[ARM,SMBIOS,V4,1/2] smbios: add smbios 3.0 support

On 08/25/2015 11:01 AM, Peter Maydell wrote:
> On 25 August 2015 at 16:59, Wei Huang <wei@redhat.com> wrote:
>> On 08/25/2015 10:29 AM, Leif Lindholm wrote:
>>> Wei - is there actually any particular point in renaming this
>>> structure? In all versions of the specification before 3.0, this was
>>> only known as the "smbios entry point". Only with the introduction of
>>> SMBIOS 3.0 this was retrospectively renamed.

Hi Leif,

While fixing up the patches, I started to lean towards keeping -21 in
smbios-entry-point naming. Here are my points:

1) It is very easy to get confused the "union SmbiosEntryPoint" with
"struct smbios_entry_point" if we remove _21 from the original "struct
smbios_21_entry_point". A symmetric naming of "struct
smbios_21_entry_point" & "struct smbios_30_entry_point" actually is
easier to read;
2) SMBIOS 3.0 specification clearly separate 2.1 and 3.0 definitions. I
understand that people who started from old spec might be a bit confused
to read the code; But for those who pick up SMBIOS 3.0 (and beyond)
fresh, they will know the difference while reading the code.
3) The issues Peter found is x86 specific and we know that QEMU only
generates SMBIOS 2.1 tables for PC model. So we can fix the test code to
only use _21 struct. In the future, when we started to create test code
for ARM, it can be further merged.

Anyway, I attached the patch for your review. It addresses some of your
concerns regarding SMBIOS 2.1 usage cases by detailed comments (see
smbios.h).

>>
>> I can take this suggestion, with clear comment in header file so nobody
>> will get confused. Peter, please let me know if you object.
> 
> I don't object (though the opinion of the qemu smbios/acpi
> folk is probably more important than mine).
> 
> Please make sure you test the x86 platform has not been broken by
> this change (preferably more thoroughly than just running
> 'make check'...).

(I have tested the code with the following methods:

* dmidecode insider an ARM guest VM
* "make check" on both ARM and x86 hosts
* dmidecode insider a x86-64 Windows 7 VM
)


> 
> thanks
> -- PMM
>

Hi Wei,

On Wed, Aug 26, 2015 at 11:41:26AM -0500, Wei Huang wrote:
> While fixing up the patches, I started to lean towards keeping -21 in
> smbios-entry-point naming. Here are my points:
> 
> 1) It is very easy to get confused the "union SmbiosEntryPoint" with
> "struct smbios_entry_point" if we remove _21 from the original "struct
> smbios_21_entry_point". A symmetric naming of "struct
> smbios_21_entry_point" & "struct smbios_30_entry_point" actually is
> easier to read;
> 2) SMBIOS 3.0 specification clearly separate 2.1 and 3.0 definitions. I
> understand that people who started from old spec might be a bit confused
> to read the code; But for those who pick up SMBIOS 3.0 (and beyond)
> fresh, they will know the difference while reading the code.
> 3) The issues Peter found is x86 specific and we know that QEMU only
> generates SMBIOS 2.1 tables for PC model. So we can fix the test code to
> only use _21 struct. In the future, when we started to create test code
> for ARM, it can be further merged.
> 
> Anyway, I attached the patch for your review. It addresses some of your
> concerns regarding SMBIOS 2.1 usage cases by detailed comments (see
> smbios.h).

In general, I care a lot more about getting this functionality than
about the finer details of the inner workings of the code. The
comments are an improvement, and using -21 aligns the code closer with
current spec (but further from Linux).

