xen/mm: reject XENMEM_claim_pages when using LLC coloring

The coloring allocator ignores claims; reject the usage of the hypercall if
LLC coloring is enabled.  Note that the usage of alloc_color_heap_page() is
selected at boot time, and it's a system wide decision.  Once enabled all
domains will use alloc_color_heap_page() for allocations, which ignores any
outstanding claims.

The hypercall can be enabled if/when LLC coloring is adjusted to support
claims.

Fixes: 95debe51a9 ("xen: add cache coloring allocator for domains")
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: b068cafc73
master date: 2026-01-07 15:54:33 +0100

xen/common/memory.c

@@ -16,6 +16,7 @@
 #include <xen/iocap.h>
 #include <xen/ioreq.h>
 #include <xen/lib.h>
+#include <xen/llc-coloring.h>
 #include <xen/mem_access.h>
 #include <xen/mm.h>
 #include <xen/numa.h>
@@ -1660,6 +1661,9 @@ long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
         break;
 
     case XENMEM_claim_pages:
+        if ( llc_coloring_enabled )
+            return -EOPNOTSUPP;
+
         if ( unlikely(start_extent) )
             return -EINVAL;