Messages in this thread | | | Date | Wed, 15 Jun 2022 11:52:00 +0800 | Subject | Re: [PATCH v5 0/5] introduce mirrored memory support for arm64 | From | Kefeng Wang <> |
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On 2022/6/14 17:21, Wupeng Ma wrote: > From: Ma Wupeng <mawupeng1@huawei.com> > > Commit b05b9f5f9dcf ("x86, mirror: x86 enabling - find mirrored memory ranges") > introduced mirrored memory support for x86. This support rely on UEFI to > report mirrored memory address ranges. See UEFI 2.5 spec pages 157-158: > > http://www.uefi.org/sites/default/files/resources/UEFI%202_5.pdf > > Memory mirroring is a technique used to separate memory into two separate > channels, usually on a memory device, like a server. In memory mirroring, > one channel is copied to another to create redundancy. This method makes > input/output (I/O) registers and memory appear with more than one address > range because the same physical byte is accessible at more than one > address. Using memory mirroring, higher memory reliability and a higher > level of memory consolidation are possible. > > These EFI memory regions have various attributes, and the "mirrored" > attribute is one of them. The physical memory region whose descriptors > in EFI memory map has EFI_MEMORY_MORE_RELIABLE attribute (bit: 16) are > mirrored. The address range mirroring feature of the kernel arranges such > mirrored regions into normal zones and other regions into movable zones. > > Arm64 can support this too. So mirrored memory support is added to support > arm64. > > The main purpose of this patch set is to introduce mirrored support for > arm64 and we have already fixed the problems we had which is shown in > patch #5 to patch #8 and try to bring total isolation in patch #9 which > will disable mirror feature if kernelcore is not specified. > > In order to test this support in arm64: > - patch this patch set > - add kernelcore=mirror in kernel parameter > - start you kernel > > Patch #1 introduce mirrored memory support form arm64. > Patch #2-#4 fix some bugs for arm64 if memory reliable is enabled. > Patch #5 disable mirror feature if kernelcore is not specified. > > Thanks to Ard Biesheuvel's hard work [1], now kernel will perfer mirrored > memory if kaslr is enabled. > > [1] https://lore.kernel.org/linux-arm-kernel/CAMj1kXEPVEzMgOM4+Yj6PxHA-jFuDOAUdDJSiSxy_XaP4P7LSw@mail.gmail.com/T/
For series,
Reviewed-by: Kefeng Wang<wangkefeng.wang@huawei.com>
> > Changelog since v4: > - merge the first two patches into one > - change __initdata to __initdata_memblock in patch #5 > > Changelog since v3: > - limit warning message in vmemmap_verify via pr_warn_once() > - only clear memblock_nomap flags rather than bring the mirrored flag back > - disable mirrored feature in memblock_mark_mirror() > > Changelog since v2: > - remove efi_fake_mem support > - remove Commit ("remove some redundant code in ia64 efi_init") since > efi_print_memmap() is not public > - add mirror flag back on initrd memory > > Changelog since v1: > - update changelog in cover letter > - use PHYS_PFN in patch #7 > > Ma Wupeng (5): > efi: arm64: Introduce ability to find mirrored memory ranges > mm: Ratelimited mirrored memory related warning messages > mm: Limit warning message in vmemmap_verify() to once > arm64: mm: Only remove nomap flag for initrd > memblock: Disable mirror feature if kernelcore is not specified > > arch/arm64/mm/init.c | 2 +- > arch/x86/include/asm/efi.h | 4 ---- > arch/x86/platform/efi/efi.c | 23 ----------------------- > drivers/firmware/efi/efi-init.c | 1 + > drivers/firmware/efi/efi.c | 23 +++++++++++++++++++++++ > include/linux/efi.h | 3 +++ > mm/internal.h | 2 ++ > mm/memblock.c | 7 +++++-- > mm/page_alloc.c | 2 +- > mm/sparse-vmemmap.c | 2 +- > 10 files changed, 37 insertions(+), 32 deletions(-) >
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