Re: [RFC v2 2/6] tpm: Use TPMState as a common struct

[Auger Eric]

Hi Philippe,

On 2/17/20 10:21 AM, Philippe Mathieu-Daudé wrote:
> Hi Eric,
> 
> On 2/14/20 7:37 PM, Eric Auger wrote:
>> As we plan to introdce a SysBus TPM TIS device, let's
>> make the TPMState a common struct usable by both the
>> ISADevice and the SysBusDevice. TPMStateISA embeds the
>> struct and inherits from the ISADevice.
>>
>> The prototype of functions bound to be used by both
>> the ISA and SysBus devices is changed to take TPMState
>> handle.
>>
>> A bunch of structs also are renamed to be specialized
>> for the ISA device. Besides those transformations, no
>> functional change is expected.
>>
>> Signed-off-by: Eric Auger <address@hidden>
>> ---
>>   hw/tpm/tpm_tis.c | 146 +++++++++++++++++++++++++++++------------------
>>   1 file changed, 91 insertions(+), 55 deletions(-)
>>
>> diff --git a/hw/tpm/tpm_tis.c b/hw/tpm/tpm_tis.c
>> index c609737272..fc6d7ca579 100644
>> --- a/hw/tpm/tpm_tis.c
>> +++ b/hw/tpm/tpm_tis.c
>> @@ -65,7 +65,6 @@ typedef struct TPMLocality {
>>   } TPMLocality;
>>     typedef struct TPMState {
>> -    ISADevice busdev;
>>       MemoryRegion mmio;
>>         unsigned char buffer[TPM_TIS_BUFFER_MAX];
>> @@ -91,7 +90,15 @@ typedef struct TPMState {
>>       TPMPPI ppi;
>>   } TPMState;
>>   -#define TPM(obj) OBJECT_CHECK(TPMState, (obj), TYPE_TPM_TIS_ISA)
>> +typedef struct TPMStateISA {
>> +    /*< private >*/
>> +    ISADevice parent_obj;
>> +
>> +    /*< public >*/
>> +    TPMState state; /* not a QOM object */
>> +} TPMStateISA;
>> +
>> +#define TPM_TIS_ISA(obj) OBJECT_CHECK(TPMStateISA, (obj),
>> TYPE_TPM_TIS_ISA)
>>     #define DEBUG_TIS 0
>>   @@ -281,9 +288,8 @@ static void tpm_tis_prep_abort(TPMState *s,
>> uint8_t locty, uint8_t newlocty)
>>   /*
>>    * Callback from the TPM to indicate that the response was received.
>>    */
>> -static void tpm_tis_request_completed(TPMIf *ti, int ret)
>> +static void tpm_tis_request_completed(TPMState *s, int ret)
>>   {
>> -    TPMState *s = TPM(ti);
>>       uint8_t locty = s->cmd.locty;
>>       uint8_t l;
>>   @@ -338,7 +344,7 @@ static uint32_t tpm_tis_data_read(TPMState *s,
>> uint8_t locty)
>>   }
>>     #ifdef DEBUG_TIS
>> -static void tpm_tis_dump_state(void *opaque, hwaddr addr)
>> +static void tpm_tis_dump_state(TPMState *s, hwaddr addr)
>>   {
>>       static const unsigned regs[] = {
>>           TPM_TIS_REG_ACCESS,
>> @@ -353,7 +359,6 @@ static void tpm_tis_dump_state(void *opaque,
>> hwaddr addr)
>>       int idx;
>>       uint8_t locty = tpm_tis_locality_from_addr(addr);
>>       hwaddr base = addr & ~0xfff;
>> -    TPMState *s = opaque;
>>         printf("tpm_tis: active locality      : %d\n"
>>              "tpm_tis: state of locality %d : %d\n"
>> @@ -363,7 +368,7 @@ static void tpm_tis_dump_state(void *opaque,
>> hwaddr addr)
>>         for (idx = 0; regs[idx] != 0xfff; idx++) {
>>           printf("tpm_tis: 0x%04x : 0x%08x\n", regs[idx],
>> -               (int)tpm_tis_mmio_read(opaque, base + regs[idx], 4));
>> +               (int)tpm_tis_mmio_read(s, base + regs[idx], 4));
>>       }
>>         printf("tpm_tis: r/w offset    : %d\n"
