hw/arm/virt: generate 64-bit addressable ACPI objects

Message ID 20170406212209.22788-1-ard.biesheuvel@linaro.org
State New
Headers show

Commit Message

Ard Biesheuvel April 6, 2017, 9:22 p.m.
Our current ACPI table generation code limits the placement of ACPI
tables to 32-bit addressable memory, in order to be able to emit the
root pointer (RSDP) and root table (RSDT) using table types from the
ACPI 1.0 days.

Since ARM was not supported by ACPI before version 5.0, it makes sense
to lift this restriction. This is not crucial for mach-virt, which is
guaranteed to have some memory available below the 4 GB mark, but it
is a nice to have for QEMU machines that do not have any 32-bit
addressable, not unlike some real world 64-bit ARM systems.

Since we already emit a version of the RSDP root pointer that carries
a 64-bit wide address for the 64-bit root table (XSDT), all we need to
do is replace the RSDT generation with the generation of an XSDT table,
and use a different slot in the FADT table to refer to the DSDT.

Note that this only modifies the private interaction between QEMU and
UEFI. Since these tables are all handled by the generic AcpiTableDxe
driver which generates its own RSDP, RSDT and XSDT tables and manages
the DSDT pointer in FADT itself, the tables that are present to the
guest are identical, and so no mach-virt versioning is required for
this change.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

---
 hw/arm/virt-acpi-build.c    | 55 ++++++++++++++++++++++++++++++++++-----------
 include/hw/acpi/acpi-defs.h | 11 +++++++++
 2 files changed, 53 insertions(+), 13 deletions(-)

-- 
2.9.3

Comments

Andrew Jones April 7, 2017, 8:55 a.m. | #1
On Thu, Apr 06, 2017 at 10:22:09PM +0100, Ard Biesheuvel wrote:
> Our current ACPI table generation code limits the placement of ACPI

> tables to 32-bit addressable memory, in order to be able to emit the

> root pointer (RSDP) and root table (RSDT) using table types from the

> ACPI 1.0 days.

> 

> Since ARM was not supported by ACPI before version 5.0, it makes sense

> to lift this restriction. This is not crucial for mach-virt, which is

> guaranteed to have some memory available below the 4 GB mark, but it

> is a nice to have for QEMU machines that do not have any 32-bit

> addressable, not unlike some real world 64-bit ARM systems.

> 

> Since we already emit a version of the RSDP root pointer that carries

> a 64-bit wide address for the 64-bit root table (XSDT), all we need to

> do is replace the RSDT generation with the generation of an XSDT table,

> and use a different slot in the FADT table to refer to the DSDT.

> 

> Note that this only modifies the private interaction between QEMU and

> UEFI. Since these tables are all handled by the generic AcpiTableDxe

> driver which generates its own RSDP, RSDT and XSDT tables and manages

> the DSDT pointer in FADT itself, the tables that are present to the

> guest are identical, and so no mach-virt versioning is required for

> this change.

> 

> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

> ---

>  hw/arm/virt-acpi-build.c    | 55 ++++++++++++++++++++++++++++++++++-----------

>  include/hw/acpi/acpi-defs.h | 11 +++++++++

>  2 files changed, 53 insertions(+), 13 deletions(-)

> 

> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c

> index b173bd109b91..d18368094c00 100644

> --- a/hw/arm/virt-acpi-build.c

> +++ b/hw/arm/virt-acpi-build.c

> @@ -391,12 +391,12 @@ static void acpi_dsdt_add_power_button(Aml *scope)

>  

>  /* RSDP */

>  static GArray *

> -build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offset)

> +build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned xsdt_tbl_offset)

>  {

>      AcpiRsdpDescriptor *rsdp = acpi_data_push(rsdp_table, sizeof *rsdp);

> -    unsigned rsdt_pa_size = sizeof(rsdp->rsdt_physical_address);

> -    unsigned rsdt_pa_offset =

> -        (char *)&rsdp->rsdt_physical_address - rsdp_table->data;

> +    unsigned xsdt_pa_size = sizeof(rsdp->xsdt_physical_address);

> +    unsigned xsdt_pa_offset =

> +        (char *)&rsdp->xsdt_physical_address - rsdp_table->data;

>  

>      bios_linker_loader_alloc(linker, ACPI_BUILD_RSDP_FILE, rsdp_table, 16,

>                               true /* fseg memory */);

> @@ -408,8 +408,8 @@ build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offset)

>  

>      /* Address to be filled by Guest linker */

>      bios_linker_loader_add_pointer(linker,

> -        ACPI_BUILD_RSDP_FILE, rsdt_pa_offset, rsdt_pa_size,

> -        ACPI_BUILD_TABLE_FILE, rsdt_tbl_offset);

> +        ACPI_BUILD_RSDP_FILE, xsdt_pa_offset, xsdt_pa_size,

> +        ACPI_BUILD_TABLE_FILE, xsdt_tbl_offset);

>  

>      /* Checksum to be filled by Guest linker */

>      bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE,

> @@ -686,7 +686,7 @@ static void build_fadt(GArray *table_data, BIOSLinker *linker,

>                         VirtMachineState *vms, unsigned dsdt_tbl_offset)

>  {

>      AcpiFadtDescriptorRev5_1 *fadt = acpi_data_push(table_data, sizeof(*fadt));

> -    unsigned dsdt_entry_offset = (char *)&fadt->dsdt - table_data->data;

> +    unsigned xdsdt_entry_offset = (char *)&fadt->Xdsdt - table_data->data;

>      uint16_t bootflags;

>  

>      switch (vms->psci_conduit) {

> @@ -712,7 +712,7 @@ static void build_fadt(GArray *table_data, BIOSLinker *linker,

>  

>      /* DSDT address to be filled by Guest linker */

>      bios_linker_loader_add_pointer(linker,

> -        ACPI_BUILD_TABLE_FILE, dsdt_entry_offset, sizeof(fadt->dsdt),

> +        ACPI_BUILD_TABLE_FILE, xdsdt_entry_offset, sizeof(fadt->Xdsdt),

>          ACPI_BUILD_TABLE_FILE, dsdt_tbl_offset);

>  

>      build_header(linker, table_data,

> @@ -772,12 +772,41 @@ struct AcpiBuildState {

>      bool patched;

>  } AcpiBuildState;

>  

> +/* Build xsdt table */

> +

> +static

> +void build_xsdt(GArray *table_data, BIOSLinker *linker, GArray *table_offsets,

> +                const char *oem_id, const char *oem_table_id)

> +{

> +    int i;

> +    unsigned xsdt_entries_offset;

> +    AcpiXsdtDescriptorRev2 *xsdt;

> +    const unsigned table_data_len = (sizeof(uint64_t) * table_offsets->len);

> +    const unsigned xsdt_entry_size = sizeof(xsdt->table_offset_entry[0]);

> +    const size_t xsdt_len = sizeof(*xsdt) + table_data_len;

> +

> +    xsdt = acpi_data_push(table_data, xsdt_len);

> +    xsdt_entries_offset = (char *)xsdt->table_offset_entry - table_data->data;

> +    for (i = 0; i < table_offsets->len; ++i) {

> +        uint64_t ref_tbl_offset = g_array_index(table_offsets, uint32_t, i);

> +        uint64_t xsdt_entry_offset = xsdt_entries_offset + xsdt_entry_size * i;

> +

> +        /* xsdt->table_offset_entry to be filled by Guest linker */

> +        bios_linker_loader_add_pointer(linker,

> +            ACPI_BUILD_TABLE_FILE, xsdt_entry_offset, xsdt_entry_size,

> +            ACPI_BUILD_TABLE_FILE, ref_tbl_offset);

> +    }

> +    build_header(linker, table_data,

> +                 (void *)xsdt, "XSDT", xsdt_len, 1, oem_id, oem_table_id);

> +}


build_xsdt should probably go in hw/acpi/aml-build.c

> +

> +

>  static

>  void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)

>  {

>      VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(vms);

>      GArray *table_offsets;

> -    unsigned dsdt, rsdt;

> +    unsigned dsdt, xsdt;

>      GArray *tables_blob = tables->table_data;

>  

>      table_offsets = g_array_new(false, true /* clear */,

> @@ -817,12 +846,12 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)

>          build_iort(tables_blob, tables->linker);

>      }

>  

> -    /* RSDT is pointed to by RSDP */

> -    rsdt = tables_blob->len;

> -    build_rsdt(tables_blob, tables->linker, table_offsets, NULL, NULL);

> +    /* XSDT is pointed to by RSDP */

> +    xsdt = tables_blob->len;

> +    build_xsdt(tables_blob, tables->linker, table_offsets, NULL, NULL);

>  

>      /* RSDP is in FSEG memory, so allocate it separately */

> -    build_rsdp(tables->rsdp, tables->linker, rsdt);

> +    build_rsdp(tables->rsdp, tables->linker, xsdt);

>  

>      /* Cleanup memory that's no longer used. */

>      g_array_free(table_offsets, true);

> diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h

> index 4cc3630e613e..bf37acf4c4c6 100644

> --- a/include/hw/acpi/acpi-defs.h

> +++ b/include/hw/acpi/acpi-defs.h

> @@ -238,6 +238,17 @@ struct AcpiRsdtDescriptorRev1

>  typedef struct AcpiRsdtDescriptorRev1 AcpiRsdtDescriptorRev1;

>  

>  /*

> + * ACPI 2.0 eXtended System Description Table (XSDT)

> + */

> +struct AcpiXsdtDescriptorRev2

> +{

> +    ACPI_TABLE_HEADER_DEF       /* ACPI common table header */

> +    uint64_t table_offset_entry[0];  /* Array of pointers to other */

> +    /* ACPI tables */

> +} QEMU_PACKED;

> +typedef struct AcpiXsdtDescriptorRev2 AcpiXsdtDescriptorRev2;

> +

> +/*

>   * ACPI 1.0 Firmware ACPI Control Structure (FACS)

>   */

>  struct AcpiFacsDescriptorRev1

> -- 

> 2.9.3

> 

>


Otherwise

Reviewed-by: Andrew Jones <drjones@redhat.com>
Laszlo Ersek April 7, 2017, 9:11 a.m. | #2
On 04/07/17 10:55, Andrew Jones wrote:
> On Thu, Apr 06, 2017 at 10:22:09PM +0100, Ard Biesheuvel wrote:

>> Our current ACPI table generation code limits the placement of ACPI

>> tables to 32-bit addressable memory, in order to be able to emit the

>> root pointer (RSDP) and root table (RSDT) using table types from the

>> ACPI 1.0 days.

