From 86d2fda1a16bc6d2566acfb6a566e13d704fd25a Mon Sep 17 00:00:00 2001

Message-Id: <86d2fda1a16bc6d2566acfb6a566e13d704fd25a@dist-git>

From: Laine Stump <laine@redhat.com>

Date: Mon, 20 Feb 2023 18:26:51 -0500

Subject: [PATCH] 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)

Resolves: https://bugzilla.redhat.com/2172098

Signed-off-by: Laine Stump <laine@redhat.com>

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

(cherry picked from commit acd8333f763f1e45728fac4e727fef4e33141ebf)

Signed-off-by: Laine Stump <laine@redhat.com>

---

 src/qemu/qemu_passt.c                         | 11 ++++++

 .../net-user-passt.x86_64-7.2.0.args          | 37 +++++++++++++++++++

 .../net-user-passt.x86_64-latest.args         |  2 +-

 tests/qemuxml2argvtest.c                      |  1 +

 4 files changed, 50 insertions(+), 1 deletion(-)

 create mode 100644 tests/qemuxml2argvdata/net-user-passt.x86_64-7.2.0.args

diff --git a/src/qemu/qemu_passt.c b/src/qemu/qemu_passt.c

index 88b7df4453..8d28a55455 100644

--- 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

index 0000000000..037dabb87d

--- /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 48e3e8ca8b..f84bec2ec1 100644

--- 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 8c52feb83c..e23b32e96a 100644

--- 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");

-- 

2.39.2