[PATCH v2 0/6] arm64: Clean up and simplify PA space size handling

From: Ard Biesheuvel
Date: Thu Dec 05 2024 - 10:04:09 EST


From: Ard Biesheuvel <ardb@xxxxxxxxxx>

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.

Changes since v1:
- rebase onto v6.13-rc1
- add Anshuman's ack to patch #1
- incorporate Anshuman's feedback on patches #1 and #2
- tweak owner_update logic in patch #4

Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Marc Zyngier <maz@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Quentin Perret <qperret@xxxxxxxxxx>

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 | 33 ++++++-----------
arch/arm64/mm/init.c | 7 +++-
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, 63 insertions(+), 117 deletions(-)

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2.47.0.338.g60cca15819-goog