plumb migration pages through

edwintorok · edwintorok · commit 769dd6d7c1cd · 2026-01-08T10:21:23.000Z
diff --git a/ocaml/xapi-idl/memory/memory.ml b/ocaml/xapi-idl/memory/memory.ml
@@ -185,6 +185,7 @@ type memory_config = {
   ; shadow_mib: int64
   ; required_host_free_mib: int64
   ; overhead_mib: int64
+  ; build_claim_pages: int64
 }
 
 module Memory_model (D : MEMORY_MODEL_DATA) = struct
@@ -226,14 +227,16 @@ module Memory_model (D : MEMORY_MODEL_DATA) = struct
   let shadow_multiplier_default = 1.0
 
   let full_config static_max_mib video_mib target_mib vcpus shadow_multiplier =
+    let build_start_mib = build_start_mib static_max_mib target_mib video_mib in
     {
       build_max_mib= build_max_mib static_max_mib video_mib
-    ; build_start_mib= build_start_mib static_max_mib target_mib video_mib
+    ; build_start_mib
     ; xen_max_mib= xen_max_mib static_max_mib
     ; shadow_mib= shadow_mib static_max_mib vcpus shadow_multiplier
     ; required_host_free_mib=
         footprint_mib target_mib static_max_mib vcpus shadow_multiplier
     ; overhead_mib= overhead_mib static_max_mib vcpus shadow_multiplier
+    ; build_claim_pages= pages_of_mib build_start_mib
     }
 end
 
diff --git a/ocaml/xenopsd/xc/domain.ml b/ocaml/xenopsd/xc/domain.ml
@@ -150,6 +150,8 @@ type builder_spec_info =
 type build_info = {
     memory_max: int64  (** memory max in kilobytes *)
   ; memory_target: int64  (** memory target in kilobytes *)
+  ; memory_total_source: int64 option
+        (** amount of memory to claim (during migration) *)
   ; kernel: string  (** in hvm case, point to hvmloader *)
   ; vcpus: int  (** vcpus max *)
   ; priv: builder_spec_info
@@ -1003,7 +1005,7 @@ let numa_placement domid ~vcpus ~cores ~memory affinity =
               __FUNCTION__ domid ;
             None
       in
-      let nr_pages = (Int64.div memory 4096L |> Int64.to_int) (*- 32*) in
+      let nr_pages = Int64.div memory 4096L |> Int64.to_int (*- 32*) in
       try
         D.debug "NUMAClaim domid %d: local claim on node %d: %d pages" domid
           node nr_pages ;
@@ -1029,11 +1031,13 @@ let numa_placement domid ~vcpus ~cores ~memory affinity =
 let build_pre ~xc ~xs ~vcpus ~memory ~hard_affinity domid =
   let open Memory in
   let uuid = get_uuid ~xc domid in
-  debug "VM = %s, build_max_mib = %Ld, build_start_mib = %Ld, xen_max_mib =
-    %Ld, shadow_mib = %Ld, required_host_free_mib = %Ld, overhead_mib = %Ld"
-    (Uuidx.to_string uuid)
-    memory.build_max_mib memory.build_start_mib memory.xen_max_mib
-    memory.shadow_mib memory.required_host_free_mib memory.overhead_mib;
+  debug
+    "VM = %s, build_max_mib = %Ld, build_start_mib = %Ld, xen_max_mib =\n\
+    \    %Ld, shadow_mib = %Ld, required_host_free_mib = %Ld, overhead_mib = \
+     %Ld"
+    (Uuidx.to_string uuid) memory.build_max_mib memory.build_start_mib
+    memory.xen_max_mib memory.shadow_mib memory.required_host_free_mib
+    memory.overhead_mib ;
   debug "VM = %s; domid = %d; waiting for %Ld MiB of free host memory"
     (Uuidx.to_string uuid) domid memory.required_host_free_mib ;
   (* CA-39743: Wait, if necessary, for the Xen scrubber to catch up. *)
@@ -1121,9 +1125,14 @@ let build_pre ~xc ~xs ~vcpus ~memory ~hard_affinity domid =
               and cores =
                 Xenops_server.cores_of_numa_affinity_policy pin ~vcpus
               in
-              let memory =
-                Int64.(mul memory.build_start_mib (shift_left 1L 20))
+
+              let build_claim_bytes =
+                Memory.bytes_of_pages memory.build_claim_pages
               in
+              D.debug "VM = %s; domid = %d; will claim %Ld bytes = %Ld pages"
+                (Uuidx.to_string uuid) domid build_claim_bytes
+                memory.build_claim_pages ;
+              let memory = build_claim_bytes in
