From: Stefan Berger <stef...@linux.vnet.ibm.com>

The TPM Physical Presence interface consists of an ACPI part, a shared
memory part, and code in the firmware. Users can send messages to the
firmware by writing a code into the shared memory through invoking the
ACPI code. When a reboot happens, the firmware looks for the code and
acts on it by sending sequences of commands to the TPM.

This patch adds the ACPI code. It is similar to the one in EDK2 but doesn't
assume that SMIs are necessary to use. It uses a similar datastructure for
the shared memory as EDK2 does so that EDK2 and SeaBIOS could both make use
of it. I extended the shared memory data structure with an array of 256
bytes, one for each code that could be implemented. The array contains
flags describing the individual codes. This decouples the ACPI implementation
from the firmware implementation.

The underlying TCG specification is accessible from the following page.

https://trustedcomputinggroup.org/tcg-physical-presence-interface-specification/

This patch implements version 1.30.

Signed-off-by: Stefan Berger <stef...@linux.vnet.ibm.com>

---

v4 (Marc-André):
 - replace 'DerefOf (FUNC [N])' with a function, to fix Windows ACPI
    handling.
 - replace 'return Package (..) {} ' with scoped variables, to fix
   Windows ACPI handling.

v3:
 - add support for PPI to CRB
 - split up OperationRegion TPPI into two parts, one containing
   the registers (TPP1) and the other one the flags (TPP2); switched
   the order of the flags versus registers in the code
 - adapted ACPI code to small changes to the array of flags where
   previous flag 0 was removed and now shifting right wasn't always
   necessary anymore

v2:
 - get rid of FAIL variable; function 5 was using it and always
   returns 0; the value is related to the ACPI function call not
   a possible failure of the TPM function call.
 - extend shared memory data structure with per-opcode entries
   holding flags and use those flags to determine what to return
   to caller
 - implement interface version 1.3
---
 include/hw/acpi/tpm.h |  21 +++
 hw/i386/acpi-build.c  | 294 +++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 314 insertions(+), 1 deletion(-)

diff --git a/include/hw/acpi/tpm.h b/include/hw/acpi/tpm.h
index f79d68a77a..fc53f08827 100644
--- a/include/hw/acpi/tpm.h
+++ b/include/hw/acpi/tpm.h
@@ -196,4 +196,25 @@ REG32(CRB_DATA_BUFFER, 0x80)
 #define TPM_PPI_VERSION_NONE        0
 #define TPM_PPI_VERSION_1_30        1
 
+struct tpm_ppi {
+    uint8_t  func[256];      /* 0x000: per TPM function implementation flags;
+                                       set by BIOS */
+/* whether function is blocked by BIOS settings; bits 0, 1, 2 */
+#define TPM_PPI_FUNC_NOT_IMPLEMENTED     (0 << 0)
+#define TPM_PPI_FUNC_BIOS_ONLY           (1 << 0)
+#define TPM_PPI_FUNC_BLOCKED             (2 << 0)
+#define TPM_PPI_FUNC_ALLOWED_USR_REQ     (3 << 0)
+#define TPM_PPI_FUNC_ALLOWED_USR_NOT_REQ (4 << 0)
+#define TPM_PPI_FUNC_MASK                (7 << 0)
+    uint8_t ppin;            /* 0x100 : set by BIOS */
+    uint32_t ppip;           /* 0x101 : set by ACPI; not used */
+    uint32_t pprp;           /* 0x105 : response from TPM; set by BIOS */
+    uint32_t pprq;           /* 0x109 : opcode; set by ACPI */
+    uint32_t pprm;           /* 0x10d : parameter for opcode; set by ACPI */
+    uint32_t lppr;           /* 0x111 : last opcode; set by BIOS */
+    uint32_t fret;           /* 0x115 : set by ACPI; not used */
+    uint8_t res1[0x40];      /* 0x119 : reserved for future use */
+    uint8_t next_step;       /* 0x159 : next step after reboot; set by BIOS */
+} QEMU_PACKED;
+
 #endif /* HW_ACPI_TPM_H */
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index f6d447f03a..95be4f0710 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -43,6 +43,7 @@
 #include "hw/acpi/memory_hotplug.h"
 #include "sysemu/tpm.h"
 #include "hw/acpi/tpm.h"
+#include "hw/tpm/tpm_ppi.h"
 #include "hw/acpi/vmgenid.h"
 #include "sysemu/tpm_backend.h"
 #include "hw/timer/mc146818rtc_regs.h"
@@ -1789,6 +1790,292 @@ static Aml *build_q35_osc_method(void)
     return method;
 }
 
