Re: [Qemu-devel] [PATCH V6 3/5] docs: add pvrdma device documentation.

[Marcel Apfelbaum]

On 09/01/2018 11:17, Cornelia Huck wrote:
> On Sun,  7 Jan 2018 14:32:22 +0200
> Marcel Apfelbaum <address@hidden> wrote:
>
> > Signed-off-by: Marcel Apfelbaum <address@hidden>
> > Signed-off-by: Yuval Shaia <address@hidden>
> > Reviewed-by: Shamir Rabinovitch <address@hidden>
> > ---
> >   docs/pvrdma.txt | 254 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >   1 file changed, 254 insertions(+)
> >   create mode 100644 docs/pvrdma.txt
>
> > +5. Limitations
> > +==============
> > +- The device obviously is limited by the Guest Linux Driver features 
> > implementation
> > +  of the VMware device API.
> > +- Memory registration mechanism requires mremap for every page in the buffer 
> > in order
> > +  to map it to a contiguous virtual address range. Since this is not the data 
> > path
> > +  it should not matter much.
> > +- The device requires target page size to be the same as the host page size.
> > +- QEMU cannot map guest RAM from a file descriptor if a pvrdma device is 
> > attached,
> > +  so it can't work with huge pages. The limitation will be addressed in the 
> > future,
> > +  however QEMU allocates Gust RAM with MADV_HUGEPAGE so if there are enough 
> > huge
>
> s/Gust/Guest/

Fixed (for V7)

Thanks!
Marcel

> > +  pages available, QEMU will use them.
> > +- As previously stated, migration is not supported yet, however with some 
> > hardware
> > +  support can be done.