>>

>> Since ARM was not supported by ACPI before version 5.0, it makes sense

>> to lift this restriction. This is not crucial for mach-virt, which is

>> guaranteed to have some memory available below the 4 GB mark, but it

>> is a nice to have for QEMU machines that do not have any 32-bit

>> addressable, not unlike some real world 64-bit ARM systems.

>>

>> Since we already emit a version of the RSDP root pointer that carries

>> a 64-bit wide address for the 64-bit root table (XSDT), all we need to

>> do is replace the RSDT generation with the generation of an XSDT table,

>> and use a different slot in the FADT table to refer to the DSDT.

>>

>> Note that this only modifies the private interaction between QEMU and

>> UEFI. Since these tables are all handled by the generic AcpiTableDxe

>> driver which generates its own RSDP, RSDT and XSDT tables and manages

>> the DSDT pointer in FADT itself, the tables that are present to the

>> guest are identical, and so no mach-virt versioning is required for

>> this change.


The last paragraph could be dropped from the commit message (or trimmed
a bit). Not really necessary, saying it just FYI. Namely, we don't
version firmware blobs (i.e., we don't tie different firmware blobs to
different versions of a machine type), and ACPI tables are considered
part of the firmware (from the OS's POV), despite the fact that
technically we generate them in QEMU. So, in my understanding, the ACPI
content we generate never needs to consider machine types.

>>

>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

>> ---

>>  hw/arm/virt-acpi-build.c    | 55 ++++++++++++++++++++++++++++++++++-----------

>>  include/hw/acpi/acpi-defs.h | 11 +++++++++

>>  2 files changed, 53 insertions(+), 13 deletions(-)

>>

>> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c

>> index b173bd109b91..d18368094c00 100644

>> --- a/hw/arm/virt-acpi-build.c

>> +++ b/hw/arm/virt-acpi-build.c

>> @@ -391,12 +391,12 @@ static void acpi_dsdt_add_power_button(Aml *scope)

>>  

>>  /* RSDP */

>>  static GArray *

>> -build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offset)

>> +build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned xsdt_tbl_offset)

>>  {

>>      AcpiRsdpDescriptor *rsdp = acpi_data_push(rsdp_table, sizeof *rsdp);

>> -    unsigned rsdt_pa_size = sizeof(rsdp->rsdt_physical_address);

>> -    unsigned rsdt_pa_offset =

>> -        (char *)&rsdp->rsdt_physical_address - rsdp_table->data;

>> +    unsigned xsdt_pa_size = sizeof(rsdp->xsdt_physical_address);

>> +    unsigned xsdt_pa_offset =

>> +        (char *)&rsdp->xsdt_physical_address - rsdp_table->data;

>>  

>>      bios_linker_loader_alloc(linker, ACPI_BUILD_RSDP_FILE, rsdp_table, 16,

>>                               true /* fseg memory */);

>> @@ -408,8 +408,8 @@ build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offset)

>>  

>>      /* Address to be filled by Guest linker */

>>      bios_linker_loader_add_pointer(linker,

>> -        ACPI_BUILD_RSDP_FILE, rsdt_pa_offset, rsdt_pa_size,

>> -        ACPI_BUILD_TABLE_FILE, rsdt_tbl_offset);

>> +        ACPI_BUILD_RSDP_FILE, xsdt_pa_offset, xsdt_pa_size,

>> +        ACPI_BUILD_TABLE_FILE, xsdt_tbl_offset);

>>  

>>      /* Checksum to be filled by Guest linker */

>>      bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE,

>> @@ -686,7 +686,7 @@ static void build_fadt(GArray *table_data, BIOSLinker *linker,

>>                         VirtMachineState *vms, unsigned dsdt_tbl_offset)

>>  {

>>      AcpiFadtDescriptorRev5_1 *fadt = acpi_data_push(table_data, sizeof(*fadt));

>> -    unsigned dsdt_entry_offset = (char *)&fadt->dsdt - table_data->data;

>> +    unsigned xdsdt_entry_offset = (char *)&fadt->Xdsdt - table_data->data;

>>      uint16_t bootflags;

>>  

>>      switch (vms->psci_conduit) {

>> @@ -712,7 +712,7 @@ static void build_fadt(GArray *table_data, BIOSLinker *linker,

>>  

>>      /* DSDT address to be filled by Guest linker */

>>      bios_linker_loader_add_pointer(linker,

>> -        ACPI_BUILD_TABLE_FILE, dsdt_entry_offset, sizeof(fadt->dsdt),

>> +        ACPI_BUILD_TABLE_FILE, xdsdt_entry_offset, sizeof(fadt->Xdsdt),

>>          ACPI_BUILD_TABLE_FILE, dsdt_tbl_offset);

>>  

>>      build_header(linker, table_data,

>> @@ -772,12 +772,41 @@ struct AcpiBuildState {

>>      bool patched;

>>  } AcpiBuildState;

>>  

>> +/* Build xsdt table */

>> +

>> +static

>> +void build_xsdt(GArray *table_data, BIOSLinker *linker, GArray *table_offsets,

>> +                const char *oem_id, const char *oem_table_id)

>> +{

>> +    int i;

>> +    unsigned xsdt_entries_offset;

>> +    AcpiXsdtDescriptorRev2 *xsdt;

>> +    const unsigned table_data_len = (sizeof(uint64_t) * table_offsets->len);

>> +    const unsigned xsdt_entry_size = sizeof(xsdt->table_offset_entry[0]);

>> +    const size_t xsdt_len = sizeof(*xsdt) + table_data_len;

>> +

>> +    xsdt = acpi_data_push(table_data, xsdt_len);

>> +    xsdt_entries_offset = (char *)xsdt->table_offset_entry - table_data->data;

>> +    for (i = 0; i < table_offsets->len; ++i) {

>> +        uint64_t ref_tbl_offset = g_array_index(table_offsets, uint32_t, i);

>> +        uint64_t xsdt_entry_offset = xsdt_entries_offset + xsdt_entry_size * i;

>> +

>> +        /* xsdt->table_offset_entry to be filled by Guest linker */

>> +        bios_linker_loader_add_pointer(linker,

>> +            ACPI_BUILD_TABLE_FILE, xsdt_entry_offset, xsdt_entry_size,

>> +            ACPI_BUILD_TABLE_FILE, ref_tbl_offset);

>> +    }

>> +    build_header(linker, table_data,

>> +                 (void *)xsdt, "XSDT", xsdt_len, 1, oem_id, oem_table_id);

>> +}

> 

> build_xsdt should probably go in hw/acpi/aml-build.c

> 

>> +

>> +

>>  static

>>  void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)

>>  {

>>      VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(vms);

>>      GArray *table_offsets;

>> -    unsigned dsdt, rsdt;

>> +    unsigned dsdt, xsdt;

>>      GArray *tables_blob = tables->table_data;

>>  

>>      table_offsets = g_array_new(false, true /* clear */,

>> @@ -817,12 +846,12 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)

>>          build_iort(tables_blob, tables->linker);

>>      }

>>  

>> -    /* RSDT is pointed to by RSDP */

>> -    rsdt = tables_blob->len;

>> -    build_rsdt(tables_blob, tables->linker, table_offsets, NULL, NULL);

>> +    /* XSDT is pointed to by RSDP */

>> +    xsdt = tables_blob->len;

>> +    build_xsdt(tables_blob, tables->linker, table_offsets, NULL, NULL);

>>  

>>      /* RSDP is in FSEG memory, so allocate it separately */

>> -    build_rsdp(tables->rsdp, tables->linker, rsdt);

>> +    build_rsdp(tables->rsdp, tables->linker, xsdt);

>>  

>>      /* Cleanup memory that's no longer used. */

>>      g_array_free(table_offsets, true);

>> diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h

>> index 4cc3630e613e..bf37acf4c4c6 100644

>> --- a/include/hw/acpi/acpi-defs.h

>> +++ b/include/hw/acpi/acpi-defs.h

>> @@ -238,6 +238,17 @@ struct AcpiRsdtDescriptorRev1

>>  typedef struct AcpiRsdtDescriptorRev1 AcpiRsdtDescriptorRev1;

>>  

>>  /*

>> + * ACPI 2.0 eXtended System Description Table (XSDT)

>> + */

>> +struct AcpiXsdtDescriptorRev2

>> +{

>> +    ACPI_TABLE_HEADER_DEF       /* ACPI common table header */

>> +    uint64_t table_offset_entry[0];  /* Array of pointers to other */

>> +    /* ACPI tables */

>> +} QEMU_PACKED;

>> +typedef struct AcpiXsdtDescriptorRev2 AcpiXsdtDescriptorRev2;

>> +

>> +/*

>>   * ACPI 1.0 Firmware ACPI Control Structure (FACS)

>>   */

>>  struct AcpiFacsDescriptorRev1

>> -- 

>> 2.9.3

>>

>>

> 

> Otherwise

> 

> Reviewed-by: Andrew Jones <drjones@redhat.com>

> 


Great, I didn't want to be the first one to provide public feedback. :)

Personally I'm fine if we keep the XSDT generation local to
"hw/arm/virt-acpi-build.c" for now, and we upstream it to
"hw/acpi/aml-build.c" later (for example when i386 actually puts it to
use -- which shouldn't be that far out, AIUI, since Phil will probably
need XSDT for OSX guests). However, I also wouldn't mind if the XSDT
builder were moved to "hw/acpi/aml-build.c" right now.

