From 0165d714e9150595c6bceb0d538018d486d7c519 Mon Sep 17 00:00:00 2001
From: "Daniel P. Berrange" <berrange@redhat.com>
Date: Mon, 5 Feb 2018 11:10:04 +0100
Subject: [PATCH 10/20] ui: correctly reset framebuffer update state after
processing dirty regions
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RH-Author: Daniel P. Berrange <berrange@redhat.com>
Message-id: <20180205111012.6210-10-berrange@redhat.com>
Patchwork-id: 78885
O-Subject: [RHV-7.5 qemu-kvm-rhev PATCH v2 09/17] ui: correctly reset framebuffer update state after processing dirty regions
Bugzilla: 1527404
RH-Acked-by: Gerd Hoffmann <kraxel@redhat.com>
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
RH-Acked-by: Thomas Huth <thuth@redhat.com>
From: "Daniel P. Berrange" <berrange@redhat.com>
According to the RFB protocol, a client sends one or more framebuffer update
requests to the server. The server can reply with a single framebuffer update
response, that covers all previously received requests. Once the client has
read this update from the server, it may send further framebuffer update
requests to monitor future changes. The client is free to delay sending the
framebuffer update request if it needs to throttle the amount of data it is
reading from the server.
The QEMU VNC server, however, has never correctly handled the framebuffer
update requests. Once QEMU has received an update request, it will continue to
send client updates forever, even if the client hasn't asked for further
updates. This prevents the client from throttling back data it gets from the
server. This change fixes the flawed logic such that after a set of updates are
sent out, QEMU waits for a further update request before sending more data.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20171218191228.31018-8-berrange@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
(cherry picked from commit 728a7ac95484a7ba5e624ccbac4c1326571576b0)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
ui/vnc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/ui/vnc.c b/ui/vnc.c
index 2320421..3707b87 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -1031,7 +1031,7 @@ static int vnc_update_client(VncState *vs, int has_dirty)
}
vnc_job_push(job);
- vs->update = VNC_STATE_UPDATE_INCREMENTAL;
+ vs->update = VNC_STATE_UPDATE_NONE;
vs->has_dirty = 0;
return n;
}
--
1.8.3.1