acpi: Permit OEM ID and OEM table ID fields to be changed

Qemu's ACPI table generation sets the fields OEM ID and OEM table ID
to "BOCHS " and "BXPCxxxx" where "xxxx" is replaced by the ACPI
table name.

Some games like Red Dead Redemption 2 seem to check the ACPI OEM ID
and OEM table ID for the strings "BOCHS" and "BXPC" and if they are
found, the game crashes(this may be an intentional detection
mechanism to prevent playing the game in a virtualized environment).

This patch allows you to override these default values.

The feature can be used in this manner:
qemu -machine oem-id=ABCDEF,oem-table-id=GHIJKLMN

The oem-id string can be up to 6 bytes in size, and the
oem-table-id string can be up to 8 bytes in size. If the string are
smaller than their respective sizes they will be padded with space.
If either of these parameters is not set, the current default values
will be used for the one missing.

Note that the the OEM Table ID field will not be extended with the
name of the table, but will use either the default name or the user
provided one.

This does not affect the -acpitable option (for user-defined ACPI
tables), which has precedence over -machine option.

Signed-off-by: Marian Postevca <posteuca@mutex.one>
Message-Id: <20210119003216.17637-3-posteuca@mutex.one>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 64 insertions, 0 deletions

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 5458f61d10..437977c49e 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1611,6 +1611,50 @@ static void pc_machine_set_max_fw_size(Object *obj, Visitor *v,
     pcms->max_fw_size = value;
 }
 
+static char *pc_machine_get_oem_id(Object *obj, Error **errp)
+{
+    PCMachineState *pcms = PC_MACHINE(obj);
+
+    return g_strdup(pcms->oem_id);
+}
+
+static void pc_machine_set_oem_id(Object *obj, const char *value, Error **errp)
+{
+    PCMachineState *pcms = PC_MACHINE(obj);
+    size_t len = strlen(value);
+
+    if (len > 6) {
+        error_setg(errp,
+          "User specified "PC_MACHINE_OEM_ID" value is bigger than "
+          "6 bytes in size");
+        return;
+    }
+
+    strncpy(pcms->oem_id, value, len + 1);
+}
+
+static char *pc_machine_get_oem_table_id(Object *obj, Error **errp)
+{
+    PCMachineState *pcms = PC_MACHINE(obj);
+
+    return g_strdup(pcms->oem_table_id);
+}
+
+static void pc_machine_set_oem_table_id(Object *obj, const char *value,
+                                        Error **errp)
+{
+    PCMachineState *pcms = PC_MACHINE(obj);
+    size_t len = strlen(value);
+
+    if (len > 8) {
+        error_setg(errp,
+          "User specified "PC_MACHINE_OEM_TABLE_ID" value is bigger than "
+          "8 bytes in size");
+        return;
+    }
+    strncpy(pcms->oem_table_id, value, len + 1);
+}
+
 static void pc_machine_initfn(Object *obj)
 {
     PCMachineState *pcms = PC_MACHINE(obj);
@@ -1623,6 +1667,8 @@ static void pc_machine_initfn(Object *obj)
     pcms->max_ram_below_4g = 0; /* use default */
     /* acpi build is enabled by default if machine supports it */
     pcms->acpi_build_enabled = PC_MACHINE_GET_CLASS(pcms)->has_acpi_build;
+    pcms->oem_id = g_strndup(ACPI_BUILD_APPNAME6, 6);
+    pcms->oem_table_id = g_strndup(ACPI_BUILD_APPNAME8, 8);
     pcms->smbus_enabled = true;
     pcms->sata_enabled = true;
     pcms->pit_enabled = true;
@@ -1759,6 +1805,24 @@ static void pc_machine_class_init(ObjectClass *oc, void *data)
         NULL, NULL);
     object_class_property_set_description(oc, PC_MACHINE_MAX_FW_SIZE,
         "Maximum combined firmware size");
+
+    object_class_property_add_str(oc, PC_MACHINE_OEM_ID,
+                                  pc_machine_get_oem_id,
+                                  pc_machine_set_oem_id);
+    object_class_property_set_description(oc, PC_MACHINE_OEM_ID,
+                                          "Override the default value of field OEMID "
+                                          "in ACPI table header."
+                                          "The string may be up to 6 bytes in size");
+
+
+    object_class_property_add_str(oc, PC_MACHINE_OEM_TABLE_ID,
+                                  pc_machine_get_oem_table_id,
+                                  pc_machine_set_oem_table_id);
+    object_class_property_set_description(oc, PC_MACHINE_OEM_TABLE_ID,
+                                          "Override the default value of field OEM Table ID "
+                                          "in ACPI table header."
+                                          "The string may be up to 8 bytes in size");
+
 }
 
 static const TypeInfo pc_machine_info = {