+static void
+build_tpm_ppi(Aml *dev)
+{
+    Aml *method, *name, *field, *ifctx, *ifctx2, *ifctx3, *pak;
+    struct tpm_ppi *tpm_ppi = NULL;
+    int i;
+
+    /*
+     * TPP1 is for the flags that indicate which PPI operations
+     * are supported by the firmware. The firmware is expected to
+     * write these flags.
+     */
+    aml_append(dev,
+               aml_operation_region("TPP1", AML_SYSTEM_MEMORY,
+                                    aml_int(TPM_PPI_ADDR_BASE),
+                                    sizeof(tpm_ppi->func)));
+    field = aml_field("TPP1", AML_ANY_ACC, AML_NOLOCK, AML_PRESERVE);
+    for (i = 0; i < sizeof(tpm_ppi->func); i++) {
+        char *tmp = g_strdup_printf("FN%02X", i);
+        aml_append(field, aml_named_field(tmp, BITS_PER_BYTE));
+        g_free(tmp);
+    }
+    aml_append(dev, field);
+
+    /*
+     * TPP2 is for the registers that ACPI code used to pass
+     * the PPI code and parameter (PPRQ, PPRM) to the firmware.
+     */
+    aml_append(dev,
+               aml_operation_region("TPP2", AML_SYSTEM_MEMORY,
+                                    aml_int(TPM_PPI_ADDR_BASE +
+                                            offsetof(struct tpm_ppi, ppin)),
+                                    sizeof(struct tpm_ppi) -
+                                        sizeof(tpm_ppi->func)));
+    field = aml_field("TPP2", AML_ANY_ACC, AML_NOLOCK, AML_PRESERVE);
+    aml_append(field, aml_named_field("PPIN",
+               sizeof(uint8_t) * BITS_PER_BYTE));
+    aml_append(field, aml_named_field("PPIP",
+               sizeof(uint32_t) * BITS_PER_BYTE));
+    aml_append(field, aml_named_field("PPRP",
+               sizeof(uint32_t) * BITS_PER_BYTE));
+    aml_append(field, aml_named_field("PPRQ",
+               sizeof(uint32_t) * BITS_PER_BYTE));
+    aml_append(field, aml_named_field("PPRM",
+               sizeof(uint32_t) * BITS_PER_BYTE));
+    aml_append(field, aml_named_field("LPPR",
+               sizeof(uint32_t) * BITS_PER_BYTE));
+    aml_append(dev, field);
+
+    method = aml_method("TPFN", 1, AML_SERIALIZED);
+    {
+        for (i = 0; i < sizeof(tpm_ppi->func); i++) {
+            ifctx = aml_if(aml_equal(aml_int(i), aml_arg(0)));
+            {
+                aml_append(ifctx, aml_return(aml_name("FN%02X", i)));
+            }
+            aml_append(method, ifctx);
+        }
+        aml_append(method, aml_return(aml_int(0)));
+    }
+    aml_append(dev, method);
+
+    pak = aml_package(2);
+    aml_append(pak, aml_int(0));
+    aml_append(pak, aml_int(0));
+    name = aml_name_decl("TPM2", pak);
+    aml_append(dev, name);
+
+    pak = aml_package(3);
+    aml_append(pak, aml_int(0));
+    aml_append(pak, aml_int(0));
+    aml_append(pak, aml_int(0));
+    name = aml_name_decl("TPM3", pak);
+    aml_append(dev, name);
+
+    method = aml_method("_DSM", 4, AML_SERIALIZED);
+    {
+        uint8_t zerobyte[1] = { 0 };
+
+        ifctx = aml_if(
+            aml_equal(aml_arg(0),
+                      aml_touuid("3DDDFAA6-361B-4EB4-A424-8D10089D1653")));
+        {
+            aml_append(ifctx,
+                       aml_store(aml_to_integer(aml_arg(2)), aml_local(0)));
+
+            /* standard DSM query function */
+            ifctx2 = aml_if(aml_equal(aml_local(0), aml_int(0)));
+            {
+                uint8_t byte_list[2] = { 0xff, 0x01 };
+                aml_append(ifctx2, aml_return(aml_buffer(2, byte_list)));
+            }
+            aml_append(ifctx, ifctx2);
+
+            /* interface version: 1.3 */
+            ifctx2 = aml_if(aml_equal(aml_local(0), aml_int(1)));
+            {
+                aml_append(ifctx2, aml_return(aml_string("1.3")));
+            }
+            aml_append(ifctx, ifctx2);
+
+            /* submit TPM operation */
+            ifctx2 = aml_if(aml_equal(aml_local(0), aml_int(2)));
+            {
+                /* get opcode */
+                aml_append(ifctx2,
+                           aml_store(aml_derefof(aml_index(aml_arg(3),
+                                                           aml_int(0))),
+                                     aml_local(0)));
+                /* get opcode flags */
+                aml_append(ifctx2,
+                           aml_store(aml_call1("TPFN", aml_local(0)),
+                                     aml_local(1)));
