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Date: Wed, 25 Jun 2014 18:29:36 +0300
From: "Michael S. Tsirkin" <mst@redhat.com>
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Subject: Re: [Qemu-devel] vhost-user: broken mem regions
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To: "Damjan Marion (damarion)" <damarion@cisco.com>
Cc: "pbonzini@redhat.com" <pbonzini@redhat.com>, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>, Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>

On Wed, Jun 25, 2014 at 02:57:52PM +0000, Damjan Marion (damarion) wrote:
>=20
> On 25 Jun 2014, at 16:27, Michael S. Tsirkin <mst@redhat.com> wrote:
>=20
> > On Wed, Jun 25, 2014 at 02:20:56PM +0000, Damjan Marion (damarion) wr=
ote:
> >>=20
> >> On 25 Jun 2014, at 16:13, Nikolay Nikolaev <n.nikolaev@virtualopensy=
stems.com> wrote:
> >>=20
> >>>>> - it will require changes on the user side also
> >>>>=20
> >>>> why would it?
> >>>> format seems unchanged, right?
> >>>=20
> >>> yes, but it will happen that multiple regions have same FD so call =
to mmap()
> >>> should look different, I=E2=80=99m still playing with this on user =
side...
> >>> but then you shoudl somehow accumulate the sizes and send just a si=
ngle fd, something along these lines.=20
> >>=20
> >> Yes, so I=E2=80=99m not very happy with that approach and looking if=
 there is better proposal,=20
> >> or at least wider agreement how to address this issue.
> >>=20
> >> Damjan
> >=20
> > still not sure what the issue is ...
> >=20
>=20
> No issue, just additional logic is needed on user side to calculate tot=
al size of shared regions and call mmap() once per FD.
>=20
> Agree?

why not just call it multiple times? AFAIK linux handles this just fine.

> If this is the way to go I will submit patch when I get it tested..
>=20
> Damjan
>=20
>=20