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arm64: alternatives: kvm: prepare for cap changes

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The KVM patching callbacks use cpus_have_final_cap() internally within
has_vhe(), and subsequent patches will make it invalid to call
cpus_have_final_cap() before alternatives patching has completed, and
will mean that cpus_have_const_cap() will always fall back to dynamic
checks prior to alternatives patching.

In preparation for said change, this patch modifies the KVM patching
callbacks to use cpus_have_cap() directly. This is not subject to
patching, and will dynamically check the cpu_hwcaps array, which is
functionally equivalent to the existing behaviour.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220912162210.3626215-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Mark Rutland 2022-09-12 17:22:04 +01:00 committed by Catalin Marinas
parent 92b4b5619f
commit 34bbfdfb14
1 changed files with 3 additions and 2 deletions
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5
arch/arm64/kvm/va_layout.c
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@ -169,7 +169,7 @@ void __init kvm_update_va_mask(struct alt_instr *alt,
* dictates it and we don't have any spare bits in the
* address), NOP everything after masking the kernel VA.
*/
if (has_vhe() || (!tag_val && i > 0)) {
if (cpus_have_cap(ARM64_HAS_VIRT_HOST_EXTN) || (!tag_val && i > 0)) {
updptr[i] = cpu_to_le32(aarch64_insn_gen_nop());
continue;
}
@ -193,7 +193,8 @@ void kvm_patch_vector_branch(struct alt_instr *alt,
BUG_ON(nr_inst != 4);
if (!cpus_have_const_cap(ARM64_SPECTRE_V3A) || WARN_ON_ONCE(has_vhe()))
if (!cpus_have_cap(ARM64_SPECTRE_V3A) ||
WARN_ON_ONCE(cpus_have_cap(ARM64_HAS_VIRT_HOST_EXTN)))
return;
/*