I posted a fix that takes care of this in SCSI this morning:
https://marc.info/?l=linux-scsi&m=156378725427719&w=2
I suspect for virtio-blk we should do the same.
> static inline bool dma_addressing_limited(struct device *dev)
> {
> - return min_not_zero(*dev->dma_mask, dev->bus_dma_mask) <
> - dma_get_required_mask(dev);
> + return dev->dma_mask ? min_not_zero(*dev->dma_mask, dev->bus_dma_mask) <
> + dma_get_required_mask(dev) : false;
But to be on the safe side we could still do an early return here,
but it should have a WARN_ON_ONCE.
