Re: [RFC v2 5/6] tpm: Add the SysBus TPM TIS device

[Auger Eric]

Hi Ard,

On 2/25/20 10:52 AM, Ard Biesheuvel wrote:
> On Tue, 25 Feb 2020 at 10:19, Auger Eric <address@hidden> wrote:
>>
>> Hi,
>>
>> On 2/17/20 7:13 PM, Auger Eric wrote:
>>> Hi Stefan,
>>>
>>> On 2/16/20 7:32 PM, Stefan Berger wrote:
>>>> On 2/14/20 1:37 PM, Eric Auger wrote:
>>>>> Introduce the tpm-tis-device which is a sysbus device
>>>>> and is bound to be used on ARM.
>>>>>
>>>>> Signed-off-by: Eric Auger <address@hidden>
>>>>> ---
>>>>>   hw/tpm/Kconfig          |   5 ++
>>>>>   hw/tpm/Makefile.objs    |   1 +
>>>>>   hw/tpm/tpm_tis_sysbus.c | 159 ++++++++++++++++++++++++++++++++++++++++
>>>>>   include/sysemu/tpm.h    |   1 +
>>>>>   4 files changed, 166 insertions(+)
>>>>>   create mode 100644 hw/tpm/tpm_tis_sysbus.c
>>>>>
>>>>> diff --git a/hw/tpm/Kconfig b/hw/tpm/Kconfig
>>>>> index 686f8206bb..4794e7fe28 100644
>>>>> --- a/hw/tpm/Kconfig
>>>>> +++ b/hw/tpm/Kconfig
>>>>> @@ -7,6 +7,11 @@ config TPM_TIS_ISA
>>>>>       depends on TPM && ISA_BUS
>>>>>       select TPM_TIS
>>>>>   +config TPM_TIS_SYSBUS
>>>>> +    bool
>>>>> +    depends on TPM
>>>>> +    select TPM_TIS
>>>>> +
>>>>>   config TPM_TIS
>>>>>       bool
>>>>>       depends on TPM
>>>>> diff --git a/hw/tpm/Makefile.objs b/hw/tpm/Makefile.objs
>>>>> index 3ef2036cca..f1ec4beb95 100644
>>>>> --- a/hw/tpm/Makefile.objs
>>>>> +++ b/hw/tpm/Makefile.objs
>>>>> @@ -1,6 +1,7 @@
>>>>>   common-obj-$(CONFIG_TPM) += tpm_util.o
>>>>>   obj-$(call lor,$(CONFIG_TPM_TIS),$(CONFIG_TPM_CRB)) += tpm_ppi.o
>>>>>   common-obj-$(CONFIG_TPM_TIS_ISA) += tpm_tis_isa.o
>>>>> +common-obj-$(CONFIG_TPM_TIS_SYSBUS) += tpm_tis_sysbus.o
>>>>>   common-obj-$(CONFIG_TPM_TIS) += tpm_tis_common.o
>>>>>   common-obj-$(CONFIG_TPM_CRB) += tpm_crb.o
>>>>>   common-obj-$(CONFIG_TPM_PASSTHROUGH) += tpm_passthrough.o
>>>>> diff --git a/hw/tpm/tpm_tis_sysbus.c b/hw/tpm/tpm_tis_sysbus.c
>>>>> new file mode 100644
>>>>> index 0000000000..18c02aed67
>>>>> --- /dev/null
>>>>> +++ b/hw/tpm/tpm_tis_sysbus.c
>>>>> @@ -0,0 +1,159 @@
>>>>> +/*
>>>>> + * tpm_tis_sysbus.c - QEMU's TPM TIS SYSBUS Device
>>>>> + *
>>>>> + * Copyright (C) 2006,2010-2013 IBM Corporation
>>>>> + *
>>>>> + * Authors:
>>>>> + *  Stefan Berger <address@hidden>
>>>>> + *  David Safford <address@hidden>
>>>>> + *
>>>>> + * Xen 4 support: Andrease Niederl <address@hidden>
>>>>> + *
>>>>> + * This work is licensed under the terms of the GNU GPL, version 2 or
>>>>> later.
>>>>> + * See the COPYING file in the top-level directory.
>>>>> + *
>>>>> + * Implementation of the TIS interface according to specs found at
>>>>> + * http://www.trustedcomputinggroup.org. This implementation currently
>>>>> + * supports version 1.3, 21 March 2013
>>>>> + * In the developers menu choose the PC Client section then find the TIS
>>>>> + * specification.
>>>>> + *
>>>>> + * TPM TIS for TPM 2 implementation following TCG PC Client Platform
>>>>> + * TPM Profile (PTP) Specification, Familiy 2.0, Revision 00.43
>>>>> + */
>>>>> +
>>>>> +#include "qemu/osdep.h"
>>>>> +#include "hw/qdev-properties.h"
>>>>> +#include "migration/vmstate.h"
>>>>> +#include "tpm_util.h"
>>>>> +#include "hw/sysbus.h"
>>>>> +#include "tpm_tis.h"
>>>>> +
