Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 3272f0d0 authored by Marc Zyngier's avatar Marc Zyngier Committed by Christoffer Dall
Browse files

arm64: KVM: Inject a vSerror if detecting a bad GICV access at EL2 



If, when proxying a GICV access at EL2, we detect that the guest is
doing something silly, report an EL1 SError instead ofgnoring the
access.

Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
parent 21977a4c

arch/arm64/include/asm/kvm_hyp.h

+1 −1
Original line number Diff line number Diff line
@@ -123,7 +123,7 @@ typeof(orig) * __hyp_text fname(void) \ 


void __vgic_v2_save_state(struct kvm_vcpu *vcpu);

void __vgic_v2_restore_state(struct kvm_vcpu *vcpu);

bool __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu);

int __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu);



void __vgic_v3_save_state(struct kvm_vcpu *vcpu);

void __vgic_v3_restore_state(struct kvm_vcpu *vcpu);

arch/arm64/kvm/hyp/switch.c

+15 −3
Original line number Diff line number Diff line
@@ -311,10 +311,22 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu) 
			!kvm_vcpu_dabt_isextabt(vcpu) &&

			!kvm_vcpu_dabt_iss1tw(vcpu);



		if (valid && __vgic_v2_perform_cpuif_access(vcpu)) {

		if (valid) {

			int ret = __vgic_v2_perform_cpuif_access(vcpu);



			if (ret == 1) {

				__skip_instr(vcpu);

				goto again;

			}



			if (ret == -1) {

				/* Promote an illegal access to an SError */

				__skip_instr(vcpu);

				exit_code = ARM_EXCEPTION_EL1_SERROR;

			}



			/* 0 falls through to be handler out of EL2 */

		}

	}



	fp_enabled = __fpsimd_enabled();

virt/kvm/arm/hyp/vgic-v2-sr.c

+16 −5
Original line number Diff line number Diff line
@@ -170,7 +170,18 @@ void __hyp_text __vgic_v2_restore_state(struct kvm_vcpu *vcpu) 
}



#ifdef CONFIG_ARM64

bool __hyp_text __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu)

/*

 * __vgic_v2_perform_cpuif_access -- perform a GICV access on behalf of the

 *				     guest.

 *

 * @vcpu: the offending vcpu

 *

 * Returns:

 *  1: GICV access successfully performed

 *  0: Not a GICV access

 * -1: Illegal GICV access

 */

int __hyp_text __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu)

{

	struct kvm *kvm = kern_hyp_va(vcpu->kvm);

	struct vgic_dist *vgic = &kvm->arch.vgic;
@@ -185,15 +196,15 @@ bool __hyp_text __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu) 
	/* If not for GICV, move on */

	if (fault_ipa <  vgic->vgic_cpu_base ||

	    fault_ipa >= (vgic->vgic_cpu_base + KVM_VGIC_V2_CPU_SIZE))

		return false;

		return 0;



	/* Reject anything but a 32bit access */

	if (kvm_vcpu_dabt_get_as(vcpu) != sizeof(u32))

		return false;

		return -1;



	/* Not aligned? Don't bother */

	if (fault_ipa & 3)

		return false;

		return -1;



	rd = kvm_vcpu_dabt_get_rd(vcpu);

	addr  = kern_hyp_va((kern_hyp_va(&kvm_vgic_global_state))->vcpu_base_va);
@@ -210,6 +221,6 @@ bool __hyp_text __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu) 
							       sizeof(u32)));

	}



	return true;

	return 1;

}

#endif