>> @@ -488,7 +493,7 @@ static uint64_t tpm_tis_mmio_read(void *opaque,
>> hwaddr addr,
>>           break;
>>   #ifdef DEBUG_TIS
>>       case TPM_TIS_REG_DEBUG:
>> -        tpm_tis_dump_state(opaque, addr);
>> +        tpm_tis_dump_state(s, addr);
>>           break;
>>   #endif
>>       }
>> @@ -835,10 +840,8 @@ static const MemoryRegionOps tpm_tis_memory_ops = {
>>   /*
>>    * Get the TPMVersion of the backend device being used
>>    */
>> -static enum TPMVersion tpm_tis_get_tpm_version(TPMIf *ti)
>> +static enum TPMVersion tpm_tis_get_tpm_version(TPMState *s)
>>   {
>> -    TPMState *s = TPM(ti);
>> -
>>       if (tpm_backend_had_startup_error(s->be_driver)) {
>>           return TPM_VERSION_UNSPEC;
>>       }
>> @@ -850,9 +853,8 @@ static enum TPMVersion
>> tpm_tis_get_tpm_version(TPMIf *ti)
>>    * This function is called when the machine starts, resets or due to
>>    * S3 resume.
>>    */
>> -static void tpm_tis_reset(DeviceState *dev)
>> +static void tpm_tis_reset(TPMState *s)
>>   {
>> -    TPMState *s = TPM(dev);
>>       int c;
>>         s->be_tpm_version = tpm_backend_get_tpm_version(s->be_driver);
>> @@ -896,15 +898,14 @@ static void tpm_tis_reset(DeviceState *dev)
>>     /* persistent state handling */
>>   -static int tpm_tis_pre_save(void *opaque)
>> +static int tpm_tis_pre_save(TPMState *s)
>>   {
>> -    TPMState *s = opaque;
>>       uint8_t locty = s->active_locty;
>>         trace_tpm_tis_pre_save(locty, s->rw_offset);
>>         if (DEBUG_TIS) {
>> -        tpm_tis_dump_state(opaque, 0);
>> +        tpm_tis_dump_state(s, 0);
>>       }
>>         /*
>> @@ -929,34 +930,78 @@ static const VMStateDescription vmstate_locty = {
>>       }
>>   };
>>   -static const VMStateDescription vmstate_tpm_tis = {
>> +/* ISA */
>> +
>> +static int tpm_tis_pre_save_isa(void *opaque)
>> +{
>> +    TPMStateISA *isadev = opaque;
>> +
>> +    return tpm_tis_pre_save(&isadev->state);
>> +}
>> +
>> +static const VMStateDescription vmstate_tpm_tis_isa = {
>>       .name = "tpm-tis",
>>       .version_id = 0,
>> -    .pre_save  = tpm_tis_pre_save,
>> +    .pre_save  = tpm_tis_pre_save_isa,
>>       .fields = (VMStateField[]) {
>> -        VMSTATE_BUFFER(buffer, TPMState),
>> -        VMSTATE_UINT16(rw_offset, TPMState),
>> -        VMSTATE_UINT8(active_locty, TPMState),
>> -        VMSTATE_UINT8(aborting_locty, TPMState),
>> -        VMSTATE_UINT8(next_locty, TPMState),
>> +        VMSTATE_BUFFER(state.buffer, TPMStateISA),
>> +        VMSTATE_UINT16(state.rw_offset, TPMStateISA),
>> +        VMSTATE_UINT8(state.active_locty, TPMStateISA),
>> +        VMSTATE_UINT8(state.aborting_locty, TPMStateISA),
>> +        VMSTATE_UINT8(state.next_locty, TPMStateISA),
> 
> On a second thought these fields seem to belong to a TPMCommonState.
> Why not QOM'ify an abstract common parent between ISA and SysBus?
This would mean we have double QOM inheritance (ISADevice and Sysbus
device already being QOM devices). As far as I know this is not
supported (see qom/object.h). Here I use the same trick as the one being
used in hw/vfio/platform or pci.c and also used in hw/block/fdc.c - as
pointed out by Stefan- : see FDCtrlSysBus and FDCtrlISABus.

