[PATCH v5] libxl_set_memory_target: retain the same maxmem offset on top of the current target

[PATCH v5] libxl_set_memory_target: retain the same maxmem offset on top of the current target

[Stefano Stabellini]

In libxl_set_memory_target when setting the new maxmem, retain the same
offset on top of the current target. In the future the offset will
include memory allocated by QEMU for rom files.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

---

Changes in v5:
- call libxl_dominfo_init;
- move libxl_dominfo_dispose call before returning to the caller;

Changes in v4:
- remove new_target_memkb <= 0 check.

Changes in v3:
- move call to libxl__uuid2string and libxl_dominfo_dispose earlier;
- error out if new_target_memkb <= 0.

Changes in v2:
- remove LIBXL_MAXMEM_CONSTANT from LIBXL__LOG_ERRNO.
---
 tools/libxl/libxl.c |   18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index b9a1941..7d42dc6 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -4720,6 +4720,12 @@ int libxl_set_memory_target(libxl_ctx *ctx, uint32_t domid,
     char *uuid;
     xs_transaction_t t;
 
+    libxl_dominfo_init(&info);
+    if (libxl_domain_info(ctx, &ptr, domid) < 0)
+        goto out_no_transaction;
+
+    uuid = libxl__uuid2string(gc, ptr.uuid);
+
 retry_transaction:
     t = xs_transaction_start(ctx->xsh);
 
@@ -4795,13 +4801,12 @@ retry_transaction:
     }
 
     if (enforce) {
-        memorykb = new_target_memkb + videoram;
-        rc = xc_domain_setmaxmem(ctx->xch, domid, memorykb +
-                LIBXL_MAXMEM_CONSTANT);
+        memorykb = ptr.max_memkb - current_target_memkb + new_target_memkb;
+        rc = xc_domain_setmaxmem(ctx->xch, domid, memorykb);
         if (rc != 0) {
             LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR,
                     "xc_domain_setmaxmem domid=%d memkb=%d failed "
-                    "rc=%d\n", domid, memorykb + LIBXL_MAXMEM_CONSTANT, rc);
+                    "rc=%d\n", domid, memorykb, rc);
             abort_transaction = 1;
             goto out;
         }
@@ -4826,12 +4831,8 @@ retry_transaction:
         goto out;
     }
 
-    libxl_dominfo_init(&ptr);
-    xcinfo2xlinfo(ctx, &info, &ptr);
-    uuid = libxl__uuid2string(gc, ptr.uuid);
     libxl__xs_write(gc, t, libxl__sprintf(gc, "/vm/%s/memory", uuid),
             "%"PRIu32, new_target_memkb / 1024);
-    libxl_dominfo_dispose(&ptr);
 
 out:
     if (!xs_transaction_end(ctx->xsh, t, abort_transaction)
@@ -4840,6 +4841,7 @@ out:
             goto retry_transaction;
 
 out_no_transaction:
+    libxl_dominfo_dispose(&ptr);
     GC_FREE;
     return rc;
 }
-- 
1.7.10.4