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

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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: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
This commit is contained in:
Marc Zyngier 2016-09-06 14:02:17 +01:00 committed by Christoffer Dall
parent 21977a4c57
commit 3272f0d08e
3 changed files with 32 additions and 9 deletions
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2
arch/arm64/include/asm/kvm_hyp.h
View File

@ -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);

18
arch/arm64/kvm/hyp/switch.c
View File

@ -311,9 +311,21 @@ again:
!kvm_vcpu_dabt_isextabt(vcpu) &&
!kvm_vcpu_dabt_iss1tw(vcpu);
if (valid && __vgic_v2_perform_cpuif_access(vcpu)) {
__skip_instr(vcpu);
goto again;
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 */
}
}

21
virt/kvm/arm/hyp/vgic-v2-sr.c
View File

@ -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