[xen master] tools: Fix fallout from DOMID_ANY ABI breakage

[patchbot@xxxxxxx]

commit 50a21ee067598546c6e174cf6d684add0625ff2f
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Wed May 27 17:28:39 2026 +0100
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Thu May 28 16:19:16 2026 +0100

    tools: Fix fallout from DOMID_ANY ABI breakage
    
    Commit 23e2479ff9de ("xen/domain: introduce DOMID_ANY") broke at least:
    
     * xenstored domains
     * The Python bindings
     * The Ocaml bindings (i.e XAPI, and therefore XenServer/XCP-ng)
    
    by causing Xen to reject 0 (the wildcard sentinel since the start of Xen) 
and
    DOMID_INVALID (since 4.21) without adjusting the callers of 
xc_domain_create().
    
    Under other circumstances I'd revert, but xenstored has gained a dependent 
use
    of DOMID_ANY.
    
    Fix up the remaining in-tree callers of xc_domain_create(), which covers
    init-xenstore-domain and the python bindings.
    
    The Ocaml C bindings, like libxc itself, expose this ABI detail to their
    caller, but in this case the caller is still internal to the bindings as a
    whole.  Adjust the default value in the internal transformation, adding
    domid_any for legibility.
    
    Leave a very clear message in CHANGELOG.md that all external callers need
    altering.
    
    Fixes: 23e2479ff9de ("xen/domain: introduce DOMID_ANY")
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Acked-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
    Acked-by: Pau Ruiz Safont <pau.safont@xxxxxxxxxx>
---
 CHANGELOG.md                         | 4 ++++
 tools/helpers/init-xenstore-domain.c | 2 +-
 tools/ocaml/libs/xc/xenctrl.ml       | 4 +++-
 tools/python/xen/lowlevel/xc/xc.c    | 2 +-
 4 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 25f5a192ed..1db3efc486 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,10 @@ The format is based on [Keep a 
Changelog](https://keepachangelog.com/en/1.0.0/)
 ## [4.22.0 
UNRELEASED](https://xenbits.xenproject.org/gitweb/?p=xen.git;a=shortlog;h=staging)
 - TBD
 
 ### Changed
+ - Users of XEN_DOMCTL_createdomain/xc_domain_create() must now pass DOMID_ANY
+   to obtain an automatically allocated domid.  The prior sentinel values (0
+   since the start of Xen, and DOMID_INVALID since Xen 4.21) now no longer
+   represent a wildcard input.
  - On x86:
    - Enable pf-fixup option by default for PVH dom0.
 
diff --git a/tools/helpers/init-xenstore-domain.c 
b/tools/helpers/init-xenstore-domain.c
index 01ca667d25..2be5831a57 100644
--- a/tools/helpers/init-xenstore-domain.c
+++ b/tools/helpers/init-xenstore-domain.c
@@ -21,7 +21,7 @@
 
 #define LAPIC_BASE_ADDRESS  0xfee00000UL
 
-static uint32_t domid = ~0;
+static uint32_t domid = DOMID_ANY;
 static char *kernel;
 static char *ramdisk;
 static char *flask;
diff --git a/tools/ocaml/libs/xc/xenctrl.ml b/tools/ocaml/libs/xc/xenctrl.ml
index 97108b9d86..147afa62c2 100644
--- a/tools/ocaml/libs/xc/xenctrl.ml
+++ b/tools/ocaml/libs/xc/xenctrl.ml
@@ -208,7 +208,9 @@ let with_intf f =
 external domain_create_stub: handle -> domid -> domctl_create_config -> domid
   = "stub_xc_domain_create"
 
-let domain_create handle ?(domid=0) config =
+let domid_any = 0x7ff5 (* DOMID_ANY from public/xen.h *)
+
+let domain_create handle ?(domid=domid_any) config =
   domain_create_stub handle domid config
 
 external domain_sethandle: handle -> domid -> string -> unit
diff --git a/tools/python/xen/lowlevel/xc/xc.c 
b/tools/python/xen/lowlevel/xc/xc.c
index 9feb12ae2b..a94f01d40b 100644
--- a/tools/python/xen/lowlevel/xc/xc.c
+++ b/tools/python/xen/lowlevel/xc/xc.c
@@ -118,7 +118,7 @@ static PyObject *pyxc_domain_create(XcObject *self,
                                     PyObject *args,
                                     PyObject *kwds)
 {
-    uint32_t dom = 0, target = 0, max_grant_version = 2;
+    uint32_t dom = DOMID_ANY, target = 0, max_grant_version = 2;
     int      ret;
     size_t   i;
     PyObject *pyhandle = NULL;
--
generated by git-patchbot for /home/xen/git/xen.git#master