KVM: arm64: Enable GICv3 Group-0 sysreg trapping via command-line

[mirror_ubuntu-zesty-kernel.git] / virt / kvm / arm / vgic / vgic-v3.c

diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index e6b03fd8c374ca7a4dcb1e272141504f66c697d6..f0ace9792270dd45d60e35419504674d3043b440 100644 (file)
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -60,6 +60,9 @@ void vgic_v3_process_maintenance(struct kvm_vcpu *vcpu)
        cpuif->vgic_hcr &= ~ICH_HCR_UIE;
 }
 
+static bool group0_trap;
+static bool group1_trap;
+
 void vgic_v3_set_underflow(struct kvm_vcpu *vcpu)
 {
        struct vgic_v3_cpu_if *cpuif = &vcpu->arch.vgic_cpu.vgic_v3;
@@ -226,6 +229,10 @@ void vgic_v3_enable(struct kvm_vcpu *vcpu)
 
        /* Get the show on the road... */
        vgic_v3->vgic_hcr = ICH_HCR_EN;
+       if (group0_trap)
+               vgic_v3->vgic_hcr |= ICH_HCR_TALL0;
+       if (group1_trap)
+               vgic_v3->vgic_hcr |= ICH_HCR_TALL1;
 }
 
 /* check for overlapping regions and for regions crossing the end of memory */
@@ -305,6 +312,20 @@ out:
        return ret;
 }
 
+DEFINE_STATIC_KEY_FALSE(vgic_v3_cpuif_trap);
+
+static int __init early_group0_trap_cfg(char *buf)
+{
+       return strtobool(buf, &group0_trap);
+}
+early_param("kvm-arm.vgic_v3_group0_trap", early_group0_trap_cfg);
+
+static int __init early_group1_trap_cfg(char *buf)
+{
+       return strtobool(buf, &group1_trap);
+}
+early_param("kvm-arm.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
@@ -355,6 +376,11 @@ 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 (group0_trap || 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;