"Michael S. Tsirkin" <m...@redhat.com> wrote: > On Tue, Apr 25, 2023 at 08:42:17PM -0400, Peter Xu wrote: >> Hi, Michael, Jonathan, >> >> On Tue, Mar 07, 2023 at 08:13:53PM -0500, Michael S. Tsirkin wrote: >> This breaks the simplest migration from QEMU 8.0->7.2 binaries on all >> machine types I think as long as the cap is present, e.g. the default >> e1000e provided by the default q35 machine can already hit it with all >> default cmdline: >> >> ./qemu-system-x86_64 -M pc-q35-7.2 [-incoming XXX] >> >> 7.2 binary will have empty wmask for PCI_ERR_UNCOR_MASK, meanwhile I think >> it can also see a non-zero value, then the migration will fail at: >> >> vmstate_load 0000:00:02.0/e1000e, e1000e >> >> qemu-7.2: get_pci_config_device: Bad config data: i=0x10a read: 40 device: 0 >> cmask: ff wmask: 0 w1cmask:0 >> qemu-7.2: Failed to load PCIDevice:config >> qemu-7.2: Failed to load e1000e:parent_obj >> >> qemu-7.2: error while loading state for instance 0x0 of device >> '0000:00:02.0/e1000e' >> qemu-7.2: load of migration failed: Invalid argument >> >> We probably at least want to have the default value to be still zero, and >> we'd need to make sure it'll not be modified by the guest, iiuc. >> >> Below oneliner works for me and makes the migration work again: >> >> ===8<=== >> diff --git a/hw/pci/pcie_aer.c b/hw/pci/pcie_aer.c >> index 103667c368..563a37b79c 100644 >> --- a/hw/pci/pcie_aer.c >> +++ b/hw/pci/pcie_aer.c >> @@ -113,7 +113,7 @@ int pcie_aer_init(PCIDevice *dev, uint8_t cap_ver, >> uint16_t offset, >> pci_set_long(dev->w1cmask + offset + PCI_ERR_UNCOR_STATUS, >> PCI_ERR_UNC_SUPPORTED); >> pci_set_long(dev->config + offset + PCI_ERR_UNCOR_MASK, >> - PCI_ERR_UNC_MASK_DEFAULT); >> + 0/*PCI_ERR_UNC_MASK_DEFAULT*/); >> pci_set_long(dev->wmask + offset + PCI_ERR_UNCOR_MASK, >> PCI_ERR_UNC_SUPPORTED); >> ===8<=== >> >> Anyone could have a look on a solid solution from PCI side? >> >> Copy Juan and Leonardo. >> >> Thanks, > > My bad, I forgot about this 🤦. > So we need a property and tweak it with compat machinery depending on > machine type. Jonathan, can you work on this pls? > Or I can revert for now to relieve the time pressure, > redo the patch at your leasure.
I agree with Michael here, the best option is adding a new property. Later, Juan.
