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Re: [Qemu-devel] [PATCH v12 6/6] tpm: add ACPI memory clear interface
From: |
Igor Mammedov |
Subject: |
Re: [Qemu-devel] [PATCH v12 6/6] tpm: add ACPI memory clear interface |
Date: |
Thu, 13 Dec 2018 15:24:17 +0100 |
On Thu, 13 Dec 2018 16:18:09 +0400
Marc-André Lureau <address@hidden> wrote:
> On Thu, Dec 13, 2018 at 4:01 PM Igor Mammedov <address@hidden> wrote:
> >
> > On Wed, 12 Dec 2018 17:22:21 +0100
> > Philippe Mathieu-Daudé <address@hidden> wrote:
> >
> > > On 9/10/18 10:32 AM, Marc-André Lureau wrote:
> > > > This allows to pass the last failing test from the Windows HLK TPM 2.0
> > > > TCG PPI 1.3 tests.
> > > >
> > > > The interface is described in the "TCG Platform Reset Attack
> > > > Mitigation Specification", chapter 6 "ACPI _DSM Function". According
> > > > to Laszlo, it's not so easy to implement in OVMF, he suggested to do
> > > > it in qemu instead.
> > > >
> > > > Signed-off-by: Marc-André Lureau <address@hidden>
> > > > ---
> > > > hw/tpm/tpm_ppi.h | 2 ++
> > > > hw/i386/acpi-build.c | 46 ++++++++++++++++++++++++++++++++++++++++++++
> > > > hw/tpm/tpm_crb.c | 1 +
> > > > hw/tpm/tpm_ppi.c | 22 +++++++++++++++++++++
> > > > hw/tpm/tpm_tis.c | 1 +
> > > > docs/specs/tpm.txt | 2 ++
> > > > hw/tpm/trace-events | 3 +++
> > > > 7 files changed, 77 insertions(+)
> > > >
> > > > diff --git a/hw/tpm/tpm_ppi.h b/hw/tpm/tpm_ppi.h
> > > > index c2ab2ed300..b8f67962c7 100644
> > > > --- a/hw/tpm/tpm_ppi.h
> > > > +++ b/hw/tpm/tpm_ppi.h
> > > > @@ -23,4 +23,6 @@ typedef struct TPMPPI {
> > > > bool tpm_ppi_init(TPMPPI *tpmppi, struct MemoryRegion *m,
> > > > hwaddr addr, Object *obj, Error **errp);
> > > >
> > >
> > > Can you add documentation?
> > >
> > > > +void tpm_ppi_reset(TPMPPI *tpmppi);
> > > > +
> > > > #endif /* TPM_TPM_PPI_H */
> > > > diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> > > > index c5e9a6e11d..2ab3e8fae7 100644
> > > > --- a/hw/i386/acpi-build.c
> > > > +++ b/hw/i386/acpi-build.c
> > > > @@ -1824,6 +1824,13 @@ build_tpm_ppi(TPMIf *tpm, Aml *dev)
> > > > pprq = aml_name("PPRQ");
> > > > pprm = aml_name("PPRM");
> > > >
> > > > + aml_append(dev,
> > > > + aml_operation_region("TPP3", AML_SYSTEM_MEMORY,
> > > > + aml_int(TPM_PPI_ADDR_BASE +
> > > > 0x15a),
> > >
> > > Can you add a definition for this magic value?
> > > Maybe:
> > >
> > > #define TPM_PPI_MEMORY_OVERWRITE_OFFSET 0x15a
> > >
> > > or
> > >
> > > #define TPM_PPI_MOVV_OFFSET 0x15a
> > I'd prefer explicit numeric values there as it's a bit easier to review
> > and grep in 'spec' since one doesn't have to jump to define definition
> > first to find out value to compare with spec.
> > What I'd add though is verbatim comment from spec like we do
> > in APCI code so we could jump to the field of interest in spec
> > just doing copy&paste&search
>
> I don't mind.
> Philippe, are you okay going back to numeric values?
