On Wed, 20 Oct 2021 18:27:37 +0100
Jean-Philippe Brucker <jean-phili...@linaro.org> wrote:
> We're about to support a third vIOMMU for x86, virtio-iommu which
> doesn't inherit X86IOMMUState. Move the IOMMU singleton into
> PCMachineState, so it can be shared between all three vIOMMUs.
>
> The x86_iommu_get_default() helper is still needed by KVM and IOAPIC to
> fetch the default IRQ-remapping IOMMU. Since virtio-iommu doesn't
> support IRQ remapping, this interface doesn't need to change for the
> moment. We could later replace X86IOMMUState with an "IRQ remapping
> IOMMU" interface if necessary.
>
> Signed-off-by: Jean-Philippe Brucker <jean-phili...@linaro.org>
Reviewed-by: Igor Mammedov <imamm...@redhat.com>
> ---
> include/hw/i386/pc.h | 1 +
> hw/i386/pc.c | 12 +++++++++++-
> hw/i386/x86-iommu.c | 26 ++++++++------------------
> 3 files changed, 20 insertions(+), 19 deletions(-)
>
> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
> index 11426e26dc..b72e5bf9d1 100644
> --- a/include/hw/i386/pc.h
> +++ b/include/hw/i386/pc.h
> @@ -35,6 +35,7 @@ typedef struct PCMachineState {
> I2CBus *smbus;
> PFlashCFI01 *flash[2];
> ISADevice *pcspk;
> + DeviceState *iommu;
>
> /* Configuration options: */
> uint64_t max_ram_below_4g;
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 54e4c00dce..fcbf328e8d 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -1330,6 +1330,15 @@ static void
> pc_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
> } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
> object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
> pc_virtio_md_pci_pre_plug(hotplug_dev, dev, errp);
> + } else if (object_dynamic_cast(OBJECT(dev), TYPE_X86_IOMMU_DEVICE)) {
> + PCMachineState *pcms = PC_MACHINE(hotplug_dev);
> +
> + if (pcms->iommu) {
> + error_setg(errp, "QEMU does not support multiple vIOMMUs "
> + "for x86 yet.");
> + return;
> + }
> + pcms->iommu = dev;
> }
> }
>
> @@ -1384,7 +1393,8 @@ static HotplugHandler
> *pc_get_hotplug_handler(MachineState *machine,
> if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM) ||
> object_dynamic_cast(OBJECT(dev), TYPE_CPU) ||
> object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
> - object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
> + object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI) ||
> + object_dynamic_cast(OBJECT(dev), TYPE_X86_IOMMU_DEVICE)) {
> return HOTPLUG_HANDLER(machine);
> }
>
> diff --git a/hw/i386/x86-iommu.c b/hw/i386/x86-iommu.c
> index dc968c7a53..01d11325a6 100644
> --- a/hw/i386/x86-iommu.c
> +++ b/hw/i386/x86-iommu.c
> @@ -77,25 +77,17 @@ void x86_iommu_irq_to_msi_message(X86IOMMUIrq *irq,
> MSIMessage *msg_out)
> msg_out->data = msg.msi_data;
> }
>
> -/* Default X86 IOMMU device */
> -static X86IOMMUState *x86_iommu_default = NULL;
> -
> -static void x86_iommu_set_default(X86IOMMUState *x86_iommu)
> +X86IOMMUState *x86_iommu_get_default(void)
> {
> - assert(x86_iommu);
> + MachineState *ms = MACHINE(qdev_get_machine());
> + PCMachineState *pcms =
> + PC_MACHINE(object_dynamic_cast(OBJECT(ms), TYPE_PC_MACHINE));
>
> - if (x86_iommu_default) {
> - error_report("QEMU does not support multiple vIOMMUs "
> - "for x86 yet.");
> - exit(1);
> + if (pcms &&
> + object_dynamic_cast(OBJECT(pcms->iommu), TYPE_X86_IOMMU_DEVICE)) {
> + return X86_IOMMU_DEVICE(pcms->iommu);
> }
> -
> - x86_iommu_default = x86_iommu;
> -}
> -
> -X86IOMMUState *x86_iommu_get_default(void)
> -{
> - return x86_iommu_default;
> + return NULL;
> }
>
> static void x86_iommu_realize(DeviceState *dev, Error **errp)
> @@ -131,8 +123,6 @@ static void x86_iommu_realize(DeviceState *dev, Error
> **errp)
> if (x86_class->realize) {
> x86_class->realize(dev, errp);
> }
> -
> - x86_iommu_set_default(X86_IOMMU_DEVICE(dev));
> }
>
> static Property x86_iommu_properties[] = {
