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acpi: add helper routines to initialize ACPI tables

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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
   bb9feea431 x86: acpi: use offset instead of pointer when using build_header()
   4d027afeb3 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>
Message-Id: <20210924122802.1455362-2-imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Tested-by: Yanan Wang <wangyanan55@huawei.com>
This commit is contained in:
Igor Mammedov 2021-09-24 08:27:28 -04:00 committed by Michael S. Tsirkin
parent 46ce017167
commit c151fd8710
2 changed files with 93 additions and 0 deletions
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62
hw/acpi/aml-build.c
View File

@ -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,

31
include/hw/acpi/aml-build.h
View File

@ -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,