Re: [PULL 2/4] hw/nvme: fix assertion failure on subregion removal

Klaus Jensen <[email protected]> Thu, 30 Jul 2026 11:17:09 +0200

Newsgroups	gmane.comp.emulators.qemu.block,gmane.comp.emulators.qemu,gmane.comp.emulators.qemu.stable
Message-ID	<[email protected]>

On Jul 30 10:22, Michael Tokarev wrote:
> On 7/28/26 21:00, Klaus Jensen wrote:
> > From: Daniel Paziyski <[email protected]>
> > 
> > When a controller is created with a MSI-X exclusive BAR, the bar0 memory region
> > is not used at all, and so, the iomem region is not added as a subregion of it.
> > However, when removing a NVMe controller, the iomem region is unconditionally
> > removed as a subregion of bar0, causing an assertion failure. Remove the iomem
> > memory region as a subregion of bar0 only if not using a MSI-X exclusive BAR.
> > 
> > QEMU options (requires a hotunplug-aware OS):
> > 
> >          -M q35 -device pcie-root-port,id=rp0 \
> >          -device nvme,serial=ctrl0,id=ctrl0,bus=rp0,msix-exclusive-bar=on
> > 
> > In the QEMU monitor, or by causing an ejection from the OS:
> > 
> >          device_del ctrl0
> > 
> > Message in stderr:
> > 
> > qemu-system-x86_64: ../system/memory.c:2617: memory_region_del_subregion: Assertion `subregion->container == mr' failed.
> > 
> > Fixes: fa905f65c554 ("hw/nvme: add machine compatibility parameter to enable msix exclusive bar")
> > Fixes: 9162f1012576 ("hw/nvme: fix msix_uninit with exclusive bar")
> > Resolves: https://gitlab.com/qemu-project/qemu/-/work_items/4090
> > Signed-off-by: Daniel Paziyski <[email protected]>
> > Reviewed-by: Klaus Jensen <[email protected]>
> > Signed-off-by: Klaus Jensen <[email protected]>
> 
> It feels like this one should be picked up for the stable series too,
> should it not?  (I'm picking it up).
> 

Yes, thanks Michael!

signature.asc (application/pgp-signature, 488 B)