[PATCH 5/6] KVM: arm64: Limit the debug architecture to ARMv8.0

Marc Zyngier
2021-01-14T10:58:58Z

Let's not pretend we support anything but ARMv8.0 as far as the
debug architecture is concerned.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/sys_regs.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index dda16d60197b..8f79ec1fffa7 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1048,6 +1048,9 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu,
FEATURE(ID_AA64ISAR1_GPI));
break;
case SYS_ID_AA64DFR0_EL1:
+ /* Limit debug to ARMv8.0 */
+ val &= ~FEATURE(ID_AA64DFR0_DEBUGVER);
+ val |= FIELD_PREP(FEATURE(ID_AA64DFR0_DEBUGVER), 6);
/* Limit guests to PMUv3 for ARMv8.1 */
val = cpuid_feature_cap_perfmon_field(val,
ID_AA64DFR0_PMUVER_SHIFT,
--
2.29.2