+                ifctx3 = aml_if(
+                    aml_equal(
+                        aml_and(aml_local(1), aml_int(TPM_PPI_FUNC_MASK), 
NULL),
+                        aml_int(TPM_PPI_FUNC_NOT_IMPLEMENTED)));
+                {
+                    /* 1: not implemented */
+                    aml_append(ifctx3, aml_return(aml_int(1)));
+                }
+                aml_append(ifctx2, ifctx3);
+                aml_append(ifctx2, aml_store(aml_local(0), aml_name("PPRQ")));
+                aml_append(ifctx2, aml_store(aml_int(0), aml_name("PPRM")));
+                /* 0: success */
+                aml_append(ifctx2, aml_return(aml_int(0)));
+            }
+            aml_append(ifctx, ifctx2);
+
+            /* get pending TPM operation */
+            ifctx2 = aml_if(aml_equal(aml_local(0), aml_int(3)));
+            {
+                /* revision to integer */
+                aml_append(ifctx2,
+                           aml_store(
+                               aml_to_integer(aml_arg(1)),
+                               aml_local(1)));
+                ifctx3 = aml_if(aml_equal(aml_local(1), aml_int(1)));
+                {
+                    aml_append(ifctx3,
+                               aml_store(
+                                   aml_name("PPRQ"),
+                                   aml_index(aml_name("TPM2"), aml_int(1))));
+                    aml_append(ifctx3, aml_return(aml_name("TPM2")));
+                }
+                aml_append(ifctx2, ifctx3);
+
+                ifctx3 = aml_if(aml_equal(aml_local(1), aml_int(2)));
+                {
+                    aml_append(ifctx3,
+                               aml_store(
+                                   aml_name("PPRQ"),
+                                   aml_index(aml_name("TPM3"), aml_int(1))));
+                    aml_append(ifctx3,
+                               aml_store(
+                                   aml_name("PPRM"),
+                                   aml_index(aml_name("TPM3"), aml_int(2))));
+                    aml_append(ifctx3, aml_return(aml_name("TPM3")));
+                }
+                aml_append(ifctx2, ifctx3);
+            }
+            aml_append(ifctx, ifctx2);
+
+            /* get platform-specific action to transition to pre-OS env. */
+            ifctx2 = aml_if(aml_equal(aml_local(0), aml_int(4)));
+            {
+                /* reboot */
+                aml_append(ifctx2, aml_return(aml_int(2)));
+            }
+            aml_append(ifctx, ifctx2);
+
+            /* get TPM operation response */
+            ifctx2 = aml_if(aml_equal(aml_local(0), aml_int(5)));
+            {
+                aml_append(ifctx2,
+                           aml_store(
+                               aml_name("LPPR"),
+                               aml_index(aml_name("TPM3"), aml_int(1))));
+                aml_append(ifctx2,
+                           aml_store(
+                               aml_name("PPRP"),
+                               aml_index(aml_name("TPM3"), aml_int(2))));
+                aml_append(ifctx2, aml_return(aml_name("TPM3")));
+            }
+            aml_append(ifctx, ifctx2);
+
+            /* submit preferred user language */
+            ifctx2 = aml_if(aml_equal(aml_local(0), aml_int(6)));
+            {
+                /* 3 = not implemented */
+                aml_append(ifctx2, aml_return(aml_int(3)));
+            }
+            aml_append(ifctx, ifctx2);
+
+            /* submit TPM operation v2 */
+            ifctx2 = aml_if(aml_equal(aml_local(0), aml_int(7)));
+            {
+                /* get opcode */
+                aml_append(ifctx2,
+                           aml_store(aml_derefof(aml_index(aml_arg(3),
+                                                           aml_int(0))),
+                                     aml_local(0)));
+                /* get opcode flags */
+                aml_append(ifctx2,
+                           aml_store(aml_call1("TPFN", aml_local(0)),
+                                     aml_local(1)));
+                ifctx3 = aml_if(
+                    aml_equal(
+                        aml_and(aml_local(1), aml_int(TPM_PPI_FUNC_MASK), 
NULL),
+                        aml_int(TPM_PPI_FUNC_NOT_IMPLEMENTED)));
+                {
