/*
* Return the GIC CPU configuration:
* - [31:0] ICH_VTR_EL2
- * - [63:32] RES0
+ * - [62:32] RES0
+ * - [63] MMIO (GICv2) capable
*/
u64 __vgic_v3_get_gic_config(void)
{
- return read_gicreg(ICH_VTR_EL2);
+ u64 val, sre = read_gicreg(ICC_SRE_EL1);
+ unsigned long flags = 0;
+
+ /*
+ * To check whether we have a MMIO-based (GICv2 compatible)
+ * CPU interface, we need to disable the system register
+ * view. To do that safely, we have to prevent any interrupt
+ * from firing (which would be deadly).
+ *
+ * Note that this only makes sense on VHE, as interrupts are
+ * already masked for nVHE as part of the exception entry to
+ * EL2.
+ */
+ if (has_vhe())
+ flags = local_daif_save();
+
+ write_gicreg(0, ICC_SRE_EL1);
+ isb();
+
+ val = read_gicreg(ICC_SRE_EL1);
+
+ write_gicreg(sre, ICC_SRE_EL1);
+ isb();
+
+ if (has_vhe())
+ local_daif_restore(flags);
+
+ val = (val & ICC_SRE_EL1_SRE) ? 0 : (1ULL << 63);
+ val |= read_gicreg(ICH_VTR_EL2);
+
+ return val;
}
u64 __vgic_v3_read_vmcr(void)
int vgic_v3_probe(const struct gic_kvm_info *info)
{
u64 ich_vtr_el2 = kvm_call_hyp_ret(__vgic_v3_get_gic_config);
+ bool has_v2;
int ret;
+ has_v2 = ich_vtr_el2 >> 63;
ich_vtr_el2 = (u32)ich_vtr_el2;
/*
gicv4_enable ? "en" : "dis");
}
+ kvm_vgic_global_state.vcpu_base = 0;
+
if (!info->vcpu.start) {
kvm_info("GICv3: no GICV resource entry\n");
- kvm_vgic_global_state.vcpu_base = 0;
+ } else if (!has_v2) {
+ pr_warn(FW_BUG "CPU interface incapable of MMIO access\n");
} else if (!PAGE_ALIGNED(info->vcpu.start)) {
pr_warn("GICV physical address 0x%llx not page aligned\n",
(unsigned long long)info->vcpu.start);
- kvm_vgic_global_state.vcpu_base = 0;
} else {
kvm_vgic_global_state.vcpu_base = info->vcpu.start;
kvm_vgic_global_state.can_emulate_gicv2 = true;