7.86 (X86 Only) SWIOTLB Buffer Errors When Using Jumbo Frames on Oracle VM Server

When a network port has been configured for jumbo frames on an Oracle VM Server, errors may appear in the logs of the Oracle VM Server indicating that the SWIOTLB buffer is full. The SWIOTLB is a software component used by the Xen hypervisor. By default, 128 chunks of 512 KB of memory are allocated to SWIOTLB. On an active Oracle VM Server with jumbo frames enabled, these chunks of memory can be used up quickly, degrading network performance and resulting in errors in the system log.

Workaround: Change the Oracle VM Server grub configuration to append the swiotlb=131072 option to the kernel line.

Bug 20693762