[vbox-dev] Question regarding USB support under VirtualBOX
Hans Petter Selasky
hselasky at c2i.net
Wed Jan 26 09:00:38 PST 2011
On Wednesday 26 January 2011 17:46:41 Klaus Espenlaub wrote:
> On 23.01.2011 17:36, Hans Petter Selasky wrote:
> > Hi,
> > During usage of VirtualBOX under FreeBSD 8.2, I've noticed that the VM
> > sometimes crashes if the USB string descriptors or other descriptors
> > cannot be read or the device itself cannot be created, because the
> > device is not responding.
> > From what I can understand VirtualBox USB enumeration has two stages:
> > 1) Identifying devices
> > 2) Probing devices
> > There is no guarantee that identified devices won't disappear until they
> > are probed. Should the FreeBSD USB layer in this case return fake status
> > values, to avoid VirtualBOX from asserting.
> This is extremely vague, as it we have many thousand assertions spread
> all over the VirtualBox code.
> Generally it would be helpful to have a VBox.log with the assertion.
> > 3) Reading any USB descriptor could theoretically fail at any time. The
> > USB 1/2 specification specifies the STALL message, and there can be bus
> > errors aswell. Who is responsible for hiding these failures, so that the
> > VirtualBOX machine does not assert()?
> Again - what assertion?
I will try to get VirtualBOX compiled with debug symbols and get you the exact
assertion that it triggers on.
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