[PATCH v3 07/16] KVM: arm64: nv: Sanitise ICH_HCR_EL2 accesses

[Marc Zyngier]

As ICH_HCR_EL2 is a VNCR accessor when runnintg NV, add some
sanitising to what gets written. Crucially, mark TDIR as RES0
if the HW doesn't support it (unlikely, but hey...), as well
as anything GICv4 related, since we only expose a GICv3 to the
uest.

Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kvm/nested.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index 33d2ace686658..1cb113ee1e17a 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -1289,6 +1289,15 @@ int kvm_init_nv_sysregs(struct kvm_vcpu *vcpu)
 		res0 |= GENMASK(11, 8);
 	set_sysreg_masks(kvm, CNTHCTL_EL2, res0, res1);
 
+	/* ICH_HCR_EL2 */
+	res0 = ICH_HCR_EL2_RES0;
+	res1 = ICH_HCR_EL2_RES1;
+	if (!(kvm_vgic_global_state.ich_vtr_el2 & ICH_VTR_EL2_TDS))
+		res0 |= ICH_HCR_EL2_TDIR;
+	/* No GICv4 is presented to the guest */
+	res0 |= ICH_HCR_EL2_DVIM | ICH_HCR_EL2_vSGIEOICount;
+	set_sysreg_masks(kvm, ICH_HCR_EL2, res0, res1);
+
 out:
 	for (enum vcpu_sysreg sr = __SANITISED_REG_START__; sr < NR_SYS_REGS; sr++)
 		(void)__vcpu_sys_reg(vcpu, sr);
-- 
2.39.2