From 0452067d1acfab89dff5bebbae9791317dfc6f83 Mon Sep 17 00:00:00 2001 From: Alexander Egorenkov Date: Tue, 1 Jul 2025 08:22:44 +0200 Subject: vm/qemu: use virtio-net-ccw as virtual netdev on s390x arch virtio-net-ccw is a preferred way to set up a virtual network interface on s390x at the moment because it is faster than virtio-net-pci (eventfd and irqfd is missing). This also allows disabling of zPCI in QEMU which was required only because virtio-net-pci was used as a network interface. PCI is special on s390x and, for instance, does not use MMIO or expose topology [1,2,3]. Furthermore, any features like PXE are not supported with virtio-net-pci on s390x. [1] https://people.redhat.com/~cohuck/2018/02/19/notes-on-pci-on-s390x.html [2] https://wiki.qemu.org/Documentation/Platforms/S390X#A_note_on_PCI_support [3] https://www.qemu.org/docs/master/system/s390x/pcidevices.html Signed-off-by: Alexander Egorenkov --- vm/qemu/qemu.go | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/vm/qemu/qemu.go b/vm/qemu/qemu.go index 3fb78e9fb..ba1ecf979 100644 --- a/vm/qemu/qemu.go +++ b/vm/qemu/qemu.go @@ -201,8 +201,8 @@ var archConfigs = map[string]*archConfig{ }, "linux/s390x": { Qemu: "qemu-system-s390x", - QemuArgs: "-M s390-ccw-virtio -cpu max,zpci=on", - NetDev: "virtio-net-pci", + QemuArgs: "-M s390-ccw-virtio -cpu max", + NetDev: "virtio-net-ccw", RngDev: "virtio-rng-ccw", CmdLine: []string{ "root=/dev/vda", -- cgit mrf-deployment