               match numa_placement domid ~vcpus ~cores ~memory affinity with
               | None ->
                   (* Always perform a global claim when NUMA placement is
@@ -1138,7 +1147,8 @@ let build_pre ~xc ~xs ~vcpus ~memory ~hard_affinity domid =
                      memory later anyway
                   *)
                   let nr_pages =
-                    (Int64.div memory 4096L |> Int64.to_int)(* - 32*)
+                    Int64.div memory 4096L |> Int64.to_int
+                    (* - 32*)
                   in
                   let xcext = Xenctrlext.get_handle () in
                   D.debug "NUMAClaim domid %d: global claim: %d pages" domid
@@ -1828,6 +1838,16 @@ let restore (task : Xenops_task.task_handle) ~xc ~xs ~dm ~timeoffset ~extras
         maybe_ca_140252_workaround ~xc ~vcpus domid ;
         (memory, vm_stuff, `pvh)
   in
+  let memory =
+    match info.memory_total_source with
+    | None ->
+        memory
+    | Some bytes ->
+        let build_claim_pages = Memory.pages_of_bytes_used bytes in
+        debug "Domid %d: memory_total_source = %Ld bytes = %Ld pages" domid
+          bytes build_claim_pages ;
+        Memory.{memory with build_claim_pages}
+  in
   let store_port, console_port, numa_placements =
     build_pre ~xc ~xs ~memory ~vcpus ~hard_affinity:info.hard_affinity domid
   in
diff --git a/ocaml/xenopsd/xc/domain.mli b/ocaml/xenopsd/xc/domain.mli
@@ -130,6 +130,8 @@ val builder_spec_info : builder_spec_info Rpc.Types.def
 type build_info = {
     memory_max: int64  (** memory max in kilobytes *)
   ; memory_target: int64  (** memory target in kilobytes *)
+  ; memory_total_source: int64 option
+        (** memory used on source during migration/resume in kilobytes *)
   ; kernel: string  (** image to load. In HVM case, point to hvmloader *)
   ; vcpus: int  (** vcpus max *)
   ; priv: builder_spec_info
diff --git a/ocaml/xenopsd/xc/xenops_server_xen.ml b/ocaml/xenopsd/xc/xenops_server_xen.ml
@@ -1624,6 +1624,7 @@ module VM = struct
       {
         Domain.memory_max= vm.memory_static_max /// 1024L
       ; memory_target= vm.memory_dynamic_min /// 1024L
+      ; memory_total_source= None
       ; kernel= ""
       ; vcpus= vm.vcpu_max
       ; priv= builder_spec_info
@@ -1803,34 +1804,40 @@ module VM = struct
                  needed. If we are live migrating then we will only know an
                  upper bound. If we are starting from scratch then we have a
                  free choice. *)
-              let min_bytes, max_bytes =
+              let min_bytes, max_bytes, memory_total_source_bytes =
                 match memory_upper_bound with
                 | Some x ->
                     debug "VM = %s; using memory_upper_bound = %Ld" vm.Vm.id x ;
-                    (x, x)
+                    (x, x, Some x)
                 | None ->
                     if resuming then (
                       debug "VM = %s; using stored suspend_memory_bytes = %Ld"
                         vm.Vm.id persistent.VmExtra.suspend_memory_bytes ;
                       ( persistent.VmExtra.suspend_memory_bytes
                       , persistent.VmExtra.suspend_memory_bytes
+                      , Some persistent.VmExtra.suspend_memory_bytes
                       )
                     ) else (
                       debug
                         "VM = %s; using memory_dynamic_min = %Ld and \
                          memory_dynamic_max = %Ld"
                         vm.Vm.id vm.memory_dynamic_min vm.memory_dynamic_max ;
-                      (vm.memory_dynamic_min, vm.memory_dynamic_max)
+                      (vm.memory_dynamic_min, vm.memory_dynamic_max, None)
                     )
               in
               let min_kib = kib_of_bytes_used (min_bytes +++ overhead_bytes)
+              and memory_total_source_kib =
+                Option.map kib_of_bytes_used memory_total_source_bytes
