[Qemu-devel] [PATCH v2 04/18] hw/nvram/fw_cfg: Add trace events

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

Add fw_cfg_arch_key_name() to be able to resolve architecture
specific keys. All architectures do have specific keys, thus
implement this function. Architectures that don't use the fw_cfg
device don't have to implement this function, however to ease
the Makefile rules and satisfy the linking, we provide a stub.

Now than we can resolve keys into "well know numeric", add
trace events to display more information when keys are added
(and dump the key content when possible).

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
v2: Added fw_cfg_arch_key_name() -> reset R-b
---
 MAINTAINERS               |  1 +
 hw/i386/pc.c              | 21 +++++++++++++
 hw/nvram/fw_cfg.c         | 63 ++++++++++++++++++++++++++++++++++++++-
 hw/nvram/trace-events     |  7 ++++-
 hw/ppc/Makefile.objs      |  2 +-
 hw/ppc/fw_cfg.c           | 31 +++++++++++++++++++
 hw/sparc/sun4m.c          | 19 ++++++++++++
 hw/sparc64/sun4u.c        | 19 ++++++++++++
 include/hw/nvram/fw_cfg.h | 11 +++++++
 stubs/Makefile.objs       |  1 +
 stubs/fw_cfg.c            | 19 ++++++++++++
 11 files changed, 191 insertions(+), 3 deletions(-)
 create mode 100644 hw/ppc/fw_cfg.c
 create mode 100644 stubs/fw_cfg.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 074ad46d47..306fc2aefa 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1659,6 +1659,7 @@ R: Gerd Hoffmann <kraxel@redhat.com>
 S: Supported
 F: docs/specs/fw_cfg.txt
 F: hw/nvram/fw_cfg.c
+F: stubs/fw_cfg.c
 F: include/hw/nvram/fw_cfg.h
 F: include/standard-headers/linux/qemu_fw_cfg.h
 F: tests/libqos/fw_cfg.c
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 42128183e9..0848cdc18f 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -349,6 +349,27 @@ GlobalProperty pc_compat_1_4[] = {
 };
 const size_t pc_compat_1_4_len = G_N_ELEMENTS(pc_compat_1_4);
 
+const char *fw_cfg_arch_key_name(uint16_t key)
+{
+    static const struct {
+        uint16_t key;
+        const char *name;
+    } fw_cfg_arch_wellknown_keys[] = {
+        {FW_CFG_ACPI_TABLES, "acpi_tables"},
+        {FW_CFG_SMBIOS_ENTRIES, "smbios_entries"},
+        {FW_CFG_IRQ0_OVERRIDE, "irq0_override"},
+        {FW_CFG_E820_TABLE, "e820_tables"},
+        {FW_CFG_HPET, "hpet"},
+    };
+
+    for (size_t i = 0; i < ARRAY_SIZE(fw_cfg_arch_wellknown_keys); i++) {
+        if (fw_cfg_arch_wellknown_keys[i].key == key) {
+            return fw_cfg_arch_wellknown_keys[i].name;
+        }
+    }
+    return NULL;
+}
+
 void gsi_handler(void *opaque, int n, int level)
 {
     GSIState *s = opaque;
diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
index 7fdf04adc9..684c2cf00a 100644
--- a/hw/nvram/fw_cfg.c
+++ b/hw/nvram/fw_cfg.c
@@ -60,6 +60,62 @@ struct FWCfgEntry {
     FWCfgWriteCallback write_cb;
 };
 
