qemu: Implement virtio-net rx_queue_size

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

src/qemu/qemu_command.c

@@ -3650,6 +3650,14 @@ qemuBuildNicDevStr(virDomainDefPtr def,
             virBufferAsprintf(&buf, ",mq=on,vectors=%zu", 2 * vhostfdSize + 2);
         }
     }
+    if (usingVirtio && net->driver.virtio.rx_queue_size) {
+        if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_VIRTIO_NET_RX_QUEUE_SIZE)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("virtio rx_queue_size option is not supported with this QEMU binary"));
+            goto error;
+        }
+        virBufferAsprintf(&buf, ",rx_queue_size=%u", net->driver.virtio.rx_queue_size);
+    }
     if (vlan == -1)
         virBufferAsprintf(&buf, ",netdev=host%s", net->info.alias);
     else

tests/qemuxml2argvdata/qemuxml2argv-net-virtio-rxqueuesize.args

@@ -0,0 +1,25 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/home/test \
+USER=test \
+LOGNAME=test \
+QEMU_AUDIO_DRV=none \
+/usr/bin/qemu \
+-name QEMUGuest1 \
+-S \
+-M pc \
+-m 214 \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-nographic \
+-nodefaults \
+-monitor unix:/tmp/lib/domain--1-QEMUGuest1/monitor.sock,server,nowait \
+-no-acpi \
+-boot c \
+-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 \
+-device virtio-net-pci,rx_queue_size=512,vlan=0,id=net0,mac=00:11:22:33:44:55,\
+bus=pci.0,addr=0x3 \
+-net user,vlan=0,name=hostnet0 \
+-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x4

tests/qemuxml2argvtest.c

@@ -1047,6 +1047,8 @@ mymain(void)
             QEMU_CAPS_VIRTIO_S390);
     DO_TEST("net-virtio-ccw",
             QEMU_CAPS_VIRTIO_CCW, QEMU_CAPS_VIRTIO_S390);
+    DO_TEST("net-virtio-rxqueuesize",
+            QEMU_CAPS_VIRTIO_NET_RX_QUEUE_SIZE);
     DO_TEST_PARSE_ERROR("net-virtio-rxqueuesize-invalid-size", NONE);
     DO_TEST("net-eth", NONE);
     DO_TEST("net-eth-ifname", NONE);