KVM: arm64: Remove ad-hoc CPTR manipulation from fpsimd_sve_sync()

There's no need for fpsimd_sve_sync() to write to CPTR/CPACR. All
relevant traps are always disabled earlier within __kvm_vcpu_run(), when
__deactivate_cptr_traps() configures CPTR/CPACR.

With irrelevant details elided, the flow is:

handle___kvm_vcpu_run(...)
{
	flush_hyp_vcpu(...) {
		fpsimd_sve_flush(...);
	}

	__kvm_vcpu_run(...) {
		__activate_traps(...) {
			__activate_cptr_traps(...);
		}

		do {
			__guest_enter(...);
		} while (...);

		__deactivate_traps(....) {
			__deactivate_cptr_traps(...);
		}
	}

	sync_hyp_vcpu(...) {
		fpsimd_sve_sync(...);
	}
}

Remove the unnecessary write to CPTR/CPACR. An ISB is still necessary,
so a comment is added to describe this requirement.

Signed-off-by: Mark Rutland <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Fuad Tabba <[email protected]>
Cc: Marc Zyngier <[email protected]>
Cc: Mark Brown <[email protected]>
Cc: Oliver Upton <[email protected]>
Cc: Will Deacon <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Marc Zyngier <[email protected]>

0 files changed, 0 insertions, 0 deletions