On 1/8/19 9:40 AM, Marc-André Lureau wrote:
> Note: the "Platform Reset Attack Mitigation" specification isn't
> explicit about NVDIMM, since they could have different usages. It uses
> the term "system memory" generally (and also "volatile memory RAM" in
> its introduction). For initial support, I propose to consider
> non-volatile memory as not being subject to the memory clear. There is
> an on-going discussion in the TCG "pcclientwg" working group for
> future revisions.
>
> CPU cache clearing is done unconditionally in edk2 since commit
> d20ae95a13e851 (edk2-stable201811).
>
> Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com>
> ---
> hw/tpm/tpm_ppi.h | 10 ++++++++++
> hw/tpm/tpm_crb.c | 1 +
> hw/tpm/tpm_ppi.c | 22 ++++++++++++++++++++++
> hw/tpm/tpm_tis.c | 1 +
> hw/tpm/trace-events | 3 +++
> 5 files changed, 37 insertions(+)
>
> diff --git a/hw/tpm/tpm_ppi.h b/hw/tpm/tpm_ppi.h
> index c5e555fe2c..d33ef27de6 100644
> --- a/hw/tpm/tpm_ppi.h
> +++ b/hw/tpm/tpm_ppi.h
> @@ -33,4 +33,14 @@ typedef struct TPMPPI {
> void tpm_ppi_init(TPMPPI *tpmppi, struct MemoryRegion *m,
> hwaddr addr, Object *obj);
>
> +/**
> + * tpm_ppi_reset:
> + * @tpmppi: a TPMPPI
> + *
> + * Function to call on machine reset. It will check if the "Memory
> + * overwrite" variable is set, and perform a memory clear on volatile
> + * memory if requested.
> + **/
> +void tpm_ppi_reset(TPMPPI *tpmppi);
> +
> #endif /* TPM_TPM_PPI_H */
> diff --git a/hw/tpm/tpm_crb.c b/hw/tpm/tpm_crb.c
> index 012ec686d4..663469bd20 100644
> --- a/hw/tpm/tpm_crb.c
> +++ b/hw/tpm/tpm_crb.c
> @@ -233,6 +233,7 @@ static void tpm_crb_reset(void *dev)
> {
> CRBState *s = CRB(dev);
>
> + tpm_ppi_reset(&s->ppi);
> tpm_backend_reset(s->tpmbe);
>
> memset(s->regs, 0, sizeof(s->regs));
> diff --git a/hw/tpm/tpm_ppi.c b/hw/tpm/tpm_ppi.c
> index cf17779c20..cd8205f212 100644
> --- a/hw/tpm/tpm_ppi.c
> +++ b/hw/tpm/tpm_ppi.c
> @@ -16,8 +16,30 @@
> #include "qapi/error.h"
> #include "cpu.h"
> #include "sysemu/memory_mapping.h"
> +#include "sysemu/reset.h"
> #include "migration/vmstate.h"
> #include "tpm_ppi.h"
> +#include "trace.h"
> +
> +void tpm_ppi_reset(TPMPPI *tpmppi)
> +{
> + if (tpmppi->buf[0x15a /* movv, docs/specs/tpm.txt */] & 0x1) {
> + GuestPhysBlockList guest_phys_blocks;
> + GuestPhysBlock *block;
> +
> + guest_phys_blocks_init(&guest_phys_blocks);
> + guest_phys_blocks_append(&guest_phys_blocks);
> + QTAILQ_FOREACH(block, &guest_phys_blocks.head, next) {
> + trace_tpm_ppi_memset(block->host_addr,
> + block->target_end - block->target_start);
> + memset(block->host_addr, 0,
> + block->target_end - block->target_start);
> + memory_region_set_dirty(block->mr, 0,
> + block->target_end - block->target_start);
> + }
> + guest_phys_blocks_free(&guest_phys_blocks);
> + }
> +}
>
> void tpm_ppi_init(TPMPPI *tpmppi, struct MemoryRegion *m,
> hwaddr addr, Object *obj)
> diff --git a/hw/tpm/tpm_tis.c b/hw/tpm/tpm_tis.c
> index 02d9d5c911..6a5511e042 100644
> --- a/hw/tpm/tpm_tis.c
> +++ b/hw/tpm/tpm_tis.c
> @@ -872,6 +872,7 @@ static void tpm_tis_reset(DeviceState *dev)
> s->be_buffer_size = MIN(tpm_backend_get_buffer_size(s->be_driver),
> TPM_TIS_BUFFER_MAX);
>
> + tpm_ppi_reset(&s->ppi);
> tpm_backend_reset(s->be_driver);
>
> s->active_locty = TPM_TIS_NO_LOCALITY;
> diff --git a/hw/tpm/trace-events b/hw/tpm/trace-events
> index 25bee0cecf..920d32ad55 100644
> --- a/hw/tpm/trace-events
> +++ b/hw/tpm/trace-events
> @@ -51,3 +51,6 @@ tpm_tis_mmio_write_init_abort(void) "Initiating abort"
> tpm_tis_mmio_write_lowering_irq(void) "Lowering IRQ"
> tpm_tis_mmio_write_data2send(uint32_t value, unsigned size) "Data to send to
> TPM: 0x%08x (size=%d)"
> tpm_tis_pre_save(uint8_t locty, uint32_t rw_offset) "locty: %d, rw_offset =
> %u"
> +
> +# hw/tpm/tpm_ppi.c
> +tpm_ppi_memset(uint8_t *ptr, size_t size) "memset: %p %zu"
>
