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Could you also send me your kernel Kconfig, to > > see which combination of options are you using? > > > > Here's the .config, there are some deviations from the default Ubuntu build > but it isn't too far off. > > Thanks, > James > > # > # Automatically generated file; DO NOT EDIT. > # Linux/x86 6.8.12 Kernel Configuration [...] > # > # Xen driver support > # > CONFIG_XEN_BALLOON=y > CONFIG_XEN_BALLOON_MEMORY_HOTPLUG=y > CONFIG_XEN_MEMORY_HOTPLUG_LIMIT=512 > CONFIG_XEN_SCRUB_PAGES_DEFAULT=y > CONFIG_XEN_DEV_EVTCHN=m > CONFIG_XEN_BACKEND=y > CONFIG_XENFS=m > CONFIG_XEN_COMPAT_XENFS=y > CONFIG_XEN_SYS_HYPERVISOR=y > CONFIG_XEN_XENBUS_FRONTEND=y > CONFIG_XEN_GNTDEV=m > CONFIG_XEN_GNTDEV_DMABUF=y > CONFIG_XEN_GRANT_DEV_ALLOC=m > CONFIG_XEN_GRANT_DMA_ALLOC=y > CONFIG_SWIOTLB_XEN=y > CONFIG_XEN_PCI_STUB=y > CONFIG_XEN_PCIDEV_BACKEND=m > CONFIG_XEN_PVCALLS_FRONTEND=m > # CONFIG_XEN_PVCALLS_BACKEND is not set > CONFIG_XEN_SCSI_BACKEND=m > CONFIG_XEN_PRIVCMD=m > CONFIG_XEN_PRIVCMD_EVENTFD=y > CONFIG_XEN_ACPI_PROCESSOR=y > CONFIG_XEN_MCE_LOG=y > CONFIG_XEN_HAVE_PVMMU=y > CONFIG_XEN_EFI=y > CONFIG_XEN_AUTO_XLATE=y > CONFIG_XEN_ACPI=y > CONFIG_XEN_SYMS=y > CONFIG_XEN_HAVE_VPMU=y > CONFIG_XEN_FRONT_PGDIR_SHBUF=m > CONFIG_XEN_UNPOPULATED_ALLOC=y Can you confirm that the config used to build the non-working kernel also has CONFIG_XEN_UNPOPULATED_ALLOC=y? Can you also provide the output of `cat /proc/iomem` for both the working and non-working kernels? Thanks, Roger.