RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.

Description of problem:

With any qemu version containing commit [83d768b5640946b7da55ce8335509df297e2c7cd] virtio: set ISR on dataplane
notifications, the guest vNIC does not get any IP. Interrupts look broken. This is linked to the usage of vhost=on. A QEMU command line without the vhost option works fine.

Shannon's patch fixes the issue:
[Qemu-devel] [PATCH] virtio: Fix no interrupt when not creating msi
controller
https://patchwork.kernel.org/patch/9527215/

Version-Release number of selected component (if applicable):
any qemu including 83d768b  virtio: set ISR on dataplane notifications 

How reproducible:
100% on Mustang or Cavium ThunderX. 

Steps to Reproduce:
Launch the guest with virtio-net-device (virtio-mmio). Pay attention the default now is virtio-pci using libvirt 3.0.0

Actual results:
vNIC does not get an IP address when guest started in dhcp mode

Expected results:
vNIC gets an IP address

Fix in 2.9 (commit b4b9862b536f41fcdf6ad193a306a852c5b5b71a)