @@ int register_machine(
                                 SD_BUS_MESSAGE_APPEND_ID128(uuid),
                                 service,
                                 "vm",
-                                (uint32_t) getpid_cached(),
+                                (uint32_t) (pidref_is_set(pidref) ? pidref->pid : 0),
                                 strempty(directory));
                 if (r < 0)
                        return log_error_errno(r, "Failed to register machine: %s", bus_error_message(&error, r));
@@ -77,7 +80,8 @@ int register_machine(
                         SD_JSON_BUILD_PAIR_CONDITION(!!address, "sshAddress", SD_JSON_BUILD_STRING(address)),
                         SD_JSON_BUILD_PAIR_CONDITION(!!key_path, "sshPrivateKeyPath", SD_JSON_BUILD_STRING(key_path)),
                         SD_JSON_BUILD_PAIR_CONDITION(isatty_safe(STDIN_FILENO), "allowInteractiveAuthentication", SD_JSON_BUILD_BOOLEAN(true)),
-                        SD_JSON_BUILD_PAIR_CONDITION(!keep_unit, "allocateUnit", SD_JSON_BUILD_BOOLEAN(true)));
+                        SD_JSON_BUILD_PAIR_CONDITION(!keep_unit, "allocateUnit", SD_JSON_BUILD_BOOLEAN(true)),
+                        SD_JSON_BUILD_PAIR_CONDITION(pidref_is_set(pidref), "leaderProcessId", JSON_BUILD_PIDREF(pidref)));
 }
 
 int unregister_machine(sd_bus *bus, const char *machine_name) {
diff --git a/src/vmspawn/vmspawn-register.h b/src/vmspawn/vmspawn-register.h
index 58cae542ceb..2adfabdc030 100644
--- a/src/vmspawn/vmspawn-register.h
+++ b/src/vmspawn/vmspawn-register.h
@@ -7,6 +7,7 @@ int register_machine(
                 const char *machine_name,
                 sd_id128_t uuid,
                 const char *service,
+                const PidRef *pidref,
                 const char *directory,
                 unsigned cid,
                 const char *address,
diff --git a/src/vmspawn/vmspawn.c b/src/vmspawn/vmspawn.c
index 0ddc1cdb5af..bf16056b15f 100644
--- a/src/vmspawn/vmspawn.c
+++ b/src/vmspawn/vmspawn.c
@@ -2326,34 +2326,8 @@ static int run_virtual_machine(int kvm_device_fd, int vhost_device_fd) {
                 log_debug("Executing: %s", joined);
         }
 
-        if (arg_register) {
-                char vm_address[STRLEN("vsock/") + DECIMAL_STR_MAX(unsigned)];
-
-                xsprintf(vm_address, "vsock/%u", child_cid);
-                r = register_machine(
-                                bus,
-                                arg_machine,
-                                arg_uuid,
-                                "systemd-vmspawn",
-                                arg_directory,
-                                child_cid,
-                                child_cid != VMADDR_CID_ANY ? vm_address : NULL,
-                                ssh_private_key_path,
-                                arg_keep_unit);
-                if (r < 0)
-                        return r;
-        }
-
         assert_se(sigprocmask_many(SIG_BLOCK, /* ret_old_mask=*/ NULL, SIGCHLD) >= 0);
 
-        _cleanup_(sd_event_source_unrefp) sd_event_source *notify_event_source = NULL;
-        _cleanup_(sd_event_unrefp) sd_event *event = NULL;
-        r = sd_event_new(&event);
-        if (r < 0)
-                return log_error_errno(r, "Failed to get default event source: %m");
-
-        (void) sd_event_set_watchdog(event, true);
-
         _cleanup_(pidref_done) PidRef child_pidref = PIDREF_NULL;
 
         r = pidref_safe_fork_full(
@@ -2386,6 +2360,32 @@ static int run_virtual_machine(int kvm_device_fd, int vhost_device_fd) {
         child_vsock_fd = safe_close(child_vsock_fd);
         tap_fd = safe_close(tap_fd);
 
+        if (arg_register) {
+                char vm_address[STRLEN("vsock/") + DECIMAL_STR_MAX(unsigned)];
+                xsprintf(vm_address, "vsock/%u", child_cid);
+                r = register_machine(
+                                bus,
+                                arg_machine,
+                                arg_uuid,
+                                "systemd-vmspawn",
+                                &child_pidref,
+                                arg_directory,
+                                child_cid,
+                                child_cid != VMADDR_CID_ANY ? vm_address : NULL,
+                                ssh_private_key_path,
+                                arg_keep_unit);
+                if (r < 0)
+                        return r;
+        }
+
+        _cleanup_(sd_event_source_unrefp) sd_event_source *notify_event_source = NULL;
+        _cleanup_(sd_event_unrefp) sd_event *event = NULL;
+        r = sd_event_new(&event);
+        if (r < 0)
+                return log_error_errno(r, "Failed to get default event source: %m");
+
+        (void) sd_event_set_watchdog(event, true);
+
         int exit_status = INT_MAX;
         if (use_vsock) {
                 r = setup_notify_parent(event, notify_sock_fd, &exit_status, &notify_event_source);