diff options
Diffstat (limited to 'arch/arm64/kvm/hyp/vgic-v3-sr.c')
| -rw-r--r-- | arch/arm64/kvm/hyp/vgic-v3-sr.c | 49 |
1 files changed, 47 insertions, 2 deletions
diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c b/arch/arm64/kvm/hyp/vgic-v3-sr.c index 80406f463c28..39f8f7f9227c 100644 --- a/arch/arm64/kvm/hyp/vgic-v3-sr.c +++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c @@ -405,9 +405,54 @@ void __vgic_v3_init_lrs(void) __gic_v3_set_lr(0, i); } -u64 __vgic_v3_get_ich_vtr_el2(void) +/* + * Return the GIC CPU configuration: + * - [31:0] ICH_VTR_EL2 + * - [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(); + + /* + * Table 11-2 "Permitted ICC_SRE_ELx.SRE settings" indicates + * that to be able to set ICC_SRE_EL1.SRE to 0, all the + * interrupt overrides must be set. You've got to love this. + */ + sysreg_clear_set(hcr_el2, 0, HCR_AMO | HCR_FMO | HCR_IMO); + isb(); + write_gicreg(0, ICC_SRE_EL1); + isb(); + + val = read_gicreg(ICC_SRE_EL1); + + write_gicreg(sre, ICC_SRE_EL1); + isb(); + sysreg_clear_set(hcr_el2, HCR_AMO | HCR_FMO | HCR_IMO, 0); + 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) |