On Fri, 1 Oct 2021 18:33:55 +0100
Jean-Philippe Brucker <jean-phili...@linaro.org> wrote:
> Allow instantiating a virtio-iommu device by adding an ACPI Virtual I/O
> Translation table (VIOT), which describes the relation between the
> virtio-iommu and the endpoints it manages.
>
> Add a hotplug handler for virtio-iommu on x86 and set the necessary
> reserved region property. On x86, the [0xfee00000, 0xfeefffff] DMA
> region is reserved for MSIs. DMA transactions to this range either
> trigger IRQ remapping in the IOMMU or bypasses IOMMU translation.
>
> Although virtio-iommu does not support IRQ remapping it must be informed
> of the reserved region so that it can forward DMA transactions targeting
> this region.
>
> Signed-off-by: Jean-Philippe Brucker <jean-phili...@linaro.org>
> ---
> include/hw/i386/pc.h | 2 ++
> hw/i386/acpi-build.c | 5 +++++
> hw/i386/pc.c | 24 ++++++++++++++++++++++--
> hw/i386/Kconfig | 1 +
> 4 files changed, 30 insertions(+), 2 deletions(-)
>
> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
> index 82cf7b7e30..f3ba1ee4c0 100644
> --- a/include/hw/i386/pc.h
> +++ b/include/hw/i386/pc.h
> @@ -45,6 +45,8 @@ typedef struct PCMachineState {
> bool pit_enabled;
> bool hpet_enabled;
> bool default_bus_bypass_iommu;
> + bool virtio_iommu;
> + uint16_t virtio_iommu_bdf;
> uint64_t max_fw_size;
>
> /* ACPI Memory hotplug IO base address */
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index d1c28440f4..4e46585709 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -71,6 +71,7 @@
>
> #include "hw/acpi/ipmi.h"
> #include "hw/acpi/hmat.h"
> +#include "hw/acpi/viot.h"
>
> /* These are used to size the ACPI tables for -M pc-i440fx-1.7 and
> * -M pc-i440fx-2.0. Even if the actual amount of AML generated grows
> @@ -2593,6 +2594,10 @@ void acpi_build(AcpiBuildTables *tables, MachineState
> *machine)
> build_dmar_q35(tables_blob, tables->linker, x86ms->oem_id,
> x86ms->oem_table_id);
> }
> + } else if (pcms->virtio_iommu) {
> + acpi_add_table(table_offsets, tables_blob);
> + build_viot(machine, tables_blob, tables->linker,
> pcms->virtio_iommu_bdf,
I'd drop PCMachineState::virtio_iommu_bdf and
s/pcms->virtio_iommu_bdf/pci_get_bdf(iommu)/
> + x86ms->oem_id, x86ms->oem_table_id);
> }
> if (machine->nvdimms_state->is_enabled) {
> nvdimm_build_acpi(table_offsets, tables_blob, tables->linker,
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 789ccb6ef4..31710bc4fb 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -83,6 +83,7 @@
> #include "hw/i386/intel_iommu.h"
> #include "hw/net/ne2000-isa.h"
> #include "standard-headers/asm-x86/bootparam.h"
> +#include "hw/virtio/virtio-iommu.h"
> #include "hw/virtio/virtio-pmem-pci.h"
> #include "hw/virtio/virtio-mem-pci.h"
> #include "hw/mem/memory-device.h"
> @@ -1367,8 +1368,11 @@ static void pc_virtio_md_pci_unplug(HotplugHandler
> *hotplug_dev,
> static void pc_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
> DeviceState *dev, Error **errp)
> {
> - if (object_dynamic_cast(OBJECT(dev), TYPE_X86_IOMMU_DEVICE) &&
> - x86_iommu_get_default()) {
> + PCMachineState *pcms = PC_MACHINE(hotplug_dev);
> +
> + if ((object_dynamic_cast(OBJECT(dev), TYPE_X86_IOMMU_DEVICE) ||
> + object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_IOMMU_PCI)) &&
> + (x86_iommu_get_default() || pcms->virtio_iommu)) {
this check is getting uglier,
may be instead of introducing pcms->virtio_iommu boolean, better approach
would be adding 'Device* PCMachineState::iommu' and setting it to IOMMU
so the check would reduce to:
if ((object_dynamic_cast(OBJECT(dev), TYPE_X86_IOMMU_DEVICE) ||
object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_IOMMU_PCI)))
{
if (pcms->iommu)
err
else set pcms->iommu in plug handler or here
}
that also will let to cleanup/get rid of x86_iommu_[s|g]et_default()
and x86_iommu_default 'global'.
Maybe replace previous patch with one that would remove
x86_iommu_[s|g]et_default().
> error_setg(errp, "QEMU does not support multiple vIOMMUs "
> "for x86 yet.");
> return;
> @@ -1381,6 +1385,15 @@ 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_VIRTIO_IOMMU_PCI)) {
> + /* Declare the APIC range as the reserved MSI region */
> + char *resv_prop_str = g_strdup_printf("0xfee00000:0xfeefffff:%d",
> + VIRTIO_IOMMU_RESV_MEM_T_MSI);
> +
> + object_property_set_uint(OBJECT(dev), "len-reserved-regions", 1,
> errp);
> + object_property_set_str(OBJECT(dev), "reserved-regions[0]",
> + resv_prop_str, errp);
> + g_free(resv_prop_str);
> }
> }
>
> @@ -1394,6 +1407,12 @@ static void pc_machine_device_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_plug(hotplug_dev, dev, errp);
> + } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_IOMMU_PCI)) {
> + PCMachineState *pcms = PC_MACHINE(hotplug_dev);
> + PCIDevice *pdev = PCI_DEVICE(dev);
> +
> + pcms->virtio_iommu = true;
> + pcms->virtio_iommu_bdf = pci_get_bdf(pdev);
> }
> }
>
> @@ -1436,6 +1455,7 @@ static HotplugHandler
> *pc_get_hotplug_handler(MachineState *machine,
> 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_IOMMU_PCI) ||
> object_dynamic_cast(OBJECT(dev), TYPE_X86_IOMMU_DEVICE)) {
> return HOTPLUG_HANDLER(machine);
> }
> diff --git a/hw/i386/Kconfig b/hw/i386/Kconfig
> index ddedcef0b2..13db05d557 100644
> --- a/hw/i386/Kconfig
> +++ b/hw/i386/Kconfig
> @@ -54,6 +54,7 @@ config PC_ACPI
> select ACPI_X86
> select ACPI_CPU_HOTPLUG
> select ACPI_MEMORY_HOTPLUG
> + select ACPI_VIOT
> select SMBUS_EEPROM
> select PFLASH_CFI01
> depends on ACPI_SMBUS