+/**
+ * key_name:
+ *
+ * @key: The uint16 selector key.
+ *
+ * Returns: The stringified name if the selector refers to a well-known
+ *          numerically defined item, or NULL on key lookup failure.
+ */
+static const char *key_name(uint16_t key)
+{
+    static const char *fw_cfg_wellknown_keys[FW_CFG_FILE_FIRST] = {
+        [FW_CFG_SIGNATURE] = "signature",
+        [FW_CFG_ID] = "id",
+        [FW_CFG_UUID] = "uuid",
+        [FW_CFG_RAM_SIZE] = "ram_size",
+        [FW_CFG_NOGRAPHIC] = "nographic",
+        [FW_CFG_NB_CPUS] = "nb_cpus",
+        [FW_CFG_MACHINE_ID] = "machine_id",
+        [FW_CFG_KERNEL_ADDR] = "kernel_addr",
+        [FW_CFG_KERNEL_SIZE] = "kernel_size",
+        [FW_CFG_KERNEL_CMDLINE] = "kernel_cmdline",
+        [FW_CFG_INITRD_ADDR] = "initrd_addr",
+        [FW_CFG_INITRD_SIZE] = "initdr_size",
+        [FW_CFG_BOOT_DEVICE] = "boot_device",
+        [FW_CFG_NUMA] = "numa",
+        [FW_CFG_BOOT_MENU] = "boot_menu",
+        [FW_CFG_MAX_CPUS] = "max_cpus",
+        [FW_CFG_KERNEL_ENTRY] = "kernel_entry",
+        [FW_CFG_KERNEL_DATA] = "kernel_data",
+        [FW_CFG_INITRD_DATA] = "initrd_data",
+        [FW_CFG_CMDLINE_ADDR] = "cmdline_addr",
+        [FW_CFG_CMDLINE_SIZE] = "cmdline_size",
+        [FW_CFG_CMDLINE_DATA] = "cmdline_data",
+        [FW_CFG_SETUP_ADDR] = "setup_addr",
+        [FW_CFG_SETUP_SIZE] = "setup_size",
+        [FW_CFG_SETUP_DATA] = "setup_data",
+        [FW_CFG_FILE_DIR] = "file_dir",
+    };
+
+    if (key & FW_CFG_ARCH_LOCAL) {
+        return fw_cfg_arch_key_name(key);
+    }
+    if (key < FW_CFG_FILE_FIRST) {
+        return fw_cfg_wellknown_keys[key];
+    }
+
+    return NULL;
+}
+
+static inline const char *trace_key_name(uint16_t key)
+{
+    const char *name = key_name(key);
+
+    return name ? name : "unknown";
+}
+
 #define JPG_FILE 0
 #define BMP_FILE 1
 
@@ -234,7 +290,7 @@ static int fw_cfg_select(FWCfgState *s, uint16_t key)
         }
     }
 
-    trace_fw_cfg_select(s, key, ret);
+    trace_fw_cfg_select(s, key, trace_key_name(key), ret);
     return ret;
 }
 
@@ -617,6 +673,7 @@ static void *fw_cfg_modify_bytes_read(FWCfgState *s, uint16_t key,
 
 void fw_cfg_add_bytes(FWCfgState *s, uint16_t key, void *data, size_t len)
 {
+    trace_fw_cfg_add_bytes(key, trace_key_name(key), len);
     fw_cfg_add_bytes_callback(s, key, NULL, NULL, NULL, data, len, true);
 }
 
@@ -624,6 +681,7 @@ void fw_cfg_add_string(FWCfgState *s, uint16_t key, const char *value)
 {
     size_t sz = strlen(value) + 1;
 
+    trace_fw_cfg_add_string(key, trace_key_name(key), value);
     fw_cfg_add_bytes(s, key, g_memdup(value, sz), sz);
 }
 
@@ -633,6 +691,7 @@ void fw_cfg_add_i16(FWCfgState *s, uint16_t key, uint16_t value)
 
     copy = g_malloc(sizeof(value));
     *copy = cpu_to_le16(value);
+    trace_fw_cfg_add_i16(key, trace_key_name(key), value);
     fw_cfg_add_bytes(s, key, copy, sizeof(value));
 }
 
@@ -652,6 +711,7 @@ void fw_cfg_add_i32(FWCfgState *s, uint16_t key, uint32_t value)
 
     copy = g_malloc(sizeof(value));
     *copy = cpu_to_le32(value);
+    trace_fw_cfg_add_i32(key, trace_key_name(key), value);
     fw_cfg_add_bytes(s, key, copy, sizeof(value));
 }
 
@@ -661,6 +721,7 @@ void fw_cfg_add_i64(FWCfgState *s, uint16_t key, uint64_t value)
 
     copy = g_malloc(sizeof(value));
     *copy = cpu_to_le64(value);
+    trace_fw_cfg_add_i64(key, trace_key_name(key), value);
     fw_cfg_add_bytes(s, key, copy, sizeof(value));
 }
 
diff --git a/hw/nvram/trace-events b/hw/nvram/trace-events
index 6b55ba7a09..4d8fa992fe 100644
--- a/hw/nvram/trace-events
+++ b/hw/nvram/trace-events
@@ -5,6 +5,11 @@ nvram_read(uint32_t addr, uint32_t ret) "read addr %d: 0x%02x"
 nvram_write(uint32_t addr, uint32_t old, uint32_t val) "write addr %d: 0x%02x -> 0x%02x"
 