So one way or another,

Acked-by: Laszlo Ersek <lersek@redhat.com>


Thanks
Laszlo
Phil Dennis-Jordan April 7, 2017, 9:36 a.m. | #3
On 7 April 2017 at 21:11, Laszlo Ersek <lersek@redhat.com> wrote:
> On 04/07/17 10:55, Andrew Jones wrote:

>> On Thu, Apr 06, 2017 at 10:22:09PM +0100, Ard Biesheuvel wrote:

>>> Our current ACPI table generation code limits the placement of ACPI

>>> tables to 32-bit addressable memory, in order to be able to emit the

>>> root pointer (RSDP) and root table (RSDT) using table types from the

>>> ACPI 1.0 days.

>>>

>>> Since ARM was not supported by ACPI before version 5.0, it makes sense

>>> to lift this restriction. This is not crucial for mach-virt, which is

>>> guaranteed to have some memory available below the 4 GB mark, but it

>>> is a nice to have for QEMU machines that do not have any 32-bit

>>> addressable, not unlike some real world 64-bit ARM systems.


"QEMU machines that do not have any 32-bit addressable memory," perhaps?

>>> Since we already emit a version of the RSDP root pointer that carries

>>> a 64-bit wide address for the 64-bit root table (XSDT), all we need to

>>> do is replace the RSDT generation with the generation of an XSDT table,

>>> and use a different slot in the FADT table to refer to the DSDT.

>>>

>>> Note that this only modifies the private interaction between QEMU and

>>> UEFI. Since these tables are all handled by the generic AcpiTableDxe

>>> driver which generates its own RSDP, RSDT and XSDT tables and manages

>>> the DSDT pointer in FADT itself, the tables that are present to the

>>> guest are identical, and so no mach-virt versioning is required for

>>> this change.

>

> The last paragraph could be dropped from the commit message (or trimmed

> a bit). Not really necessary, saying it just FYI. Namely, we don't

> version firmware blobs (i.e., we don't tie different firmware blobs to

> different versions of a machine type), and ACPI tables are considered

> part of the firmware (from the OS's POV), despite the fact that

> technically we generate them in QEMU. So, in my understanding, the ACPI

> content we generate never needs to consider machine types.

>

>>>

>>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

>>> ---

>>>  hw/arm/virt-acpi-build.c    | 55 ++++++++++++++++++++++++++++++++++-----------

>>>  include/hw/acpi/acpi-defs.h | 11 +++++++++

>>>  2 files changed, 53 insertions(+), 13 deletions(-)

>>>

>>> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c

>>> index b173bd109b91..d18368094c00 100644

>>> --- a/hw/arm/virt-acpi-build.c

>>> +++ b/hw/arm/virt-acpi-build.c

>>> @@ -391,12 +391,12 @@ static void acpi_dsdt_add_power_button(Aml *scope)

>>>

>>>  /* RSDP */

>>>  static GArray *

>>> -build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offset)

>>> +build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned xsdt_tbl_offset)

>>>  {

>>>      AcpiRsdpDescriptor *rsdp = acpi_data_push(rsdp_table, sizeof *rsdp);

>>> -    unsigned rsdt_pa_size = sizeof(rsdp->rsdt_physical_address);

>>> -    unsigned rsdt_pa_offset =

>>> -        (char *)&rsdp->rsdt_physical_address - rsdp_table->data;

>>> +    unsigned xsdt_pa_size = sizeof(rsdp->xsdt_physical_address);

>>> +    unsigned xsdt_pa_offset =

>>> +        (char *)&rsdp->xsdt_physical_address - rsdp_table->data;

>>>

>>>      bios_linker_loader_alloc(linker, ACPI_BUILD_RSDP_FILE, rsdp_table, 16,

>>>                               true /* fseg memory */);

>>> @@ -408,8 +408,8 @@ build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offset)

>>>

>>>      /* Address to be filled by Guest linker */

>>>      bios_linker_loader_add_pointer(linker,

>>> -        ACPI_BUILD_RSDP_FILE, rsdt_pa_offset, rsdt_pa_size,

>>> -        ACPI_BUILD_TABLE_FILE, rsdt_tbl_offset);

>>> +        ACPI_BUILD_RSDP_FILE, xsdt_pa_offset, xsdt_pa_size,

>>> +        ACPI_BUILD_TABLE_FILE, xsdt_tbl_offset);

>>>

>>>      /* Checksum to be filled by Guest linker */

>>>      bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE,

>>> @@ -686,7 +686,7 @@ static void build_fadt(GArray *table_data, BIOSLinker *linker,

>>>                         VirtMachineState *vms, unsigned dsdt_tbl_offset)

>>>  {

>>>      AcpiFadtDescriptorRev5_1 *fadt = acpi_data_push(table_data, sizeof(*fadt));

>>> -    unsigned dsdt_entry_offset = (char *)&fadt->dsdt - table_data->data;

>>> +    unsigned xdsdt_entry_offset = (char *)&fadt->Xdsdt - table_data->data;

>>>      uint16_t bootflags;

>>>

>>>      switch (vms->psci_conduit) {

>>> @@ -712,7 +712,7 @@ static void build_fadt(GArray *table_data, BIOSLinker *linker,

>>>

>>>      /* DSDT address to be filled by Guest linker */

>>>      bios_linker_loader_add_pointer(linker,

>>> -        ACPI_BUILD_TABLE_FILE, dsdt_entry_offset, sizeof(fadt->dsdt),

>>> +        ACPI_BUILD_TABLE_FILE, xdsdt_entry_offset, sizeof(fadt->Xdsdt),

>>>          ACPI_BUILD_TABLE_FILE, dsdt_tbl_offset);

>>>

>>>      build_header(linker, table_data,


I don't know what it's like in ARM-Land, but X64 Windows does not take
kindly to a zero DSDT pointer in my experience. It might make sense to
make the choice between DSDT and XDSDT conditional on whether the
pointer is actually above 4GB? Mind you, I don't even know if
Microsoft makes ARM variants of Windows generally available, and
whether they currently work in Qemu; the FOSS OSes are typically more
lenient.

See also the discussion in this thread on qemu-devel:
https://lists.gnu.org/archive/html/qemu-devel/2017-01/msg05754.html
and a related issue on edk2-devel:
https://lists.01.org/pipermail/edk2-devel/2017-March/008460.html

>>> @@ -772,12 +772,41 @@ struct AcpiBuildState {

>>>      bool patched;

>>>  } AcpiBuildState;

>>>

>>> +/* Build xsdt table */

>>> +

>>> +static

>>> +void build_xsdt(GArray *table_data, BIOSLinker *linker, GArray *table_offsets,

>>> +                const char *oem_id, const char *oem_table_id)

>>> +{

>>> +    int i;

>>> +    unsigned xsdt_entries_offset;

>>> +    AcpiXsdtDescriptorRev2 *xsdt;

>>> +    const unsigned table_data_len = (sizeof(uint64_t) * table_offsets->len);

>>> +    const unsigned xsdt_entry_size = sizeof(xsdt->table_offset_entry[0]);

>>> +    const size_t xsdt_len = sizeof(*xsdt) + table_data_len;

>>> +

>>> +    xsdt = acpi_data_push(table_data, xsdt_len);

>>> +    xsdt_entries_offset = (char *)xsdt->table_offset_entry - table_data->data;

>>> +    for (i = 0; i < table_offsets->len; ++i) {

>>> +        uint64_t ref_tbl_offset = g_array_index(table_offsets, uint32_t, i);

>>> +        uint64_t xsdt_entry_offset = xsdt_entries_offset + xsdt_entry_size * i;

>>> +

>>> +        /* xsdt->table_offset_entry to be filled by Guest linker */

>>> +        bios_linker_loader_add_pointer(linker,

>>> +            ACPI_BUILD_TABLE_FILE, xsdt_entry_offset, xsdt_entry_size,

>>> +            ACPI_BUILD_TABLE_FILE, ref_tbl_offset);

>>> +    }

>>> +    build_header(linker, table_data,

>>> +                 (void *)xsdt, "XSDT", xsdt_len, 1, oem_id, oem_table_id);

>>> +}

>>

>> build_xsdt should probably go in hw/acpi/aml-build.c

>>

>>> +

>>> +

>>>  static

>>>  void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)

>>>  {

>>>      VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(vms);

>>>      GArray *table_offsets;

>>> -    unsigned dsdt, rsdt;

>>> +    unsigned dsdt, xsdt;

>>>      GArray *tables_blob = tables->table_data;

>>>

>>>      table_offsets = g_array_new(false, true /* clear */,

>>> @@ -817,12 +846,12 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)

>>>          build_iort(tables_blob, tables->linker);

>>>      }

>>>

>>> -    /* RSDT is pointed to by RSDP */

>>> -    rsdt = tables_blob->len;

>>> -    build_rsdt(tables_blob, tables->linker, table_offsets, NULL, NULL);

>>> +    /* XSDT is pointed to by RSDP */

>>> +    xsdt = tables_blob->len;

