On Feb 8, 2008 5:01 AM, Christian Borntraeger <borntraeger@xxxxxxxxxx> wrote: > Currently the virtio_ring structure are not declared packed, but they > describe an hardware like interface. We should not allow compilers to make > alignments and optimizations that can be different between the guest and > host compiler. > > I propose to declare all structures that are in shared memory as packed. > > Does anybody see a problem with packed? yes, I see many problems with packed. We went through this discussion already on another hypervisor several years ago. They started out with packed and later dropped it. Packed doesn't really solve any problems -- it just buries them somewhere. The problem for me is that gcc packed is not compatible with the plan 9 C compiler. So, for a truly heterogeneous setup, you are going to have to have code to marshall the structures when transferring between domains, and you are better off not trying to fake it with packed -- it can actually make the marshalling less efficient. Thanks ron _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
