We generally don't expect FEAT_LS64* instructions to trap, unless
they are trapped by a guest hypervisor.
Otherwise, this is just the guest playing tricks on us by using
an instruction that isn't advertised, which we handle with a well
deserved UNDEF.
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
arch/arm64/kvm/handle_exit.c | 56 ++++++++++++++++++++++++++++++++++++
1 file changed, 56 insertions(+)
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index 512d152233ff2..b2d11cd0447c1 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -294,6 +294,61 @@ static int handle_svc(struct kvm_vcpu *vcpu)
return 1;
}
+static int handle_other(struct kvm_vcpu *vcpu)
+{
+ bool is_l2 = vcpu_has_nv(vcpu) && !is_hyp_ctxt(vcpu);
+ u64 hcrx = __vcpu_sys_reg(vcpu, HCRX_EL2);
+ u64 esr = kvm_vcpu_get_esr(vcpu);
+ u64 iss = ESR_ELx_ISS(esr);
+ struct kvm *kvm = vcpu->kvm;
+ bool allowed, fwd = false;
+
+ /*
+ * We only trap for two reasons:
+ *
+ * - the feature is disabled, and the only outcome is to
+ * generate an UNDEF.
+ *
+ * - the feature is enabled, but a NV guest wants to trap the
+ * feature used my its L2 guest. We forward the exception in
+ * this case.
+ *
+ * What we don't expect is to end-up here if the guest is
+ * expected be be able to directly use the feature, hence the
+ * WARN_ON below.
+ */
+ switch (iss) {
+ case ESR_ELx_ISS_OTHER_ST64BV:
+ allowed = kvm_has_feat(kvm, ID_AA64ISAR1_EL1, LS64, LS64_V);
+ if (is_l2)
+ fwd = !(hcrx & HCRX_EL2_EnASR);
+ break;
+ case ESR_ELx_ISS_OTHER_ST64BV0:
+ allowed = kvm_has_feat(kvm, ID_AA64ISAR1_EL1, LS64, LS64_ACCDATA);
+ if (is_l2)
+ fwd = !(hcrx & HCRX_EL2_EnAS0);
+ break;
+ case ESR_ELx_ISS_OTHER_LDST64B:
+ allowed = kvm_has_feat(kvm, ID_AA64ISAR1_EL1, LS64, LS64);
+ if (is_l2)
+ fwd = !(hcrx & HCRX_EL2_EnALS);
+ break;
+ default:
+ /* Clearly, we're missing something. */
+ WARN_ON_ONCE(1);
+ allowed = false;
+ }
+
+ WARN_ON_ONCE(allowed && !fwd);
+
+ if (allowed && fwd)
+ kvm_inject_nested_sync(vcpu, esr);
+ else
+ kvm_inject_undefined(vcpu);
+
+ return 1;
+}
+
static exit_handle_fn arm_exit_handlers[] = {
[0 ... ESR_ELx_EC_MAX] = kvm_handle_unknown_ec,
[ESR_ELx_EC_WFx] = kvm_handle_wfx,
@@ -303,6 +358,7 @@ static exit_handle_fn arm_exit_handlers[] = {
[ESR_ELx_EC_CP14_LS] = kvm_handle_cp14_load_store,
[ESR_ELx_EC_CP10_ID] = kvm_handle_cp10_id,
[ESR_ELx_EC_CP14_64] = kvm_handle_cp14_64,
+ [ESR_ELx_EC_OTHER] = handle_other,
[ESR_ELx_EC_HVC32] = handle_hvc,
[ESR_ELx_EC_SMC32] = handle_smc,
[ESR_ELx_EC_HVC64] = handle_hvc,
--
2.39.2