>>>>> +typedef struct TPMStateSysBus {
>>>>> +    /*< private >*/
>>>>> +    SysBusDevice parent_obj;
>>>>> +
>>>>> +    /*< public >*/
>>>>> +    TPMState state; /* not a QOM object */
>>>>> +} TPMStateSysBus;
>>>>> +
>>>>> +#define TPM_TIS_SYSBUS(obj) OBJECT_CHECK(TPMStateSysBus, (obj),
>>>>> TYPE_TPM_TIS_SYSBUS)
>>>>> +
>>>>> +static int tpm_tis_pre_save_sysbus(void *opaque)
>>>>> +{
>>>>> +    TPMStateSysBus *sbdev = opaque;
>>>>> +
>>>>> +    return tpm_tis_pre_save(&sbdev->state);
>>>>> +}
>>>>> +
>>>>> +static const VMStateDescription vmstate_tpm_tis_sysbus = {
>>>>> +    .name = "tpm-tis",
>>>>> +    .version_id = 0,
>>>>> +    .pre_save  = tpm_tis_pre_save_sysbus,
>>>>> +    .fields = (VMStateField[]) {
>>>>> +        VMSTATE_BUFFER(state.buffer, TPMStateSysBus),
>>>>> +        VMSTATE_UINT16(state.rw_offset, TPMStateSysBus),
>>>>> +        VMSTATE_UINT8(state.active_locty, TPMStateSysBus),
>>>>> +        VMSTATE_UINT8(state.aborting_locty, TPMStateSysBus),
>>>>> +        VMSTATE_UINT8(state.next_locty, TPMStateSysBus),
>>>>> +
>>>>> +        VMSTATE_STRUCT_ARRAY(state.loc, TPMStateSysBus,
>>>>> TPM_TIS_NUM_LOCALITIES,
>>>>> +                             0, vmstate_locty, TPMLocality),
>>>>> +
>>>>> +        VMSTATE_END_OF_LIST()
>>>>> +    }
>>>>> +};
>>>>> +
>>>>> +static void tpm_tis_sysbus_request_completed(TPMIf *ti, int ret)
>>>>> +{
>>>>> +    TPMStateSysBus *sbdev = TPM_TIS_SYSBUS(ti);
>>>>> +    TPMState *s = &sbdev->state;
>>>>> +
>>>>> +    tpm_tis_request_completed(s, ret);
>>>>> +}
>>>>> +
>>>>> +static enum TPMVersion tpm_tis_sysbus_get_tpm_version(TPMIf *ti)
>>>>> +{
>>>>> +    TPMStateSysBus *sbdev = TPM_TIS_SYSBUS(ti);
>>>>> +    TPMState *s = &sbdev->state;
>>>>> +
>>>>> +    return tpm_tis_get_tpm_version(s);
>>>>> +}
>>>>> +
>>>>> +static void tpm_tis_sysbus_reset(DeviceState *dev)
>>>>> +{
>>>>> +    TPMStateSysBus *sbdev = TPM_TIS_SYSBUS(dev);
>>>>> +    TPMState *s = &sbdev->state;
>>>>> +
>>>>> +    return tpm_tis_reset(s);
>>>>> +}
>>>>> +
>>>>> +static Property tpm_tis_sysbus_properties[] = {
>>>>> +    DEFINE_PROP_UINT32("irq", TPMStateSysBus, state.irq_num,
>>>>> TPM_TIS_IRQ),
>>>>> +    DEFINE_PROP_TPMBE("tpmdev", TPMStateSysBus, state.be_driver),
>>>>> +    DEFINE_PROP_BOOL("ppi", TPMStateSysBus, state.ppi_enabled, true),
>>>>> +    DEFINE_PROP_END_OF_LIST(),
>>>>> +};
>>>>> +
>>>>> +static void tpm_tis_sysbus_initfn(Object *obj)
>>>>> +{
>>>>> +    TPMStateSysBus *sbdev = TPM_TIS_SYSBUS(obj);
>>>>> +    TPMState *s = &sbdev->state;
>>>>> +
>>>>> +    memory_region_init_io(&s->mmio, obj, &tpm_tis_memory_ops,
>>>>> +                          s, "tpm-tis-mmio",
>>>>> +                          TPM_TIS_NUM_LOCALITIES <<
>>>>> TPM_TIS_LOCALITY_SHIFT);
>>>>> +
>>>>> +    sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
>>>>> +    sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irq);
>>>>> +}
>>>>> +
>>>>> +static void tpm_tis_sysbus_realizefn(DeviceState *dev, Error **errp)
>>>>> +{
>>>>> +    TPMStateSysBus *sbdev = TPM_TIS_SYSBUS(dev);
>>>>> +    TPMState *s = &sbdev->state;
>>>>> +
>>>>> +    if (!tpm_find()) {
>>>>> +        error_setg(errp, "at most one TPM device is permitted");
>>>>> +        return;
>>>>> +    }
>>>>> +
>>>>> +    if (!s->be_driver) {
