Re: [Qemu-devel] [PULL 19/21] tests: Add unit tests for the VM Generation ID feature

[Ben Warren]

Hi,
> On Jul 13, 2017, at 4:51 AM, Marc-André Lureau <address@hidden> wrote:
> 
> Hi
> 
> On Thu, Jul 13, 2017 at 1:32 PM Laszlo Ersek <address@hidden 
> <mailto:address@hidden>> wrote:
> On 07/13/17 12:47, Peter Maydell wrote:
> > On 12 July 2017 at 00:43, Ben Warren <address@hidden 
> > <mailto:address@hidden>> wrote:
> >> Yes, it’s definitely a setup time problem.  With the values that are 
> >> checked
> >> in, I can’t get it to fail on my setup, but if I wind the numbers down I 
> >> see
> >> the same failure as Peter.  So now we have the ages-old problem of “what 
> >> new
> >> arbitrary value should I use that will not cause false failures but will
> >> eventually time out”.
> >
> > Empirically, we already have an answer to this, in the form
> > of the existing code in tests/boot-sector.c, which is used
> > by both that test and the bios-tables-test.c code to wait
> > for the BIOS initialization to complete, and which doesn't
> > cause false test timeouts in practice.
> >
> > Can we make this test just use that existing function to
> > wait for the BIOS to be done, rather than having its own
> > timeout loop?
> 
> This is incredibly cool. Now that I've looked at "tests/boot-sector.c"
> (again), I recall having seen it earlier, but I couldn't have remembered
> it off-hand.
> 
> Perhaps this boot sector code should be factored out and moved to
> "tests/acpi-utils".
> 
> Marc-André, do you think it would be feasible for the vmcoreinfo unit
> test as well? (Which is derived from the vmgenid unit test.)
> 
> It seems likely.
> 
> Ben, are you going to work on the fix?
> 
Yes, I will take care of this.  I remember seeing the boot-sector 
synchronization code before, but didn’t really grok it.  This time I’ll dig 
deeper.
> Thanks
> -- 
> Marc-André Lureau

—Ben