Re: [PATCH v1 1/1] hw/pci: Disable PCI_ERR_UNCOR_MASK register for machine type < 8.0

[Michael S. Tsirkin]

On Tue, May 09, 2023 at 07:01:53AM -0700, Peter Xu wrote:
> On Tue, May 02, 2023 at 09:27:02PM -0300, Leonardo Bras wrote:
> > Since it's implementation on v8.0.0-rc0, having the PCI_ERR_UNCOR_MASK
> > set for machine types < 8.0 will cause migration to fail if the target
> > QEMU version is < 8.0.0 :
> > 
> > qemu-system-x86_64: get_pci_config_device: Bad config data: i=0x10a read: 
> > 40 device: 0 cmask: ff wmask: 0 w1cmask:0
> > qemu-system-x86_64: Failed to load PCIDevice:config
> > qemu-system-x86_64: Failed to load e1000e:parent_obj
> > qemu-system-x86_64: error while loading state for instance 0x0 of device 
> > '0000:00:02.0/e1000e'
> > qemu-system-x86_64: load of migration failed: Invalid argument
> > 
> > The above test migrated a 7.2 machine type from QEMU master to QEMU 7.2.0,
> > with this cmdline:
> > 
> > ./qemu-system-x86_64 -M pc-q35-7.2 [-incoming XXX]
> > 
> > In order to fix this, property x-pcie-err-unc-mask was introduced to
> > control when PCI_ERR_UNCOR_MASK is enabled. This property is enabled by
> > default, but is disabled if machine type <= 7.2.
> > 
> > Fixes: 010746ae1d ("hw/pci/aer: Implement PCI_ERR_UNCOR_MASK register")
> > Suggested-by: Michael S. Tsirkin <mst@redhat.com>
> > Signed-off-by: Leonardo Bras <leobras@redhat.com>
> 
> Since this one blocks mostly all backward migration for current master and
> all the downstream trees, shall we consider pick it up sooner?
> 
> And I think we should make sure qemu-stable gets this too, I'm not pretty
> sure how we normally do that and whether we need explicit CC: to stable
> list, perhaps not..
> 
> Thanks!
> 
> -- 
> Peter Xu


Yes will be in the pull I'm working on, targeting end of week.

-- 
MST