Re: [PATCH v2 1/4] exec/memattrs: Add iopmp source id, start address, end address to MemTxAttrs

[Ethan Chen via <qemu-riscv@nongnu.org>]

On Tue, Nov 07, 2023 at 10:53:40AM +0000, Peter Maydell wrote:
> On Tue, 7 Nov 2023 at 03:02, Ethan Chen <ethan84@andestech.com> wrote:
> >
> > On Mon, Nov 06, 2023 at 10:34:41AM +0000, Peter Maydell wrote:
> > > What AXI bus signals? You already get address and size in the
> > > actual memory transaction, they don't need to go in the MemTxAttrs.
> > >
> >
> > A burst contains multiple continuous read or write operations. In current
> > transaction, I can only get the size and address of a single operation. IOPMP
> > checks not only a single operation but also the burst information. I propose
> > to add those signals to MemTxAttrs.
> 
> QEMU doesn't emulate bus transactions at that level -- we have
> no concept of burst transactions. You should have the IOMMU
> do whatever it would do for a series of simple transactions.
>

I propose to use another method like StreamSink in hw/dma/xilinx_axidma.c to
let DMA send the signals to IOPMP instead of modifying IOMMU.

Thanks,
Ethan Chen