Patch introduces acpi_table_begin()/ acpi_table_end() API
that hides pointer/offset arithmetic from user as opposed
to build_header(), to prevent errors caused by it [1].
acpi_table_begin():
initializes table header and keeps track of
table data/offsets
acpi_table_end():
sets actual table length and tells bios loader
where table is for the later initialization on
guest side.
1) commits
bb9feea43179 x86: acpi: use offset instead of pointer when using
build_header()
4d027afeb3a9 Virt: ACPI: fix qemu assert due to re-assigned table data
address
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
---
CC: eric.auger@redhat.com
---
include/hw/acpi/aml-build.h | 31 +++++++++++++++++++
hw/acpi/aml-build.c | 62 +++++++++++++++++++++++++++++++++++++
2 files changed, 93 insertions(+)
diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
index 471266d739..4242382399 100644
--- a/include/hw/acpi/aml-build.h
+++ b/include/hw/acpi/aml-build.h
@@ -413,6 +413,37 @@ Aml *aml_concatenate(Aml *source1, Aml *source2, Aml
*target);
Aml *aml_object_type(Aml *object);
void build_append_int_noprefix(GArray *table, uint64_t value, int size);
+
+typedef struct AcpiTable {
+ const char *sig;
+ const uint8_t rev;
+ const char *oem_id;
+ const char *oem_table_id;
+ /* private vars tracking table state */
+ GArray *array;
+ unsigned table_offset;
+} AcpiTable;
+
+/**
+ * acpi_table_begin:
+ * initializes table header and keeps track of
+ * table data/offsets
+ * @desc: ACPI table descriptor
+ * @array: blob where the ACPI table will be composed/stored.
+ */
+void acpi_table_begin(AcpiTable *desc, GArray *array);
+
+/**
+ * acpi_table_end:
+ * sets actual table length and tells bios loader
+ * where table is for the later initialization on
+ * guest side.
+ * @linker: reference to BIOSLinker object to use for the table
+ * @table: ACPI table descriptor that was used with @acpi_table_begin
+ * counterpart
+ */
+void acpi_table_end(BIOSLinker *linker, AcpiTable *table);
+
void
build_header(BIOSLinker *linker, GArray *table_data,
AcpiTableHeader *h, const char *sig, int len, uint8_t rev,
diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
index d5103e6d7b..229a3eb654 100644
--- a/hw/acpi/aml-build.c
+++ b/hw/acpi/aml-build.c
@@ -52,6 +52,19 @@ static void build_append_byte(GArray *array, uint8_t val)
g_array_append_val(array, val);
}
+static void build_append_padded_str(GArray *array, const char *str,
+ size_t maxlen, char pad)
+{
+ size_t i;
+ size_t len = strlen(str);
+
+ g_assert(len <= maxlen);
+ g_array_append_vals(array, str, len);
+ for (i = maxlen - len; i > 0; i--) {
+ g_array_append_val(array, pad);
+ }
+}
+
static void build_append_array(GArray *array, GArray *val)
{
g_array_append_vals(array, val->data, val->len);
@@ -1692,6 +1705,55 @@ Aml *aml_object_type(Aml *object)
return var;
}
+void acpi_table_begin(AcpiTable *desc, GArray *array)
+{
+
+ desc->array = array;
+ desc->table_offset = array->len;
+
+ /*
+ * ACPI spec 1.0b
+ * 5.2.3 System Description Table Header
+ */
+ g_assert(strlen(desc->sig) == 4);
+ g_array_append_vals(array, desc->sig, 4); /* Signature */
+ /*
+ * reserve space for Length field, which will be patched by
+ * acpi_table_end() when the table creation is finished.
+ */
+ build_append_int_noprefix(array, 0, 4); /* Length */
+ build_append_int_noprefix(array, desc->rev, 1); /* Revision */
+ build_append_int_noprefix(array, 0, 1); /* Checksum */
+ build_append_padded_str(array, desc->oem_id, 6, ' '); /* OEMID */
+ /* OEM Table ID */
+ build_append_padded_str(array, desc->oem_table_id, 8, ' ');
+ build_append_int_noprefix(array, 1, 4); /* OEM Revision */
+ g_array_append_vals(array, ACPI_BUILD_APPNAME8, 4); /* Creator ID */
+ build_append_int_noprefix(array, 1, 4); /* Creator Revision */
+}
+
+void acpi_table_end(BIOSLinker *linker, AcpiTable *desc)
+{
+ /*
+ * ACPI spec 1.0b
+ * 5.2.3 System Description Table Header
+ * Table 5-2 DESCRIPTION_HEADER Fields
+ */
+ const unsigned checksum_offset = 9;
+ uint32_t table_len = desc->array->len - desc->table_offset;
+ uint32_t table_len_le = cpu_to_le32(table_len);
+ gchar *len_ptr = &desc->array->data[desc->table_offset + 4];
+
+ /* patch "Length" field that has been reserved by acpi_table_begin()
+ * to the actual length, i.e. accumulated table length from
+ * acpi_table_begin() till acpi_table_end()
+ */
+ memcpy(len_ptr, &table_len_le, sizeof table_len_le);
+
+ bios_linker_loader_add_checksum(linker, ACPI_BUILD_TABLE_FILE,
+ desc->table_offset, table_len, desc->table_offset + checksum_offset);
+}
+
void
build_header(BIOSLinker *linker, GArray *table_data,
AcpiTableHeader *h, const char *sig, int len, uint8_t rev,