On Mi, 2015-07-01 at 10:08 +0200, Michael S. Tsirkin wrote: > On Tue, Jun 30, 2015 at 10:38:53AM +0200, Gerd Hoffmann wrote: > > virtio version 1.0 registers can (and actually do in the qemu > > implementation) live in mmio space. So we must run the blk and > > scsi virtio drivers in 32bit mode, otherwise we can't access them. > > > > This also allows to drop a bunch of GET_LOWFLAT calls from the virtio > > code in the following patches. > > > > Signed-off-by: Gerd Hoffmann <kra...@redhat.com> > > Is there an advantage to running them in a 16 bit mode?
Not really any more. Switching from 32bit mode back to whatever-was-active-before used to be problematic before we had smm mode support. In theory. Because you can't save/restore the complete x86 processor state. In practice we had surprisingly few problems, appearently linux boot loaders simply don't play dirty tricks. cheers, Gerd