               and max_kib = kib_of_bytes_used (max_bytes +++ overhead_bytes) in
               (* XXX: we would like to be able to cancel an in-progress
                  with_reservation *)
               let dbg = Xenops_task.get_dbg task in
               Mem.with_reservation dbg min_kib max_kib
                 (fun target_plus_overhead_kib reservation_id ->
-                  debug "VM = %s, memory [%Ld KiB, %Ld KiB], target_plus_overhead=%Ld KiB" vm.Vm.id min_kib max_kib target_plus_overhead_kib;
+                  debug
+                    "VM = %s, memory [%Ld KiB, %Ld KiB], \
+                     target_plus_overhead=%Ld KiB"
+                    vm.Vm.id min_kib max_kib target_plus_overhead_kib ;
                   let domain_config, persistent =
                     match persistent.VmExtra.domain_config with
                     | Some dc ->
@@ -1871,9 +1878,26 @@ module VM = struct
                     let target_bytes =
                       target_plus_overhead_bytes --- overhead_bytes
                     in
-                    debug "VM = %s, memory target_bytes = %Ld, dynamic max = %Ld" vm.Vm.id target_bytes vm.memory_dynamic_max;
+                    debug
+                      "VM = %s, memory target_bytes = %Ld, dynamic max = %Ld"
+                      vm.Vm.id target_bytes vm.memory_dynamic_max ;
                     min vm.memory_dynamic_max target_bytes
                   in
+                  let persistent =
+                    match persistent with
+                    | {VmExtra.build_info= Some x; _} as t ->
+                        {
+                          t with
+                          build_info=
+                            Some
+                              {
+                                x with
+                                memory_total_source= memory_total_source_kib
+                              }
+                        }
+                    | _ ->
+                        persistent
+                  in
                   set_initial_target ~xs domid (Int64.div initial_target 1024L) ;
                   (* Log uses of obsolete option *)
                   if vm.suppress_spurious_page_faults then
@@ -2347,6 +2371,7 @@ module VM = struct
       {
         Domain.memory_max= static_max_kib
       ; memory_target= initial_target
+      ; memory_total_source= None
       ; kernel
       ; vcpus= vm.vcpu_max
       ; priv
@@ -2969,7 +2994,7 @@ module VM = struct
               | _ ->
                   ""
             in
-            debug "VM = %s, initial_target = %Ld" vm.Vm.id initial_target;
+            debug "VM = %s, initial_target = %Ld" vm.Vm.id initial_target ;
             ({x with Domain.memory_target= initial_target}, timeoffset)
       in
       let vtpm = vtpm_of ~vm in
@@ -3110,7 +3135,8 @@ module VM = struct
               let pages = Int64.of_nativeint di.Xenctrl.total_memory_pages in
               let kib = Xenctrl.pages_to_kib pages in
               let bytes = Memory.bytes_of_kib kib in
-              D.debug "VM %s memory actual: %Ld pages = %Ld KiB = %Ld bytes" (Uuidm.to_string uuid) pages kib bytes;
+              D.debug "VM %s memory actual: %Ld pages = %Ld KiB = %Ld bytes"
+                (Uuidm.to_string uuid) pages kib bytes ;
               bytes
             in
             let memory_limit =
@@ -3135,7 +3161,8 @@ module VM = struct
               (* CA-31764: may be larger than static_max if maxmem has been
                  increased to initial-reservation. *)
               let result = max memory_actual max_memory_bytes in
-              D.debug "VM %s memory limit = %Ld bytes" (Uuidm.to_string uuid) result;
+              D.debug "VM %s memory limit = %Ld bytes" (Uuidm.to_string uuid)
+                result ;
               result
             in
             let rtc =
