Re: [Qemu-devel] [PATCH 8/8] hw: acpi: Remove AcpiRsdpDescriptor and fix tests

[Igor Mammedov <imammedo@redhat.com>]

On Mon, 26 Nov 2018 17:29:41 +0100
Samuel Ortiz <sameo@linux.intel.com> wrote:

> We switched to the build_append_*() API for all RSDP callers, and this
> patch converts all existing tests depending on this structure.
> It is no longer needed and we can thus remove it.
I'd rephrase it as following:

The sole user of AcpiRsdpDescriptor structure is test,
drop test dependency on it and remove no longer used structure.


> 
> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
> ---
>  include/hw/acpi/acpi-defs.h | 13 ----------
>  tests/acpi-utils.h          |  5 +++-
>  tests/acpi-utils.c          | 48 ++++++++++++++++++++++++++++++-------
>  tests/bios-tables-test.c    | 27 ++++++++++++++-------
>  tests/vmgenid-test.c        |  8 ++++---
>  5 files changed, 67 insertions(+), 34 deletions(-)
> 
> diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h
> index 9b2f6b8043..abef1d57ae 100644
> --- a/include/hw/acpi/acpi-defs.h
> +++ b/include/hw/acpi/acpi-defs.h
> @@ -40,19 +40,6 @@ enum {
>      ACPI_FADT_F_LOW_POWER_S0_IDLE_CAPABLE,
>  };
>  
> -struct AcpiRsdpDescriptor {        /* Root System Descriptor Pointer */
> -    uint64_t signature;              /* ACPI signature, contains "RSD PTR " */
> -    uint8_t  checksum;               /* To make sum of struct == 0 */
> -    uint8_t  oem_id [6];             /* OEM identification */
> -    uint8_t  revision;               /* Must be 0 for 1.0, 2 for 2.0 */
> -    uint32_t rsdt_physical_address;  /* 32-bit physical address of RSDT */
> -    uint32_t length;                 /* XSDT Length in bytes including hdr */
> -    uint64_t xsdt_physical_address;  /* 64-bit physical address of XSDT */
> -    uint8_t  extended_checksum;      /* Checksum of entire table */
> -    uint8_t  reserved [3];           /* Reserved field must be 0 */
> -} QEMU_PACKED;
> -typedef struct AcpiRsdpDescriptor AcpiRsdpDescriptor;
> -
>  typedef struct AcpiRsdpData {
>      uint8_t oem_id[6]; /* OEM identification */
>      uint8_t revision;  /* Must be 0 for 1.0, 2 for 2.0 */
> diff --git a/tests/acpi-utils.h b/tests/acpi-utils.h
> index ac52abd0dd..fb1a67a21f 100644
> --- a/tests/acpi-utils.h
> +++ b/tests/acpi-utils.h
> @@ -82,6 +82,9 @@ typedef struct {
>  
>  uint8_t acpi_calc_checksum(const uint8_t *data, int len);
>  uint32_t acpi_find_rsdp_address(void);
> -void acpi_parse_rsdp_table(uint32_t addr, AcpiRsdpDescriptor *rsdp_table);
> +uint32_t acpi_find_rsdt_address(uint8_t *rsdp_table);
> +uint64_t acpi_find_xsdt_address(uint8_t *rsdp_table);
> +void acpi_parse_rsdp_table(uint32_t addr, uint8_t *rsdp_table,
> +                           uint8_t revision);
>  
>  #endif  /* TEST_ACPI_UTILS_H */
> diff --git a/tests/acpi-utils.c b/tests/acpi-utils.c
> index 41dc1ea9b4..c8fe2d1342 100644
> --- a/tests/acpi-utils.c
> +++ b/tests/acpi-utils.c
> @@ -52,14 +52,44 @@ uint32_t acpi_find_rsdp_address(void)
>      return off;
>  }
>  
> -void acpi_parse_rsdp_table(uint32_t addr, AcpiRsdpDescriptor *rsdp_table)
> +uint32_t acpi_find_rsdt_address(uint8_t *rsdp_table)
s/acpi_find_rsdt_address/acpi_get_rsdt_address/
likewise for xsdt

>  {
> -    ACPI_READ_FIELD(rsdp_table->signature, addr);
> -    ACPI_ASSERT_CMP64(rsdp_table->signature, "RSD PTR ");
> -
> -    ACPI_READ_FIELD(rsdp_table->checksum, addr);
> -    ACPI_READ_ARRAY(rsdp_table->oem_id, addr);
> -    ACPI_READ_FIELD(rsdp_table->revision, addr);
> -    ACPI_READ_FIELD(rsdp_table->rsdt_physical_address, addr);
> -    ACPI_READ_FIELD(rsdp_table->length, addr);
> +    uint32_t rsdt_physical_address = *((uint32_t *)(rsdp_table +
> +                                                    ACPI_RSDP_RSDT_OFFSET));
above cast looks pretty ugly and on some hw it might trigger SIGBUS
maybe:

       memcpy(addr, &rsdp_table[16 /* RsdtAddress offset */], 4);

> +    uint8_t revision = rsdp_table[ACPI_RSDP_REVISION_OFFSET];
> +
> +    if (revision != ACPI_RSDP_REV_1) {
theoretically not rev1 might have rsdt pointer as well for legacy OS
but we don't do this in QEMU, so it doesn't really matter

> +        return 0;
> +    }
> +
> +    return le32_to_cpu(rsdt_physical_address);
> +}
> +
> +uint64_t acpi_find_xsdt_address(uint8_t *rsdp_table)
> +{
> +    uint64_t xsdt_physical_address = *((uint64_t *)(rsdp_table +
> +                                                    ACPI_RSDP_XSDT_OFFSET));
access to uninitialized data if not rev2,
here it's not harmful but it's better not to confuse tools and fetch value after revision check

