From 85592114ffda568b507bc2b04f5e9afbe7c13b62 Mon Sep 17 00:00:00 2001 From: Alexandru Elisei Date: Wed, 12 Nov 2025 10:28:53 +0000 Subject: [PATCH] KVM: arm64: VHE: Compute fgt traps before activating them On VHE, the Fine Grain Traps registers are written to hardware in kvm_arch_vcpu_load()->..->__activate_traps_hfgxtr(), but the fgt array is computed later, in kvm_vcpu_load_fgt(). This can lead to zero being written to the FGT registers the first time a VCPU is loaded. Also, any changes to the fgt array will be visible only after the VCPU is scheduled out, and then back in, which is not the intended behaviour. Fix it by computing the fgt array just before the fgt traps are written to hardware. Fixes: fb10ddf35c1c ("KVM: arm64: Compute per-vCPU FGTs at vcpu_load()") Signed-off-by: Alexandru Elisei Reviewed-by: Oliver Upton Link: https://patch.msgid.link/20251112102853.47759-1-alexandru.elisei@arm.com Signed-off-by: Marc Zyngier --- arch/arm64/kvm/arm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 870953b4a8a7..052bf0d4d0b0 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -624,6 +624,7 @@ nommu: kvm_timer_vcpu_load(vcpu); kvm_vgic_load(vcpu); kvm_vcpu_load_debug(vcpu); + kvm_vcpu_load_fgt(vcpu); if (has_vhe()) kvm_vcpu_load_vhe(vcpu); kvm_arch_vcpu_load_fp(vcpu); @@ -642,7 +643,6 @@ nommu: vcpu->arch.hcr_el2 |= HCR_TWI; vcpu_set_pauth_traps(vcpu); - kvm_vcpu_load_fgt(vcpu); if (is_protected_kvm_enabled()) { kvm_call_hyp_nvhe(__pkvm_vcpu_load, -- 2.47.3