Architectures that require CONFIG_ARCH_KEEP_MEMBLOCK=y, such as arm64, don't cleanly support add_memory_driver_managed() yet. Most prominently, kexec_file can still end up placing images on such driver-managed memory, resulting in undesired behavior.
Teaching kexec to not place images on driver-managed memory is especially relevant for virtio-mem. Details can be found in commit 7b7b27214bba ("mm/memory_hotplug: introduce add_memory_driver_managed()"). Extend memblock with a new flag and set it from memory hotplug code when applicable. This is required to fully support virtio-mem on arm64, making also kexec_file behave like on x86-64. Alternative A: Extend kexec_walk_memblock() to consult the kernel resource tree whether IORESOURCE_SYSRAM_DRIVER_MANAGED is set. This feels wrong, because the goal was to rely on memblock and not the resource tree. Alternative B: Reuse MEMBLOCK_HOTPLUG. MEMBLOCK_HOTPLUG serves a different purpose, though. Cc: Andrew Morton <a...@linux-foundation.org> Cc: Mike Rapoport <r...@kernel.org> Cc: Michal Hocko <mho...@suse.com> Cc: Oscar Salvador <osalva...@suse.de> Cc: Jianyong Wu <jianyong...@arm.com> Cc: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com> Cc: Vineet Gupta <vgu...@kernel.org> Cc: Geert Uytterhoeven <ge...@linux-m68k.org> Cc: Huacai Chen <chenhua...@kernel.org> Cc: Jiaxun Yang <jiaxun.y...@flygoat.com> Cc: Thomas Bogendoerfer <tsbog...@alpha.franken.de> Cc: Heiko Carstens <h...@linux.ibm.com> Cc: Vasily Gorbik <g...@linux.ibm.com> Cc: Christian Borntraeger <borntrae...@de.ibm.com> Cc: Eric Biederman <ebied...@xmission.com> Cc: Arnd Bergmann <a...@arndb.de> Cc: linux-snps-arc@lists.infradead.org Cc: linux-i...@vger.kernel.org Cc: linux-m...@lists.linux-m68k.org Cc: linux-m...@vger.kernel.org Cc: linux-s...@vger.kernel.org Cc: linux...@kvack.org Cc: ke...@lists.infradead.org David Hildenbrand (4): mm/memory_hotplug: handle memblock_add_node() failures in add_memory_resource() memblock: allow to specify flags with memblock_add_node() memblock: add MEMBLOCK_DRIVER_MANAGED to mimic IORESOURCE_SYSRAM_DRIVER_MANAGED mm/memory_hotplug: indicate MEMBLOCK_DRIVER_MANAGED with IORESOURCE_SYSRAM_DRIVER_MANAGED arch/arc/mm/init.c | 4 ++-- arch/ia64/mm/contig.c | 2 +- arch/ia64/mm/init.c | 2 +- arch/m68k/mm/mcfmmu.c | 3 ++- arch/m68k/mm/motorola.c | 6 ++++-- arch/mips/loongson64/init.c | 4 +++- arch/mips/sgi-ip27/ip27-memory.c | 3 ++- arch/s390/kernel/setup.c | 3 ++- include/linux/memblock.h | 19 ++++++++++++++++--- include/linux/mm.h | 2 +- kernel/kexec_file.c | 5 +++++ mm/memblock.c | 13 +++++++++---- mm/memory_hotplug.c | 11 +++++++++-- 13 files changed, 57 insertions(+), 20 deletions(-) base-commit: 5816b3e6577eaa676ceb00a848f0fd65fe2adc29 -- 2.31.1 _______________________________________________ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc