[PATCH v21 09/15] KVM: arm64: Allow GCS to be enabled for guests

[Mark Brown <broonie@kernel.org>]

Now that required functionality for GCS is in place expose
ID_AA64PFR1_EL1.GCS, allowing guests to be given the feature.

Reviewed-by: Leonardo Bras <leo.bras@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 arch/arm64/kvm/nested.c   | 3 +--
 arch/arm64/kvm/sys_regs.c | 5 +++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index 3c4fc566eafc..f62d9ab7f31c 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -1702,11 +1702,10 @@ u64 limit_nv_id_reg(struct kvm *kvm, u32 reg, u64 val)
 		break;
 
 	case SYS_ID_AA64PFR1_EL1:
-		/* Only support BTI, SSBS, CSV2_frac */
+		/* Only support GCS, BTI, SSBS, CSV2_frac */
 		val &= ~(ID_AA64PFR1_EL1_PFAR		|
 			 ID_AA64PFR1_EL1_MTEX		|
 			 ID_AA64PFR1_EL1_THE		|
-			 ID_AA64PFR1_EL1_GCS		|
 			 ID_AA64PFR1_EL1_MTE_frac	|
 			 ID_AA64PFR1_EL1_NMI		|
 			 ID_AA64PFR1_EL1_SME		|
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index faecf4657ec5..5de4ba1bef6b 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2193,10 +2193,12 @@ static u64 sanitise_id_aa64pfr1_el1(const struct kvm_vcpu *vcpu, u64 val)
 	      SYS_FIELD_GET(ID_AA64PFR0_EL1, RAS, pfr0) == ID_AA64PFR0_EL1_RAS_IMP))
 		val &= ~ID_AA64PFR1_EL1_RAS_frac;
 
+	if (!system_supports_gcs())
+		val &= ~ID_AA64PFR1_EL1_GCS;
+
 	val &= ~ID_AA64PFR1_EL1_SME;
 	val &= ~ID_AA64PFR1_EL1_RNDR_trap;
 	val &= ~ID_AA64PFR1_EL1_NMI;
-	val &= ~ID_AA64PFR1_EL1_GCS;
 	val &= ~ID_AA64PFR1_EL1_THE;
 	val &= ~ID_AA64PFR1_EL1_MTEX;
 	val &= ~ID_AA64PFR1_EL1_PFAR;
@@ -3444,7 +3446,6 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 				     ~(ID_AA64PFR1_EL1_PFAR |
 				       ID_AA64PFR1_EL1_MTEX |
 				       ID_AA64PFR1_EL1_THE |
-				       ID_AA64PFR1_EL1_GCS |
 				       ID_AA64PFR1_EL1_MTE_frac |
 				       ID_AA64PFR1_EL1_NMI |
 				       ID_AA64PFR1_EL1_RNDR_trap |

-- 
2.47.3