+                    /* 1: not implemented */
+                    aml_append(ifctx3, aml_return(aml_int(1)));
+                }
+                aml_append(ifctx2, ifctx3);
+
+                ifctx3 = aml_if(
+                    aml_equal(
+                        aml_and(aml_local(1), aml_int(TPM_PPI_FUNC_MASK), 
NULL),
+                        aml_int(TPM_PPI_FUNC_BLOCKED)));
+                {
+                    /* 3: blocked by firmware */
+                    aml_append(ifctx3, aml_return(aml_int(3)));
+                }
+                aml_append(ifctx2, ifctx3);
+
+                /* revision to integer */
+                aml_append(ifctx2,
+                           aml_store(
+                               aml_to_integer(aml_arg(1)),
+                               aml_local(1)));
+
+                ifctx3 = aml_if(aml_equal(aml_local(1), aml_int(1)));
+                {
+                    /* revision 1 */
+                    aml_append(ifctx3, aml_store(aml_local(0),
+                                                 aml_name("PPRQ")));
+                    aml_append(ifctx3, aml_store(aml_int(0),
+                                                 aml_name("PPRM")));
+                }
+                aml_append(ifctx2, ifctx3);
+
+                ifctx3 = aml_if(aml_equal(aml_local(1), aml_int(2)));
+                {
+                    /* revision 2 */
+                    aml_append(ifctx3,
+                               aml_store(aml_local(0), aml_name("PPRQ")));
+                    aml_append(ifctx3,
+                               aml_store(
+                                   aml_derefof(aml_index(aml_arg(3),
+                                                         aml_int(1))),
+                                   aml_name("PPRM")));
+                }
+                aml_append(ifctx2, ifctx3);
+                /* 0: success */
+                aml_append(ifctx2, aml_return(aml_int(0)));
+            }
+            aml_append(ifctx, ifctx2);
+
+            /* get user confirmation status for operation */
+            ifctx2 = aml_if(aml_equal(aml_local(0), aml_int(8)));
+            {
+                /* get opcode */
+                aml_append(ifctx2,
+                           aml_store(aml_derefof(aml_index(aml_arg(3),
+                                                           aml_int(0))),
+                                     aml_local(0)));
+                /* get opcode flags */
+                aml_append(ifctx2,
+                           aml_store(aml_call1("TPFN", aml_local(0)),
+                                     aml_local(1)));
+                /* return confirmation status code */
+                aml_append(ifctx2,
+                           aml_return(
+                               aml_and(aml_local(1),
+                                       aml_int(TPM_PPI_FUNC_MASK), NULL)));
+            }
+            aml_append(ifctx, ifctx2);
+
+            aml_append(ifctx, aml_return(aml_buffer(1, zerobyte)));
+        }
+        aml_append(method, ifctx);
+    }
+    aml_append(dev, method);
+}
+
 static void
 build_dsdt(GArray *table_data, BIOSLinker *linker,
            AcpiPmInfo *pm, AcpiMiscInfo *misc,
@@ -2153,6 +2440,9 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
                  */
                 /* aml_append(crs, aml_irq_no_flags(TPM_TIS_IRQ)); */
                 aml_append(dev, aml_name_decl("_CRS", crs));
+
+                build_tpm_ppi(dev);
+
                 aml_append(scope, dev);
             }
 
@@ -2172,6 +2462,8 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
         aml_append(method, aml_return(aml_int(0x0f)));
         aml_append(dev, method);
 
+        build_tpm_ppi(dev);
+
         aml_append(sb_scope, dev);
     }
 
@@ -2918,7 +3210,7 @@ void acpi_setup(void)
         tpm_config = (FWCfgTPMConfig) {
             .tpmppi_address = cpu_to_le32(TPM_PPI_ADDR_BASE),
             .tpm_version = cpu_to_le32(tpm_get_version(tpm_find())),
-            .tpmppi_version = cpu_to_le32(TPM_PPI_VERSION_NONE)
+            .tpmppi_version = cpu_to_le32(TPM_PPI_VERSION_1_30)
         };
         fw_cfg_add_file(pcms->fw_cfg, "etc/tpm/config",
                         &tpm_config, sizeof tpm_config);
-- 
2.17.0.253.g3dd125b46d


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