lkml.org 
[lkml]   [2022]   [Jun]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH v5 0/5] introduce mirrored memory support for arm64
From

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(-)
>

\
 
 \ /
  Last update: 2022-06-15 05:53    [W:0.133 / U:0.024 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site