Patchwork [1,of,2] Introduce a new 'connected' xendev op called when Connected.

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Submitter Stefano Stabellini
Date Aug. 27, 2010, 2:43 p.m.
Message ID <alpine.DEB.2.00.1008271543250.2545@kaball-desktop>
Download mbox | patch
Permalink /patch/62857/
State New
Headers show

Comments

Stefano Stabellini - Aug. 27, 2010, 2:43 p.m.
From: John Haxby <john.haxby@oracle.com>

Introduce a new 'connected' xendev op called when Connected.

Rename the existing xendev 'connect' op to 'initialised' and introduce
a new 'connected' op.  This new op, if defined, is called when the
backend is connected.  Note that since there is no state transition this
may be called more than once.

Signed-off-by: John Haxby <john.haxby@oracle.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
John Haxby - March 11, 2011, 1:15 p.m.
It's been something over six months since this patch was submitted
(actually it was  resend because the first version didn't say "PATCH" in
the subject.  So far as I can tell it's not made it into qemu git
(hw/xen_backend.h, for example, doesn't show the extra field in struct
XenDevOps).

This problem came up again on the xen-devel lists today and it's a shame
that there's been a patch out there since last summer that people are
now having to re-discover and re-patch :-(

jch

On 27/08/10 15:43, Stefano Stabellini wrote:
> From: John Haxby <john.haxby@oracle.com>
>
> Introduce a new 'connected' xendev op called when Connected.
>
> Rename the existing xendev 'connect' op to 'initialised' and introduce
> a new 'connected' op.  This new op, if defined, is called when the
> backend is connected.  Note that since there is no state transition this
> may be called more than once.
>
> Signed-off-by: John Haxby <john.haxby@oracle.com>
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
>
>
[snip]

Patch

diff --git a/hw/xen_backend.c b/hw/xen_backend.c
index a2e408f..b99055a 100644
--- a/hw/xen_backend.c
+++ b/hw/xen_backend.c
@@ -400,13 +400,13 @@  static int xen_be_try_init(struct XenDevice *xendev)
 }
 
 /*
- * Try to connect xendev.  Depends on the frontend being ready
+ * Try to initialise xendev.  Depends on the frontend being ready
  * for it (shared ring and evtchn info in xenstore, state being
  * Initialised or Connected).
  *
  * Goes to Connected on success.
  */
-static int xen_be_try_connect(struct XenDevice *xendev)
+static int xen_be_try_initialise(struct XenDevice *xendev)
 {
     int rc = 0;
 
@@ -420,10 +420,10 @@  static int xen_be_try_connect(struct XenDevice *xendev)
 	}
     }
 
-    if (xendev->ops->connect)
-	rc = xendev->ops->connect(xendev);
+    if (xendev->ops->initialise)
+	rc = xendev->ops->initialise(xendev);
     if (rc != 0) {
-	xen_be_printf(xendev, 0, "connect() failed\n");
+	xen_be_printf(xendev, 0, "initialise() failed\n");
 	return rc;
     }
 
@@ -432,6 +432,28 @@  static int xen_be_try_connect(struct XenDevice *xendev)
 }
 
 /*
+ * Try to let xendev know that it is connected.  Depends on the
+ * frontend being Connected.  Note that this may be called more
+ * than once since the backend state is not modified.
+ */
+static void xen_be_try_connected(struct XenDevice *xendev)
+{
+    if (!xendev->ops->connected)
+	return;
+
+    if (xendev->fe_state != XenbusStateConnected) {
+	if (xendev->ops->flags & DEVOPS_FLAG_IGNORE_STATE) {
+	    xen_be_printf(xendev, 2, "frontend not ready, ignoring\n");
+	} else {
+	    xen_be_printf(xendev, 2, "frontend not ready (yet)\n");
+	    return;
+	}
+    }
+
+    xendev->ops->connected(xendev);
+}
+
+/*
  * Teardown connection.
  *
  * Goes to Closed when done.
@@ -483,7 +505,12 @@  void xen_be_check_state(struct XenDevice *xendev)
 	    rc = xen_be_try_init(xendev);
 	    break;
 	case XenbusStateInitWait:
-	    rc = xen_be_try_connect(xendev);
+	    rc = xen_be_try_initialise(xendev);
+	    break;
+	case XenbusStateConnected:
+	    /* xendev->be_state doesn't change */
+	    xen_be_try_connected(xendev);
+	    rc = -1;
 	    break;
         case XenbusStateClosed:
             rc = xen_be_try_reset(xendev);
diff --git a/hw/xen_backend.h b/hw/xen_backend.h
index cc25f9d..154922a 100644
--- a/hw/xen_backend.h
+++ b/hw/xen_backend.h
@@ -23,7 +23,8 @@  struct XenDevOps {
     uint32_t  flags;
     void      (*alloc)(struct XenDevice *xendev);
     int       (*init)(struct XenDevice *xendev);
-    int       (*connect)(struct XenDevice *xendev);
+    int       (*initialise)(struct XenDevice *xendev);
+    void      (*connected)(struct XenDevice *xendev);
     void      (*event)(struct XenDevice *xendev);
     void      (*disconnect)(struct XenDevice *xendev);
     int       (*free)(struct XenDevice *xendev);
diff --git a/hw/xen_console.c b/hw/xen_console.c
index d2261f4..258c003 100644
--- a/hw/xen_console.c
+++ b/hw/xen_console.c
@@ -202,7 +202,7 @@  static int con_init(struct XenDevice *xendev)
     return 0;
 }
 
-static int con_connect(struct XenDevice *xendev)
+static int con_initialise(struct XenDevice *xendev)
 {
     struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
     int limit;
@@ -263,7 +263,7 @@  struct XenDevOps xen_console_ops = {
     .size       = sizeof(struct XenConsole),
     .flags      = DEVOPS_FLAG_IGNORE_STATE,
     .init       = con_init,
-    .connect    = con_connect,
+    .initialise = con_initialise,
     .event      = con_event,
     .disconnect = con_disconnect,
 };
diff --git a/hw/xenfb.c b/hw/xenfb.c
index da5297b..b535d8c 100644
--- a/hw/xenfb.c
+++ b/hw/xenfb.c
@@ -359,7 +359,7 @@  static int input_init(struct XenDevice *xendev)
     return 0;
 }
 
-static int input_connect(struct XenDevice *xendev)
+static int input_initialise(struct XenDevice *xendev)
 {
     struct XenInput *in = container_of(xendev, struct XenInput, c.xendev);
     int rc;
@@ -861,7 +861,7 @@  static int fb_init(struct XenDevice *xendev)
     return 0;
 }
 
-static int fb_connect(struct XenDevice *xendev)
+static int fb_initialise(struct XenDevice *xendev)
 {
     struct XenFB *fb = container_of(xendev, struct XenFB, c.xendev);
     struct xenfb_page *fb_page;
@@ -955,7 +955,7 @@  static void fb_event(struct XenDevice *xendev)
 struct XenDevOps xen_kbdmouse_ops = {
     .size       = sizeof(struct XenInput),
     .init       = input_init,
-    .connect    = input_connect,
+    .initialise = input_initialise,
     .disconnect = input_disconnect,
     .event      = input_event,
 };
@@ -963,7 +963,7 @@  struct XenDevOps xen_kbdmouse_ops = {
 struct XenDevOps xen_framebuffer_ops = {
     .size       = sizeof(struct XenFB),
     .init       = fb_init,
-    .connect    = fb_connect,
+    .initialise = fb_initialise,
     .disconnect = fb_disconnect,
     .event      = fb_event,
     .frontend_changed = fb_frontend_changed,