Thanks,

Leif

> >> I can take this suggestion, with clear comment in header file so nobody
> >> will get confused. Peter, please let me know if you object.
> > 
> > I don't object (though the opinion of the qemu smbios/acpi
> > folk is probably more important than mine).
> > 
> > Please make sure you test the x86 platform has not been broken by
> > this change (preferably more thoroughly than just running
> > 'make check'...).
> 
> (I have tested the code with the following methods:
> 
> * dmidecode insider an ARM guest VM
> * "make check" on both ARM and x86 hosts
> * dmidecode insider a x86-64 Windows 7 VM
> )
> 
> 
> > 
> > thanks
> > -- PMM
> > 
> 
> commit 4abc639a34a43acccd81725f2176760058bb9849
> Author: Wei Huang <wei@redhat.com>
> Date:   Tue Aug 25 16:34:47 2015 -0400
> 
>     smbios: add smbios 3.0 support
>     
>     This patch adds support for SMBIOS 3.0 entry point. When caller invokes
>     smbios_set_defaults(), it can specify entry point as 2.1 or 3.0. Then
>     smbios_get_tables() will return the entry point table in right format.
>     
>     Acked-by: Gabriel Somlo <somlo@cmu.edu>
>     Tested-by: Gabriel Somlo <somlo@cmu.edu>
>     Tested-by: Leif Lindholm <leif.lindholm@linaro.org>
>     Signed-off-by: Wei Huang <wei@redhat.com>
> 
> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> index 9558467..b82921d 100644
> --- a/hw/i386/pc_piix.c
> +++ b/hw/i386/pc_piix.c
> @@ -173,7 +173,8 @@ static void pc_init1(MachineState *machine)
>          MachineClass *mc = MACHINE_GET_CLASS(machine);
>          /* These values are guest ABI, do not change */
>          smbios_set_defaults("QEMU", "Standard PC (i440FX + PIIX, 1996)",
> -                            mc->name, smbios_legacy_mode, smbios_uuid_encoded);
> +                            mc->name, smbios_legacy_mode, smbios_uuid_encoded,
> +                            SMBIOS_ENTRY_POINT_21);
>      }
>  
>      /* allocate ram and load rom/bios */
> diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
> index c07d65b..7217cbf 100644
> --- a/hw/i386/pc_q35.c
> +++ b/hw/i386/pc_q35.c
> @@ -165,7 +165,8 @@ static void pc_q35_init(MachineState *machine)
>      if (smbios_defaults) {
>          /* These values are guest ABI, do not change */
>          smbios_set_defaults("QEMU", "Standard PC (Q35 + ICH9, 2009)",
> -                            mc->name, smbios_legacy_mode, smbios_uuid_encoded);
> +                            mc->name, smbios_legacy_mode, smbios_uuid_encoded,
> +                            SMBIOS_ENTRY_POINT_21);
>      }
>  
>      /* allocate ram and load rom/bios */
> diff --git a/hw/smbios/smbios.c b/hw/smbios/smbios.c
> index efdbb5d..b81a1d3 100644
> --- a/hw/smbios/smbios.c
> +++ b/hw/smbios/smbios.c
> @@ -55,7 +55,9 @@ static uint8_t *smbios_tables;
>  static size_t smbios_tables_len;
>  static unsigned smbios_table_max;
>  static unsigned smbios_table_cnt;
> -static struct smbios_entry_point ep;
> +static SmbiosEntryPointType smbios_ep_type = SMBIOS_ENTRY_POINT_21;
> +
> +static SmbiosEntryPoint ep;
>  
>  static int smbios_type4_count = 0;
>  static bool smbios_immutable;
> @@ -771,11 +773,12 @@ void smbios_set_cpuid(uint32_t version, uint32_t features)
>  
>  void smbios_set_defaults(const char *manufacturer, const char *product,
>                           const char *version, bool legacy_mode,
> -                         bool uuid_encoded)
> +                         bool uuid_encoded, SmbiosEntryPointType ep_type)
>  {
>      smbios_have_defaults = true;
>      smbios_legacy = legacy_mode;
>      smbios_uuid_encoded = uuid_encoded;
> +    smbios_ep_type = ep_type;
>  
>      /* drop unwanted version of command-line file blob(s) */
>      if (smbios_legacy) {
> @@ -808,26 +811,53 @@ void smbios_set_defaults(const char *manufacturer, const char *product,
>  
>  static void smbios_entry_point_setup(void)
>  {
> -    memcpy(ep.anchor_string, "_SM_", 4);
> -    memcpy(ep.intermediate_anchor_string, "_DMI_", 5);
> -    ep.length = sizeof(struct smbios_entry_point);