>>>>> +        error_setg(errp, "'tpmdev' property is required");
>>>>> +        return;
>>>>> +    }
>>>>> +}
>>>>> +
>>>>> +static void tpm_tis_sysbus_class_init(ObjectClass *klass, void *data)
>>>>> +{
>>>>> +    DeviceClass *dc = DEVICE_CLASS(klass);
>>>>> +    TPMIfClass *tc = TPM_IF_CLASS(klass);
>>>>> +
>>>>> +    device_class_set_props(dc, tpm_tis_sysbus_properties);
>>>>> +    dc->vmsd  = &vmstate_tpm_tis_sysbus;
>>>>> +    tc->model = TPM_MODEL_TPM_TIS;
>>>>> +    dc->realize = tpm_tis_sysbus_realizefn;
>>>>> +    dc->user_creatable = true;
>>>>> +    dc->reset = tpm_tis_sysbus_reset;
>>>>> +    tc->request_completed = tpm_tis_sysbus_request_completed;
>>>>> +    tc->get_version = tpm_tis_sysbus_get_tpm_version;
>>>>> +}
>>>>> +
>>>>> +static const TypeInfo tpm_tis_sysbus_info = {
>>>>> +    .name = TYPE_TPM_TIS_SYSBUS,
>>>>> +    .parent = TYPE_SYS_BUS_DEVICE,
>>>>> +    .instance_size = sizeof(TPMStateSysBus),
>>>>> +    .instance_init = tpm_tis_sysbus_initfn,
>>>>> +    .class_init  = tpm_tis_sysbus_class_init,
>>>>> +    .interfaces = (InterfaceInfo[]) {
>>>>> +        { TYPE_TPM_IF },
>>>>> +        { }
>>>>> +    }
>>>>> +};
>>>>> +
>>>>> +static void tpm_tis_sysbus_register(void)
>>>>> +{
>>>>> +    type_register_static(&tpm_tis_sysbus_info);
>>>>> +}
>>>>> +
>>>>> +type_init(tpm_tis_sysbus_register)
>>>>> diff --git a/include/sysemu/tpm.h b/include/sysemu/tpm.h
>>>>> index 1691b92c28..f37851b1aa 100644
>>>>> --- a/include/sysemu/tpm.h
>>>>> +++ b/include/sysemu/tpm.h
>>>>> @@ -44,6 +44,7 @@ typedef struct TPMIfClass {
>>>>>   } TPMIfClass;
>>>>>     #define TYPE_TPM_TIS_ISA            "tpm-tis"
>>>>> +#define TYPE_TPM_TIS_SYSBUS         "tpm-tis-device"
>>>>
>>>>
>>>> hm, replace the rather generic 'device' with 'sysbus'?
>>> I used the "-device" suffix because this kind of naming was used for
>>> virtio-<type>-device when based on MMIO rather than virtio-<type>-pci.
>>> For instance virtio-net-device instead of virtio-net-pci. There are
>>> quite a lot of devices using that suffix. I only see xen-sysbus with the
>>> sysbus suffix.
>>>
>>> Now personally I don't have any strong preference and I will pick up the
>>> name chosen by consensus.
>>
>> Does anyone else have an opinion on the name to be chosen for this new
>> device:
>>
>> 1) tpm-tis-device or
>> 2) tpm-tis-sysbus ?
>>
> 
> It is slightly unfortunate that we cannot retain the 'tpm-tis' name,
> given that this is simply a TPM with a memory mapped TIS frame, like
> the ISA one, and the fact that QEMU instantiates this differently
> based on the emulated architecture is really an implementation detail.
I agree with you. However I don't see any other solution. The
#ifdef'eries are frown upon. As I mentioned we have the same case for
virtio devices (virtio-net-pci vs virtio-net-device for instance).
> 
> So I prefer 'tpm-tis-device', since it doesn't define how it is backed
> under the hood, and allows us to potentially instantiate it in a
> different way in the future if we wanted to. Alternatively, something
> like 'tpm-tis-mmmio' might be appropriate.

At the moment I have chosen to keep tpm-tis-device. But as I mentioned I
am open to other choices if any consensus arises.

Thanks

Eric
>