Now that we're able to safely handle Group-1 sysreg access, let's give the user the opportunity to enable it by passing a specific command-line option (vgic_v3.group1_trap).
Signed-off-by: Marc Zyngier <[email protected]> --- virt/kvm/arm/hyp/vgic-v3-sr.c | 6 +++++- virt/kvm/arm/vgic/vgic-v3.c | 11 +++++++++++ 2 files changed, 16 insertions(+), 1 deletion(-) diff --git a/virt/kvm/arm/hyp/vgic-v3-sr.c b/virt/kvm/arm/hyp/vgic-v3-sr.c index 8973bad35748..42ac9ee7650a 100644 --- a/virt/kvm/arm/hyp/vgic-v3-sr.c +++ b/virt/kvm/arm/hyp/vgic-v3-sr.c @@ -334,7 +334,11 @@ void __hyp_text __vgic_v3_restore_state(struct kvm_vcpu *vcpu) for (i = 0; i < used_lrs; i++) __gic_v3_set_lr(cpu_if->vgic_lr[i], i); } else { - /* Always write ICH_HCR_EL2 to enable trapping */ + /* + * If we don't have any interrupt to inject, but that + * trapping is enabled, write the ICH_HCR_EL2 config + * anyway. + */ if (static_branch_unlikely(&vgic_v3_cpuif_trap)) write_gicreg(cpu_if->vgic_hcr, ICH_HCR_EL2); } diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c index fbd678bc046d..a16769276efd 100644 --- a/virt/kvm/arm/vgic/vgic-v3.c +++ b/virt/kvm/arm/vgic/vgic-v3.c @@ -416,6 +416,12 @@ int vgic_v3_map_resources(struct kvm *kvm) DEFINE_STATIC_KEY_FALSE(vgic_v3_cpuif_trap); +static int __init early_group1_trap_cfg(char *buf) +{ + return strtobool(buf, &group1_trap); +} +early_param("vgic_v3.group1_trap", early_group1_trap_cfg); + /** * vgic_v3_probe - probe for a GICv3 compatible interrupt controller in DT * @node: pointer to the DT node @@ -467,6 +473,11 @@ int vgic_v3_probe(const struct gic_kvm_info *info) if (kvm_vgic_global_state.vcpu_base == 0) kvm_info("disabling GICv2 emulation\n"); + if (group1_trap) { + kvm_info("GICv3 sysreg trapping enabled (reduced performance)\n"); + static_branch_enable(&vgic_v3_cpuif_trap); + } + kvm_vgic_global_state.vctrl_base = NULL; kvm_vgic_global_state.type = VGIC_V3; kvm_vgic_global_state.max_gic_vcpus = VGIC_V3_MAX_CPUS; -- 2.11.0 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
