qemu: fix multiple missing setup/teardown of passt process for interface type='vhostuser'

passt networking support was originally added only for <interface
type='user'>, and all of the codepaths leading to qemuPasst*()
functions were protected with

   if (net->type == VIR_DOMAIN_NET_TYPE_USER &&
       net->backend.type == VIR_DOMAIN_NET_BACKEND_PASST)

When support was later added to use a vhost-user socket to connect
between the passt process and qemu process, *some* of the conditionals
similar to the above were changed to be

   if ((net->type == VIR_DOMAIN_NET_TYPE_USER ||
        net->type == VIR_DOMAIN_NET_TYPE_VHOSTUSER) &&
       net->backend.type == VIR_DOMAIN_NET_BACKEND_PASST)

As a matter of fact, enough of these places were changed to make
passt+vhostuser work. However I missed a few places that resulted in
the passt process not being properly shutdown/cleaned up when the
interface type was vhostuser, and also as far as I can see from
examining the code, the passt process wasn't being added to the cgroup
for the domain.

We could fix these problems by adding the extra condition to all the
missing places (checking for either 'user' or 'vhostuser' as well as
for backend type of 'passt'), but since validation already guarantees
that if backend type='passt' then the interface type MUST be either
'user' or 'vhostuser', it's really just adding extra code for no good
purpose (and would leave open the possibility of the same problem
recurring in the future if a different interface type begins using
passt as well). So the better solution is to not bother checking
net->type at all in those locations - if backend type is 'passt' then
we call the passt-related code.

Resolves: https://issues.redhat.com/browse/RHEL-80285
Resolves: https://issues.redhat.com/browse/RHEL-92842
Fixes: 1e9054b9c79d721a55f413c2983c5370044f8f60
Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>

diff --git a/src/qemu/qemu_extdevice.c b/src/qemu/qemu_extdevice.c
index 8df93a77ceb532b947a7981b418cbd382f2bde47..28cea52980577d3ce980d46b2e29456716993458 100644 (file)
--- a/src/qemu/qemu_extdevice.c
+++ b/src/qemu/qemu_extdevice.c
@@ -213,11 +213,6 @@ qemuExtDevicesStart(virQEMUDriver *driver,
     for (i = 0; i < def->nnets; i++) {
         virDomainNetDef *net = def->nets[i];
 
-        if (net->type != VIR_DOMAIN_NET_TYPE_USER &&
-            net->type != VIR_DOMAIN_NET_TYPE_VHOSTUSER) {
-            continue;
-        }
-
         if (net->backend.type == VIR_DOMAIN_NET_BACKEND_PASST) {
             if (qemuPasstStart(vm, net) < 0)
                 return -1;
@@ -310,10 +305,8 @@ qemuExtDevicesStop(virQEMUDriver *driver,
         if (slirp)
             qemuSlirpStop(slirp, vm, driver, net);
 
-        if (net->type == VIR_DOMAIN_NET_TYPE_USER &&
-            net->backend.type == VIR_DOMAIN_NET_BACKEND_PASST) {
+        if (net->backend.type == VIR_DOMAIN_NET_BACKEND_PASST)
             qemuPasstStop(vm, net);
-        }
 
         if (actualType == VIR_DOMAIN_NET_TYPE_ETHERNET && net->downscript)
             virNetDevRunEthernetScript(net->ifname, net->downscript);
@@ -373,8 +366,7 @@ qemuExtDevicesHasDevice(virDomainDef *def)
         if (QEMU_DOMAIN_NETWORK_PRIVATE(net)->slirp)
             return true;
 
-        if (net->type == VIR_DOMAIN_NET_TYPE_USER &&
-            net->backend.type == VIR_DOMAIN_NET_BACKEND_PASST)
+        if (net->backend.type == VIR_DOMAIN_NET_BACKEND_PASST)
             return true;
     }
 
@@ -455,8 +447,7 @@ qemuExtDevicesSetupCgroup(virQEMUDriver *driver,
         if (slirp && qemuSlirpSetupCgroup(slirp, cgroup) < 0)
             return -1;
 
-        if (net->type == VIR_DOMAIN_NET_TYPE_USER &&
-            net->backend.type == VIR_DOMAIN_NET_BACKEND_PASST &&
+        if (net->backend.type == VIR_DOMAIN_NET_BACKEND_PASST &&
             qemuPasstSetupCgroup(vm, net, cgroup) < 0) {
             return -1;
         }

diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index afc75072aedc8f9addf9777392515b6fbc649bfb..fb426deb1a2244de6655609bc349f0197ee9f6de 100644 (file)
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -1298,8 +1298,6 @@ qemuDomainAttachNetDevice(virQEMUDriver *driver,
 
             qemuPasstPrepareVhostUser(vm, net);
 
-            if (qemuPasstStart(vm, net) < 0)
-                goto cleanup;
         } else {
             if (virNetDevOpenvswitchGetVhostuserIfname(net->data.vhostuser->data.nix.path,
                                                        net->data.vhostuser->data.nix.listen,
@@ -1313,13 +1311,8 @@ qemuDomainAttachNetDevice(virQEMUDriver *driver,
         break;
 
     case VIR_DOMAIN_NET_TYPE_USER:
-        if (net->backend.type == VIR_DOMAIN_NET_BACKEND_PASST) {
-
-            if (qemuPasstStart(vm, net) < 0)
-                goto cleanup;
-
-        } else if (!priv->disableSlirp &&
-                   virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_DBUS_VMSTATE)) {
+        if (!priv->disableSlirp &&
+            virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_DBUS_VMSTATE)) {
 
             if (qemuInterfacePrepareSlirp(driver, net) < 0)
                 goto cleanup;
@@ -1356,6 +1349,12 @@ qemuDomainAttachNetDevice(virQEMUDriver *driver,
         goto cleanup;
     }
 
+    /* both NET_TYPE_USER and NET_TYPE_VHOSTUSER might use passt */
+    if (net->backend.type == VIR_DOMAIN_NET_BACKEND_PASST &&
+        qemuPasstStart(vm, net) < 0) {
+        goto cleanup;
+    }
+
     /* Set device online immediately */
     if (virDomainInterfaceStartDevice(net) < 0)
         goto cleanup;
@@ -1539,10 +1538,8 @@ qemuDomainAttachNetDevice(virQEMUDriver *driver,
     if (QEMU_DOMAIN_NETWORK_PRIVATE(net)->slirp)
         qemuSlirpStop(QEMU_DOMAIN_NETWORK_PRIVATE(net)->slirp, vm, driver, net);
 
-    if (net->type == VIR_DOMAIN_NET_TYPE_USER &&
-        net->backend.type == VIR_DOMAIN_NET_BACKEND_PASST) {
+    if (net->backend.type == VIR_DOMAIN_NET_BACKEND_PASST)
         qemuPasstStop(vm, net);
-    }
 
     qemuDomainObjEnterMonitor(vm);
     if (charDevPlugged &&
@@ -5112,10 +5109,8 @@ qemuDomainRemoveNetDevice(virQEMUDriver *driver,
     if (QEMU_DOMAIN_NETWORK_PRIVATE(net)->slirp)
         qemuSlirpStop(QEMU_DOMAIN_NETWORK_PRIVATE(net)->slirp, vm, driver, net);
 
-    if (net->type == VIR_DOMAIN_NET_TYPE_USER &&
-        net->backend.type == VIR_DOMAIN_NET_BACKEND_PASST) {
+    if (net->backend.type == VIR_DOMAIN_NET_BACKEND_PASST)
         qemuPasstStop(vm, net);
-    }
 
     virDomainAuditNet(vm, net, NULL, "detach", true);