Re: [Qemu-devel] [PATCH v3] tpm: add CRB device

[Igor Mammedov <imammedo@redhat.com>]

On Fri, 26 Jan 2018 13:03:06 +0100
Marc-André Lureau <marcandre.lureau@redhat.com> wrote:

> tpm_crb is a device for TPM 2.0 Command Response Buffer (CRB)
> Interface as defined in TCG PC Client Platform TPM Profile (PTP)
> Specification Family “2.0” Level 00 Revision 01.03 v22.
> 
> The PTP allows device implementation to switch between TIS and CRB
> model at run time, but given that CRB is a simpler device to
> implement, I chose to implement it as a different device.
> 
> The device doesn't implement other locality than 0 for now (my laptop
> TPM doesn't either, so I assume this isn't so bad)
> 
> Tested with some success with Linux upstream and Windows 10, seabios &
> modified ovmf. The device is recognized and correctly transmit
> command/response with passthrough & emu. However, we are missing PPI
> ACPI part atm.
> 
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
> 
> The patch is based on stefanb/tpm-next git branch.
> 
[...]

> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index dc4b2b9ffe..ed78c4ed9f 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -2224,6 +2224,22 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
>              aml_append(sb_scope, scope);
>          }
>      }
> +
> +    if (TPM_IS_CRB(tpm_find())) {
> +        dev = aml_device("TPM");
> +        aml_append(dev, aml_name_decl("_HID", aml_string("MSFT0101")));
> +        crs = aml_resource_template();
> +        aml_append(crs, aml_memory32_fixed(TPM_CRB_ADDR_BASE,
> +                                           TPM_CRB_ADDR_SIZE, AML_READ_WRITE));
> +        aml_append(dev, aml_name_decl("_CRS", crs));
> +
[...]
> +        method = aml_method("_STA", 0, AML_NOTSERIALIZED);
> +        aml_append(method, aml_return(aml_int(0x0f)));
> +        aml_append(dev, method);
this is not needed as 0x0f is assumed default value if _STA is missing

[...]

> diff --git a/hw/tpm/tpm_crb.c b/hw/tpm/tpm_crb.c
> new file mode 100644
> index 0000000000..687d2557b7
> --- /dev/null
> +++ b/hw/tpm/tpm_crb.c
[...]

> +static void tpm_crb_realize(DeviceState *dev, Error **errp)
> +{
> +    CRBState *s = CRB(dev);
> +
> +    if (!tpm_find()) {
> +        error_setg(errp, "at most one TPM device is permitted");
> +        return;
> +    }
> +    if (!s->tpmbe) {
> +        error_setg(errp, "'tpmdev' property is required");
> +        return;
> +    }
> +
> +    memory_region_init_io(&s->mmio, OBJECT(s), &tpm_crb_memory_ops, s,
> +        "tpm-crb-mmio", sizeof(s->regs));
> +    memory_region_init_ram(&s->cmdmem, OBJECT(s),
> +        "tpm-crb-cmd", CRB_CTRL_CMD_SIZE, errp);
> +
> +    memory_region_add_subregion(get_system_memory(),
> +        TPM_CRB_ADDR_BASE, &s->mmio);
> +    memory_region_add_subregion(get_system_memory(),
> +        TPM_CRB_ADDR_BASE + sizeof(s->regs), &s->cmdmem);
just curious, what if there is something else mapped at this addresses,
will it fail or just ignore error? 

> +
> +    tpm_backend_reset(s->tpmbe);
> +
> +    ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
> +                     InterfaceType, CRB_INTF_TYPE_CRB_ACTIVE);
> +    ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
> +                     InterfaceVersion, CRB_INTF_VERSION_CRB);
> +    ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
> +                     CapLocality, CRB_INTF_CAP_LOCALITY_0_ONLY);
> +    ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
> +                     CapCRBIdleBypass, CRB_INTF_CAP_IDLE_FAST);
> +    ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
> +                     CapDataXferSizeSupport, CRB_INTF_CAP_XFER_SIZE_64);
> +    ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
> +                     CapFIFO, CRB_INTF_CAP_FIFO_NOT_SUPPORTED);
> +    ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
> +                     CapCRB, CRB_INTF_CAP_CRB_SUPPORTED);
> +    ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
> +                     InterfaceSelector, CRB_INTF_IF_SELECTOR_CRB);
> +    ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
> +                     RID, 0b0000);
> +    ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID2,
> +                     VID, PCI_VENDOR_ID_IBM);
> +
> +    s->regs[R_CRB_CTRL_CMD_SIZE] = CRB_CTRL_CMD_SIZE;
> +    s->regs[R_CRB_CTRL_CMD_LADDR] = TPM_CRB_ADDR_BASE + A_CRB_DATA_BUFFER;
> +    s->regs[R_CRB_CTRL_RSP_SIZE] = CRB_CTRL_CMD_SIZE;
> +    s->regs[R_CRB_CTRL_RSP_ADDR] = TPM_CRB_ADDR_BASE + A_CRB_DATA_BUFFER;
> +
> +    s->be_buffer_size = MIN(tpm_backend_get_buffer_size(s->tpmbe),
> +                            CRB_CTRL_CMD_SIZE);
> +
> +    tpm_backend_startup_tpm(s->tpmbe, s->be_buffer_size);
> +}
[...]