From c151fd87102cbb4082ac5dbcd704196b0495d28a Mon Sep 17 00:00:00 2001 From: Igor Mammedov Date: Fri, 24 Sep 2021 08:27:28 -0400 Subject: [PATCH] acpi: add helper routines to initialize ACPI tables 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 Reviewed-by: Eric Auger Message-Id: <20210924122802.1455362-2-imammedo@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Tested-by: Stefan Berger Tested-by: Yanan Wang --- hw/acpi/aml-build.c | 62 +++++++++++++++++++++++++++++++++++++++++++++ include/hw/acpi/aml-build.h | 31 +++++++++++++++++++++++ 2 files changed, 93 insertions(+) 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, 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, -- 2.11.0