From: "Michael S. Tsirkin" <mst@redhat.com>
To: Johannes Berg <johannes@sipsolutions.net>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [RFC] libvhost-user: implement VHOST_USER_PROTOCOL_F_KICK_CALL_MSGS
Date: Mon, 9 Sep 2019 08:41:11 -0400 [thread overview]
Message-ID: <20190909083902-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <8a9cf8a1726afce7fed8992a4f19fc808004ef88.camel@sipsolutions.net>
On Mon, Sep 09, 2019 at 01:35:19PM +0200, Johannes Berg wrote:
> On Sun, 2019-09-08 at 09:13 -0400, Michael S. Tsirkin wrote:
>
> > > I think the only use for this extension would be for simulation
> > > purposes, and even then only combined with the REPLY_ACK and SLAVE_REQ
> > > extensions, i.e. you explicitly *want* your virtual machine to lock up /
> > > wait for a response to the KICK command (and respectively, the device to
> > > wait for a response to the CALL command).
> >
> > OK so when combined with these, it's OK I think.
>
> OK.
>
> > Do we want to force this restriction in code maybe then?
>
> Unlike in this patch, I was planning to not actually advertise
> VHOST_USER_PROTOCOL_F_KICK_CALL_MSGS, and do that only if the user of
> the library wants to advertise it, since devices used for simulation
> also have to be careful about how they use this.
>
> However, if I understand correctly we cannot enforce that all of them
> are used at the same time - we're the device side, so we only advertise
> our features and the master actually sets the ones it wants to use, no?
>
> The only thing we could do is crash if it wants to use this feature
> without the others, but would that really be helpful?
We can return failure from SET_PROTOCOL_FEATURES.
We can also fail all following messages.
> I'm starting to actually get this working, so I'll post new patches in a
> few days or so.
>
> johannes
next prev parent reply other threads:[~2019-09-09 12:42 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-02 12:12 [Qemu-devel] [RFC] vhost-user simulation extension Johannes Berg
2019-09-02 12:12 ` [Qemu-devel] [RFC] docs: vhost-user: add in-band kick/call messages Johannes Berg
2019-09-05 20:28 ` Johannes Berg
2019-09-09 16:00 ` Stefan Hajnoczi
2019-09-09 17:34 ` Johannes Berg
2019-09-10 15:03 ` Stefan Hajnoczi
2019-09-10 15:14 ` Johannes Berg
2019-09-10 15:33 ` Michael S. Tsirkin
2019-09-10 15:34 ` Johannes Berg
2019-09-11 6:56 ` Stefan Hajnoczi
2019-09-11 7:35 ` Stefan Hajnoczi
2019-09-11 8:26 ` Johannes Berg
2019-09-11 15:17 ` Stefan Hajnoczi
2019-09-11 15:31 ` Stefan Hajnoczi
2019-09-11 15:36 ` Johannes Berg
2019-09-11 15:38 ` Johannes Berg
2019-09-12 12:22 ` Stefan Hajnoczi
2019-09-12 20:37 ` Johannes Berg
2019-09-06 12:13 ` [Qemu-devel] [RFC] libvhost-user: implement VHOST_USER_PROTOCOL_F_KICK_CALL_MSGS Johannes Berg
2019-09-06 14:22 ` Michael S. Tsirkin
2019-09-06 14:48 ` Johannes Berg
2019-09-06 15:12 ` Michael S. Tsirkin
2019-09-06 15:32 ` Johannes Berg
2019-09-08 13:13 ` Michael S. Tsirkin
2019-09-09 11:35 ` Johannes Berg
2019-09-09 12:41 ` Michael S. Tsirkin [this message]
2019-09-09 13:05 ` Johannes Berg
2019-09-09 13:48 ` Michael S. Tsirkin
2019-09-09 13:50 ` Johannes Berg
2019-09-09 14:59 ` Michael S. Tsirkin
2019-09-09 15:26 ` Johannes Berg
2019-09-09 15:34 ` Johannes Berg
2019-09-09 15:45 ` Michael S. Tsirkin
2019-09-09 15:47 ` Johannes Berg
2019-09-10 15:52 ` Johannes Berg
2019-09-11 9:16 ` Michael S. Tsirkin
2019-09-11 9:20 ` Johannes Berg
2019-09-11 9:54 ` Michael S. Tsirkin
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