Commit 673638f4 authored by Steven Price's avatar Steven Price Committed by Marc Zyngier
Browse files

KVM: arm64: Expose KVM_ARM_CAP_MTE 



It's now safe for the VMM to enable MTE in a guest, so expose the
capability to user space.

Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarSteven Price <steven.price@arm.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210621111716.37157-5-steven.price@arm.com
parent e1f358b5

arch/arm64/kvm/arm.c

+9 −0
Original line number Diff line number Diff line
@@ -93,6 +93,12 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, 
		r = 0;

		kvm->arch.return_nisv_io_abort_to_user = true;

		break;

	case KVM_CAP_ARM_MTE:

		if (!system_supports_mte() || kvm->created_vcpus)

			return -EINVAL;

		r = 0;

		kvm->arch.mte_enabled = true;

		break;

	default:

		r = -EINVAL;

		break;
@@ -237,6 +243,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) 
		 */

		r = 1;

		break;

	case KVM_CAP_ARM_MTE:

		r = system_supports_mte();

		break;

	case KVM_CAP_STEAL_TIME:

		r = kvm_arm_pvtime_supported();

		break;

arch/arm64/kvm/reset.c

+4 −0
Original line number Diff line number Diff line
@@ -176,6 +176,10 @@ static bool vcpu_allowed_register_width(struct kvm_vcpu *vcpu) 
	if (!cpus_have_const_cap(ARM64_HAS_32BIT_EL1) && is32bit)

		return false;



	/* MTE is incompatible with AArch32 */

	if (kvm_has_mte(vcpu->kvm) && is32bit)

		return false;



	/* Check that the vcpus are either all 32bit or all 64bit */

	kvm_for_each_vcpu(i, tmp, vcpu->kvm) {

		if (vcpu_has_feature(tmp, KVM_ARM_VCPU_EL1_32BIT) != is32bit)

arch/arm64/kvm/sys_regs.c

+3 −0
Original line number Diff line number Diff line
@@ -1312,6 +1312,9 @@ static bool access_ccsidr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, 
static unsigned int mte_visibility(const struct kvm_vcpu *vcpu,

				   const struct sys_reg_desc *rd)

{

	if (kvm_has_mte(vcpu->kvm))

		return 0;



	return REG_HIDDEN;

}