oxenstored: Don't re-open a xenctrl handle for every domain introduction

Currently, an xc handle is opened in main() which is used for cleanup
activities, and a new xc handle is temporarily opened every time a domain is
introduced.  This is inefficient, and amongst other things, requires full root
privileges for the lifetime of oxenstored.

All code using the Xenctrl handle is in domains.ml, so initialise xc as a
global (now happens just before main() is called) and drop it as a parameter
from Domains.create and Domains.cleanup.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>

diff --git a/tools/ocaml/xenstored/domains.ml b/tools/ocaml/xenstored/domains.ml
index 4134630c583539afd5723aaa0d3a6f80498f27c8..71dde16afa83e8225e1fbfefe1646fbfa09d6c7e 100644 (file)
--- a/tools/ocaml/xenstored/domains.ml
+++ b/tools/ocaml/xenstored/domains.ml
@@ -18,6 +18,8 @@ let debug fmt = Logging.debug "domains" fmt
 let error fmt = Logging.error "domains" fmt
 let warn fmt  = Logging.warn  "domains" fmt
 
+let xc = Xenctrl.interface_open ()
+
 type domains = {
        eventchn: Event.t;
        table: (Xenctrl.domid, Domain.t) Hashtbl.t;
@@ -86,7 +88,7 @@ let remove_from_queue dom queue =
                | None -> ()
                | Some x -> if x=dom then d := None) queue
 
-let cleanup xc doms =
+let cleanup doms =
        let notify = ref false in
        let dead_dom = ref [] in
 
@@ -120,7 +122,7 @@ let cleanup xc doms =
 let resume doms domid =
        ()
 
-let create xc doms domid mfn port =
+let create doms domid mfn port =
        let interface = Xenctrl.map_foreign_range xc domid (Xenmmap.getpagesize()) mfn in
        let dom = Domain.make domid mfn port interface doms.eventchn in
        Hashtbl.add doms.table domid dom;

diff --git a/tools/ocaml/xenstored/process.ml b/tools/ocaml/xenstored/process.ml
index 217a344806f90cdf0c3c3584a90b8500f5429b4c..977e7c11bec3e4ff2ca1f7d1f48c94ebe33bd598 100644 (file)
--- a/tools/ocaml/xenstored/process.ml
+++ b/tools/ocaml/xenstored/process.ml
@@ -410,8 +410,7 @@ let do_introduce con t domains cons data =
                if Domains.exist domains domid then
                        Domains.find domains domid
                else try
-                       let ndom = Xenctrl.with_intf (fun xc ->
-                               Domains.create xc domains domid mfn port) in
+                       let ndom = Domains.create domains domid mfn port in
                        Connections.add_domain cons ndom;
                        Connections.fire_spec_watches cons "@introduceDomain";
                        ndom

diff --git a/tools/ocaml/xenstored/xenstored.ml b/tools/ocaml/xenstored/xenstored.ml
index 40a05e9dba449f4f52bb754bfe27887cecb13f05..7df02ed5744c91f6f50526bae201801be363b939 100644 (file)
--- a/tools/ocaml/xenstored/xenstored.ml
+++ b/tools/ocaml/xenstored/xenstored.ml
@@ -177,12 +177,11 @@ let from_channel_f chan domain_f watch_f store_f =
 let from_channel store cons doms chan =
        (* don't let the permission get on our way, full perm ! *)
        let op = Store.get_ops store Perms.Connection.full_rights in
-       let xc = Xenctrl.interface_open () in
 
        let domain_f domid mfn port =
                let ndom =
                        if domid > 0 then
-                               Domains.create xc doms domid mfn port
+                               Domains.create doms domid mfn port
                        else
                                Domains.create0 doms
                        in
@@ -196,8 +195,7 @@ let from_channel store cons doms chan =
                op.Store.write path value;
                op.Store.setperms path perms
                in
-       finally (fun () -> from_channel_f chan domain_f watch_f store_f)
-               (fun () -> Xenctrl.interface_close xc)
+       from_channel_f chan domain_f watch_f store_f
 
 let from_file store cons doms file =
        let channel = open_in file in
@@ -328,8 +326,6 @@ let _ =
                (if cf.domain_init then [ Event.fd eventchn ] else [])
                in
 
-       let xc = Xenctrl.interface_open () in
-
        let process_special_fds rset =
                let accept_connection can_write fd =
                        let (cfd, addr) = Unix.accept fd in
@@ -340,7 +336,7 @@ let _ =
                        debug "pending port %d" (Xeneventchn.to_int port);
                        finally (fun () ->
                                if Some port = eventchn.Event.virq_port then (
-                                       let (notify, deaddom) = Domains.cleanup xc domains in
+                                       let (notify, deaddom) = Domains.cleanup domains in
                                        List.iter (Connections.del_domain cons) deaddom;
                                        if deaddom <> [] || notify then
                                                Connections.fire_spec_watches cons "@releaseDomain"