Re: [Qemu-devel] [PATCH v12 3/6] tpm: allocate/map buffer for TPM Physical Presence interface

[Marc-André Lureau]

Hi

On Wed, Dec 12, 2018 at 8:13 PM Philippe Mathieu-Daudé
<address@hidden> wrote:
>
> Hi Stefan, Marc-André,
>
> On 9/10/18 10:32 AM, Marc-André Lureau wrote:
> > From: Stefan Berger <address@hidden>
> >
> > Implement a virtual memory device for the TPM Physical Presence interface.
> > The memory is located at 0xFED45000 and used by ACPI to send messages to the
> > firmware (BIOS) and by the firmware to provide parameters for each one of
> > the supported codes.
> >
> > This interface should be used by all TPM devices on x86 and can be
> > added by calling tpm_ppi_init_io().
> >
> > Note: bios_linker cannot be used to allocate the PPI memory region,
> > since the reserved memory should stay stable across reboots, and might
> > be needed before the ACPI tables are installed.
> >
> > Signed-off-by: Stefan Berger <address@hidden>
> > Signed-off-by: Marc-André Lureau <address@hidden>
> > Reviewed-by: Igor Mammedov <address@hidden>
> > ---
> >  hw/tpm/tpm_ppi.h      | 26 ++++++++++++++++++++++++++
> >  include/hw/acpi/tpm.h |  6 ++++++
> >  hw/tpm/tpm_crb.c      |  8 ++++++++
> >  hw/tpm/tpm_ppi.c      | 32 ++++++++++++++++++++++++++++++++
> >  hw/tpm/tpm_tis.c      |  8 ++++++++
> >  hw/tpm/Makefile.objs  |  1 +
> >  6 files changed, 81 insertions(+)
> >  create mode 100644 hw/tpm/tpm_ppi.h
> >  create mode 100644 hw/tpm/tpm_ppi.c
> >
> > diff --git a/hw/tpm/tpm_ppi.h b/hw/tpm/tpm_ppi.h
> > new file mode 100644
> > index 0000000000..c2ab2ed300
> > --- /dev/null
> > +++ b/hw/tpm/tpm_ppi.h
> > @@ -0,0 +1,26 @@
> > +/*
> > + * TPM Physical Presence Interface
> > + *
> > + * Copyright (C) 2018 IBM Corporation
> > + *
> > + * Authors:
> > + *  Stefan Berger    <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.
> > + */
> > +#ifndef TPM_TPM_PPI_H
> > +#define TPM_TPM_PPI_H
> > +
> > +#include "hw/acpi/tpm.h"
> > +#include "exec/address-spaces.h"
> > +
> > +typedef struct TPMPPI {
> > +    MemoryRegion ram;
> > +    uint8_t *buf;
> > +} TPMPPI;
> > +
>
> Can you add a description for this public function?

