From: Marc Zyngier <maz@kernel.org>
Date: Sun, 16 Feb 2020 17:44:29 +0000 (+0000)
Subject: KVM: arm64: Limit the debug architecture to ARMv8.0
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=94893fc9ad8cdb05fdb64e00128997bc530e2ca9;p=linux.git

KVM: arm64: Limit the debug architecture to ARMv8.0

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

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index dda16d60197b8..8f79ec1fffa7e 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,