Messages in this thread | | | Subject | Re: [PATCH] virtio_console: remove vq buf while unpluging port | From | Amit Shah <> | Date | Tue, 28 May 2019 14:59:46 +0200 |
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On Fri, 2019-05-24 at 20:51 +0200, Greg KH wrote: > On Sun, Apr 28, 2019 at 09:50:04AM +0800, zhenwei pi wrote: > > A bug can be easily reproduced: > > Host# cat guest-agent.xml > > <channel type="unix"> > > <source mode="bind" path="/var/lib/libvirt/qemu/stretch.agent"/> > > <target type="virtio" name="org.qemu.guest_agent.0" > > state="connected"/> > > </channel> > > Host# virsh attach-device instance guest-agent.xml > > Host# virsh detach-device instance guest-agent.xml > > Host# virsh attach-device instance guest-agent.xml > > > > and guest report: virtio-ports vport0p1: Error allocating inbufs > > > > The reason is that the port is unplugged and the vq buf still > > remained. > > So, fix two cases in this patch: > > 1, fix memory leak with attach-device/detach-device. > > 2, fix logic bug with attach-device/detach-device/attach-device.
The "leak" happens because the host-side of the connection is still connected. This is by design -- if a guest has written data before being unplugged, the port isn't released till the host connection goes down to ensure a host process reads all the data out of the port.
Can you try similar, but also disconnecting the host side and see if that fixes things?
> Amit, any ideas if this is valid or not and if this should be > applied?
This had indeed been missed, thanks!
Amit
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