diff options
| author | Marc-André Lureau <marcandre.lureau@redhat.com> | 2019-01-15 02:27:54 +0400 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2019-01-17 21:10:57 -0500 |
| commit | ffab1be70692c55f4c81642f03d629fd84eb4b18 (patch) | |
| tree | f0a87fc9b9ba448fd50b12d7d70ee5d3a4e95343 /hw/tpm/tpm_ppi.c | |
| parent | ec86c0f678a9402fb4265c8874bd2ec712b33127 (diff) | |
tpm: clear RAM when "memory overwrite" requested
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.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'hw/tpm/tpm_ppi.c')
| -rw-r--r-- | hw/tpm/tpm_ppi.c | 22 |
1 files changed, 22 insertions, 0 deletions
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) |