Bug 1285697

The current RHEL 7.3 used libvirtd version 2.0.0 and QEMU version 2.6, below are proposed patches that adds 'nowait' functionality:

QEMU:
diff --git a/net/vhost-user.c b/net/vhost-user.c
index 1b9e73a..aaa223e 100644
--- a/net/vhost-user.c
+++ b/net/vhost-user.c
@@ -239,6 +239,7 @@ static int net_vhost_chardev_opts(void *opaque,
     } else if (strcmp(name, "path") == 0) {
         props->is_unix = true;
     } else if (strcmp(name, "server") == 0) {
+    } else if (strcmp(name, "wait") == 0) {
     } else {
         error_setg(errp,
                    "vhost-user does not support a chardev with option %s=%s",

LIBVIRT:
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 7eb6c0a..7708c90 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -7668,7 +7668,7 @@ qemuBuildVhostuserCommandLine(virCommandPtr cmd,
     case VIR_DOMAIN_CHR_TYPE_UNIX:
         virBufferAsprintf(&chardev_buf, "socket,id=char%s,path=%s%s",
                           net->info.alias, net->data.vhostuser->data.nix.path,
-                          net->data.vhostuser->data.nix.listen ? ",server" : "");
+                          net->data.vhostuser->data.nix.listen ? ",server,nowait" : "");
         break;

     case VIR_DOMAIN_CHR_TYPE_NULL:
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-net-vhostuser-multiq.args b/tests/qemuxml2argvdata/qemuxml2argv-net-vhostuser-multiq.args
index 3229034..f65ead8 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-net-vhostuser-multiq.args
+++ b/tests/qemuxml2argvdata/qemuxml2argv-net-vhostuser-multiq.args
@@ -19,7 +19,7 @@ QEMU_AUDIO_DRV=none \
 -usb \
 -drive file=/dev/HostVG/QEMUGuest1,format=raw,if=none,id=drive-ide0-0-0 \
 -device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 \
--chardev socket,id=charnet0,path=/tmp/vhost0.sock,server \
+-chardev socket,id=charnet0,path=/tmp/vhost0.sock,server,nowait \
 -netdev type=vhost-user,id=hostnet0,chardev=charnet0 \
 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:ee:96:6b,bus=pci.0,\
 addr=0x3 \
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-net-vhostuser.args b/tests/qemuxml2argvdata/qemuxml2argv-net-vhostuser.args
index a9989b8..df334b1 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-net-vhostuser.args
+++ b/tests/qemuxml2argvdata/qemuxml2argv-net-vhostuser.args
@@ -19,7 +19,7 @@ QEMU_AUDIO_DRV=none \
 -usb \
 -drive file=/dev/HostVG/QEMUGuest1,format=raw,if=none,id=drive-ide0-0-0 \
 -device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 \
--chardev socket,id=charnet0,path=/tmp/vhost0.sock,server \
+-chardev socket,id=charnet0,path=/tmp/vhost0.sock,server,nowait \
 -netdev type=vhost-user,id=hostnet0,chardev=charnet0 \
 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:ee:96:6b,bus=pci.0,\
 addr=0x3 \

LIBVIRT fix is relevant for all, but QEMU is specific for 2.6, 'master' branch of QEMU drops chardev parameters validation in the way it is done in 2.6, so QEMU master doesn't need a fix

Should I open a new bug for libvirt fix?

Hi Peter,

So what do you say is, passing "nowait" as the socket param solves the bug, and the only problem from the QEMU point of view is the ned to validate "nowait" as a legal parameter. Right?

If so, it is still not clear to me why you propose to check in net/vhost-user.c
+    } else if (strcmp(name, "wait") == 0) {
for "wait" instead of "nowait"...


-- 
Victor

Hi Victor,
After our phone conversation,
I can confirm that I did test vhost-user socket connected at a much later time.
The interface is set up correctly and packets do pass.