>
> Igor, is this comment what you would expect where the 0x15a value is used:
> /* 0x15a: movv field in ACPI PPI Interface, see specs/tpm.txt */
>
usually field name is sufficient, so something like:
foo(0.15a /* movv, docs/specs/tpm.txt */)
> thanks
> >
> > >
> > > > + 0x1));
> > > > + field = aml_field("TPP3", AML_BYTE_ACC, AML_NOLOCK, AML_PRESERVE);
> > > > + aml_append(field, aml_named_field("MOVV", 8));
> > > > + aml_append(dev, field);
> > > > /*
> > > > * DerefOf in Windows is broken with SYSTEM_MEMORY. Use a dynamic
> > > > * operation region inside of a method for getting FUNC[op].
> > > > @@ -2166,7 +2173,46 @@ build_tpm_ppi(TPMIf *tpm, Aml *dev)
> > > > aml_append(ifctx, aml_return(aml_buffer(1, zerobyte)));
> > > > }
> > > > aml_append(method, ifctx);
> > > > +
> > > > + ifctx = aml_if(
> > > > + aml_equal(uuid,
> > > > +
> > > > aml_touuid("376054ED-CC13-4675-901C-4756D7F2D45D")));
> > > > + {
> > > > + /* standard DSM query function */
> > > > + ifctx2 = aml_if(aml_equal(function, zero));
> > > > + {
> > > > + uint8_t byte_list[1] = { 0x03 };
> > > > + aml_append(ifctx2, aml_return(aml_buffer(1,
> > > > byte_list)));
> > > > + }
> > > > + aml_append(ifctx, ifctx2);
> > > > +
> > > > + /*
> > > > + * TCG Platform Reset Attack Mitigation Specification 1.0
> > > > Ch.6
> > > > + *
> > > > + * Arg 2 (Integer): Function Index = 1
> > > > + * Arg 3 (Package): Arguments = Package: Type: Integer
> > > > + * Operation Value of the Request
> > > > + * Returns: Type: Integer
> > > > + * 0: Success
> > > > + * 1: General Failure
> > > > + */
> > > > + ifctx2 = aml_if(aml_equal(function, one));
> > > > + {
> > > > + aml_append(ifctx2,
> > > > + aml_store(aml_derefof(aml_index(arguments,
> > > > zero)),
> > > > + op));
> > > > + {
> > > > + aml_append(ifctx2, aml_store(op,
> > > > aml_name("MOVV")));
> > > > +
> > > > + /* 0: success */
> > > > + aml_append(ifctx2, aml_return(zero));
> > > > + }
> > > > + }
> > > > + aml_append(ifctx, ifctx2);
> > > > + }
> > > > + aml_append(method, ifctx);
> > > > }
> > > > +
> > > > aml_append(dev, method);
> > > > }
> > > >
> > > > diff --git a/hw/tpm/tpm_crb.c b/hw/tpm/tpm_crb.c
> > > > index b243222fd6..48f6a716ad 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 f2f07f895e..ac05ba8d3c 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] & 0x1) {
> > >
> > > TPM_PPI_MOVV_OFFSET
> > >
> > > > + 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);
> > > > + }
> > > > +}
> > > >
> > > > bool tpm_ppi_init(TPMPPI *tpmppi, struct MemoryRegion *m,
> > > > hwaddr addr, Object *obj, Error **errp)
> > > > diff --git a/hw/tpm/tpm_tis.c b/hw/tpm/tpm_tis.c
> > > > index 70432ffe8b..d9bfa956cc 100644
> > > > --- a/hw/tpm/tpm_tis.c
> > > > +++ b/hw/tpm/tpm_tis.c
> > > > @@ -868,6 +868,7 @@ 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/docs/specs/tpm.txt b/docs/specs/tpm.txt
> > > > index 332c2ae597..ce9bda3c89 100644
> > > > --- a/docs/specs/tpm.txt
> > > > +++ b/docs/specs/tpm.txt
> > > > @@ -121,6 +121,8 @@ layout:
> > > >
> > > > +----------+--------+--------+-------------------------------------------+
> > > > | next_step| 0x1 | 0x159 | Operation to execute after reboot by
> > > > |
> > > > | | | | firmware. Used by firmware.
> > > > |
> > > > +
> > > > +----------+--------+--------+-------------------------------------------+
> > > > + | movv | 0x1 | 0x15a | Memory overwrite variable
> > > > |
> > > >
> > > > +----------+--------+--------+-------------------------------------------+
> > > >
> > > > The following values are supported for the 'func' field. They
> > > > correspond
> > > > 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"
> > > >
> > >
> > > I'd split this patch in 2: Add ACPI, Add tpm_ppi_reset.
> >
>