ok

>
> > +bool tpm_ppi_init(TPMPPI *tpmppi, struct MemoryRegion *m,
> > +                  hwaddr addr, Object *obj, Error **errp);
> > +
> > +#endif /* TPM_TPM_PPI_H */
> > diff --git a/include/hw/acpi/tpm.h b/include/hw/acpi/tpm.h
> > index 3580ffd50c..b8796df916 100644
> > --- a/include/hw/acpi/tpm.h
> > +++ b/include/hw/acpi/tpm.h
> > @@ -188,4 +188,10 @@ REG32(CRB_DATA_BUFFER, 0x80)
> >  #define TPM2_START_METHOD_MMIO      6
> >  #define TPM2_START_METHOD_CRB       7
> >
> > +/*
> > + * Physical Presence Interface
> > + */
> > +#define TPM_PPI_ADDR_SIZE           0x400
> > +#define TPM_PPI_ADDR_BASE           0xFED45000
> > +
> >  #endif /* HW_ACPI_TPM_H */
> > diff --git a/hw/tpm/tpm_crb.c b/hw/tpm/tpm_crb.c
> > index d5b0ac5920..b243222fd6 100644
> > --- a/hw/tpm/tpm_crb.c
> > +++ b/hw/tpm/tpm_crb.c
> > @@ -29,6 +29,7 @@
> >  #include "sysemu/reset.h"
> >  #include "tpm_int.h"
> >  #include "tpm_util.h"
> > +#include "tpm_ppi.h"
> >  #include "trace.h"
> >
> >  typedef struct CRBState {
> > @@ -43,6 +44,7 @@ typedef struct CRBState {
> >      size_t be_buffer_size;
> >
> >      bool ppi_enabled;
> > +    TPMPPI ppi;
> >  } CRBState;
> >
> >  #define CRB(obj) OBJECT_CHECK(CRBState, (obj), TYPE_TPM_CRB)
> > @@ -294,6 +296,12 @@ static void tpm_crb_realize(DeviceState *dev, Error 
> > **errp)
> >      memory_region_add_subregion(get_system_memory(),
> >          TPM_CRB_ADDR_BASE + sizeof(s->regs), &s->cmdmem);
> >
> > +    if (s->ppi_enabled &&
> > +        !tpm_ppi_init(&s->ppi, get_system_memory(),
> > +                      TPM_PPI_ADDR_BASE, OBJECT(s), errp)) {
> > +        return;
> > +    }
> > +
> >      qemu_register_reset(tpm_crb_reset, dev);
> >  }
> >
> > diff --git a/hw/tpm/tpm_ppi.c b/hw/tpm/tpm_ppi.c
> > new file mode 100644
> > index 0000000000..f2f07f895e
> > --- /dev/null
> > +++ b/hw/tpm/tpm_ppi.c
> > @@ -0,0 +1,32 @@
> > +/*
> > + * tpm_ppi.c - TPM Physical Presence Interface
> > + *
> > + * Copyright (C) 2018 IBM Corporation
> > + *
> > + * Authors:
> > + *  Stefan Berger <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.
> > + *
> > + */
> > +
> > +#include "qemu/osdep.h"
> > +
> > +#include "qapi/error.h"
> > +#include "cpu.h"
> > +#include "sysemu/memory_mapping.h"
> > +#include "migration/vmstate.h"
> > +#include "tpm_ppi.h"
> > +
> > +bool tpm_ppi_init(TPMPPI *tpmppi, struct MemoryRegion *m,
> > +                  hwaddr addr, Object *obj, Error **errp)
> > +{
> > +    tpmppi->buf = g_malloc0(HOST_PAGE_ALIGN(TPM_PPI_ADDR_SIZE));
> > +    memory_region_init_ram_device_ptr(&tpmppi->ram, obj, "tpm-ppi",
> > +                                      TPM_PPI_ADDR_SIZE, tpmppi->buf);
> > +    vmstate_register_ram(&tpmppi->ram, DEVICE(obj));
> > +
> > +    memory_region_add_subregion(m, addr, &tpmppi->ram);
> > +    return true;
> > +}
> > diff --git a/hw/tpm/tpm_tis.c b/hw/tpm/tpm_tis.c
> > index d9ddf9b723..70432ffe8b 100644
> > --- a/hw/tpm/tpm_tis.c
> > +++ b/hw/tpm/tpm_tis.c
> > @@ -31,6 +31,7 @@
> >  #include "sysemu/tpm_backend.h"
> >  #include "tpm_int.h"
> >  #include "tpm_util.h"
> > +#include "tpm_ppi.h"
> >  #include "trace.h"
> >
> >  #define TPM_TIS_NUM_LOCALITIES      5     /* per spec */
> > @@ -83,6 +84,7 @@ typedef struct TPMState {
> >      size_t be_buffer_size;
> >
> >      bool ppi_enabled;
> > +    TPMPPI ppi;
> >  } TPMState;
> >
> >  #define TPM(obj) OBJECT_CHECK(TPMState, (obj), TYPE_TPM_TIS)
> > @@ -979,6 +981,12 @@ static void tpm_tis_realizefn(DeviceState *dev, Error 
> > **errp)
> >
> >      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), errp)) {
> > +        return;
> > +    }
> >  }
> >
>
> Shouldn't you implement the unrealize() function, destroying the PPI buffer?

I don't think it's necessary since the TPM and PPI are not hotpluggable.

> Patch looks good otherwise.
>
> >  static void tpm_tis_initfn(Object *obj)
> > diff --git a/hw/tpm/Makefile.objs b/hw/tpm/Makefile.objs
> > index 1dc9f8bf2c..700c878622 100644
> > --- a/hw/tpm/Makefile.objs
> > +++ b/hw/tpm/Makefile.objs
> > @@ -1,4 +1,5 @@
> >  common-obj-y += tpm_util.o
> > +obj-y += tpm_ppi.o
> >  common-obj-$(CONFIG_TPM_TIS) += tpm_tis.o
> >  common-obj-$(CONFIG_TPM_CRB) += tpm_crb.o
> >  common-obj-$(CONFIG_TPM_PASSTHROUGH) += tpm_passthrough.o
> >
>


-- 
Marc-André Lureau