Re: [PATCH v4 1/5] vsock/virtio: limit the memory used per-socket

From: Michael S. Tsirkin
Date: Tue Sep 03 2019 - 03:52:32 EST


On Tue, Sep 03, 2019 at 09:45:54AM +0200, Stefano Garzarella wrote:
> On Tue, Sep 03, 2019 at 12:39:19AM -0400, Michael S. Tsirkin wrote:
> > On Mon, Sep 02, 2019 at 11:57:23AM +0200, Stefano Garzarella wrote:
> > > >
> > > > Assuming we miss nothing and buffers < 4K are broken,
> > > > I think we need to add this to the spec, possibly with
> > > > a feature bit to relax the requirement that all buffers
> > > > are at least 4k in size.
> > > >
> > >
> > > Okay, should I send a proposal to virtio-dev@xxxxxxxxxxxxxxxxxxxx?
> >
> > How about we also fix the bug for now?
>
> This series unintentionally fix the bug because we are introducing a way
> to split the packet depending on the buffer size ([PATCH 4/5] vhost/vsock:
> split packets to send using multiple buffers) and we removed the limit
> to 4K buffers ([PATCH 5/5] vsock/virtio: change the maximum packet size
> allowed).
>
> I discovered that there was a bug while we discussed memory accounting.
>
> Do you think it's enough while we introduce the feature bit in the spec?
>
> Thanks,
> Stefano

Well locking is also broken (patch 3/5). It seems that 3/5 and 4/5 work
by themselves, right? So how about we ask Dave to send these to stable?
Also, how about 1/5? Also needed for stable?


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MST