arm64: cpufeature: upgrade hyp caps to final

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We finalize caps before initializing kvm hyp code, and any use of
cpus_have_const_cap() in kvm hyp code generates redundant and
potentially unsound code to read the cpu_hwcaps array.

A number of helper functions used in both hyp context and regular kernel
context use cpus_have_const_cap(), as some regular kernel code runs
before the capabilities are finalized. It's tedious and error-prone to
write separate copies of these for hyp and non-hyp code.

So that we can avoid the redundant code, let's automatically upgrade
cpus_have_const_cap() to cpus_have_final_cap() when used in hyp context.
With this change, there's never a reason to access to cpu_hwcaps array
from hyp code, and we don't need to create an NVHE alias for this.

This should have no effect on non-hyp code.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: David Brazdil <dbrazdil@google.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201026134931.28246-4-mark.rutland@arm.com

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This commit is contained in:

Mark Rutland 2020-10-26 13:49:31 +00:00 • committed by Marc Zyngier

parent dfc4e3f089

commit d86de40dec

3 changed files with 24 additions and 15 deletions

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26

arch/arm64/include/asm/cpufeature.h

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arch/arm64/include/asm/virt.h

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arch/arm64/kernel/image-vars.h

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