> -    ep.entry_point_revision = 0; /* formatted_area reserved, per spec v2.1+ */
> -    memset(ep.formatted_area, 0, 5);
> -
> -    /* compliant with smbios spec v2.8 */
> -    ep.smbios_major_version = 2;
> -    ep.smbios_minor_version = 8;
> -    ep.smbios_bcd_revision = 0x28;
> -
> -    /* set during table construction, but BIOS may override: */
> -    ep.structure_table_length = cpu_to_le16(smbios_tables_len);
> -    ep.max_structure_size = cpu_to_le16(smbios_table_max);
> -    ep.number_of_structures = cpu_to_le16(smbios_table_cnt);
> -
> -    /* BIOS must recalculate: */
> -    ep.checksum = 0;
> -    ep.intermediate_checksum = 0;
> -    ep.structure_table_address = cpu_to_le32(0);
> +    switch (smbios_ep_type) {
> +    case SMBIOS_ENTRY_POINT_21:
> +        memcpy(ep.ep21.anchor_string, "_SM_", 4);
> +        memcpy(ep.ep21.intermediate_anchor_string, "_DMI_", 5);
> +        ep.ep21.length = sizeof(struct smbios_21_entry_point);
> +        ep.ep21.entry_point_revision = 0; /* formatted_area reserved */
> +        memset(ep.ep21.formatted_area, 0, 5);
> +
> +        /* compliant with smbios spec v2.8 */
> +        ep.ep21.smbios_major_version = 2;
> +        ep.ep21.smbios_minor_version = 8;
> +        ep.ep21.smbios_bcd_revision = 0x28;
> +
> +        /* set during table construction, but BIOS may override: */
> +        ep.ep21.structure_table_length = cpu_to_le16(smbios_tables_len);
> +        ep.ep21.max_structure_size = cpu_to_le16(smbios_table_max);
> +        ep.ep21.number_of_structures = cpu_to_le16(smbios_table_cnt);
> +
> +        /* BIOS must recalculate */
> +        ep.ep21.checksum = 0;
> +        ep.ep21.intermediate_checksum = 0;
> +        ep.ep21.structure_table_address = cpu_to_le32(0);
> +
> +        break;
> +    case SMBIOS_ENTRY_POINT_30:
> +        memcpy(ep.ep30.anchor_string, "_SM3_", 5);
> +        ep.ep30.length = sizeof(struct smbios_30_entry_point);
> +        ep.ep30.entry_point_revision = 1;
> +        ep.ep30.reserved = 0;
> +
> +        /* compliant with smbios spec 3.0 */
> +        ep.ep30.smbios_major_version = 3;
> +        ep.ep30.smbios_minor_version = 0;
> +        ep.ep30.smbios_doc_rev = 0;
> +
> +        /* set during table construct, but BIOS might override */
> +        ep.ep30.structure_table_max_size = cpu_to_le32(smbios_tables_len);
> +
> +        /* BIOS must recalculate */
> +        ep.ep30.checksum = 0;
> +        ep.ep30.structure_table_address = cpu_to_le64(0);
> +
> +        break;
> +    default:
> +        abort();
> +        break;
> +    }
>  }
>  
>  void smbios_get_tables(const struct smbios_phys_mem_area *mem_array,
> @@ -885,7 +915,15 @@ void smbios_get_tables(const struct smbios_phys_mem_area *mem_array,
>      *tables = smbios_tables;
>      *tables_len = smbios_tables_len;
>      *anchor = (uint8_t *)&ep;
> -    *anchor_len = sizeof(struct smbios_entry_point);
> +
> +    /* calculate length based on anchor string */
> +    if (!strncmp((char *)&ep, "_SM_", 4)) {
> +        *anchor_len = sizeof(struct smbios_21_entry_point);
> +    } else if (!strncmp((char *)&ep, "_SM3_", 5)) {
> +        *anchor_len = sizeof(struct smbios_30_entry_point);
> +    } else {
> +        abort();
> +    }
>  }
>  
>  static void save_opt(const char **dest, QemuOpts *opts, const char *name)
> diff --git a/include/hw/smbios/smbios.h b/include/hw/smbios/smbios.h
> index 4269aab..76ccf70 100644
> --- a/include/hw/smbios/smbios.h
> +++ b/include/hw/smbios/smbios.h
> @@ -23,25 +23,27 @@ struct smbios_phys_mem_area {
>      uint64_t length;
>  };
>  
> -void smbios_entry_add(QemuOpts *opts);
> -void smbios_set_cpuid(uint32_t version, uint32_t features);
> -void smbios_set_defaults(const char *manufacturer, const char *product,
> -                         const char *version, bool legacy_mode,
> -                         bool uuid_encoded);
> -uint8_t *smbios_get_table_legacy(size_t *length);
> -void smbios_get_tables(const struct smbios_phys_mem_area *mem_array,
> -                       const unsigned int mem_array_size,
