On Wed, Aug 31, 2011 at 10:35:54AM -0400, Stefan Berger wrote:
> This patch adds support for handling of persistent state to the TPM TIS
> frontend.
>
> The currently used buffer is determined (can only be in currently active
> locality and either be a read or a write buffer) and only that buffer's
> content
> is stored. The reverse is done when the state is restored from disk
> where the buffer's content are copied into the currently used buffer.
>
> To keep compatibility with existing Xen implementation the VMStateDescription
> was adapted to be compatible with existing state. For that I am adding Andreas
> Niederl as an author to the file.
>
> v5:
> - removing qdev.no_user=1
>
> v4:
> - main thread releases the 'state' lock while periodically calling the
> backends function that may request it to write data into block storage.
>
> v3:
> - all functions prefixed with tis_
> - while the main thread is waiting for an outstanding TPM command to finish,
> it periodically does some work (writes data to the block storage)
>
> Signed-off-by: Stefan Berger <stef...@linux.vnet.ibm.com>
>
> ---
> hw/tpm_tis.c | 166
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 166 insertions(+)
>
> Index: qemu-git/hw/tpm_tis.c
> ===================================================================
> --- qemu-git.orig/hw/tpm_tis.c
> +++ qemu-git/hw/tpm_tis.c
> @@ -6,6 +6,8 @@
> * Author: Stefan Berger <stef...@us.ibm.com>
> * David Safford <saff...@us.ibm.com>
> *
> + * Xen 4 support: Andrease Niederl <andreas.nied...@iaik.tugraz.at>
> + *
> * This program is free software; you can redistribute it and/or
> * modify it under the terms of the GNU General Public License as
> * published by the Free Software Foundation, version 2 of the
> @@ -839,3 +841,167 @@ static int tis_init(ISADevice *dev)
> err_exit:
> return -1;
> }
> +
> +/* persistent state handling */
> +
> +static void tis_pre_save(void *opaque)
> +{
> + TPMState *s = opaque;
> + uint8_t locty = s->active_locty;
> +
> + qemu_mutex_lock(&s->state_lock);
> +
> + /* wait for outstanding requests to complete */
> + if (IS_VALID_LOCTY(locty) && s->loc[locty].state == STATE_EXECUTION) {
> + if (!s->be_driver->ops->job_for_main_thread) {
> + qemu_cond_wait(&s->from_tpm_cond, &s->state_lock);
> + } else {
> + while (s->loc[locty].state == STATE_EXECUTION) {
> + qemu_mutex_unlock(&s->state_lock);
> +
> + s->be_driver->ops->job_for_main_thread(NULL);
> + usleep(10000);
> +
> + qemu_mutex_lock(&s->state_lock);
> + }
> + }
> + }
> +
> +#ifdef DEBUG_TIS_SR
> + fprintf(stderr,
> + "tpm_tis: suspend: locty 0 : r_offset = %d, w_offset = %d\n",
> + s->loc[0].r_offset, s->loc[0].w_offset);
> + if (s->loc[0].r_offset) {
> + tis_dump_state(opaque, 0);
> + }
> +#endif
> +
> + qemu_mutex_unlock(&s->state_lock);
> +
> + /* copy current active read or write buffer into the buffer
> + written to disk */
> + if (IS_VALID_LOCTY(locty)) {
> + switch (s->loc[locty].state) {
> + case STATE_RECEPTION:
> + memcpy(s->buf,
> + s->loc[locty].w_buffer.buffer,
> + MIN(sizeof(s->buf),
> + s->loc[locty].w_buffer.size));
> + s->offset = s->loc[locty].w_offset;
> + break;
> + case STATE_COMPLETION:
> + memcpy(s->buf,
> + s->loc[locty].r_buffer.buffer,
> + MIN(sizeof(s->buf),
> + s->loc[locty].r_buffer.size));
> + s->offset = s->loc[locty].r_offset;
> + break;
> + default:
> + /* leak nothing */
> + memset(s->buf, 0x0, sizeof(s->buf));
> + break;
> + }
> + }
> +
> + s->be_driver->ops->save_volatile_data();
> +}
> +
> +
> +static int tis_post_load(void *opaque,
> + int version_id __attribute__((unused)))
> +{
> + TPMState *s = opaque;
> +
> + uint8_t locty = s->active_locty;
> +
> + if (IS_VALID_LOCTY(locty)) {
> + switch (s->loc[locty].state) {
> + case STATE_RECEPTION:
> + memcpy(s->loc[locty].w_buffer.buffer,
> + s->buf,
> + MIN(sizeof(s->buf),
> + s->loc[locty].w_buffer.size));
> + s->loc[locty].w_offset = s->offset;
> + break;
> + case STATE_COMPLETION:
> + memcpy(s->loc[locty].r_buffer.buffer,
> + s->buf,
> + MIN(sizeof(s->buf),
> + s->loc[locty].r_buffer.size));
> + s->loc[locty].r_offset = s->offset;
> + break;
> + default:
> + break;
> + }
> + }
Should this do something with interrupts as well?
