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

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

On Thu, Nov 02, 2023 at 09:49:17AM -0400, Peter Xu wrote:
> On Thu, Nov 02, 2023 at 05:40:12PM +0800, Ethan Chen wrote:
> > Signed-off-by: Ethan Chen <ethan84@andestech.com>
> > ---
> >  include/exec/memattrs.h | 6 ++++++
> >  1 file changed, 6 insertions(+)
> > 
> > diff --git a/include/exec/memattrs.h b/include/exec/memattrs.h
> > index d04170aa27..fc15e5d7d3 100644
> > --- a/include/exec/memattrs.h
> > +++ b/include/exec/memattrs.h
> > @@ -64,6 +64,12 @@ typedef struct MemTxAttrs {
> >      unsigned int target_tlb_bit0 : 1;
> >      unsigned int target_tlb_bit1 : 1;
> >      unsigned int target_tlb_bit2 : 1;
> > +
> > +    /* IOPMP support up to 65535 sources */
> > +    unsigned int iopmp_sid:16;
> 
> There's MemTxAttrs.requester_id, SID for pci, same length.  Reuse it?

OK, I will reuse it.

> 
> > +    /* Transaction infomation for IOPMP */
> > +    unsigned long long iopmp_start_addr;
> > +    unsigned long long iopmp_end_addr;
> 
> PS: encoding addresses into memattrs is.. strange, but since I know nothing
> about iopmp, I'll leave that for other reviewers.

Current IOMMU translate function only have address need to be translate. 
In IOPMP, It needs the transfer start and end address to check this transfer
is valid or not.

> 
> Currently MemTxAttrs are passed as a whole int on the stack, if it keeps
> growing we may start to consider a pointer, but need to check the side
> effects of unexpected fields modified within a call.

It's good for me to use a pointer.

Thanks,
Ethan Chen