From 25f5e14869b02d369e16ab3980900b71fea2f78e Mon Sep 17 00:00:00 2001
From: David Scott <dave.scott@eu.citrix.com>
Date: Mon, 11 Oct 2010 23:00:16 +0100
Subject: [PATCH] CA-46050: allow more than 2 PCI devices to be hotplugged into
 a domain (!)

There is much confusion about the meaning of the X in
(X, (domain, bus, path, func)). Sometimes it means "order the device was
plugged"; other times it means something more device related.

With this change, more than 2 devices can be plugged into a domain and the
#devices and plug order remains constant over reboot.

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
---
 ocaml/xapi/vmops.ml     |  4 ++--
 ocaml/xenops/device.ml  | 21 ++++++++++++---------
 ocaml/xenops/device.mli |  2 +-
 ocaml/xenops/xenops.ml  |  2 +-
 4 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/ocaml/xapi/vmops.ml b/ocaml/xapi/vmops.ml
index bc066d0c..8ad15f9b 100644
--- a/ocaml/xapi/vmops.ml
+++ b/ocaml/xapi/vmops.ml
@@ -506,12 +506,12 @@ let plug_pcidevs_noexn ~__context ~vm domid pcidevs =
 	   (fun xc xs ->
 	      if (Xc.domain_getinfo xc domid).Xc.hvm_guest then begin
 			List.iter 
-				(fun (devid, devices) ->
+				(fun (_, devices) ->
 					 Device.PCI.bind devices;
 					 List.iter
 						 (fun ((a, b, c, d) as device) ->
 							  debug "hotplugging PCI device %04x:%02x:%02x.%01x into domid: %d" a b c d domid;
-							  Device.PCI.plug ~xc ~xs device domid devid
+							  Device.PCI.plug ~xc ~xs device domid
 						 ) devices
 				) (sort_pcidevs pcidevs)
 	      end
diff --git a/ocaml/xenops/device.ml b/ocaml/xenops/device.ml
index 3094a993..92b476cf 100644
--- a/ocaml/xenops/device.ml
+++ b/ocaml/xenops/device.ml
@@ -1174,25 +1174,28 @@ let wait_device_model ~xc ~xs domid =
   xs.Xs.rm (device_model_state_path xs be_domid domid);
   answer
 							
-(* Return a list of PCI devices *)
-let list ~xc ~xs domid = 
+(* Given a domid, return a list of [ X, (domain, bus, dev, func) ] where X indicates the order in
+   which the device was plugged. *)
+let read_pcidir ~xc ~xs domid = 
   let path = device_model_pci_device_path xs 0 domid in
   let prefix = "dev-" in
   let all = List.filter (String.startswith prefix) (try xs.Xs.directory path with Xb.Noent -> []) in
   (* The values are the PCI device (domain, bus, dev, func) strings *)
-  let pairs = List.map (fun x -> x, xs.Xs.read (path ^ "/" ^ x)) all in
   let device_number_of_string x =
     (* remove the silly prefix *)
     int_of_string (String.sub x (String.length prefix) (String.length x - (String.length prefix))) in
-  let pairs' = List.map (fun (x, y) -> device_number_of_string x, of_string y) pairs in
+  let pairs = List.map (fun x -> device_number_of_string x, of_string (xs.Xs.read (path ^ "/" ^ x))) all in
   (* Sort into the order the devices were plugged *)
-  let sorted = List.sort (fun a b -> compare (fst a) (fst b)) pairs' in
-  (* Assume the PCI bus ID is 0 *)
-  List.map (fun (_, y) -> 0, y) sorted
+  List.sort (fun a b -> compare (fst a) (fst b)) pairs
+
+(* Return a list of PCI devices *)
+let list ~xc ~xs domid = 
+	(* replace the sort index with the default '0' -- XXX must figure out whether this matters to anyone *)
+	List.map (fun (_, y) -> (0, y)) (read_pcidir ~xc ~xs domid)
 
 
-let plug ~xc ~xs (domain, bus, dev, func) domid devid = 
-    let current = list ~xc ~xs domid in
+let plug ~xc ~xs (domain, bus, dev, func) domid = 
+    let current = read_pcidir ~xc ~xs domid in
 	let next_idx = List.fold_left max (-1) (List.map fst current) + 1 in
 	
 	let pci = to_string (domain, bus, dev, func) in
diff --git a/ocaml/xenops/device.mli b/ocaml/xenops/device.mli
index 6dd153cd..fa034ff3 100644
--- a/ocaml/xenops/device.mli
+++ b/ocaml/xenops/device.mli
@@ -145,7 +145,7 @@ sig
 	val reset : xs:Xs.xsh -> device -> unit
 	val bind : (int * int * int * int) list -> unit
 	val plug : xc:Xc.handle -> xs:Xs.xsh
-		-> (int * int * int * int) -> Xc.domid -> int -> unit
+		-> (int * int * int * int) -> Xc.domid -> unit
 	val unplug : xc:Xc.handle -> xs:Xs.xsh
 		-> (int * int * int * int) -> Xc.domid -> unit
 	val list : xc:Xc.handle -> xs:Xs.xsh -> Xc.domid -> (int * (int * int * int * int)) list
diff --git a/ocaml/xenops/xenops.ml b/ocaml/xenops/xenops.ml
index 08148fb1..5a13cc97 100644
--- a/ocaml/xenops/xenops.ml
+++ b/ocaml/xenops/xenops.ml
@@ -258,7 +258,7 @@ let add_pci ~xc ~xs ~hvm ~domid ~devid ~pci =
 
 let plug_pci ~xc ~xs ~domid ~devid ~pci = 
 	let pcidev = pci_of_string pci in
-	Device.PCI.plug ~xc ~xs pcidev domid devid
+	Device.PCI.plug ~xc ~xs pcidev domid
 
 let unplug_pci ~xc ~xs ~domid ~devid ~pci = 
 	let pcidev = pci_of_string pci in
-- 
2.39.5