>>> +    build_xsdt(tables_blob, tables->linker, table_offsets, NULL, NULL);

>>>

>>>      /* RSDP is in FSEG memory, so allocate it separately */

>>> -    build_rsdp(tables->rsdp, tables->linker, rsdt);

>>> +    build_rsdp(tables->rsdp, tables->linker, xsdt);

>>>

>>>      /* Cleanup memory that's no longer used. */

>>>      g_array_free(table_offsets, true);

>>> diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h

>>> index 4cc3630e613e..bf37acf4c4c6 100644

>>> --- a/include/hw/acpi/acpi-defs.h

>>> +++ b/include/hw/acpi/acpi-defs.h

>>> @@ -238,6 +238,17 @@ struct AcpiRsdtDescriptorRev1

>>>  typedef struct AcpiRsdtDescriptorRev1 AcpiRsdtDescriptorRev1;

>>>

>>>  /*

>>> + * ACPI 2.0 eXtended System Description Table (XSDT)

>>> + */

>>> +struct AcpiXsdtDescriptorRev2

>>> +{

>>> +    ACPI_TABLE_HEADER_DEF       /* ACPI common table header */

>>> +    uint64_t table_offset_entry[0];  /* Array of pointers to other */

>>> +    /* ACPI tables */

>>> +} QEMU_PACKED;

>>> +typedef struct AcpiXsdtDescriptorRev2 AcpiXsdtDescriptorRev2;

>>> +

>>> +/*

>>>   * ACPI 1.0 Firmware ACPI Control Structure (FACS)

>>>   */

>>>  struct AcpiFacsDescriptorRev1

>>> --

>>> 2.9.3

>>>

>>>

>>

>> Otherwise

>>

>> Reviewed-by: Andrew Jones <drjones@redhat.com>

>>

>

> Great, I didn't want to be the first one to provide public feedback. :)

>

> Personally I'm fine if we keep the XSDT generation local to

> "hw/arm/virt-acpi-build.c" for now, and we upstream it to

> "hw/acpi/aml-build.c" later (for example when i386 actually puts it to

> use -- which shouldn't be that far out, AIUI, since Phil will probably

> need XSDT for OSX guests). However, I also wouldn't mind if the XSDT

> builder were moved to "hw/acpi/aml-build.c" right now.


FWIW, OS X guests don't appear to care about an XSDT, and I'm not
planning any work in that area. My patch only affects the x86 FADT
(Rev1->Rev3). From what I saw, this is, aside from the struct
definition, completely independent from Qemu's ARM FADT, which I think
has always used the Rev5(.1?) variant.
(Are patches for 2.10 already being accepted? Michael previously said
I should wait until 2.9 is out, that's the only reason I'm still
hanging onto my patch.)

> So one way or another,

>

> Acked-by: Laszlo Ersek <lersek@redhat.com>

>

> Thanks

> Laszlo
Ard Biesheuvel April 7, 2017, 9:44 a.m. | #4
On 7 April 2017 at 10:36, Phil Dennis-Jordan <phil@philjordan.eu> wrote:
> On 7 April 2017 at 21:11, Laszlo Ersek <lersek@redhat.com> wrote:

>> On 04/07/17 10:55, Andrew Jones wrote:

>>> On Thu, Apr 06, 2017 at 10:22:09PM +0100, Ard Biesheuvel wrote:

>>>> Our current ACPI table generation code limits the placement of ACPI

>>>> tables to 32-bit addressable memory, in order to be able to emit the

>>>> root pointer (RSDP) and root table (RSDT) using table types from the

>>>> ACPI 1.0 days.

>>>>

>>>> Since ARM was not supported by ACPI before version 5.0, it makes sense

>>>> to lift this restriction. This is not crucial for mach-virt, which is

>>>> guaranteed to have some memory available below the 4 GB mark, but it

>>>> is a nice to have for QEMU machines that do not have any 32-bit

>>>> addressable, not unlike some real world 64-bit ARM systems.

>

> "QEMU machines that do not have any 32-bit addressable memory," perhaps?

>


Yes, better.

>>>> Since we already emit a version of the RSDP root pointer that carries

>>>> a 64-bit wide address for the 64-bit root table (XSDT), all we need to

>>>> do is replace the RSDT generation with the generation of an XSDT table,

>>>> and use a different slot in the FADT table to refer to the DSDT.

>>>>

>>>> Note that this only modifies the private interaction between QEMU and

>>>> UEFI. Since these tables are all handled by the generic AcpiTableDxe

>>>> driver which generates its own RSDP, RSDT and XSDT tables and manages

>>>> the DSDT pointer in FADT itself, the tables that are present to the

>>>> guest are identical, and so no mach-virt versioning is required for

>>>> this change.

>>

>> The last paragraph could be dropped from the commit message (or trimmed

>> a bit). Not really necessary, saying it just FYI. Namely, we don't

>> version firmware blobs (i.e., we don't tie different firmware blobs to

>> different versions of a machine type), and ACPI tables are considered

>> part of the firmware (from the OS's POV), despite the fact that

>> technically we generate them in QEMU. So, in my understanding, the ACPI

>> content we generate never needs to consider machine types.

>>

>>>>

>>>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

>>>> ---

>>>>  hw/arm/virt-acpi-build.c    | 55 ++++++++++++++++++++++++++++++++++-----------

>>>>  include/hw/acpi/acpi-defs.h | 11 +++++++++

>>>>  2 files changed, 53 insertions(+), 13 deletions(-)

>>>>

>>>> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c

>>>> index b173bd109b91..d18368094c00 100644

>>>> --- a/hw/arm/virt-acpi-build.c

>>>> +++ b/hw/arm/virt-acpi-build.c

>>>> @@ -391,12 +391,12 @@ static void acpi_dsdt_add_power_button(Aml *scope)

>>>>

>>>>  /* RSDP */

>>>>  static GArray *

>>>> -build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offset)

>>>> +build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned xsdt_tbl_offset)

>>>>  {

>>>>      AcpiRsdpDescriptor *rsdp = acpi_data_push(rsdp_table, sizeof *rsdp);

>>>> -    unsigned rsdt_pa_size = sizeof(rsdp->rsdt_physical_address);

>>>> -    unsigned rsdt_pa_offset =

>>>> -        (char *)&rsdp->rsdt_physical_address - rsdp_table->data;

>>>> +    unsigned xsdt_pa_size = sizeof(rsdp->xsdt_physical_address);

>>>> +    unsigned xsdt_pa_offset =

>>>> +        (char *)&rsdp->xsdt_physical_address - rsdp_table->data;

>>>>

>>>>      bios_linker_loader_alloc(linker, ACPI_BUILD_RSDP_FILE, rsdp_table, 16,

>>>>                               true /* fseg memory */);

>>>> @@ -408,8 +408,8 @@ build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offset)

>>>>

>>>>      /* Address to be filled by Guest linker */

>>>>      bios_linker_loader_add_pointer(linker,

>>>> -        ACPI_BUILD_RSDP_FILE, rsdt_pa_offset, rsdt_pa_size,

>>>> -        ACPI_BUILD_TABLE_FILE, rsdt_tbl_offset);

>>>> +        ACPI_BUILD_RSDP_FILE, xsdt_pa_offset, xsdt_pa_size,

>>>> +        ACPI_BUILD_TABLE_FILE, xsdt_tbl_offset);

>>>>

>>>>      /* Checksum to be filled by Guest linker */

>>>>      bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE,

>>>> @@ -686,7 +686,7 @@ static void build_fadt(GArray *table_data, BIOSLinker *linker,

>>>>                         VirtMachineState *vms, unsigned dsdt_tbl_offset)

>>>>  {

>>>>      AcpiFadtDescriptorRev5_1 *fadt = acpi_data_push(table_data, sizeof(*fadt));

>>>> -    unsigned dsdt_entry_offset = (char *)&fadt->dsdt - table_data->data;

>>>> +    unsigned xdsdt_entry_offset = (char *)&fadt->Xdsdt - table_data->data;

>>>>      uint16_t bootflags;

>>>>

>>>>      switch (vms->psci_conduit) {

>>>> @@ -712,7 +712,7 @@ static void build_fadt(GArray *table_data, BIOSLinker *linker,

>>>>

>>>>      /* DSDT address to be filled by Guest linker */

>>>>      bios_linker_loader_add_pointer(linker,

>>>> -        ACPI_BUILD_TABLE_FILE, dsdt_entry_offset, sizeof(fadt->dsdt),

>>>> +        ACPI_BUILD_TABLE_FILE, xdsdt_entry_offset, sizeof(fadt->Xdsdt),

>>>>          ACPI_BUILD_TABLE_FILE, dsdt_tbl_offset);

>>>>

>>>>      build_header(linker, table_data,

>

> I don't know what it's like in ARM-Land, but X64 Windows does not take

> kindly to a zero DSDT pointer in my experience. It might make sense to

> make the choice between DSDT and XDSDT conditional on whether the

> pointer is actually above 4GB? Mind you, I don't even know if

> Microsoft makes ARM variants of Windows generally available, and

> whether they currently work in Qemu; the FOSS OSes are typically more

> lenient.

>


Documentation/arm64/acpi_object_usage.txt in the kernel contains this under FADT

   For the DSDT that is also required, the X_DSDT field is to be used,
   not the DSDT field.

and so we should be using xdsdt anyway. *However*, this is all moot
given that UEFI is in charge of populating these fields. What we
generate here and what the guest sees are two different things that
are almost completely disconnected when it comes to RSDP, RSDT/XSDT
and the DSDT field in FADT.