> -                       uint8_t **tables, size_t *tables_len,
> -                       uint8_t **anchor, size_t *anchor_len);
> -
>  /*
>   * SMBIOS spec defined tables
>   */
> +typedef enum SmbiosEntryPointType {
> +    SMBIOS_ENTRY_POINT_21,
> +    SMBIOS_ENTRY_POINT_30,
> +} SmbiosEntryPointType;
> +
> +/* SMBIOS Entry Point
> + * There are two types of entry points defined in the SMBIOS specification
> + * (see below). BIOS must place the entry point(s) at a 16-bit-aligned
> + * address between 0xf0000 and 0xfffff. Note that either entry point type
> + * can be used in a 64-bit target system, except that SMBIOS 2.1 entry point
> + * only allows the SMBIOS struct table to reside below 4GB address space.
> + */
>  
> -/* SMBIOS entry point (anchor).
> - * BIOS must place this at a 16-bit-aligned address between 0xf0000 and 0xfffff.
> +/* SMBIOS 2.1 (32-bit) Entry Point
> + *  - introduced since SMBIOS 2.1
> + *  - supports structure table below 4GB only
>   */
> -struct smbios_entry_point {
> +struct smbios_21_entry_point {
>      uint8_t anchor_string[4];
>      uint8_t checksum;
>      uint8_t length;
> @@ -58,6 +60,28 @@ struct smbios_entry_point {
>      uint8_t smbios_bcd_revision;
>  } QEMU_PACKED;
>  
> +/* SMBIOS 3.0 (64-bit) Entry Point
> + *  - introduced since SMBIOS 3.0
> + *  - supports structure table at 64-bit address space
> + */
> +struct smbios_30_entry_point {
> +    uint8_t anchor_string[5];
> +    uint8_t checksum;
> +    uint8_t length;
> +    uint8_t smbios_major_version;
> +    uint8_t smbios_minor_version;
> +    uint8_t smbios_doc_rev;
> +    uint8_t entry_point_revision;
> +    uint8_t reserved;
> +    uint32_t structure_table_max_size;
> +    uint64_t structure_table_address;
> +} QEMU_PACKED;
> +
> +typedef union {
> +    struct smbios_21_entry_point ep21;
> +    struct smbios_30_entry_point ep30;
> +} QEMU_PACKED SmbiosEntryPoint;
> +
>  /* This goes at the beginning of every SMBIOS structure. */
>  struct smbios_structure_header {
>      uint8_t type;
> @@ -232,4 +256,14 @@ struct smbios_type_127 {
>      struct smbios_structure_header header;
>  } QEMU_PACKED;
>  
> +void smbios_entry_add(QemuOpts *opts);
> +void smbios_set_cpuid(uint32_t version, uint32_t features);
> +void smbios_set_defaults(const char *manufacturer, const char *product,
> +                         const char *version, bool legacy_mode,
> +                         bool uuid_encoded, SmbiosEntryPointType ep_type);
> +uint8_t *smbios_get_table_legacy(size_t *length);
> +void smbios_get_tables(const struct smbios_phys_mem_area *mem_array,
> +                       const unsigned int mem_array_size,
> +                       uint8_t **tables, size_t *tables_len,
> +                       uint8_t **anchor, size_t *anchor_len);
>  #endif /*QEMU_SMBIOS_H */
> diff --git a/tests/bios-tables-test.c b/tests/bios-tables-test.c
> index 613867a..9686328 100644
> --- a/tests/bios-tables-test.c
> +++ b/tests/bios-tables-test.c
> @@ -50,7 +50,7 @@ typedef struct {
>      int rsdt_tables_nr;
>      GArray *tables;
>      uint32_t smbios_ep_addr;
> -    struct smbios_entry_point smbios_ep_table;
> +    struct smbios_21_entry_point smbios_ep_table;
>  } test_data;
>  
>  #define LOW(x) ((x) & 0xff)
> @@ -601,7 +601,7 @@ static void test_acpi_asl(test_data *data)
>  
>  static bool smbios_ep_table_ok(test_data *data)
>  {
> -    struct smbios_entry_point *ep_table = &data->smbios_ep_table;
> +    struct smbios_21_entry_point *ep_table = &data->smbios_ep_table;
>      uint32_t addr = data->smbios_ep_addr;
>  
>      ACPI_READ_ARRAY(ep_table->anchor_string, addr);
> @@ -681,7 +681,7 @@ static inline bool smbios_single_instance(uint8_t type)
>  static void test_smbios_structs(test_data *data)
>  {
>      DECLARE_BITMAP(struct_bitmap, SMBIOS_MAX_TYPE+1) = { 0 };
> -    struct smbios_entry_point *ep_table = &data->smbios_ep_table;
> +    struct smbios_21_entry_point *ep_table = &data->smbios_ep_table;
>      uint32_t addr = ep_table->structure_table_address;
>      int i, len, max_len = 0;
>      uint8_t type, prv, crt;