[PATCH v1 0/4] mm/memory_hotplug: full support for

[David Hildenbrand]

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 <akpm at linux-foundation.org>
Cc: Mike Rapoport <rppt at kernel.org>
Cc: Michal Hocko <mhocko at suse.com>
Cc: Oscar Salvador <osalvador at suse.de>
Cc: Jianyong Wu <Jianyong.Wu at arm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar at linux.ibm.com>
Cc: Vineet Gupta <vgupta at kernel.org>
Cc: Geert Uytterhoeven <geert at linux-m68k.org>
Cc: Huacai Chen <chenhuacai at kernel.org>
Cc: Jiaxun Yang <jiaxun.yang at flygoat.com>
Cc: Thomas Bogendoerfer <tsbogend at alpha.franken.de>
Cc: Heiko Carstens <hca at linux.ibm.com>
Cc: Vasily Gorbik <gor at linux.ibm.com>
Cc: Christian Borntraeger <borntraeger at de.ibm.com>
Cc: Eric Biederman <ebiederm at xmission.com>
Cc: Arnd Bergmann <arnd at arndb.de>
Cc: linux-snps-arc at lists.infradead.org
Cc: linux-ia64 at vger.kernel.org
Cc: linux-m68k at lists.linux-m68k.org
Cc: linux-mips at vger.kernel.org
Cc: linux-s390 at vger.kernel.org
Cc: linux-mm at kvack.org
Cc: kexec at 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