> See also the discussion in this thread on qemu-devel:

> https://lists.gnu.org/archive/html/qemu-devel/2017-01/msg05754.html

> and a related issue on edk2-devel:

> https://lists.01.org/pipermail/edk2-devel/2017-March/008460.html

>

>>>> @@ -772,12 +772,41 @@ struct AcpiBuildState {

>>>>      bool patched;

>>>>  } AcpiBuildState;

>>>>

>>>> +/* Build xsdt table */

>>>> +

>>>> +static

>>>> +void build_xsdt(GArray *table_data, BIOSLinker *linker, GArray *table_offsets,

>>>> +                const char *oem_id, const char *oem_table_id)

>>>> +{

>>>> +    int i;

>>>> +    unsigned xsdt_entries_offset;

>>>> +    AcpiXsdtDescriptorRev2 *xsdt;

>>>> +    const unsigned table_data_len = (sizeof(uint64_t) * table_offsets->len);

>>>> +    const unsigned xsdt_entry_size = sizeof(xsdt->table_offset_entry[0]);

>>>> +    const size_t xsdt_len = sizeof(*xsdt) + table_data_len;

>>>> +

>>>> +    xsdt = acpi_data_push(table_data, xsdt_len);

>>>> +    xsdt_entries_offset = (char *)xsdt->table_offset_entry - table_data->data;

>>>> +    for (i = 0; i < table_offsets->len; ++i) {

>>>> +        uint64_t ref_tbl_offset = g_array_index(table_offsets, uint32_t, i);

>>>> +        uint64_t xsdt_entry_offset = xsdt_entries_offset + xsdt_entry_size * i;

>>>> +

>>>> +        /* xsdt->table_offset_entry to be filled by Guest linker */

>>>> +        bios_linker_loader_add_pointer(linker,

>>>> +            ACPI_BUILD_TABLE_FILE, xsdt_entry_offset, xsdt_entry_size,

>>>> +            ACPI_BUILD_TABLE_FILE, ref_tbl_offset);

>>>> +    }

>>>> +    build_header(linker, table_data,

>>>> +                 (void *)xsdt, "XSDT", xsdt_len, 1, oem_id, oem_table_id);

>>>> +}

>>>

>>> build_xsdt should probably go in hw/acpi/aml-build.c

>>>

>>>> +

>>>> +

>>>>  static

>>>>  void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)

>>>>  {

>>>>      VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(vms);

>>>>      GArray *table_offsets;

>>>> -    unsigned dsdt, rsdt;

>>>> +    unsigned dsdt, xsdt;

>>>>      GArray *tables_blob = tables->table_data;

>>>>

>>>>      table_offsets = g_array_new(false, true /* clear */,

>>>> @@ -817,12 +846,12 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)

>>>>          build_iort(tables_blob, tables->linker);

>>>>      }

>>>>

>>>> -    /* RSDT is pointed to by RSDP */

>>>> -    rsdt = tables_blob->len;

>>>> -    build_rsdt(tables_blob, tables->linker, table_offsets, NULL, NULL);

>>>> +    /* XSDT is pointed to by RSDP */

>>>> +    xsdt = tables_blob->len;

>>>> +    build_xsdt(tables_blob, tables->linker, table_offsets, NULL, NULL);

>>>>

>>>>      /* RSDP is in FSEG memory, so allocate it separately */

>>>> -    build_rsdp(tables->rsdp, tables->linker, rsdt);

>>>> +    build_rsdp(tables->rsdp, tables->linker, xsdt);

>>>>

>>>>      /* Cleanup memory that's no longer used. */

>>>>      g_array_free(table_offsets, true);

>>>> diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h

>>>> index 4cc3630e613e..bf37acf4c4c6 100644

>>>> --- a/include/hw/acpi/acpi-defs.h

>>>> +++ b/include/hw/acpi/acpi-defs.h

>>>> @@ -238,6 +238,17 @@ struct AcpiRsdtDescriptorRev1

>>>>  typedef struct AcpiRsdtDescriptorRev1 AcpiRsdtDescriptorRev1;

>>>>

>>>>  /*

>>>> + * ACPI 2.0 eXtended System Description Table (XSDT)

>>>> + */

>>>> +struct AcpiXsdtDescriptorRev2

>>>> +{

>>>> +    ACPI_TABLE_HEADER_DEF       /* ACPI common table header */

>>>> +    uint64_t table_offset_entry[0];  /* Array of pointers to other */

>>>> +    /* ACPI tables */

>>>> +} QEMU_PACKED;

>>>> +typedef struct AcpiXsdtDescriptorRev2 AcpiXsdtDescriptorRev2;

>>>> +

>>>> +/*

>>>>   * ACPI 1.0 Firmware ACPI Control Structure (FACS)

>>>>   */

>>>>  struct AcpiFacsDescriptorRev1

>>>> --

>>>> 2.9.3

>>>>

>>>>

>>>

>>> Otherwise

>>>

>>> Reviewed-by: Andrew Jones <drjones@redhat.com>

>>>

>>

>> Great, I didn't want to be the first one to provide public feedback. :)

>>

>> Personally I'm fine if we keep the XSDT generation local to

>> "hw/arm/virt-acpi-build.c" for now, and we upstream it to

>> "hw/acpi/aml-build.c" later (for example when i386 actually puts it to

>> use -- which shouldn't be that far out, AIUI, since Phil will probably

>> need XSDT for OSX guests). However, I also wouldn't mind if the XSDT

>> builder were moved to "hw/acpi/aml-build.c" right now.

>

> FWIW, OS X guests don't appear to care about an XSDT, and I'm not

> planning any work in that area. My patch only affects the x86 FADT

> (Rev1->Rev3). From what I saw, this is, aside from the struct

> definition, completely independent from Qemu's ARM FADT, which I think

> has always used the Rev5(.1?) variant.

> (Are patches for 2.10 already being accepted? Michael previously said

> I should wait until 2.9 is out, that's the only reason I'm still

> hanging onto my patch.)

>

>> So one way or another,

>>

>> Acked-by: Laszlo Ersek <lersek@redhat.com>

>>

>> Thanks

>> Laszlo
Phil Dennis-Jordan April 7, 2017, 9:50 a.m. | #5
On Fri, Apr 7, 2017 at 9:44 PM, Ard Biesheuvel
<ard.biesheuvel@linaro.org> wrote:
> On 7 April 2017 at 10:36, Phil Dennis-Jordan <phil@philjordan.eu> wrote:

>> On 7 April 2017 at 21:11, Laszlo Ersek <lersek@redhat.com> wrote:

>>> On 04/07/17 10:55, Andrew Jones wrote:

>>>> On Thu, Apr 06, 2017 at 10:22:09PM +0100, Ard Biesheuvel wrote:

>>>>> Our current ACPI table generation code limits the placement of ACPI

>>>>> tables to 32-bit addressable memory, in order to be able to emit the

>>>>> root pointer (RSDP) and root table (RSDT) using table types from the

>>>>> ACPI 1.0 days.

>>>>>

>>>>> Since ARM was not supported by ACPI before version 5.0, it makes sense

>>>>> to lift this restriction. This is not crucial for mach-virt, which is

>>>>> guaranteed to have some memory available below the 4 GB mark, but it

>>>>> is a nice to have for QEMU machines that do not have any 32-bit

>>>>> addressable, not unlike some real world 64-bit ARM systems.

>>

>> "QEMU machines that do not have any 32-bit addressable memory," perhaps?

>>

>

> Yes, better.

>

>>>>> Since we already emit a version of the RSDP root pointer that carries

>>>>> a 64-bit wide address for the 64-bit root table (XSDT), all we need to

>>>>> do is replace the RSDT generation with the generation of an XSDT table,

>>>>> and use a different slot in the FADT table to refer to the DSDT.

>>>>>

>>>>> Note that this only modifies the private interaction between QEMU and

>>>>> UEFI. Since these tables are all handled by the generic AcpiTableDxe

>>>>> driver which generates its own RSDP, RSDT and XSDT tables and manages

>>>>> the DSDT pointer in FADT itself, the tables that are present to the

>>>>> guest are identical, and so no mach-virt versioning is required for

>>>>> this change.

>>>

>>> The last paragraph could be dropped from the commit message (or trimmed

>>> a bit). Not really necessary, saying it just FYI. Namely, we don't

>>> version firmware blobs (i.e., we don't tie different firmware blobs to

>>> different versions of a machine type), and ACPI tables are considered

>>> part of the firmware (from the OS's POV), despite the fact that

>>> technically we generate them in QEMU. So, in my understanding, the ACPI

>>> content we generate never needs to consider machine types.

