As it turns out, not all the interrupt controllers are able to expose a vGIC maintenance interrupt as a distrete signal. And to be fair, it doesn't really matter as all we require is for *something* to kick us out of guest mode out way or another.
On systems that do not expose a maintenance interrupt as such, there are two outcomes: - either the virtual CPUIF does generate an interrupt, and by the time we are back to the host the interrupt will have long been disabled (as we set ICH_HCR_EL2.EN to 0 on exit). In this case, interrupt latency is as good as it gets. - or some other event (physical timer) will take us out of the guest anyway, and the only drawback is a bad interrupt latency. So let's be tolerant to the lack of maintenance interrupt, and just let the user know that their mileage may vary... Signed-off-by: Marc Zyngier <[email protected]> --- arch/arm64/kvm/vgic/vgic-init.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c index 9b491263f5f7..00c75495fd0c 100644 --- a/arch/arm64/kvm/vgic/vgic-init.c +++ b/arch/arm64/kvm/vgic/vgic-init.c @@ -521,11 +521,6 @@ int kvm_vgic_hyp_init(void) if (!gic_kvm_info) return -ENODEV; - if (!gic_kvm_info->maint_irq) { - kvm_err("No vgic maintenance irq\n"); - return -ENXIO; - } - switch (gic_kvm_info->type) { case GIC_V2: ret = vgic_v2_probe(gic_kvm_info); @@ -549,6 +544,11 @@ int kvm_vgic_hyp_init(void) if (ret) return ret; + if (!kvm_vgic_global_state.maint_irq) { + kvm_err("No maintenance interrupt available, fingers crossed...\n"); + return 0; + } + ret = request_percpu_irq(kvm_vgic_global_state.maint_irq, vgic_maintenance_handler, "vgic", kvm_get_running_vcpus()); -- 2.29.2 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
