Commit cde5042a authored by Will Deacon's avatar Will Deacon Committed by Marc Zyngier
Browse files

KVM: arm64: Ignore 'kvm-arm.mode=protected' when using VHE 



Ignore 'kvm-arm.mode=protected' when using VHE so that kvm_get_mode()
only returns KVM_MODE_PROTECTED on systems where the feature is available.

Cc: David Brazdil <dbrazdil@google.com>
Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220609121223.2551-4-will@kernel.org
parent fa7a1721

Documentation/admin-guide/kernel-parameters.txt

+0 −1
Original line number Diff line number Diff line
@@ -2469,7 +2469,6 @@ 


			protected: nVHE-based mode with support for guests whose

				   state is kept private from the host.

				   Not valid if the kernel is running in EL2.



			Defaults to VHE/nVHE based on hardware support. Setting

			mode to "protected" will disable kexec and hibernation

arch/arm64/kernel/cpufeature.c

+1 −9
Original line number Diff line number Diff line
@@ -1974,15 +1974,7 @@ static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap) 
#ifdef CONFIG_KVM

static bool is_kvm_protected_mode(const struct arm64_cpu_capabilities *entry, int __unused)

{

	if (kvm_get_mode() != KVM_MODE_PROTECTED)

		return false;



	if (is_kernel_in_hyp_mode()) {

		pr_warn("Protected KVM not available with VHE\n");

		return false;

	}



	return true;

	return kvm_get_mode() == KVM_MODE_PROTECTED;

}

#endif /* CONFIG_KVM */

arch/arm64/kvm/arm.c

+5 −1
Original line number Diff line number Diff line
@@ -2273,7 +2273,11 @@ static int __init early_kvm_mode_cfg(char *arg) 
		return -EINVAL;



	if (strcmp(arg, "protected") == 0) {

		if (!is_kernel_in_hyp_mode())

			kvm_mode = KVM_MODE_PROTECTED;

		else

			pr_warn_once("Protected KVM not available with VHE\n");



		return 0;

	}