>>>

>>>>>

>>>>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

>>>>> ---

>>>>>  hw/arm/virt-acpi-build.c    | 55 ++++++++++++++++++++++++++++++++++-----------

>>>>>  include/hw/acpi/acpi-defs.h | 11 +++++++++

>>>>>  2 files changed, 53 insertions(+), 13 deletions(-)

>>>>>

>>>>> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c

>>>>> index b173bd109b91..d18368094c00 100644

>>>>> --- a/hw/arm/virt-acpi-build.c

>>>>> +++ b/hw/arm/virt-acpi-build.c

>>>>> @@ -391,12 +391,12 @@ static void acpi_dsdt_add_power_button(Aml *scope)

>>>>>

>>>>>  /* RSDP */

>>>>>  static GArray *

>>>>> -build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offset)

>>>>> +build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned xsdt_tbl_offset)

>>>>>  {

>>>>>      AcpiRsdpDescriptor *rsdp = acpi_data_push(rsdp_table, sizeof *rsdp);

>>>>> -    unsigned rsdt_pa_size = sizeof(rsdp->rsdt_physical_address);

>>>>> -    unsigned rsdt_pa_offset =

>>>>> -        (char *)&rsdp->rsdt_physical_address - rsdp_table->data;

>>>>> +    unsigned xsdt_pa_size = sizeof(rsdp->xsdt_physical_address);

>>>>> +    unsigned xsdt_pa_offset =

>>>>> +        (char *)&rsdp->xsdt_physical_address - rsdp_table->data;

>>>>>

>>>>>      bios_linker_loader_alloc(linker, ACPI_BUILD_RSDP_FILE, rsdp_table, 16,

>>>>>                               true /* fseg memory */);

>>>>> @@ -408,8 +408,8 @@ build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offset)

>>>>>

>>>>>      /* Address to be filled by Guest linker */

>>>>>      bios_linker_loader_add_pointer(linker,

>>>>> -        ACPI_BUILD_RSDP_FILE, rsdt_pa_offset, rsdt_pa_size,

>>>>> -        ACPI_BUILD_TABLE_FILE, rsdt_tbl_offset);

>>>>> +        ACPI_BUILD_RSDP_FILE, xsdt_pa_offset, xsdt_pa_size,

>>>>> +        ACPI_BUILD_TABLE_FILE, xsdt_tbl_offset);

>>>>>

>>>>>      /* Checksum to be filled by Guest linker */

>>>>>      bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE,

>>>>> @@ -686,7 +686,7 @@ static void build_fadt(GArray *table_data, BIOSLinker *linker,

>>>>>                         VirtMachineState *vms, unsigned dsdt_tbl_offset)

>>>>>  {

>>>>>      AcpiFadtDescriptorRev5_1 *fadt = acpi_data_push(table_data, sizeof(*fadt));

>>>>> -    unsigned dsdt_entry_offset = (char *)&fadt->dsdt - table_data->data;

>>>>> +    unsigned xdsdt_entry_offset = (char *)&fadt->Xdsdt - table_data->data;

>>>>>      uint16_t bootflags;

>>>>>

>>>>>      switch (vms->psci_conduit) {

>>>>> @@ -712,7 +712,7 @@ static void build_fadt(GArray *table_data, BIOSLinker *linker,

>>>>>

>>>>>      /* DSDT address to be filled by Guest linker */

>>>>>      bios_linker_loader_add_pointer(linker,

>>>>> -        ACPI_BUILD_TABLE_FILE, dsdt_entry_offset, sizeof(fadt->dsdt),

>>>>> +        ACPI_BUILD_TABLE_FILE, xdsdt_entry_offset, sizeof(fadt->Xdsdt),

>>>>>          ACPI_BUILD_TABLE_FILE, dsdt_tbl_offset);

>>>>>

>>>>>      build_header(linker, table_data,

>>

>> I don't know what it's like in ARM-Land, but X64 Windows does not take

>> kindly to a zero DSDT pointer in my experience. It might make sense to

>> make the choice between DSDT and XDSDT conditional on whether the

>> pointer is actually above 4GB? Mind you, I don't even know if

>> Microsoft makes ARM variants of Windows generally available, and

>> whether they currently work in Qemu; the FOSS OSes are typically more

>> lenient.

>>

>

> Documentation/arm64/acpi_object_usage.txt in the kernel contains this under FADT

>

>    For the DSDT that is also required, the X_DSDT field is to be used,

>    not the DSDT field.

>

> and so we should be using xdsdt anyway.


IME, what the documentation & standard say can diverge wildly from
what shipping OSes actually expect. That's all I'm saying. :-)

> *However*, this is all moot

> given that UEFI is in charge of populating these fields. What we

> generate here and what the guest sees are two different things that

> are almost completely disconnected when it comes to RSDP, RSDT/XSDT

> and the DSDT field in FADT.


Indeed. For x86 we have to care about SeaBIOS of course, I guess on
ARM there's no such concern.

>> See also the discussion in this thread on qemu-devel:

>> https://lists.gnu.org/archive/html/qemu-devel/2017-01/msg05754.html

>> and a related issue on edk2-devel:

>> https://lists.01.org/pipermail/edk2-devel/2017-March/008460.html

>>

>>>>> @@ -772,12 +772,41 @@ struct AcpiBuildState {

>>>>>      bool patched;

>>>>>  } AcpiBuildState;

>>>>>

>>>>> +/* Build xsdt table */

>>>>> +

>>>>> +static

>>>>> +void build_xsdt(GArray *table_data, BIOSLinker *linker, GArray *table_offsets,

>>>>> +                const char *oem_id, const char *oem_table_id)

>>>>> +{

>>>>> +    int i;

>>>>> +    unsigned xsdt_entries_offset;

>>>>> +    AcpiXsdtDescriptorRev2 *xsdt;

>>>>> +    const unsigned table_data_len = (sizeof(uint64_t) * table_offsets->len);

>>>>> +    const unsigned xsdt_entry_size = sizeof(xsdt->table_offset_entry[0]);

>>>>> +    const size_t xsdt_len = sizeof(*xsdt) + table_data_len;

>>>>> +

>>>>> +    xsdt = acpi_data_push(table_data, xsdt_len);

>>>>> +    xsdt_entries_offset = (char *)xsdt->table_offset_entry - table_data->data;

>>>>> +    for (i = 0; i < table_offsets->len; ++i) {

>>>>> +        uint64_t ref_tbl_offset = g_array_index(table_offsets, uint32_t, i);

>>>>> +        uint64_t xsdt_entry_offset = xsdt_entries_offset + xsdt_entry_size * i;

>>>>> +

>>>>> +        /* xsdt->table_offset_entry to be filled by Guest linker */

>>>>> +        bios_linker_loader_add_pointer(linker,

>>>>> +            ACPI_BUILD_TABLE_FILE, xsdt_entry_offset, xsdt_entry_size,

>>>>> +            ACPI_BUILD_TABLE_FILE, ref_tbl_offset);

>>>>> +    }

>>>>> +    build_header(linker, table_data,

>>>>> +                 (void *)xsdt, "XSDT", xsdt_len, 1, oem_id, oem_table_id);

>>>>> +}

>>>>

>>>> build_xsdt should probably go in hw/acpi/aml-build.c

>>>>

>>>>> +

>>>>> +

>>>>>  static

>>>>>  void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)

>>>>>  {

>>>>>      VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(vms);

>>>>>      GArray *table_offsets;

>>>>> -    unsigned dsdt, rsdt;

>>>>> +    unsigned dsdt, xsdt;

>>>>>      GArray *tables_blob = tables->table_data;

>>>>>

>>>>>      table_offsets = g_array_new(false, true /* clear */,

>>>>> @@ -817,12 +846,12 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)

>>>>>          build_iort(tables_blob, tables->linker);

>>>>>      }

>>>>>

>>>>> -    /* RSDT is pointed to by RSDP */

>>>>> -    rsdt = tables_blob->len;

>>>>> -    build_rsdt(tables_blob, tables->linker, table_offsets, NULL, NULL);

>>>>> +    /* XSDT is pointed to by RSDP */

>>>>> +    xsdt = tables_blob->len;

>>>>> +    build_xsdt(tables_blob, tables->linker, table_offsets, NULL, NULL);

>>>>>

>>>>>      /* RSDP is in FSEG memory, so allocate it separately */

>>>>> -    build_rsdp(tables->rsdp, tables->linker, rsdt);

>>>>> +    build_rsdp(tables->rsdp, tables->linker, xsdt);

>>>>>

>>>>>      /* Cleanup memory that's no longer used. */

>>>>>      g_array_free(table_offsets, true);

>>>>> diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h

>>>>> index 4cc3630e613e..bf37acf4c4c6 100644

>>>>> --- a/include/hw/acpi/acpi-defs.h

>>>>> +++ b/include/hw/acpi/acpi-defs.h

>>>>> @@ -238,6 +238,17 @@ struct AcpiRsdtDescriptorRev1

>>>>>  typedef struct AcpiRsdtDescriptorRev1 AcpiRsdtDescriptorRev1;

>>>>>

>>>>>  /*

>>>>> + * ACPI 2.0 eXtended System Description Table (XSDT)

>>>>> + */

>>>>> +struct AcpiXsdtDescriptorRev2

>>>>> +{

>>>>> +    ACPI_TABLE_HEADER_DEF       /* ACPI common table header */

>>>>> +    uint64_t table_offset_entry[0];  /* Array of pointers to other */

>>>>> +    /* ACPI tables */

>>>>> +} QEMU_PACKED;

>>>>> +typedef struct AcpiXsdtDescriptorRev2 AcpiXsdtDescriptorRev2;

>>>>> +

>>>>> +/*

>>>>>   * ACPI 1.0 Firmware ACPI Control Structure (FACS)

>>>>>   */

>>>>>  struct AcpiFacsDescriptorRev1

>>>>> --

>>>>> 2.9.3

>>>>>

>>>>>

>>>>

>>>> Otherwise

>>>>

>>>> Reviewed-by: Andrew Jones <drjones@redhat.com>

>>>>

>>>

>>> Great, I didn't want to be the first one to provide public feedback. :)

>>>

>>> Personally I'm fine if we keep the XSDT generation local to

>>> "hw/arm/virt-acpi-build.c" for now, and we upstream it to

>>> "hw/acpi/aml-build.c" later (for example when i386 actually puts it to

>>> use -- which shouldn't be that far out, AIUI, since Phil will probably

>>> need XSDT for OSX guests). However, I also wouldn't mind if the XSDT

>>> builder were moved to "hw/acpi/aml-build.c" right now.

>>

>> FWIW, OS X guests don't appear to care about an XSDT, and I'm not

>> planning any work in that area. My patch only affects the x86 FADT

>> (Rev1->Rev3). From what I saw, this is, aside from the struct

>> definition, completely independent from Qemu's ARM FADT, which I think

>> has always used the Rev5(.1?) variant.