 # hw/nvram/fw_cfg.c
-fw_cfg_select(void *s, uint16_t key, int ret) "%p key %d = %d"
+fw_cfg_select(void *s, uint16_t key_value, const char *key_name, int ret) "%p key 0x%04" PRIx16 " '%s', ret: %d"
 fw_cfg_read(void *s, uint64_t ret) "%p = 0x%"PRIx64
+fw_cfg_add_bytes(uint16_t key_value, const char *key_name, size_t len) "key 0x%04" PRIx16 " '%s', %zu bytes"
 fw_cfg_add_file(void *s, int index, char *name, size_t len) "%p #%d: %s (%zd bytes)"
+fw_cfg_add_string(uint16_t key_value, const char *key_name, const char *value) "key 0x%04" PRIx16 " '%s', value '%s'"
+fw_cfg_add_i16(uint16_t key_value, const char *key_name, uint16_t value) "key 0x%04" PRIx16 " '%s', value 0x%" PRIx16
+fw_cfg_add_i32(uint16_t key_value, const char *key_name, uint32_t value) "key 0x%04" PRIx16 " '%s', value 0x%" PRIx32
+fw_cfg_add_i64(uint16_t key_value, const char *key_name, uint64_t value) "key 0x%04" PRIx16 " '%s', value 0x%" PRIx64
diff --git a/hw/ppc/Makefile.objs b/hw/ppc/Makefile.objs
index 1111b218a0..ae94098155 100644
--- a/hw/ppc/Makefile.objs
+++ b/hw/ppc/Makefile.objs
@@ -1,5 +1,5 @@
 # shared objects
-obj-y += ppc.o ppc_booke.o fdt.o
+obj-y += ppc.o ppc_booke.o fdt.o fw_cfg.o
 # IBM pSeries (sPAPR)
 obj-$(CONFIG_PSERIES) += spapr.o spapr_caps.o spapr_vio.o spapr_events.o
 obj-$(CONFIG_PSERIES) += spapr_hcall.o spapr_iommu.o spapr_rtas.o
diff --git a/hw/ppc/fw_cfg.c b/hw/ppc/fw_cfg.c
new file mode 100644
index 0000000000..0e7616b78a
--- /dev/null
+++ b/hw/ppc/fw_cfg.c
@@ -0,0 +1,31 @@
+#include "qemu/osdep.h"
+#include "hw/ppc/ppc.h"
+#include "hw/nvram/fw_cfg.h"
+
+const char *fw_cfg_arch_key_name(uint16_t key)
+{
+    static const struct {
+        uint16_t key;
+        const char *name;
+    } fw_cfg_arch_wellknown_keys[] = {
+        {FW_CFG_PPC_WIDTH, "width"},
+        {FW_CFG_PPC_HEIGHT, "height"},
+        {FW_CFG_PPC_DEPTH, "depth"},
+        {FW_CFG_PPC_TBFREQ, "tbfreq"},
+        {FW_CFG_PPC_CLOCKFREQ, "clockfreq"},
+        {FW_CFG_PPC_IS_KVM, "is_kvm"},
+        {FW_CFG_PPC_KVM_HC, "kvm_hc"},
+        {FW_CFG_PPC_KVM_PID, "pid"},
+        {FW_CFG_PPC_NVRAM_ADDR, "nvram_addr"},
+        {FW_CFG_PPC_BUSFREQ, "busfreq"},
+        {FW_CFG_PPC_NVRAM_FLAT, "nvram_flat"},
+        {FW_CFG_PPC_VIACONFIG, "viaconfig"},
+    };
+
+    for (size_t i = 0; i < ARRAY_SIZE(fw_cfg_arch_wellknown_keys); i++) {
+        if (fw_cfg_arch_wellknown_keys[i].key == key) {
+            return fw_cfg_arch_wellknown_keys[i].name;
+        }
+    }
+    return NULL;
+}
diff --git a/hw/sparc/sun4m.c b/hw/sparc/sun4m.c
index ca1e3825d5..49251d62b3 100644
--- a/hw/sparc/sun4m.c
+++ b/hw/sparc/sun4m.c
@@ -97,6 +97,25 @@ struct sun4m_hwdef {
     uint8_t nvram_machine_id;
 };
 
