From cd94a5c750554f21ddbff37f53ff629128200259 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Wed, 6 Nov 2024 17:29:35 -0500 Subject: [PATCH 2/3] virtio-net: disable USO for RHEL9 RH-Author: MST RH-MergeRequest: 289: Disable USO for virtio-net to fix RHEL10 to RHEL9 migration RH-Jira: RHEL-40950 RH-Acked-by: Miroslav Rezanina RH-Commit: [1/1] 9fc588b66c5bad72df1e9b644f48a2a7aa82bfa3 (mstredhat/qemu-kvm-centos) Theoretically, QEMU from RHEL9.3 and on supports USO, but practically we clear the support because RHEL9 kernels do not support that. Now that RHEL10 beta does we suddenly get a migration compatibility issue. We should not have enabled the feature in RHEL9 userspace, but luckily, it's not too late to fix that. Note: if we ever change RHEL9 kernel to enable USO, we will need to mask this in RHEL9 QEMU, too. Upstream status: n/a: upstream has no guarantee if kernel features change Tested: lightly on developer's machine. JIRA: https://issues.redhat.com/browse/RHEL-40950 Signed-off-by: Michael S. Tsirkin --- hw/core/machine.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/hw/core/machine.c b/hw/core/machine.c index d95f246f66..04d180eac4 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -337,6 +337,11 @@ GlobalProperty hw_compat_rhel_9_5[] = { { TYPE_VIRTIO_IOMMU_PCI, "aw-bits", "64" }, /* hw_compat_rhel_9_5 from hw_compat_8_2 */ { "virtio-gpu-device", "x-scanout-vmstate-version", "1" }, + /* supported by userspace, but RHEL 9 *kernels* do not support USO. */ + /* TODO: if we ever add 9.6 compat, this has to be there, too */ + { TYPE_VIRTIO_NET, "host_uso", "off"}, + { TYPE_VIRTIO_NET, "guest_uso4", "off"}, + { TYPE_VIRTIO_NET, "guest_uso6", "off"}, }; const size_t hw_compat_rhel_9_5_len = G_N_ELEMENTS(hw_compat_rhel_9_5); -- 2.39.3