Re: [PATCH v15 5/6] KVM: arm64: Allow GCS to be enabled for guests

On Wed, 20 Aug 2025 15:14:45 +0100, Mark Brown broonie@kernel.org wrote:

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@kernel.org

arch/arm64/kvm/sys_regs.c | 1 - 1 file changed, 1 deletion(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 592cb5d6497a..60e234422064 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1616,7 +1616,6 @@ static u64 __kvm_read_sanitised_id_reg(const struct kvm_vcpu *vcpu, val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_SME); val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_RNDR_trap); val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_NMI);

• val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_GCS);
  

  val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_THE); val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MTEX); val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_PFAR);

Still disabled for NV in limit_nv_id_reg().

M.