qemu: add reconnect=5 to passt qemu commandline options when available

QEMU's "reconnect" option of "-netdev stream" tells QEMU to
periodically (period is given in seconds as an argument to the option)
attempt to reconnect to the same passt socket to which it had
originally connected to. This is useful in cases where the passt
process terminates, and libvirtd starts a new passt process in its
place (which doesn't happen yet, but will happen automatically after
an upcoming patch in this series).

Since there is no real hueristic for determining the "best" value of
the reconnect interval, rather than clutter up config with a knob that
nobody knows how to properly twiddle, we just set the reconnect timer
to 5 seconds.

"-netdev stream" first appeared in QEMU 7.2.0, but the reconnect
option won't be available until QEMU 8.0.0, so we need to check QEMU
capabilities just in case someone is using QEMU 7.2.0 (and thus can
support passt backend, but not reconnect)

Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

diff --git a/src/qemu/qemu_passt.c b/src/qemu/qemu_passt.c
index 88b7df445312f83b0c14fb302f1ac05f5c65a2dc..8d28a554551fa0c798279a02bd8f1f08194dd49e 100644 (file)
--- a/src/qemu/qemu_passt.c
+++ b/src/qemu/qemu_passt.c
@@ -83,6 +83,8 @@ qemuPasstAddNetProps(virDomainObj *vm,
 {
     g_autofree char *passtSocketName = qemuPasstCreateSocketPath(vm, net);
     g_autoptr(virJSONValue) addrprops = NULL;
+    qemuDomainObjPrivate *priv = vm->privateData;
+    virQEMUCaps *qemuCaps = priv->qemuCaps;
 
     if (virJSONValueObjectAdd(&addrprops,
                               "s:type", "unix",
@@ -98,6 +100,15 @@ qemuPasstAddNetProps(virDomainObj *vm,
                               NULL) < 0) {
         return -1;
     }
+
+    /* a narrow range of QEMU releases support -netdev stream, but
+     * don't support its "reconnect" option
+     */
+    if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_NETDEV_STREAM_RECONNECT) &&
+        virJSONValueObjectAdd(netprops, "u:reconnect", 5, NULL) < 0) {
+        return -1;
+    }
+
     return 0;
 }
 

diff --git a/tests/qemuxml2argvdata/net-user-passt.x86_64-7.2.0.args b/tests/qemuxml2argvdata/net-user-passt.x86_64-7.2.0.args
new file mode 100644 (file)
index 0000000..037dabb
--- /dev/null
+++ b/tests/qemuxml2argvdata/net-user-passt.x86_64-7.2.0.args
@@ -0,0 +1,37 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/tmp/lib/domain--1-QEMUGuest1 \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/tmp/lib/domain--1-QEMUGuest1/.local/share \
+XDG_CACHE_HOME=/tmp/lib/domain--1-QEMUGuest1/.cache \
+XDG_CONFIG_HOME=/tmp/lib/domain--1-QEMUGuest1/.config \
+/usr/bin/qemu-system-x86_64 \
+-name guest=QEMUGuest1,debug-threads=on \
+-S \
+-object '{"qom-type":"secret","id":"masterKey0","format":"raw","file":"/tmp/lib/domain--1-QEMUGuest1/master-key.aes"}' \
+-machine pc-i440fx-7.2,usb=off,dump-guest-core=off,memory-backend=pc.ram \
+-accel tcg \
+-cpu qemu64 \
+-m 214 \
+-object '{"qom-type":"memory-backend-ram","id":"pc.ram","size":224395264}' \
+-overcommit mem-lock=off \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-display none \
+-no-user-config \
+-nodefaults \
+-chardev socket,id=charmonitor,fd=1729,server=on,wait=off \
+-mon chardev=charmonitor,id=monitor,mode=control \
+-rtc base=utc \
+-no-shutdown \
+-no-acpi \
+-boot strict=on \
+-blockdev '{"driver":"host_device","filename":"/dev/HostVG/QEMUGuest1","node-name":"libvirt-1-storage","auto-read-only":true,"discard":"unmap"}' \
+-blockdev '{"node-name":"libvirt-1-format","read-only":false,"driver":"raw","file":"libvirt-1-storage"}' \
+-device '{"driver":"ide-hd","bus":"ide.0","unit":0,"drive":"libvirt-1-format","id":"ide0-0-0","bootindex":1}' \
+-netdev '{"type":"stream","addr":{"type":"unix","path":"/bad-test-used-env-xdg-runtime-dir/libvirt/qemu/run/passt/-1-QEMUGuest1-net0.socket"},"server":false,"id":"hostnet0"}' \
+-device '{"driver":"rtl8139","netdev":"hostnet0","id":"net0","mac":"00:11:22:33:44:55","bus":"pci.0","addr":"0x2"}' \
+-audiodev '{"id":"audio1","driver":"none"}' \
+-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
+-msg timestamp=on

diff --git a/tests/qemuxml2argvdata/net-user-passt.x86_64-latest.args b/tests/qemuxml2argvdata/net-user-passt.x86_64-latest.args
index 48e3e8ca8b1390f7b39c7cb401ebceff85d8fa9b..f84bec2ec1d9f1ed275fe6685f1881fe94e40e62 100644 (file)
--- a/tests/qemuxml2argvdata/net-user-passt.x86_64-latest.args
+++ b/tests/qemuxml2argvdata/net-user-passt.x86_64-latest.args
@@ -30,7 +30,7 @@ XDG_CONFIG_HOME=/tmp/lib/domain--1-QEMUGuest1/.config \
 -blockdev '{"driver":"host_device","filename":"/dev/HostVG/QEMUGuest1","node-name":"libvirt-1-storage","auto-read-only":true,"discard":"unmap"}' \
 -blockdev '{"node-name":"libvirt-1-format","read-only":false,"driver":"raw","file":"libvirt-1-storage"}' \
 -device '{"driver":"ide-hd","bus":"ide.0","unit":0,"drive":"libvirt-1-format","id":"ide0-0-0","bootindex":1}' \
--netdev '{"type":"stream","addr":{"type":"unix","path":"/bad-test-used-env-xdg-runtime-dir/libvirt/qemu/run/passt/-1-QEMUGuest1-net0.socket"},"server":false,"id":"hostnet0"}' \
+-netdev '{"type":"stream","addr":{"type":"unix","path":"/bad-test-used-env-xdg-runtime-dir/libvirt/qemu/run/passt/-1-QEMUGuest1-net0.socket"},"server":false,"reconnect":5,"id":"hostnet0"}' \
 -device '{"driver":"rtl8139","netdev":"hostnet0","id":"net0","mac":"00:11:22:33:44:55","bus":"pci.0","addr":"0x2"}' \
 -audiodev '{"id":"audio1","driver":"none"}' \
 -sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \

diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index b897814a5d4a4f4eb3886f0b2789654cb3c0e86f..5a33c336c8558d9039a93400949d5dfd7e84ed3e 100644 (file)
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -1471,6 +1471,7 @@ mymain(void)
     DO_TEST_CAPS_ARCH_LATEST_FULL("net-user", "x86_64", ARG_FLAGS, FLAG_SLIRP_HELPER);
     DO_TEST_NOCAPS("net-user-addr");
     DO_TEST_CAPS_LATEST("net-user-passt");
+    DO_TEST_CAPS_VER("net-user-passt", "7.2.0");
     DO_TEST_NOCAPS("net-virtio");
     DO_TEST_NOCAPS("net-virtio-device");
     DO_TEST_NOCAPS("net-virtio-disable-offloads");