[v8,1/7] tools/cpupools: Give a name to unnamed cpupools

Commit Message

Luca Fancellu May 6, 2022, noon UTC

With the introduction of boot time cpupools, Xen can create many
different cpupools at boot time other than cpupool with id 0.

Since these newly created cpupools can't have an
entry in Xenstore, create the entry using xen-init-dom0
helper with the usual convention: Pool-<cpupool id>.

Given the change, remove the check for poolid == 0 from
libxl_cpupoolid_to_name(...).

Signed-off-by: Luca Fancellu <[e-mail]>
Reviewed-by: Anthony PERARD <[e-mail]>
---
Changes in v8:
- no changes
Changes in v7:
- Add R-by from Anthony
Changes in v6:
- Reworked loop to have only one error path (Anthony)
Changes in v5:
- no changes
Changes in v4:
- no changes
Changes in v3:
- no changes, add R-by
Changes in v2:
 - Remove unused variable, moved xc_cpupool_infofree
   ahead to simplify the code, use asprintf (Juergen)
---
 tools/helpers/xen-init-dom0.c  | 37 +++++++++++++++++++++++++++++++++-
 tools/libs/light/libxl_utils.c |  3 +--
 2 files changed, 37 insertions(+), 3 deletions(-)

Patch

diff --git a/tools/helpers/xen-init-dom0.c b/tools/helpers/xen-init-dom0.c
index c99224a4b607..37eff8868f25 100644
--- a/tools/helpers/xen-init-dom0.c
+++ b/tools/helpers/xen-init-dom0.c
@@ -43,7 +43,10 @@  int main(int argc, char **argv)
     int rc;
     struct xs_handle *xsh = NULL;
     xc_interface *xch = NULL;
-    char *domname_string = NULL, *domid_string = NULL;
+    char *domname_string = NULL, *domid_string = NULL,
+         *pool_path = NULL, *pool_name = NULL;
+    xc_cpupoolinfo_t *xcinfo;
+    unsigned int pool_id = 0;
     libxl_uuid uuid;
 
     /* Accept 0 or 1 argument */
@@ -114,9 +117,41 @@  int main(int argc, char **argv)
         goto out;
     }
 
+    /* Create an entry in xenstore for each cpupool on the system */
+    do {
+        xcinfo = xc_cpupool_getinfo(xch, pool_id);
+        if (xcinfo != NULL) {
+            if (xcinfo->cpupool_id != pool_id)
+                pool_id = xcinfo->cpupool_id;
+            xc_cpupool_infofree(xch, xcinfo);
+            if (asprintf(&pool_path, "/local/pool/%d/name", pool_id) <= 0) {
+                fprintf(stderr, "cannot allocate memory for pool path\n");
+                rc = 1;
+                goto out;
+            }
+            if (asprintf(&pool_name, "Pool-%d", pool_id) <= 0) {
+                fprintf(stderr, "cannot allocate memory for pool name\n");
+                rc = 1;
+                goto out;
+            }
+            pool_id++;
+            if (!xs_write(xsh, XBT_NULL, pool_path, pool_name,
+                          strlen(pool_name))) {
+                fprintf(stderr, "cannot set pool name\n");
+                rc = 1;
+                goto out;
+            }
+            free(pool_name);
+            free(pool_path);
+            pool_path = pool_name = NULL;
+        }
+    } while(xcinfo != NULL);
+
     printf("Done setting up Dom0\n");
 
 out:
+    free(pool_path);
+    free(pool_name);
     free(domid_string);
     free(domname_string);
     xs_close(xsh);
diff --git a/tools/libs/light/libxl_utils.c b/tools/libs/light/libxl_utils.c
index 1d8a7f64ef4a..e5e6b2da9660 100644
--- a/tools/libs/light/libxl_utils.c
+++ b/tools/libs/light/libxl_utils.c
@@ -146,8 +146,7 @@  char *libxl_cpupoolid_to_name(libxl_ctx *ctx, uint32_t poolid)
 
     snprintf(path, sizeof(path), "/local/pool/%d/name", poolid);
     s = xs_read(ctx->xsh, XBT_NULL, path, &len);
-    if (!s && (poolid == 0))
-        return strdup("Pool-0");
+
     return s;
 }