Hi Peter,
On 8/12/19 9:45 AM, Peter Xu wrote:
> Instead of bailing out when trying to hotplug a vfio-pci device with
> below configuration:
>
> -device intel-iommu,caching-mode=off
>
> With this we can return a warning message to the user via QMP/HMP and
> the VM will continue to work after failing the hotplug:
>
> (qemu) device_add vfio-pci,bus=root.3,host=05:00.0,id=vfio1
> Error: Device assignment is not allowed without enabling caching-mode=on
> for Intel IOMMU.
>
> Signed-off-by: Peter Xu <pet...@redhat.com>
Reviewed-by: Eric Auger <eric.au...@redhat.com>
Eric
> ---
> hw/i386/pc.c | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 549c437050..4ea00c7bd2 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -2905,6 +2905,26 @@ static void x86_nmi(NMIState *n, int cpu_index, Error
> **errp)
> }
> }
>
> +
> +static bool pc_hotplug_allowed(MachineState *ms, DeviceState *dev, Error
> **errp)
> +{
> + X86IOMMUState *iommu = x86_iommu_get_default();
> + IntelIOMMUState *intel_iommu;
> +
> + if (iommu &&
> + object_dynamic_cast((Object *)iommu, TYPE_INTEL_IOMMU_DEVICE) &&
> + object_dynamic_cast((Object *)dev, "vfio-pci")) {
> + intel_iommu = INTEL_IOMMU_DEVICE(iommu);
> + if (!intel_iommu->caching_mode) {
> + error_setg(errp, "Device assignment is not allowed without "
> + "enabling caching-mode=on for Intel IOMMU.");
> + return false;
> + }
> + }
> +
> + return true;
> +}
> +
> static void pc_machine_class_init(ObjectClass *oc, void *data)
> {
> MachineClass *mc = MACHINE_CLASS(oc);
> @@ -2929,6 +2949,7 @@ static void pc_machine_class_init(ObjectClass *oc, void
> *data)
> pcmc->pvh_enabled = true;
> assert(!mc->get_hotplug_handler);
> mc->get_hotplug_handler = pc_get_hotplug_handler;
> + mc->hotplug_allowed = pc_hotplug_allowed;
> mc->cpu_index_to_instance_props = pc_cpu_index_to_props;
> mc->get_default_cpu_node_id = pc_get_default_cpu_node_id;
> mc->possible_cpu_arch_ids = pc_possible_cpu_arch_ids;
>