>> (Are patches for 2.10 already being accepted? Michael previously said

>> I should wait until 2.9 is out, that's the only reason I'm still

>> hanging onto my patch.)

>>

>>> So one way or another,

>>>

>>> Acked-by: Laszlo Ersek <lersek@redhat.com>

>>>

>>> Thanks

>>> Laszlo

>
Laszlo Ersek April 7, 2017, 9:51 a.m. | #6
On 04/07/17 11:36, Phil Dennis-Jordan wrote:
> On 7 April 2017 at 21:11, Laszlo Ersek <lersek@redhat.com> wrote:

>> On 04/07/17 10:55, Andrew Jones wrote:

>>> On Thu, Apr 06, 2017 at 10:22:09PM +0100, Ard Biesheuvel wrote:

>>>> Our current ACPI table generation code limits the placement of ACPI

>>>> tables to 32-bit addressable memory, in order to be able to emit the

>>>> root pointer (RSDP) and root table (RSDT) using table types from the

>>>> ACPI 1.0 days.

>>>>

>>>> Since ARM was not supported by ACPI before version 5.0, it makes sense

>>>> to lift this restriction. This is not crucial for mach-virt, which is

>>>> guaranteed to have some memory available below the 4 GB mark, but it

>>>> is a nice to have for QEMU machines that do not have any 32-bit

>>>> addressable, not unlike some real world 64-bit ARM systems.

> 

> "QEMU machines that do not have any 32-bit addressable memory," perhaps?

> 

>>>> Since we already emit a version of the RSDP root pointer that carries

>>>> a 64-bit wide address for the 64-bit root table (XSDT), all we need to

>>>> do is replace the RSDT generation with the generation of an XSDT table,

>>>> and use a different slot in the FADT table to refer to the DSDT.

>>>>

>>>> Note that this only modifies the private interaction between QEMU and

>>>> UEFI. Since these tables are all handled by the generic AcpiTableDxe

>>>> driver which generates its own RSDP, RSDT and XSDT tables and manages

>>>> the DSDT pointer in FADT itself, the tables that are present to the

>>>> guest are identical, and so no mach-virt versioning is required for

>>>> this change.

>>

>> The last paragraph could be dropped from the commit message (or trimmed

>> a bit). Not really necessary, saying it just FYI. Namely, we don't

>> version firmware blobs (i.e., we don't tie different firmware blobs to

>> different versions of a machine type), and ACPI tables are considered

>> part of the firmware (from the OS's POV), despite the fact that

>> technically we generate them in QEMU. So, in my understanding, the ACPI

>> content we generate never needs to consider machine types.

>>

>>>>

>>>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

>>>> ---

>>>>  hw/arm/virt-acpi-build.c    | 55 ++++++++++++++++++++++++++++++++++-----------

>>>>  include/hw/acpi/acpi-defs.h | 11 +++++++++

>>>>  2 files changed, 53 insertions(+), 13 deletions(-)

>>>>

>>>> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c

>>>> index b173bd109b91..d18368094c00 100644

>>>> --- a/hw/arm/virt-acpi-build.c

>>>> +++ b/hw/arm/virt-acpi-build.c

>>>> @@ -391,12 +391,12 @@ static void acpi_dsdt_add_power_button(Aml *scope)

>>>>

>>>>  /* RSDP */

>>>>  static GArray *

>>>> -build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offset)

>>>> +build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned xsdt_tbl_offset)

>>>>  {

>>>>      AcpiRsdpDescriptor *rsdp = acpi_data_push(rsdp_table, sizeof *rsdp);

>>>> -    unsigned rsdt_pa_size = sizeof(rsdp->rsdt_physical_address);

>>>> -    unsigned rsdt_pa_offset =

>>>> -        (char *)&rsdp->rsdt_physical_address - rsdp_table->data;

>>>> +    unsigned xsdt_pa_size = sizeof(rsdp->xsdt_physical_address);

>>>> +    unsigned xsdt_pa_offset =

>>>> +        (char *)&rsdp->xsdt_physical_address - rsdp_table->data;

>>>>

>>>>      bios_linker_loader_alloc(linker, ACPI_BUILD_RSDP_FILE, rsdp_table, 16,

>>>>                               true /* fseg memory */);

>>>> @@ -408,8 +408,8 @@ build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offset)

>>>>

>>>>      /* Address to be filled by Guest linker */

>>>>      bios_linker_loader_add_pointer(linker,

>>>> -        ACPI_BUILD_RSDP_FILE, rsdt_pa_offset, rsdt_pa_size,

>>>> -        ACPI_BUILD_TABLE_FILE, rsdt_tbl_offset);

>>>> +        ACPI_BUILD_RSDP_FILE, xsdt_pa_offset, xsdt_pa_size,

>>>> +        ACPI_BUILD_TABLE_FILE, xsdt_tbl_offset);

>>>>

>>>>      /* Checksum to be filled by Guest linker */

>>>>      bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE,

>>>> @@ -686,7 +686,7 @@ static void build_fadt(GArray *table_data, BIOSLinker *linker,

>>>>                         VirtMachineState *vms, unsigned dsdt_tbl_offset)

>>>>  {

>>>>      AcpiFadtDescriptorRev5_1 *fadt = acpi_data_push(table_data, sizeof(*fadt));

>>>> -    unsigned dsdt_entry_offset = (char *)&fadt->dsdt - table_data->data;

>>>> +    unsigned xdsdt_entry_offset = (char *)&fadt->Xdsdt - table_data->data;

>>>>      uint16_t bootflags;

>>>>

>>>>      switch (vms->psci_conduit) {

>>>> @@ -712,7 +712,7 @@ static void build_fadt(GArray *table_data, BIOSLinker *linker,

>>>>

>>>>      /* DSDT address to be filled by Guest linker */

>>>>      bios_linker_loader_add_pointer(linker,

>>>> -        ACPI_BUILD_TABLE_FILE, dsdt_entry_offset, sizeof(fadt->dsdt),

>>>> +        ACPI_BUILD_TABLE_FILE, xdsdt_entry_offset, sizeof(fadt->Xdsdt),

>>>>          ACPI_BUILD_TABLE_FILE, dsdt_tbl_offset);

>>>>

>>>>      build_header(linker, table_data,

> 

> I don't know what it's like in ARM-Land, but X64 Windows does not take

> kindly to a zero DSDT pointer in my experience. It might make sense to

> make the choice between DSDT and XDSDT conditional on whether the

> pointer is actually above 4GB?


This choice is already being made, in edk2's
MdeModulePkg/Universal/Acpi/AcpiTableDxe, in function AddTableToList().
The most recent commit to look at is 78807f605082
("MdeModulePkg/AcpiTableDxe: Not make FADT.{DSDT,X_DSDT} mutual
exclusion", 2017-03-16).

I think this QEMU code is fine as-is. Windows's behavior wrt. ACPI is
unpredictable; we shouldn't speculate about Windows-on-aarch64 until we
actually get to see it / run it.

Now, for guest firmware (similar to SeaBIOS) that lacks the
above-mentioned logic of AcpiTableDxe, your concern could be valid. But,
for ARM guests that consume ACPI, there is no such firmware. There is
only edk2.

> Mind you, I don't even know if

> Microsoft makes ARM variants of Windows generally available, and

> whether they currently work in Qemu; the FOSS OSes are typically more

> lenient.

> 

> See also the discussion in this thread on qemu-devel:

> https://lists.gnu.org/archive/html/qemu-devel/2017-01/msg05754.html

> and a related issue on edk2-devel:

> https://lists.01.org/pipermail/edk2-devel/2017-March/008460.html

> 

>>>> @@ -772,12 +772,41 @@ struct AcpiBuildState {

>>>>      bool patched;

>>>>  } AcpiBuildState;

>>>>

>>>> +/* Build xsdt table */

>>>> +

>>>> +static

>>>> +void build_xsdt(GArray *table_data, BIOSLinker *linker, GArray *table_offsets,

>>>> +                const char *oem_id, const char *oem_table_id)

>>>> +{

>>>> +    int i;

>>>> +    unsigned xsdt_entries_offset;

>>>> +    AcpiXsdtDescriptorRev2 *xsdt;

>>>> +    const unsigned table_data_len = (sizeof(uint64_t) * table_offsets->len);

>>>> +    const unsigned xsdt_entry_size = sizeof(xsdt->table_offset_entry[0]);

>>>> +    const size_t xsdt_len = sizeof(*xsdt) + table_data_len;

>>>> +

>>>> +    xsdt = acpi_data_push(table_data, xsdt_len);

>>>> +    xsdt_entries_offset = (char *)xsdt->table_offset_entry - table_data->data;

>>>> +    for (i = 0; i < table_offsets->len; ++i) {

>>>> +        uint64_t ref_tbl_offset = g_array_index(table_offsets, uint32_t, i);

>>>> +        uint64_t xsdt_entry_offset = xsdt_entries_offset + xsdt_entry_size * i;

>>>> +

>>>> +        /* xsdt->table_offset_entry to be filled by Guest linker */

>>>> +        bios_linker_loader_add_pointer(linker,

>>>> +            ACPI_BUILD_TABLE_FILE, xsdt_entry_offset, xsdt_entry_size,

>>>> +            ACPI_BUILD_TABLE_FILE, ref_tbl_offset);

>>>> +    }

>>>> +    build_header(linker, table_data,

>>>> +                 (void *)xsdt, "XSDT", xsdt_len, 1, oem_id, oem_table_id);

