On 2/7/23 17:38, Ming Lei wrote:
Here I meant we can export physical address of request sg from /dev/ublkb* to userspace, which can program the DMA controller using exported physical address. With this way, the userspace driver can submit IO without entering kernel, then with high performance.
Hmm ... security experts might be very unhappy about allowing user space software to program iova addresses, PASIDs etc. in DMA controllers without having this data verified by the kernel. Additionally, hardware designers every now and then propose new device multiplexing mechanisms, e.g. scalable IOV which is an alternative for SRIOV. Shouldn't we make the kernel deal with these mechanisms instead of user space?
Thanks, Bart.
