Entropy Stack update

.gitlab-ci.d/opentitan/qemu-ot.yml

@@ -1,5 +1,5 @@
 variables:
-  BAREMETAL_REF: "b0-250310-1"
+  BAREMETAL_REF: "b0-250325-1"
   QEMU_BUILD_OPTS: "--disable-install-blobs"
 
 include:

docs/opentitan/earlgrey.md

@@ -128,6 +128,9 @@ See [`tools.md`](tools.md)
   update the vCPU reset vector at startup. When this option is used, with `-kernel` option for
   example, the application is loaded in memory but the default machine reset vector is used.
 
+* `verilator=true` can be appended to the machine option switch, to select Verilator lowered clocks:
+  _i.e._ `-M ot-earlgrey,verilator=true` to select Verilator reduced clock rates.
+
 * `-cpu lowrisc-ibex,x-zbr=false` can be used to force disable the Zbr experimental-and-deprecated
   RISC-V bitmap extension for CRC32 extension.
 
@@ -155,8 +158,12 @@ See [`tools.md`](tools.md)
 
 ### OTBN
 
-* `-global ot-otbn.logfile=<filename>` dumps executed instructions on OTBN core into the specified
-  filename. Beware that is even further slows down execution speed, which could likely result into
+* `-global ot-otbn.logfile=<filename>` output OTBN execution message to the specified logfile. When
+  _logasm_ option (see below) is not enabled, only execution termination and error messages are
+  logged. `stderr` can be used to log the messages to the standard error stream instead of a file.
+
+* `-global ot-otbn.logasm=<true|false>` dumps executed instructions on OTBN core into the _logfile_
+  filename. Beware that this further slows down execution speed, which could likely result in the
   guest application on the Ibex core to time out.
 
 ### OTP

hw/opentitan/Kconfig

@@ -138,7 +138,7 @@ config OT_ROM_CTRL
 config OT_RSTMGR
     bool
 
-config OT_SENSOR
+config OT_SENSOR_EG
     bool
 
 config OT_SOC_PROXY

hw/opentitan/meson.build

@@ -45,7 +45,7 @@ system_ss.add(when: 'CONFIG_OT_PWRMGR', if_true: files('ot_pwrmgr.c'))
 system_ss.add(when: 'CONFIG_OT_RANDOM_SRC', if_true: files('ot_random_src.c'))
 system_ss.add(when: 'CONFIG_OT_ROM_CTRL', if_true: files('ot_rom_ctrl.c', 'ot_rom_ctrl_img.c'))
 system_ss.add(when: 'CONFIG_OT_RSTMGR', if_true: files('ot_rstmgr.c'))
-system_ss.add(when: 'CONFIG_OT_SENSOR', if_true: files('ot_sensor.c'))
+system_ss.add(when: 'CONFIG_OT_SENSOR_EG', if_true: files('ot_sensor_eg.c'))
 system_ss.add(when: 'CONFIG_OT_SOC_PROXY', if_true: files('ot_soc_proxy.c'))
 system_ss.add(when: 'CONFIG_OT_SOCDBG_CTRL', if_true: files('ot_socdbg_ctrl.c'))
 system_ss.add(when: 'CONFIG_OT_SPI_DEVICE', if_true: files('ot_spi_device.c'))

hw/opentitan/ot_aes.c

@@ -201,6 +201,7 @@ typedef struct OtAESRegisters {
     DECLARE_BITMAP(data_in_bm, PARAM_NUM_REGS_DATA);
     DECLARE_BITMAP(data_out_bm, PARAM_NUM_REGS_DATA);
     uint32_t key[PARAM_NUM_REGS_KEY];
+    bool data_out_rdy; /* AES output data exist, not yet published */
 } OtAESRegisters;
 
 typedef struct OtAESContext {
@@ -399,6 +400,8 @@ static inline void ot_aes_load_reseed_rate(OtAESState *s)
         break;
     }
 
+    trace_ot_aes_reseed_rate(reseed);
+
     s->reseed_count = reseed;
 }
 
@@ -803,9 +806,7 @@ static void ot_aes_push(OtAESState *s)
 
     memcpy(r->data_out, c->dst, sizeof(c->dst));
     memcpy(r->iv, c->iv, sizeof(c->iv));
-    bitmap_fill(r->data_out_bm, PARAM_NUM_REGS_DATA);
-
-    r->status |= R_STATUS_OUTPUT_VALID_MASK;
+    r->data_out_rdy = true;
 }
 
 static void ot_aes_process(OtAESState *s)
@@ -898,6 +899,15 @@ static void ot_aes_process(OtAESState *s)
     }
 }
 