Thanks

Eric
> 
>>   -        VMSTATE_STRUCT_ARRAY(loc, TPMState, TPM_TIS_NUM_LOCALITIES, 0,
>> +        VMSTATE_STRUCT_ARRAY(state.loc, TPMStateISA,
>> TPM_TIS_NUM_LOCALITIES, 0,
>>                                vmstate_locty, TPMLocality),
>>             VMSTATE_END_OF_LIST()
>>       }
>>   };
>>   -static Property tpm_tis_properties[] = {
>> -    DEFINE_PROP_UINT32("irq", TPMState, irq_num, TPM_TIS_IRQ),
>> -    DEFINE_PROP_TPMBE("tpmdev", TPMState, be_driver),
>> -    DEFINE_PROP_BOOL("ppi", TPMState, ppi_enabled, true),
>> +static void tpm_tis_isa_request_completed(TPMIf *ti, int ret)
>> +{
>> +    TPMStateISA *isadev = TPM_TIS_ISA(ti);
>> +    TPMState *s = &isadev->state;
>> +
>> +    tpm_tis_request_completed(s, ret);
>> +}
>> +
>> +static enum TPMVersion tpm_tis_isa_get_tpm_version(TPMIf *ti)
>> +{
>> +    TPMStateISA *isadev = TPM_TIS_ISA(ti);
>> +    TPMState *s = &isadev->state;
>> +
>> +    return tpm_tis_get_tpm_version(s);
>> +}
>> +
>> +static void tpm_tis_isa_reset(DeviceState *dev)
>> +{
>> +    TPMStateISA *isadev = TPM_TIS_ISA(dev);
>> +    TPMState *s = &isadev->state;
>> +
>> +    return tpm_tis_reset(s);
>> +}
>> +
>> +static Property tpm_tis_isa_properties[] = {
>> +    DEFINE_PROP_UINT32("irq", TPMStateISA, state.irq_num, TPM_TIS_IRQ),
>> +    DEFINE_PROP_TPMBE("tpmdev", TPMStateISA, state.be_driver),
>> +    DEFINE_PROP_BOOL("ppi", TPMStateISA, state.ppi_enabled, true),
>>       DEFINE_PROP_END_OF_LIST(),
>>   };
>>   -static void tpm_tis_realizefn(DeviceState *dev, Error **errp)
>> +static void tpm_tis_isa_initfn(Object *obj)
>>   {
>> -    TPMState *s = TPM(dev);
>> +    TPMStateISA *isadev = TPM_TIS_ISA(obj);
>> +    TPMState *s = &isadev->state;
>> +
>> +    memory_region_init_io(&s->mmio, obj, &tpm_tis_memory_ops,
>> +                          s, "tpm-tis-mmio",
>> +                          TPM_TIS_NUM_LOCALITIES <<
>> TPM_TIS_LOCALITY_SHIFT);
>> +}
>> +
>> +static void tpm_tis_isa_realizefn(DeviceState *dev, Error **errp)
>> +{
>> +    TPMStateISA *isadev = TPM_TIS_ISA(dev);
>> +    TPMState *s = &isadev->state;
>>         if (!tpm_find()) {
>>           error_setg(errp, "at most one TPM device is permitted");
>> @@ -973,55 +1018,46 @@ static void tpm_tis_realizefn(DeviceState *dev,
>> Error **errp)
>>           return;
>>       }
>>   -    isa_init_irq(&s->busdev, &s->irq, s->irq_num);
>> +    isa_init_irq(ISA_DEVICE(dev), &s->irq, s->irq_num);
>>         memory_region_add_subregion(isa_address_space(ISA_DEVICE(dev)),
>>                                   TPM_TIS_ADDR_BASE, &s->mmio);
>>         if (s->ppi_enabled) {
>>           tpm_ppi_init(&s->ppi, isa_address_space(ISA_DEVICE(dev)),
>> -                     TPM_PPI_ADDR_BASE, OBJECT(s));
>> +                     TPM_PPI_ADDR_BASE, OBJECT(dev));
>>       }
>>   }
>>   -static void tpm_tis_initfn(Object *obj)
>> -{
>> -    TPMState *s = TPM(obj);
>> -
>> -    memory_region_init_io(&s->mmio, OBJECT(s), &tpm_tis_memory_ops,
>> -                          s, "tpm-tis-mmio",
>> -                          TPM_TIS_NUM_LOCALITIES <<
>> TPM_TIS_LOCALITY_SHIFT);
>> -}
>> -
>> -static void tpm_tis_class_init(ObjectClass *klass, void *data)
>> +static void tpm_tis_isa_class_init(ObjectClass *klass, void *data)
>>   {
>>       DeviceClass *dc = DEVICE_CLASS(klass);
>>       TPMIfClass *tc = TPM_IF_CLASS(klass);
>>   -    dc->realize = tpm_tis_realizefn;
>> -    device_class_set_props(dc, tpm_tis_properties);
>> -    dc->reset = tpm_tis_reset;
>> -    dc->vmsd  = &vmstate_tpm_tis;
>> +    device_class_set_props(dc, tpm_tis_isa_properties);
>> +    dc->vmsd  = &vmstate_tpm_tis_isa;
>>       tc->model = TPM_MODEL_TPM_TIS;
>> -    tc->get_version = tpm_tis_get_tpm_version;
>> -    tc->request_completed = tpm_tis_request_completed;
>> +    dc->realize = tpm_tis_isa_realizefn;
>> +    dc->reset = tpm_tis_isa_reset;
>> +    tc->request_completed = tpm_tis_isa_request_completed;
>> +    tc->get_version = tpm_tis_isa_get_tpm_version;
>>   }
>>   -static const TypeInfo tpm_tis_info = {
>> +static const TypeInfo tpm_tis_isa_info = {
>>       .name = TYPE_TPM_TIS_ISA,
>>       .parent = TYPE_ISA_DEVICE,
>> -    .instance_size = sizeof(TPMState),
>> -    .instance_init = tpm_tis_initfn,
>> -    .class_init  = tpm_tis_class_init,
>> +    .instance_size = sizeof(TPMStateISA),
>> +    .instance_init = tpm_tis_isa_initfn,
>> +    .class_init  = tpm_tis_isa_class_init,
>>       .interfaces = (InterfaceInfo[]) {
>>           { TYPE_TPM_IF },
>>           { }
>>       }
>>   };
>>   -static void tpm_tis_register(void)
>> +static void tpm_tis_isa_register(void)
>>   {
>> -    type_register_static(&tpm_tis_info);
>> +    type_register_static(&tpm_tis_isa_info);
>>   }
>>   -type_init(tpm_tis_register)
>> +type_init(tpm_tis_isa_register)
>>
>