From 27698181c3dec576c6abbfc38f289f175eb9ec66 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ian.jackson@eu.citrix.com>
Date: Mon, 4 Jan 2010 16:21:55 +0000
Subject: [PATCH] implement cdrom eject from the guest

Hi all,
this patch allows a guest to eject the cdrom: when qemu detects that a
cdrom eject request ahs been issued by the guest, it writes eject to the
corresponding xenstore frontend, so that the toolstack can take care of
removing the current cdrom frontend\backend couple and create an empty one
instead.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
(cherry picked from commit 9bac5357507958e2eabcf96bce40cca336fa46ac)
---
 hw/ide.c   |  2 ++
 qemu-xen.h |  2 ++
 xenstore.c | 34 +++++++++++++++++++++++++++++++++-
 3 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/hw/ide.c b/hw/ide.c
index e8d676e8..b38de553 100644
--- a/hw/ide.c
+++ b/hw/ide.c
@@ -35,6 +35,7 @@
 #include "mac_dbdma.h"
 #include "sh.h"
 #include "dma.h"
+#include "qemu-xen.h"
 
 /* debug IDE devices */
 //#define DEBUG_IDE
@@ -2100,6 +2101,7 @@ static void ide_atapi_cmd(IDEState *s)
 
             if (eject && !start) {
                 /* eject the disk */
+                xenstore_do_eject(s->bs);
                 bdrv_eject(s->bs, 1);
             } else if (eject && start) {
                 /* close the tray */
diff --git a/qemu-xen.h b/qemu-xen.h
index 41fbc539..60116501 100644
--- a/qemu-xen.h
+++ b/qemu-xen.h
@@ -112,6 +112,8 @@ char *xenstore_read_battery_data(int battery_status);
 int xenstore_refresh_battery_status(void);
 int xenstore_pv_driver_build_blacklisted(uint16_t product_number,
                                          uint32_t build_nr);
+void xenstore_do_eject(BlockDriverState *bs);
+int xenstore_find_device(BlockDriverState *bs);
 
 /* xenfbfront.c */
 int xenfb_pv_display_init(DisplayState *ds);
diff --git a/xenstore.c b/xenstore.c
index 11b305d9..264cf977 100644
--- a/xenstore.c
+++ b/xenstore.c
@@ -33,6 +33,31 @@
 struct xs_handle *xsh = NULL;
 static char *media_filename[MAX_DRIVES+1];
 static QEMUTimer *insert_timer = NULL;
+static char *xenbus_param_paths[MAX_DRIVES+1];
+
+int xenstore_find_device(BlockDriverState *bs)
+{
+    int i;
+
+    for (i = 0; i < MAX_DRIVES + 1; i++) {
+        if (drives_table[i].bdrv == bs)
+            return i;
+    }
+    return -1;
+}
+
+void xenstore_do_eject(BlockDriverState *bs)
+{
+    int i;
+
+    i = xenstore_find_device(bs);
+    if (i == -1) {
+        fprintf(stderr, "couldn't find disk to eject.\n");
+        return;
+    }
+    if (xenbus_param_paths[i])
+        xs_write(xsh, XBT_NULL, xenbus_param_paths[i], "eject", strlen("eject"));
+}
 
 #define UWAIT_MAX (30*1000000) /* thirty seconds */
 #define UWAIT     (100000)     /* 1/10th second  */
@@ -466,8 +491,15 @@ void xenstore_parse_domain_config(int hvm_domid)
         /* check if it is a cdrom */
         if (danger_type && !strcmp(danger_type, "cdrom")) {
             bdrv_set_type_hint(bs, BDRV_TYPE_CDROM);
-            if (pasprintf(&buf, "%s/params", bpath) != -1)
+            if (pasprintf(&buf, "%s/params", bpath) != -1) {
+                char *buf2, *frontend;
                 xs_watch(xsh, buf, dev);
+                asprintf(&buf2, "%s/frontend", bpath);
+                frontend = xs_read(xsh, XBT_NULL, buf2, &len);
+                asprintf(&xenbus_param_paths[nb_drives], "%s/eject", frontend);
+                free(frontend);
+                free(buf2);
+            }
         }
 
         /* open device now if media present */
-- 
2.39.5