Re: [RFC v2 6/6] hw/arm/virt: vTPM support

[Stefan Berger <stefanb@linux.ibm.com>]

On 2/14/20 1:37 PM, Eric Auger wrote:
> Let the TPM TIS SYSBUS device be dynamically instantiable
> in ARM virt.  A device tree node is dynamically created
> (TPM via MMIO).
>
> The TPM Physical Presence interface (PPI) is not supported.
>
> To run with the swtmp TPM emulator, the qemu command line must
> be augmented with:
>
>          -chardev socket,id=chrtpm,path=swtpm-sock \
>          -tpmdev emulator,id=tpm0,chardev=chrtpm \
>          -device tpm-tis-device,tpmdev=tpm0 \
>
> swtpm/libtpms command line example:
>
> swtpm socket --tpm2 -t -d --tpmstate dir=/tmp/tpm \
> --ctrl type=unixio,path=swtpm-sock


Can you also extend docs/spec/tpm.rst for the arm case? And the test 
cases should probably also cover the arm sysbus device.


>
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> ---
>   hw/arm/Kconfig      |  1 +
>   hw/arm/sysbus-fdt.c | 36 ++++++++++++++++++++++++++++++++++++
>   hw/arm/virt.c       |  7 +++++++
>   3 files changed, 44 insertions(+)
>
> diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
> index 3d86691ae0..b6f03f7f53 100644
> --- a/hw/arm/Kconfig
> +++ b/hw/arm/Kconfig
> @@ -5,6 +5,7 @@ config ARM_VIRT
>       imply VFIO_AMD_XGBE
>       imply VFIO_PLATFORM
>       imply VFIO_XGMAC
> +    imply TPM_TIS_SYSBUS
>       select A15MPCORE
>       select ACPI
>       select ARM_SMMUV3
> diff --git a/hw/arm/sysbus-fdt.c b/hw/arm/sysbus-fdt.c
> index 022fc97ecd..adf50444c2 100644
> --- a/hw/arm/sysbus-fdt.c
> +++ b/hw/arm/sysbus-fdt.c
> @@ -30,6 +30,7 @@
>   #include "hw/arm/sysbus-fdt.h"
>   #include "qemu/error-report.h"
>   #include "sysemu/device_tree.h"
> +#include "sysemu/tpm.h"
>   #include "hw/platform-bus.h"
>   #include "hw/vfio/vfio-platform.h"
>   #include "hw/vfio/vfio-calxeda-xgmac.h"
> @@ -434,6 +435,40 @@ static bool vfio_platform_match(SysBusDevice *sbdev,
>   #define VFIO_PLATFORM_BINDING(compat, add_fn) \
>       {TYPE_VFIO_PLATFORM, (compat), (add_fn), vfio_platform_match}
>   
> +/*
> + * add_tpm_tis_fdt_node: Create a DT node for TPM TIS
> + *
> + * See kernel documentation:
> + * Documentation/devicetree/bindings/security/tpm/tpm_tis_mmio.txt
> + * Optional interrupt for command completion is not exposed
> + */
> +static int add_tpm_tis_fdt_node(SysBusDevice *sbdev, void *opaque)
> +{
> +    PlatformBusFDTData *data = opaque;
> +    PlatformBusDevice *pbus = data->pbus;
> +    void *fdt = data->fdt;
> +    const char *parent_node = data->pbus_node_name;
> +    int compat_str_len;
> +    char *nodename;
> +    uint32_t reg_attr[2];
> +    uint64_t mmio_base;
> +
> +    mmio_base = platform_bus_get_mmio_addr(pbus, sbdev, 0);

I suppose any conditional creation of this device tree entry is covered 
with the TYPE_BINDING below, meaning no device tree is created if the 
device wasn't added.


> +    nodename = g_strdup_printf("%s/tpm_tis@%" PRIx64, parent_node, mmio_base);
> +    qemu_fdt_add_subnode(fdt, nodename);
> +
> +    compat_str_len = strlen("tcg,tpm-tis-mmio") + 1;
> +    qemu_fdt_setprop(fdt, nodename, "compatible", "tcg,tpm-tis-mmio",
> +                     compat_str_len);

You probably can use qemu_fdt_setprop_string()?


> +
> +    reg_attr[0] = cpu_to_be32(mmio_base);
> +    reg_attr[1] = cpu_to_be32(0x5000);
> +    qemu_fdt_setprop(fdt, nodename, "reg", reg_attr, 2 * sizeof(uint32_t));
> +
> +    g_free(nodename);
> +    return 0;
> +}
> +
>   #endif /* CONFIG_LINUX */
>   
>   static int no_fdt_node(SysBusDevice *sbdev, void *opaque)
> @@ -455,6 +490,7 @@ static const BindingEntry bindings[] = {
>       TYPE_BINDING(TYPE_VFIO_CALXEDA_XGMAC, add_calxeda_midway_xgmac_fdt_node),
>       TYPE_BINDING(TYPE_VFIO_AMD_XGBE, add_amd_xgbe_fdt_node),
>       VFIO_PLATFORM_BINDING("amd,xgbe-seattle-v1a", add_amd_xgbe_fdt_node),
> +    TYPE_BINDING(TYPE_TPM_TIS_SYSBUS, add_tpm_tis_fdt_node),
>   #endif
>       TYPE_BINDING(TYPE_RAMFB_DEVICE, no_fdt_node),
>       TYPE_BINDING("", NULL), /* last element */
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index f788fe27d6..4b967e39d1 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -47,6 +47,7 @@
>   #include "sysemu/numa.h"
>   #include "sysemu/runstate.h"
>   #include "sysemu/sysemu.h"
> +#include "sysemu/tpm.h"
>   #include "sysemu/kvm.h"
>   #include "hw/loader.h"
>   #include "exec/address-spaces.h"
> @@ -2041,6 +2042,7 @@ static void virt_machine_class_init(ObjectClass *oc, void *data)
>       machine_class_allow_dynamic_sysbus_dev(mc, TYPE_VFIO_AMD_XGBE);
>       machine_class_allow_dynamic_sysbus_dev(mc, TYPE_RAMFB_DEVICE);
>       machine_class_allow_dynamic_sysbus_dev(mc, TYPE_VFIO_PLATFORM);
> +    machine_class_allow_dynamic_sysbus_dev(mc, TYPE_TPM_TIS_SYSBUS);
>       mc->block_default_type = IF_VIRTIO;
>       mc->no_cdrom = 1;
>       mc->pci_allow_0_address = true;
> @@ -2153,6 +2155,11 @@ type_init(machvirt_machine_init);
>   
>   static void virt_machine_5_0_options(MachineClass *mc)
>   {
> +    static GlobalProperty compat[] = {
> +        { TYPE_TPM_TIS_SYSBUS, "ppi", "false" },
> +    };
> +
> +    compat_props_add(mc->compat_props, compat, G_N_ELEMENTS(compat));
>   }
>   DEFINE_VIRT_MACHINE_AS_LATEST(5, 0)
>