[PATCH v17 09/14] KVM: arm64: Allow GCS to be enabled for guests
From: Mark Brown
Date: Fri Jul 31 2026 - 08:46:31 EST
Now that required functionality for GCS is in place expose
ID_AA64PFR1_EL1.GCS, allowing guests to be given the feature.
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
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 dfb96edbdc43..e588820b1be7 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -1632,11 +1632,10 @@ 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 3d9f4eb9d093..ba15da63758b 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2103,10 +2103,12 @@ 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;
@@ -3344,7 +3346,6 @@ 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