[PATCH 0/6] arm64: Clean up and simplify PA space size handling

[Ard Biesheuvel]

(cc Quentin)

On Mon, 11 Nov 2024 at 09:35, Ard Biesheuvel <ardb+git at google.com> wrote:
>
> From: Ard Biesheuvel <ardb at kernel.org>
>
> This series addresses a number of buglets related to how we handle the
> size of the physical address space when building LPA2 capable kernels:
>
> - reject 52-bit physical addressess in the mapping routines when LPA2 is
>   configured but not available at runtime
> - ensure that TCR.IPS is not set to 52-bits if LPA2 is not supported
> - ensure that TCR_EL2.PS and DS match the host, regardless of whether
>   LPA2 is available at stage 2
> - don't rely on kvm_get_parange() and invalid physical addresses as
>   control flags in the pKVM page donation APIs
>
> Finally, the configurable 48-bit physical address space limit is dropped
> entirely, as it doesn't buy us a lot now that all the PARange and {I}PS
> handling is done at runtime.
>
> Cc: Catalin Marinas <catalin.marinas at arm.com>
> Cc: Will Deacon <will at kernel.org>
> Cc: Marc Zyngier <maz at kernel.org>
> Cc: Mark Rutland <mark.rutland at arm.com>
> Cc: Ryan Roberts <ryan.roberts at arm.com>
> Cc: Anshuman Khandual <anshuman.khandual at arm.com>
> Cc: Kees Cook <keescook at chromium.org>
>
> Ard Biesheuvel (6):
>   arm64/mm: Reduce PA space to 48 bits when LPA2 is not enabled
>   arm64/mm: Override PARange for !LPA2 and use it consistently
>   arm64/kvm: Configure HYP TCR.PS/DS based on host stage1
>   arm64/kvm: Avoid invalid physical addresses to signal owner updates
>   arm64: Kconfig: force ARM64_PAN=y when enabling TTBR0 sw PAN
>   arm64/mm: Drop configurable 48-bit physical address space limit
>
>  arch/arm64/Kconfig                     | 37 ++------------------
>  arch/arm64/include/asm/assembler.h     | 14 +++-----
>  arch/arm64/include/asm/cpufeature.h    |  3 +-
>  arch/arm64/include/asm/kvm_pgtable.h   |  3 +-
>  arch/arm64/include/asm/pgtable-hwdef.h | 12 +------
>  arch/arm64/include/asm/pgtable-prot.h  |  7 ++++
>  arch/arm64/include/asm/pgtable.h       | 11 +-----
>  arch/arm64/include/asm/sparsemem.h     |  4 ++-
>  arch/arm64/include/asm/sysreg.h        |  6 ----
>  arch/arm64/kernel/cpufeature.c         |  2 +-
>  arch/arm64/kernel/pi/idreg-override.c  |  9 +++++
>  arch/arm64/kernel/pi/map_kernel.c      |  6 ++++
>  arch/arm64/kvm/arm.c                   |  8 ++---
>  arch/arm64/kvm/hyp/pgtable.c           | 37 ++++++++------------
>  arch/arm64/mm/init.c                   |  2 +-
>  arch/arm64/mm/pgd.c                    |  9 ++---
>  arch/arm64/mm/proc.S                   |  2 --
>  scripts/gdb/linux/constants.py.in      |  1 -
>  tools/arch/arm64/include/asm/sysreg.h  |  6 ----
>  19 files changed, 62 insertions(+), 117 deletions(-)
>
> --
> 2.47.0.277.g8800431eea-goog
>