> +    uint8_t revision = rsdp_table[ACPI_RSDP_REVISION_OFFSET];
> +
> +    if (revision != ACPI_RSDP_REV_2) {
> +        return 0;
> +    }
> +
> +    return le64_to_cpu(xsdt_physical_address);
> +}
> +
> +void acpi_parse_rsdp_table(uint32_t addr, uint8_t *rsdp_table, uint8_t revision)
> +{
> +    switch (revision) {
> +    case ACPI_RSDP_REV_1:
> +        memread(addr, rsdp_table, ACPI_RSDP_REV_1_LEN);
> +        break;
> +    case ACPI_RSDP_REV_2:
> +        memread(addr, rsdp_table, ACPI_RSDP_REV_2_LEN);
> +        break;
> +    default:
> +        g_assert_not_reached();
> +    }
> +
> +    ACPI_ASSERT_CMP64(*((uint64_t *)(rsdp_table)), ACPI_RSDP_SIGNATURE);
>  }
> diff --git a/tests/bios-tables-test.c b/tests/bios-tables-test.c
> index d661d9be62..8cde404bda 100644
> --- a/tests/bios-tables-test.c
> +++ b/tests/bios-tables-test.c
> @@ -27,7 +27,8 @@ typedef struct {
>      const char *machine;
>      const char *variant;
>      uint32_t rsdp_addr;
> -    AcpiRsdpDescriptor rsdp_table;
> +    uint8_t rsdp_table[ACPI_RSDP_REV_2_LEN];
> +    uint32_t rsdt_physical_address;
>      AcpiRsdtDescriptorRev1 rsdt_table;
>      uint32_t dsdt_addr;
>      uint32_t facs_addr;
> @@ -83,21 +84,31 @@ static void test_acpi_rsdp_address(test_data *data)
>      data->rsdp_addr = off;
>  }
>  
> -static void test_acpi_rsdp_table(test_data *data)
> +static void test_acpi_rsdp_table(test_data *data, uint8_t revision)
>  {
> -    AcpiRsdpDescriptor *rsdp_table = &data->rsdp_table;
> +    uint8_t *rsdp_table = data->rsdp_table;
>      uint32_t addr = data->rsdp_addr;
>  
> -    acpi_parse_rsdp_table(addr, rsdp_table);
> +    acpi_parse_rsdp_table(addr, rsdp_table, revision);
>  
> -    /* rsdp checksum is not for the whole table, but for the first 20 bytes */
> -    g_assert(!acpi_calc_checksum((uint8_t *)rsdp_table, 20));
> +    switch (revision) {
> +    case ACPI_RSDP_REV_1:
> +        /* With rev 1, checksum is only for the first 20 bytes */
> +        g_assert(!acpi_calc_checksum(rsdp_table,  ACPI_RSDP_REV_1_LEN));
> +        break;
> +    case ACPI_RSDP_REV_2:
> +        /* With revision 2, we have 2 checksums */
> +        g_assert(!acpi_calc_checksum(rsdp_table, ACPI_RSDP_REV_1_LEN));
> +        g_assert(!acpi_calc_checksum(rsdp_table, ACPI_RSDP_REV_2_LEN));
> +    default:
> +        g_assert_not_reached();
> +    }
>  }
>  
>  static void test_acpi_rsdt_table(test_data *data)
>  {
>      AcpiRsdtDescriptorRev1 *rsdt_table = &data->rsdt_table;
> -    uint32_t addr = le32_to_cpu(data->rsdp_table.rsdt_physical_address);
> +    uint32_t addr = acpi_find_rsdt_address(data->rsdp_table);
>      uint32_t *tables;
>      int tables_nr;
>      uint8_t checksum;
> @@ -626,7 +637,7 @@ static void test_acpi_one(const char *params, test_data *data)
>  
>      data->tables = g_array_new(false, true, sizeof(AcpiSdtTable));
>      test_acpi_rsdp_address(data);
> -    test_acpi_rsdp_table(data);
> +    test_acpi_rsdp_table(data, ACPI_RSDP_REV_1);
>      test_acpi_rsdt_table(data);
>      fadt_fetch_facs_and_dsdt_ptrs(data);
>      test_acpi_facs_table(data);
> diff --git a/tests/vmgenid-test.c b/tests/vmgenid-test.c
> index 0a6fb55f2e..db5b084c18 100644
> --- a/tests/vmgenid-test.c
> +++ b/tests/vmgenid-test.c
> @@ -35,7 +35,7 @@ static uint32_t acpi_find_vgia(void)
>  {
>      uint32_t rsdp_offset;
>      uint32_t guid_offset = 0;
> -    AcpiRsdpDescriptor rsdp_table;
> +    uint8_t rsdp_table[ACPI_RSDP_REV_2_LEN];
>      uint32_t rsdt, rsdt_table_length;
>      AcpiRsdtDescriptorRev1 rsdt_table;
>      size_t tables_nr;
> @@ -52,9 +52,11 @@ static uint32_t acpi_find_vgia(void)
>  
>      g_assert_cmphex(rsdp_offset, <, RSDP_ADDR_INVALID);
>  
> -    acpi_parse_rsdp_table(rsdp_offset, &rsdp_table);
> +    acpi_parse_rsdp_table(rsdp_offset, rsdp_table, ACPI_RSDP_REV_1);
> +
> +    rsdt = acpi_find_rsdt_address(rsdp_table);
> +    g_assert(rsdt);
>  
> -    rsdt = le32_to_cpu(rsdp_table.rsdt_physical_address);
>      /* read the header */
>      ACPI_READ_TABLE_HEADER(&rsdt_table, rsdt);
>      ACPI_ASSERT_CMP(rsdt_table.signature, "RSDT");