[libvirt] [PATCH] Allow chardev of type 'file' for UML domains.

[soren at linux2go.dk]

From: Soren Hansen <soren at linux2go.dk>

Like that comment suggested, we just open the file and pass the file
descriptor to uml. The input "stream" is set to "null", since I couldn't
find any useful way to actually use a file for input for a chardev and
this also mimics what e.g. QEmu does internally.

Signed-off-by: Soren Hansen <soren at linux2go.dk>
---
 src/uml/uml_conf.c   |   30 +++++++++++++++++++++++++-----
 src/uml/uml_conf.h   |    1 +
 src/uml/uml_driver.c |    6 +-----
 3 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/src/uml/uml_conf.c b/src/uml/uml_conf.c
index bc8cbce..659f881 100644
--- a/src/uml/uml_conf.c
+++ b/src/uml/uml_conf.c
@@ -297,7 +297,8 @@ error:
 
 static char *
 umlBuildCommandLineChr(virDomainChrDefPtr def,
-                       const char *dev)
+                       const char *dev,
+                       fd_set *keepfd)
 {
     char *ret = NULL;
 
@@ -346,8 +347,26 @@ umlBuildCommandLineChr(virDomainChrDefPtr def,
         break;
 
     case VIR_DOMAIN_CHR_TYPE_FILE:
-    case VIR_DOMAIN_CHR_TYPE_PIPE:
-        /* XXX could open the file/pipe & just pass the FDs */
+         {
+            int fd_out;
+
+            if ((fd_out = open(def->data.file.path,
+                               O_WRONLY | O_APPEND | O_CREAT, 0660)) < 0) {
+                virReportSystemError(errno,
+                                     _("failed to open chardev file: %s"),
+                                     def->data.file.path);
+                return NULL;
+            }
+            if (virAsprintf(&ret, "%s%d=null,fd:%d", dev, def->target.port, fd_out) < 0) {
+                virReportOOMError();
+                close(fd_out);
+                return NULL;
+            }
+            FD_SET(fd_out, keepfd);
+        }
+        break;
+   case VIR_DOMAIN_CHR_TYPE_PIPE:
+        /* XXX could open the pipe & just pass the FDs */
 
     case VIR_DOMAIN_CHR_TYPE_VC:
     case VIR_DOMAIN_CHR_TYPE_UDP:
@@ -393,6 +412,7 @@ static char *umlNextArg(char *args)
 int umlBuildCommandLine(virConnectPtr conn,
                         struct uml_driver *driver ATTRIBUTE_UNUSED,
                         virDomainObjPtr vm,
+                        fd_set *keepfd,
                         const char ***retargv,
                         const char ***retenv)
 {
@@ -515,7 +535,7 @@ int umlBuildCommandLine(virConnectPtr conn,
     for (i = 0 ; i < UML_MAX_CHAR_DEVICE ; i++) {
         char *ret;
         if (i == 0 && vm->def->console)
-            ret = umlBuildCommandLineChr(vm->def->console, "con");
+            ret = umlBuildCommandLineChr(vm->def->console, "con", keepfd);
         else
             if (virAsprintf(&ret, "con%d=none", i) < 0)
                 goto no_memory;
@@ -529,7 +549,7 @@ int umlBuildCommandLine(virConnectPtr conn,
             if (vm->def->serials[j]->target.port == i)
                 chr = vm->def->serials[j];
         if (chr)
-            ret = umlBuildCommandLineChr(chr, "ssl");
+            ret = umlBuildCommandLineChr(chr, "ssl", keepfd);
         else
             if (virAsprintf(&ret, "ssl%d=none", i) < 0)
                 goto no_memory;
diff --git a/src/uml/uml_conf.h b/src/uml/uml_conf.h
index b33acc8..d8b2349 100644
--- a/src/uml/uml_conf.h
+++ b/src/uml/uml_conf.h
@@ -71,6 +71,7 @@ virCapsPtr  umlCapsInit               (void);
 int         umlBuildCommandLine       (virConnectPtr conn,
                                        struct uml_driver *driver,
                                        virDomainObjPtr dom,
+                                       fd_set *keepfd,
                                        const char ***retargv,
                                        const char ***retenv);
 
diff --git a/src/uml/uml_driver.c b/src/uml/uml_driver.c
index 04493ba..5f73ce2 100644
--- a/src/uml/uml_driver.c
+++ b/src/uml/uml_driver.c
@@ -737,10 +737,6 @@ static int umlMonitorCommand(const struct uml_driver *driver,
             virReportSystemError(errno, _("cannot read reply %s"), cmd);
             goto error;
         }
-        if (nbytes < sizeof res) {
-            virReportSystemError(0, _("incomplete reply %s"), cmd);
-            goto error;
-        }
         if (sizeof res.data < res.length) {
             virReportSystemError(0, _("invalid length in reply %s"), cmd);
             goto error;
@@ -871,7 +867,7 @@ static int umlStartVMDaemon(virConnectPtr conn,
         return -1;
     }
 
-    if (umlBuildCommandLine(conn, driver, vm,
+    if (umlBuildCommandLine(conn, driver, vm, &keepfd,
                             &argv, &progenv) < 0) {
         close(logfd);
         umlCleanupTapDevices(conn, vm);
-- 
1.7.0.4