+const char *fw_cfg_arch_key_name(uint16_t key)
+{
+    static const struct {
+        uint16_t key;
+        const char *name;
+    } fw_cfg_arch_wellknown_keys[] = {
+        {FW_CFG_SUN4M_DEPTH, "depth"},
+        {FW_CFG_SUN4M_WIDTH, "width"},
+        {FW_CFG_SUN4M_HEIGHT, "height"},
+    };
+
+    for (size_t i = 0; i < ARRAY_SIZE(fw_cfg_arch_wellknown_keys); i++) {
+        if (fw_cfg_arch_wellknown_keys[i].key == key) {
+            return fw_cfg_arch_wellknown_keys[i].name;
+        }
+    }
+    return NULL;
+}
+
 static void fw_cfg_boot_set(void *opaque, const char *boot_device,
                             Error **errp)
 {
diff --git a/hw/sparc64/sun4u.c b/hw/sparc64/sun4u.c
index 399f2d73c8..4230b17b87 100644
--- a/hw/sparc64/sun4u.c
+++ b/hw/sparc64/sun4u.c
@@ -91,6 +91,25 @@ typedef struct EbusState {
 #define TYPE_EBUS "ebus"
 #define EBUS(obj) OBJECT_CHECK(EbusState, (obj), TYPE_EBUS)
 
+const char *fw_cfg_arch_key_name(uint16_t key)
+{
+    static const struct {
+        uint16_t key;
+        const char *name;
+    } fw_cfg_arch_wellknown_keys[] = {
+        {FW_CFG_SPARC64_WIDTH, "width"},
+        {FW_CFG_SPARC64_HEIGHT, "height"},
+        {FW_CFG_SPARC64_DEPTH, "depth"},
+    };
+
+    for (size_t i = 0; i < ARRAY_SIZE(fw_cfg_arch_wellknown_keys); i++) {
+        if (fw_cfg_arch_wellknown_keys[i].key == key) {
+            return fw_cfg_arch_wellknown_keys[i].name;
+        }
+    }
+    return NULL;
+}
+
 static void fw_cfg_boot_set(void *opaque, const char *boot_device,
                             Error **errp)
 {
diff --git a/include/hw/nvram/fw_cfg.h b/include/hw/nvram/fw_cfg.h
index f5a6895a74..828ad9dedc 100644
--- a/include/hw/nvram/fw_cfg.h
+++ b/include/hw/nvram/fw_cfg.h
@@ -226,4 +226,15 @@ FWCfgState *fw_cfg_init_mem_wide(hwaddr ctl_addr,
 FWCfgState *fw_cfg_find(void);
 bool fw_cfg_dma_enabled(void *opaque);
 
+/**
+ * fw_cfg_arch_key_name:
+ *
+ * @key: The uint16 selector key.
+ *
+ * Returns: The stringified architecture-specific name if the selector
+ *          refers to a well-known numerically defined item, or NULL on
+ *          key lookup failure.
+ */
+const char *fw_cfg_arch_key_name(uint16_t key);
+
 #endif
diff --git a/stubs/Makefile.objs b/stubs/Makefile.objs
index 269dfa5832..73452ad265 100644
--- a/stubs/Makefile.objs
+++ b/stubs/Makefile.objs
@@ -39,3 +39,4 @@ stub-obj-y += xen-hvm.o
 stub-obj-y += pci-host-piix.o
 stub-obj-y += ram-block.o
 stub-obj-y += ramfb.o
+stub-obj-y += fw_cfg.o
diff --git a/stubs/fw_cfg.c b/stubs/fw_cfg.c
new file mode 100644
index 0000000000..2b886c94d6
--- /dev/null
+++ b/stubs/fw_cfg.c
@@ -0,0 +1,19 @@
+/*
+ * fw_cfg stubs
+ *
+ * Copyright (c) 2019 Red Hat, Inc.
+ *
+ * Author:
+ *   Philippe Mathieu-Daudé <philmd@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/nvram/fw_cfg.h"
+
+const char *fw_cfg_arch_key_name(uint16_t key)
+{
+    return NULL;
+}
-- 
2.20.1