[Xen-devel] [PATCH] qemu-xen: fix cpu hotplug

[Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>]

qemu-xen: fix cpu hotplug

The current xenstore watch path for a vcpu-set event is wrong and is
also wrong the code to parse it.
This patch fixes both of them: a xenstore vcpu hotplug command is of the
following form:

path: /local/domain/DOMID/cpu/VCPU_NUMBER/availability
values: "online" or "offline"

Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>

diff --git a/xenstore.c b/xenstore.c
index 6d24613..2c325ad 100644
--- a/xenstore.c
+++ b/xenstore.c
@@ -680,9 +680,12 @@ void xenstore_parse_domain_config(int hvm_domid)
     }
 
     /* Set a watch for vcpu-set */
-    if (pasprintf(&buf, "/local/domain/%u/cpu", domid) != -1) {
-        xs_watch(xsh, buf, "vcpu-set");
-        fprintf(logfile, "Watching %s\n", buf);
+    for (i = 0; i < vcpus; i++) {
+        if (pasprintf(&buf, "/local/domain/%u/cpu/%u/availability",
+                    domid, i) != -1) {
+            xs_watch(xsh, buf, "vcpu-set");
+            fprintf(logfile, "Watching %s\n", buf);
+        }
     }
 
     /* no need for ifdef CONFIG_STUBDOM, since in the qemu case
@@ -970,15 +973,14 @@ void xenstore_record_dm_state(const char *state)
 static void xenstore_process_vcpu_set_event(char **vec)
 {
     char *act = NULL;
-    char *vcpustr, *node = vec[XS_WATCH_PATH];
-    unsigned int vcpu, len;
+    char *node = vec[XS_WATCH_PATH];
+    unsigned int vcpu, len, domid;
 
-    vcpustr = strstr(node, "cpu/");
-    if (!vcpustr) {
-        fprintf(stderr, "vcpu-set: watch node error.\n");
+    if (sscanf(node, "/local/domain/%u/cpu/%u/availability",
+                &domid, &vcpu) <= 0) {
+        fprintf(stderr, "vcpu-set: watch node error, path=%s\n", node);
         return;
     }
-    sscanf(vcpustr, "cpu/%u", &vcpu);
 
     act = xs_read(xsh, XBT_NULL, node, &len);
     if (!act) {

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel