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From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
To: Miklos Szeredi <miklos@szeredi.hu>
Cc: Stefan Hajnoczi <stefanha@redhat.com>,
	Vivek Goyal <vgoyal@redhat.com>,
	virtualization@lists.linux-foundation.org
Subject: Re: virtq questions
Date: Wed, 2 Oct 2019 15:52:51 +0100	[thread overview]
Message-ID: <20191002145251.GD2710@work-vm> (raw)
In-Reply-To: <CAJfpegsGNoT4NUai-=HHkqOrmjgMb=4TDk79EgxDBCd8fxCGZA@mail.gmail.com>

* Miklos Szeredi (miklos@szeredi.hu) wrote:
> Looking at the ugly retry logic in virtiofs and have some questions.
> First one is, where do these features come from:
> 
> VIRTIO_F_RING_PACKED
> VIRTIO_RING_F_INDIRECT_DESC
> 
> I see that in virtiofs "packed" is off and "indirect" is on.  Is this
> guaranteed?

I think the xdindirect is coming from qemu's hw/virtio/virtio.h DEFINE_VIRTIO_COMMON_FEATURES
which has:
    DEFINE_PROP_BIT64("indirect_desc", _state, _field,    \
                      VIRTIO_RING_F_INDIRECT_DESC, true), \

Dave

> Thanks,
> Miklos
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

      parent reply	other threads:[~2019-10-02 14:52 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CAJfpegsGNoT4NUai-=HHkqOrmjgMb=4TDk79EgxDBCd8fxCGZA@mail.gmail.com>
2019-10-02 13:27 ` virtq questions Vivek Goyal
     [not found]   ` <CAJfpegvJGTFiJh5MFRNQF8dQQo7KS5f0Ei7vEYOBTw4RzVtA2w@mail.gmail.com>
2019-10-03 19:45     ` Vivek Goyal
2019-10-02 14:52 ` Dr. David Alan Gilbert [this message]

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