+static void ot_aes_commit_data_out(OtAESRegisters *r)
+{
+    if (r->data_out_rdy) {
+        bitmap_fill(r->data_out_bm, PARAM_NUM_REGS_DATA);
+        r->status |= R_STATUS_OUTPUT_VALID_MASK;
+        r->data_out_rdy = false;
+    }
+}
+
 static inline void ot_aes_do_process(OtAESState *s)
 {
     ot_aes_process(s);
@@ -906,10 +916,18 @@ static inline void ot_aes_do_process(OtAESState *s)
         s->reseed_count -= 1u;
     }
     if (!s->reseed_count) {
+        /*
+         * delay availability of pushed data till completion of reseed
+         * otherwise, IDLE status may be false once the vCPU has read the data,
+         * which would not match the HW behavior
+         */
         trace_ot_aes_reseed("reseed_count reached");
         s->regs->trigger |= R_TRIGGER_PRNG_RESEED_MASK;
         ot_aes_trigger_reseed(s);
         ot_aes_load_reseed_rate(s);
+    } else {
+        /* flag pushed data as immediately available */
+        ot_aes_commit_data_out(s->regs);
     }
 
     OtAESRegisters *r = s->regs;
@@ -968,6 +986,13 @@ static void ot_aes_fill_entropy(void *opaque, uint32_t bits, bool fips)
     edn->scheduled = false;
     r->trigger &= ~R_TRIGGER_PRNG_RESEED_MASK;
 
+    /*
+     * if a previous AES data output generation had completed, flag the output
+     * as valid, as this state was delayed till entropy collection was
+     * completed to maintain a coherent IDLE state.
+     */
+    ot_aes_commit_data_out(r);
+
     ot_prng_reseed(s->prng, bits);
 
     ot_aes_handle_trigger(s);
@@ -1270,6 +1295,7 @@ static void ot_aes_reset(DeviceState *dev)
     r->ctrl_aux_regwen = 1u;
     r->trigger = 0xeu;
     r->status = 0u;
+    r->data_out_rdy = false;
     e->scheduled = false;
     ot_aes_load_reseed_rate(s);
 

hw/opentitan/ot_ast_dj.c

@@ -1,7 +1,7 @@
 /*
  * QEMU OpenTitan Darjeeling Analog Sensor Top device
  *
- * Copyright (c) 2023-2024 Rivos, Inc.
+ * Copyright (c) 2023-2025 Rivos, Inc.
  *
  * Author(s):
  *  Emmanuel Blot <eblot@rivosinc.com>
@@ -152,26 +152,12 @@ struct OtASTDjState {
 /* Private implementation */
 /* -------------------------------------------------------------------------- */
 
-static int ot_ast_dj_get_generation(OtRandomSrcIf *dev)
-{
-    (void)dev;
-
-    return -1;
-}
-
-static int ot_ast_dj_get_random(OtRandomSrcIf *dev, int genid,
-                                uint64_t random[OT_RANDOM_SRC_DWORD_COUNT],
-                                bool *fips)
+static int ot_ast_dj_get_random(
+    OtRandomSrcIf *dev, uint64_t random[OT_RANDOM_SRC_DWORD_COUNT], bool *fips)
 {
     OtASTDjState *s = OT_AST_DJ(dev);
     OtASTDjRandom *rnd = &s->random;
 
-    if (genid != -1) {
-        qemu_log_mask(LOG_GUEST_ERROR, "%s: AST gennum mismatch req:%d\n",
-                      __func__, genid);
-        return -2;
-    }
-
     if (!rnd->avail) {
         /* not ready */
         trace_ot_ast_no_entropy(0);
@@ -441,7 +427,6 @@ static void ot_ast_dj_class_init(ObjectClass *klass, void *data)
     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 
     OtRandomSrcIfClass *rdc = OT_RANDOM_SRC_IF_CLASS(klass);
-    rdc->get_random_generation = &ot_ast_dj_get_generation;
     rdc->get_random_values = &ot_ast_dj_get_random;
 }
 

hw/opentitan/ot_common.c

@@ -1,7 +1,8 @@
 /*
  * QEMU OpenTitan utilities
  *
- * Copyright (c) 2023 Rivos, Inc.
+ * Copyright (c) 2023-2024 Rivos, Inc.
+ * Copyright (c) 2025 lowRISC contributors.
  *
  * Author(s):
  *  Emmanuel Blot <eblot@rivosinc.com>
@@ -221,8 +222,7 @@ AddressSpace *ot_common_get_local_address_space(DeviceState *s)
     return cpu ? cpu->as : NULL;
 }
 
-static void
-ot_common_configure_device_opts(DeviceState **devices, unsigned count)
+void ot_common_configure_device_opts(DeviceState **devices, unsigned count)
 {
     // TODO need to use qemu_find_opts_err if no config is ok
     QemuOptsList *optlist = qemu_find_opts("ot_device");