> +
> +#ifdef DEBUG_TIS_SR
> + fprintf(stderr,
> + "tpm_tis: resume : locty 0 : r_offset = %d, w_offset = %d\n",
> + s->loc[0].r_offset, s->loc[0].w_offset);
> +#endif
> +
> + return s->be_driver->ops->load_volatile_data(s);
> +}
> +
> +
> +static const VMStateDescription vmstate_locty = {
> + .name = "loc",
> + .version_id = 1,
> + .minimum_version_id = 0,
> + .minimum_version_id_old = 0,
> + .fields = (VMStateField[]) {
> + VMSTATE_UINT32(state, TPMLocality),
> + VMSTATE_UINT32(inte, TPMLocality),
> + VMSTATE_UINT32(ints, TPMLocality),
> + VMSTATE_UINT8(access, TPMLocality),
> + VMSTATE_UINT8(sts, TPMLocality),
> + VMSTATE_END_OF_LIST(),
> + }
> +};
> +
> +
> +static const VMStateDescription vmstate_tis = {
> + .name = "tpm",
> + .version_id = 1,
> + .minimum_version_id = 0,
> + .minimum_version_id_old = 0,
> + .pre_save = tis_pre_save,
> + .post_load = tis_post_load,
> + .fields = (VMStateField[]) {
> + VMSTATE_UINT32(irq_num, TPMState),
> + VMSTATE_UINT32(offset, TPMState),
> + VMSTATE_BUFFER(buf, TPMState),
> + VMSTATE_UINT8(active_locty, TPMState),
> + VMSTATE_UINT8(aborting_locty, TPMState),
> + VMSTATE_UINT8(next_locty, TPMState),
Is irq_num guest modifiable?
If yes post load should do something with it?
If not, why are we migrating it?
> +
> + VMSTATE_STRUCT_ARRAY(loc, TPMState, NUM_LOCALITIES, 1,
> + vmstate_locty, TPMLocality),
> +
> + VMSTATE_END_OF_LIST()
> + }
> +};
> +
> +
> +static ISADeviceInfo tis_device_info = {
> + .init = tis_init,
> + .qdev.name = "tpm-tis",
> + .qdev.size = sizeof(TPMState),
> + .qdev.vmsd = &vmstate_tis,
> + .qdev.reset = tis_reset,
> + .qdev.props = (Property[]) {
> + DEFINE_PROP_UINT32("irq", TPMState,
> + irq_num, TPM_TIS_IRQ),
> + DEFINE_PROP_STRING("tpmdev", TPMState, backend),
> + DEFINE_PROP_END_OF_LIST(),
> + },
> +};
> +
> +
> +static void tis_register_device(void)
> +{
> + isa_qdev_register(&tis_device_info);
> +}
> +
> +device_init(tis_register_device)
>
So this is a qdev device. Why do we need a new flag to set it up then?
