Re: [PATCH v1 10/12] hw/arm: introduce xenpv machine

[Alex Bennée <alex.bennee@xxxxxxxxxx>]

Vikram Garhwal <vikram.garhwal@xxxxxxx> writes:

<snip>
> Optional: When CONFIG_TPM is enabled, it also creates a tpm-tis-device, adds a
> TPM emulator and connects to swtpm running on host machine via chardev socket
> and support TPM functionalities for a guest domain.
>
> Extra command line for aarch64 xenpv QEMU to connect to swtpm:
>     -chardev socket,id=chrtpm,path=/tmp/myvtpm2/swtpm-sock \
>     -tpmdev emulator,id=tpm0,chardev=chrtpm \
>
> swtpm implements a TPM software emulator(TPM 1.2 & TPM 2) built on libtpms and
> provides access to TPM functionality over socket, chardev and CUSE interface.
> Github repo: https://github.com/stefanberger/swtpm
> Example for starting swtpm on host machine:
>     mkdir /tmp/vtpm2
>     swtpm socket --tpmstate dir=/tmp/vtpm2 \
>     --ctrl type=unixio,path=/tmp/vtpm2/swtpm-sock &

<snip>
> +static void xen_enable_tpm(void)
> +{
> +/* qemu_find_tpm_be is only available when CONFIG_TPM is enabled. */
> +#ifdef CONFIG_TPM
> +    Error *errp = NULL;
> +    DeviceState *dev;
> +    SysBusDevice *busdev;
> +
> +    TPMBackend *be = qemu_find_tpm_be("tpm0");
> +    if (be == NULL) {
> +        DPRINTF("Couldn't fine the backend for tpm0\n");
> +        return;
> +    }
> +    dev = qdev_new(TYPE_TPM_TIS_SYSBUS);
> +    object_property_set_link(OBJECT(dev), "tpmdev", OBJECT(be), &errp);
> +    object_property_set_str(OBJECT(dev), "tpmdev", be->id, &errp);
> +    busdev = SYS_BUS_DEVICE(dev);
> +    sysbus_realize_and_unref(busdev, &error_fatal);
> +    sysbus_mmio_map(busdev, 0, GUEST_TPM_BASE);

I'm not sure what has gone wrong here but I'm getting:

  ../../hw/arm/xen_arm.c: In function ‘xen_enable_tpm’:
  ../../hw/arm/xen_arm.c:120:32: error: ‘GUEST_TPM_BASE’ undeclared (first use 
in this function); did you mean ‘GUEST_RAM_BASE’?
    120 |     sysbus_mmio_map(busdev, 0, GUEST_TPM_BASE);
        |                                ^~~~~~~~~~~~~~
        |                                GUEST_RAM_BASE
  ../../hw/arm/xen_arm.c:120:32: note: each undeclared identifier is reported 
only once for each function it appears in

In my cross build:

  # Configured with: '../../configure' '--disable-docs' 
'--target-list=aarch64-softmmu' '--disable-kvm' '--enable-xen' 
'--disable-opengl' '--disable-libudev' '--enable-tpm' 
'--disable-xen-pci-passthrough' '--cross-prefix=aarch64-linux-gnu-' 
'--skip-meson'

which makes me wonder if this is a configure failure or a confusion
about being able to have host swtpm implementations during emulation but
needing target tpm for Xen?

-- 
Alex Bennée