Xen devel - Nov 2012 - [PATCH] xen: implement support for secondary consoles in the console backend

This patch corresponds to commit
840184a106bc24e745beda5c77e392f6cecd2bc9 from
git://xenbits.xensource.com/qemu-xen-unstable.git.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

diff --git a/hw/xen_console.c b/hw/xen_console.c
index 9426d73..1349881 100644
--- a/hw/xen_console.c
+++ b/hw/xen_console.c
@@ -184,7 +184,11 @@ static int con_init(struct XenDevice *xendev)
 
     /* setup */
     dom = xs_get_domain_path(xenstore, con->xendev.dom);
-    snprintf(con->console, sizeof(con->console), "%s/console",
dom);
+    if (!xendev->dev) {
+        snprintf(con->console, sizeof(con->console),
"%s/console", dom);
+    } else {
+        snprintf(con->console, sizeof(con->console),
"%s/device/console/%d", dom, xendev->dev);
+    }
     free(dom);
 
     type = xenstore_read_str(con->console, "type");
@@ -223,10 +227,16 @@ static int con_initialise(struct XenDevice *xendev)
     if (xenstore_read_int(con->console, "limit", &limit) == 0)
 	con->buffer.max_capacity = limit;
 
-    con->sring = xc_map_foreign_range(xen_xc, con->xendev.dom,
-				      XC_PAGE_SIZE,
-				      PROT_READ|PROT_WRITE,
-				      con->ring_ref);
+    if (!xendev->dev) {
+        con->sring = xc_map_foreign_range(xen_xc, con->xendev.dom,
+                                          XC_PAGE_SIZE,
+                                          PROT_READ|PROT_WRITE,
+                                          con->ring_ref);
+    } else {
+        con->sring = xc_gnttab_map_grant_ref(xendev->gnttabdev,
con->xendev.dom,
+                                             con->ring_ref,
+                                             PROT_READ|PROT_WRITE);
+    }
     if (!con->sring)
 	return -1;
 
@@ -255,7 +265,11 @@ static void con_disconnect(struct XenDevice *xendev)
     xen_be_unbind_evtchn(&con->xendev);
 
     if (con->sring) {
-	munmap(con->sring, XC_PAGE_SIZE);
+        if (!xendev->gnttabdev) {
+            munmap(con->sring, XC_PAGE_SIZE);
+        } else {
+            xc_gnttab_munmap(xendev->gnttabdev, con->sring, 1);
+        }
 	con->sring = NULL;
     }
 }
@@ -273,7 +287,7 @@ static void con_event(struct XenDevice *xendev)
 
 struct XenDevOps xen_console_ops = {
     .size       = sizeof(struct XenConsole),
-    .flags      = DEVOPS_FLAG_IGNORE_STATE,
+    .flags      = DEVOPS_FLAG_IGNORE_STATE|DEVOPS_FLAG_NEED_GNTDEV,
     .init       = con_init,
     .initialise = con_initialise,
     .event      = con_event,