Re: [PATCH] hw/display/tcx: Init memory regions in realize

[Peter Xu <peterx@redhat.com>]

On Tue, Mar 17, 2026 at 11:24:16AM +0100, BALATON Zoltan wrote:
> On Tue, 17 Mar 2026, BALATON Zoltan wrote:
> > On Tue, 17 Mar 2026, Thomas Huth wrote:
> > > On 17/03/2026 06.41, Thomas Huth wrote:
> > > > On 16/03/2026 23.30, BALATON Zoltan wrote:
> > > > > On Mon, 16 Mar 2026, Peter Xu wrote:
> > > > > > On Mon, Mar 16, 2026 at 07:10:05PM +0100, BALATON Zoltan wrote:
> > > > > > > On Mon, 16 Mar 2026, Peter Xu wrote:
> > > > > > > > On Mon, Mar 16, 2026 at 02:06:51PM +0100, BALATON Zoltan wrote:
> > > > > > > > > Due to aux-ram-share property qemu_ram_alloc_internal dereferences
> > > > > > > > > current_machine which is not set during init when inspecting the
> > > > > > > > > device. This causes the qtest/device-introspect-test to fail since a
> > > > > > > > 
> > > > > > > > Does it has anything to do with aux-ram-share? 
> > > > > > > > I thought it's because the
> > > > > > > > qom introspect test will create yet another
> > > > > > > > sun-tcx device, causing double
> > > > > > > > registration?
> > > > > > > 
> > > > > > > I could reproduce it like this:
> > > > > > 
> > > > > > I would treat this one a separate bug, because it
> > > > > > doesn't look special to
> > > > > > sparc systems.
> > > > > 
> > > > > I thought this is the issue Thomas has reported. I found
> > > > > this command by looking at what the test does but looks like
> > > > > this gets a different error but the fix is the same.
> > > > 
> > > > It's slightly different. The bug that I found via the device
> > > > introspection test is using "-M SS-20" and then it's crashing
> > > > when a second sun-tcx device is instantiated.
> > > > The bug that you found is crashing because using "-device
> > > > sun-tcx,help" instantiates the device for introspection before
> > > > the machine has been created, so code that dereferences
> > > > current_machine is running into a NULL pointer related
> > > > segmentation fault.
> > > 
> > > By the way, "qemu-system-sparc -device cgthree,help" crashes in the
> > > same way.
> > 
> > OK, I'll send a v2 fixing that and updating the commit message to
> > mention both issues.
> 
> Looks like you were faster, Then I won't do it.

Note that I've queued this patch with amended commit message.  If anyone
thinks I should drop it please say so.. otherwise I'll keep it to make sure
it is fixed in 11.0 (as it fixes a qtest failure introduced in the previous
mem pull).

Thanks,

-- 
Peter Xu