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Date: Mon, 20 Sep 2010 21:21:22 +0200
From: "Michael S. Tsirkin" <mst@redhat.com>
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Subject: [Qemu-devel] Re: [PULL] vhost,e1000 fixes
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To: Blue Swirl <blauwirbel@gmail.com>
Cc: qemu-devel@nongnu.org

On Mon, Sep 20, 2010 at 06:23:55PM +0000, Blue Swirl wrote:
> On Mon, Sep 20, 2010 at 6:08 PM, Michael S. Tsirkin <mst@redhat.com> wr=
ote:
> > This fixes a bug in vhost error handling
> > (also triggers build warning with vhost enabled)
> > and fixes e1000 handling of short frames.
> >
> > Discussion on best ways to fix the e1000 issue
> > is still ongoing but the =A0bug is severe enough
> > for some guests and the fix is safe enough
> > that I feel we should have it fixed ASAP
> > and look for that perfect approach later.
> >
> > Both fixes are 0.13 material IMO.
> >
> > The following changes since commit 952afb719f3c965bae12b5bd5f0f0f7ed0=
251cb8:
> >
> > =A0mingw: use ASLR, no-SEH and DEP if available (2010-09-19 08:36:34 =
+0000)
> >
> > are available in the git repository at:
> > =A0git://git.kernel.org/pub/scm/linux/kernel/git/mst/qemu.git for_ant=
hony
> >
> > Michael S. Tsirkin (1):
> > =A0 =A0 =A0vhost: fix infinite loop on error path
>=20
> I don't think your fix is correct either, it will call the ioctl()
> with file.index =3D=3D -1.

This is my patch:

-    while (--file.index >=3D 0) {
+    while (file.index-- > 0) {
         int r =3D ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file);
         assert(r >=3D 0);
     }

For ioctl to get called with -1, index needs to be 0
before the decrement, and while won't be entered ...
what am I missing?

> How about int i; for (i =3D file.index; i >=3D 0;
> i--) { file.index =3D i;... ?