Re: [PATCH v2 00/10] Introduce sv48 support without relocatable kernel

["Heiko Stübner" <heiko@sntech.de>]

Am Montag, 6. Dezember 2021, 11:49:55 CET schrieb Alexandre ghiti:
> On 11/25/21 00:29, Heiko Stübner wrote:
> > Am Mittwoch, 29. September 2021, 16:51:03 CET schrieb Alexandre Ghiti:
> >> This patchset allows to have a single kernel for sv39 and sv48 without
> >> being relocatable.
> >>                                                                                   
> >> The idea comes from Arnd Bergmann who suggested to do the same as x86,
> >> that is mapping the kernel to the end of the address space, which allows
> >> the kernel to be linked at the same address for both sv39 and sv48 and
> >> then does not require to be relocated at runtime.
> >>                                                                                   
> >> This implements sv48 support at runtime. The kernel will try to
> >> boot with 4-level page table and will fallback to 3-level if the HW does not
> >> support it. Folding the 4th level into a 3-level page table has almost no
> >> cost at runtime.
> >>                                                                                   
> >> Tested on:
> >>    - qemu rv64 sv39: OK
> >>    - qemu rv64 sv48: OK
> >>    - qemu rv64 sv39 + kasan: OK
> >>    - qemu rv64 sv48 + kasan: OK
> >>    - qemu rv32: OK
> >>    - Unmatched: OK
> > On a beagleV (which supports only sv39) I've tested both the limit via
> > the mmu-type in the devicetree and also that the fallback works when
> > I disable the mmu-type in the dt, so
> >
> > Tested-by: Heiko Stuebner <heiko@sntech.de>
> >
> 
> Thanks Heiko for testing this, unfortunately I could not add this tag to 
> the latest version as significant changes came up.
> 
> Thanks again for taking the time to test this,

No worries, I can repeat that with your new version :-)

Heiko


> >>    
> >>                                                                                   
> >> Changes in v2:
> >>    - Rebase onto for-next
> >>    - Fix KASAN
> >>    - Fix stack canary
> >>    - Get completely rid of MAXPHYSMEM configs
> >>    - Add documentation
> >>
> >> Alexandre Ghiti (10):
> >>    riscv: Allow to dynamically define VA_BITS
> >>    riscv: Get rid of MAXPHYSMEM configs
> >>    asm-generic: Prepare for riscv use of pud_alloc_one and pud_free
> >>    riscv: Implement sv48 support
> >>    riscv: Use pgtable_l4_enabled to output mmu_type in cpuinfo
> >>    riscv: Explicit comment about user virtual address space size
> >>    riscv: Improve virtual kernel memory layout dump
> >>    Documentation: riscv: Add sv48 description to VM layout
> >>    riscv: Initialize thread pointer before calling C functions
> >>    riscv: Allow user to downgrade to sv39 when hw supports sv48
> >>
> >>   Documentation/riscv/vm-layout.rst             |  36 ++
> >>   arch/riscv/Kconfig                            |  35 +-
> >>   arch/riscv/configs/nommu_k210_defconfig       |   1 -
> >>   .../riscv/configs/nommu_k210_sdcard_defconfig |   1 -
> >>   arch/riscv/configs/nommu_virt_defconfig       |   1 -
> >>   arch/riscv/include/asm/csr.h                  |   3 +-
> >>   arch/riscv/include/asm/fixmap.h               |   1 +
> >>   arch/riscv/include/asm/kasan.h                |   2 +-
> >>   arch/riscv/include/asm/page.h                 |  10 +
> >>   arch/riscv/include/asm/pgalloc.h              |  40 +++
> >>   arch/riscv/include/asm/pgtable-64.h           | 108 +++++-
> >>   arch/riscv/include/asm/pgtable.h              |  30 +-
> >>   arch/riscv/include/asm/sparsemem.h            |   6 +-
> >>   arch/riscv/kernel/cpu.c                       |  23 +-
> >>   arch/riscv/kernel/head.S                      |   4 +-
> >>   arch/riscv/mm/context.c                       |   4 +-
> >>   arch/riscv/mm/init.c                          | 323 +++++++++++++++---
> >>   arch/riscv/mm/kasan_init.c                    |  91 +++--
> >>   drivers/firmware/efi/libstub/efi-stub.c       |   2 +
> >>   include/asm-generic/pgalloc.h                 |  24 +-
> >>   include/linux/sizes.h                         |   1 +
> >>   21 files changed, 615 insertions(+), 131 deletions(-)
> >>
> >>
> >
> >
> >
> 
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