Stefan Berger <stef...@linux.vnet.ibm.com> writes:
> This patch adds the main code of the TPM frontend driver, the TPM TIS
> interface, to Qemu. The code is largely based on my previous implementation
> for Xen but has been significantly extended to meet the standard's
> requirements, such as the support for changing of localities and all the
> functionality of the available flags.
>
> Communication with the backend (i.e., for Xen or the libtpms-based one)
> is cleanly separated through an interface which the backend driver needs
> to implement.
>
> The TPM TIS driver's backend was previously chosen in the code added
> to arch_init. The frontend holds a pointer to the chosen backend (interface).
>
> Communication with the backend is largely based on signals and conditions.
> Whenever the frontend has collected a complete packet, it will signal
> the backend, which then starts processing the command. Once the result
> has been returned, the backend invokes a callback function
> (tis_tpm_receive_cb()).
>
> The one tricky part is support for VM suspend while the TPM is processing
> a command. In this case the frontend driver is waiting for the backend
> to return the result of the last command before shutting down. It waits
> on a condition for a signal from the backend, which is delivered in
> tis_tpm_receive_cb().
>
> Testing the proper functioning of the different flags and localities
> cannot be done from user space when running in Linux for example, since
> access to the address space of the TPM TIS interface is not possible. Also
> the Linux driver itself does not exercise all functionality. So, for
> testing there is a fairly extensive test suite as part of the SeaBIOS patches
> since from within the BIOS one can have full access to all the TPM's
> registers.
>
> v3:
> - prefixing functions with tis_
> - added a function to the backend interface 'early_startup_tpm' that
> allows to detect the presence of the block storage and gracefully fails
> Qemu if it's not available. This works with migration using shared
> storage but doesn't support migration with block storage migration.
> For encyrypted QCoW2 and in case of a snapshot resue the late_startup_tpm
> interface function is called
>
> Signed-off-by: Stefan Berger <stef...@linux.vnet.ibm.com>
>
> ---
> hw/tpm_tis.c | 871
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 871 insertions(+)
>
> Index: qemu-git/hw/tpm_tis.c
> ===================================================================
> --- /dev/null
> +++ qemu-git/hw/tpm_tis.c
[...]
> +static void tis_reset(DeviceState *d)
> +{
> + TPMState *s = container_of(d, TPMState, busdev.qdev);
> + tis_s_reset(s);
> +}
> +
> +
> +static int tis_init(ISADevice *dev)
Function not used, sure this compiles with -Werror? If not, it needs
fixing.
As far as I can see, the use is added in 03/10, where you add the
missing qdev parts. Makes it hard to review for qdev sanity, so I did
*not* do that.
> +{
> + TPMState *s = DO_UPCAST(TPMState, busdev, dev);
> + int iomemtype, rc;
> +
> + qemu_mutex_init(&s->state_lock);
> + qemu_cond_init(&s->from_tpm_cond);
> + qemu_cond_init(&s->to_tpm_cond);
> +
> + if (active_be->init(s, tis_tpm_receive_cb)) {
> + goto err_exit;
> + }
> +
> + isa_init_irq(dev, &s->irq, s->irq_num);
> +
> + iomemtype = cpu_register_io_memory(tis_readfn, tis_writefn, s,
> + DEVICE_LITTLE_ENDIAN);
> + cpu_register_physical_memory(TIS_ADDR_BASE, 0x1000 * NUM_LOCALITIES,
> + iomemtype);
> +
> + /*
> + * startup the TPM backend early to detect problems early
> + */
> + rc = tis_do_early_startup_tpm(s);
> + if (rc != 0 && rc != -ENOKEY) {
> + fprintf(stderr,"tpm_tis: Fatal error accessing TPM's block
> storage.\n");
> + goto err_exit;
> + }
> +
> + return 0;
> +
> + err_exit:
> + return -1;
> +}
> +
Please fix "new blank line at EOF."