>>>> +}

>>>

>>> build_xsdt should probably go in hw/acpi/aml-build.c

>>>

>>>> +

>>>> +

>>>>  static

>>>>  void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)

>>>>  {

>>>>      VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(vms);

>>>>      GArray *table_offsets;

>>>> -    unsigned dsdt, rsdt;

>>>> +    unsigned dsdt, xsdt;

>>>>      GArray *tables_blob = tables->table_data;

>>>>

>>>>      table_offsets = g_array_new(false, true /* clear */,

>>>> @@ -817,12 +846,12 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)

>>>>          build_iort(tables_blob, tables->linker);

>>>>      }

>>>>

>>>> -    /* RSDT is pointed to by RSDP */

>>>> -    rsdt = tables_blob->len;

>>>> -    build_rsdt(tables_blob, tables->linker, table_offsets, NULL, NULL);

>>>> +    /* XSDT is pointed to by RSDP */

>>>> +    xsdt = tables_blob->len;

>>>> +    build_xsdt(tables_blob, tables->linker, table_offsets, NULL, NULL);

>>>>

>>>>      /* RSDP is in FSEG memory, so allocate it separately */

>>>> -    build_rsdp(tables->rsdp, tables->linker, rsdt);

>>>> +    build_rsdp(tables->rsdp, tables->linker, xsdt);

>>>>

>>>>      /* Cleanup memory that's no longer used. */

>>>>      g_array_free(table_offsets, true);

>>>> diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h

>>>> index 4cc3630e613e..bf37acf4c4c6 100644

>>>> --- a/include/hw/acpi/acpi-defs.h

>>>> +++ b/include/hw/acpi/acpi-defs.h

>>>> @@ -238,6 +238,17 @@ struct AcpiRsdtDescriptorRev1

>>>>  typedef struct AcpiRsdtDescriptorRev1 AcpiRsdtDescriptorRev1;

>>>>

>>>>  /*

>>>> + * ACPI 2.0 eXtended System Description Table (XSDT)

>>>> + */

>>>> +struct AcpiXsdtDescriptorRev2

>>>> +{

>>>> +    ACPI_TABLE_HEADER_DEF       /* ACPI common table header */

>>>> +    uint64_t table_offset_entry[0];  /* Array of pointers to other */

>>>> +    /* ACPI tables */

>>>> +} QEMU_PACKED;

>>>> +typedef struct AcpiXsdtDescriptorRev2 AcpiXsdtDescriptorRev2;

>>>> +

>>>> +/*

>>>>   * ACPI 1.0 Firmware ACPI Control Structure (FACS)

>>>>   */

>>>>  struct AcpiFacsDescriptorRev1

>>>> --

>>>> 2.9.3

>>>>

>>>>

>>>

>>> Otherwise

>>>

>>> Reviewed-by: Andrew Jones <drjones@redhat.com>

>>>

>>

>> Great, I didn't want to be the first one to provide public feedback. :)

>>

>> Personally I'm fine if we keep the XSDT generation local to

>> "hw/arm/virt-acpi-build.c" for now, and we upstream it to

>> "hw/acpi/aml-build.c" later (for example when i386 actually puts it to

>> use -- which shouldn't be that far out, AIUI, since Phil will probably

>> need XSDT for OSX guests). However, I also wouldn't mind if the XSDT

>> builder were moved to "hw/acpi/aml-build.c" right now.

> 

> FWIW, OS X guests don't appear to care about an XSDT, and I'm not

> planning any work in that area. My patch only affects the x86 FADT

> (Rev1->Rev3).


Ah, okay, I missed that bit, sorry. Thanks for the info.

> From what I saw, this is, aside from the struct

> definition, completely independent from Qemu's ARM FADT, which I think

> has always used the Rev5(.1?) variant.

> (Are patches for 2.10 already being accepted?


Reviewed & discussed, yes; merged, no.

Thanks,
Laszlo

> Michael previously said

> I should wait until 2.9 is out, that's the only reason I'm still

> hanging onto my patch.)

> 

>> So one way or another,

>>

>> Acked-by: Laszlo Ersek <lersek@redhat.com>

>>

>> Thanks

>> Laszlo
Laszlo Ersek April 7, 2017, 9:57 a.m. | #7
On 04/07/17 11:44, Ard Biesheuvel wrote:
> On 7 April 2017 at 10:36, Phil Dennis-Jordan <phil@philjordan.eu> wrote:

>> On 7 April 2017 at 21:11, Laszlo Ersek <lersek@redhat.com> wrote:

>>> On 04/07/17 10:55, Andrew Jones wrote:

>>>> On Thu, Apr 06, 2017 at 10:22:09PM +0100, Ard Biesheuvel wrote:


>>>>> @@ -712,7 +712,7 @@ static void build_fadt(GArray *table_data, BIOSLinker *linker,

>>>>>

>>>>>      /* DSDT address to be filled by Guest linker */

>>>>>      bios_linker_loader_add_pointer(linker,

>>>>> -        ACPI_BUILD_TABLE_FILE, dsdt_entry_offset, sizeof(fadt->dsdt),

>>>>> +        ACPI_BUILD_TABLE_FILE, xdsdt_entry_offset, sizeof(fadt->Xdsdt),

>>>>>          ACPI_BUILD_TABLE_FILE, dsdt_tbl_offset);

>>>>>

>>>>>      build_header(linker, table_data,

>>

>> I don't know what it's like in ARM-Land, but X64 Windows does not take

>> kindly to a zero DSDT pointer in my experience. It might make sense to

>> make the choice between DSDT and XDSDT conditional on whether the

>> pointer is actually above 4GB? Mind you, I don't even know if

>> Microsoft makes ARM variants of Windows generally available, and

>> whether they currently work in Qemu; the FOSS OSes are typically more

>> lenient.

>>

> 

> Documentation/arm64/acpi_object_usage.txt in the kernel contains this under FADT

> 

>    For the DSDT that is also required, the X_DSDT field is to be used,

>    not the DSDT field.

> 

> and so we should be using xdsdt anyway. *However*, this is all moot

> given that UEFI is in charge of populating these fields. What we

> generate here and what the guest sees are two different things that

> are almost completely disconnected when it comes to RSDP, RSDT/XSDT

> and the DSDT field in FADT.


Agreed; in ARM guests, there is no ACPI without UEFI, and UEFI handles
the above stuff internally. For UEFI guests, some of the linker/loader
commands have a somewhat indirect meaning.

Laszlo

Patch hide | download patch | download mbox

diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index b173bd109b91..d18368094c00 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -391,12 +391,12 @@  static void acpi_dsdt_add_power_button(Aml *scope)
 
 /* RSDP */
 static GArray *
-build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offset)
+build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned xsdt_tbl_offset)
 {
     AcpiRsdpDescriptor *rsdp = acpi_data_push(rsdp_table, sizeof *rsdp);
-    unsigned rsdt_pa_size = sizeof(rsdp->rsdt_physical_address);
-    unsigned rsdt_pa_offset =
-        (char *)&rsdp->rsdt_physical_address - rsdp_table->data;
+    unsigned xsdt_pa_size = sizeof(rsdp->xsdt_physical_address);
+    unsigned xsdt_pa_offset =
+        (char *)&rsdp->xsdt_physical_address - rsdp_table->data;
 
     bios_linker_loader_alloc(linker, ACPI_BUILD_RSDP_FILE, rsdp_table, 16,
                              true /* fseg memory */);
@@ -408,8 +408,8 @@  build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offset)
 
     /* Address to be filled by Guest linker */
     bios_linker_loader_add_pointer(linker,
-        ACPI_BUILD_RSDP_FILE, rsdt_pa_offset, rsdt_pa_size,
-        ACPI_BUILD_TABLE_FILE, rsdt_tbl_offset);
+        ACPI_BUILD_RSDP_FILE, xsdt_pa_offset, xsdt_pa_size,
+        ACPI_BUILD_TABLE_FILE, xsdt_tbl_offset);
 
     /* Checksum to be filled by Guest linker */
     bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE,
@@ -686,7 +686,7 @@  static void build_fadt(GArray *table_data, BIOSLinker *linker,
                        VirtMachineState *vms, unsigned dsdt_tbl_offset)
 {
     AcpiFadtDescriptorRev5_1 *fadt = acpi_data_push(table_data, sizeof(*fadt));
-    unsigned dsdt_entry_offset = (char *)&fadt->dsdt - table_data->data;
+    unsigned xdsdt_entry_offset = (char *)&fadt->Xdsdt - table_data->data;
     uint16_t bootflags;
 
     switch (vms->psci_conduit) {
@@ -712,7 +712,7 @@  static void build_fadt(GArray *table_data, BIOSLinker *linker,
 
     /* DSDT address to be filled by Guest linker */
     bios_linker_loader_add_pointer(linker,
-        ACPI_BUILD_TABLE_FILE, dsdt_entry_offset, sizeof(fadt->dsdt),
+        ACPI_BUILD_TABLE_FILE, xdsdt_entry_offset, sizeof(fadt->Xdsdt),
         ACPI_BUILD_TABLE_FILE, dsdt_tbl_offset);
 
     build_header(linker, table_data,
@@ -772,12 +772,41 @@  struct AcpiBuildState {
     bool patched;
 } AcpiBuildState;
 
+/* Build xsdt table */
+
+static
+void build_xsdt(GArray *table_data, BIOSLinker *linker, GArray *table_offsets,
+                const char *oem_id, const char *oem_table_id)
+{
+    int i;
+    unsigned xsdt_entries_offset;
+    AcpiXsdtDescriptorRev2 *xsdt;
+    const unsigned table_data_len = (sizeof(uint64_t) * table_offsets->len);
+    const unsigned xsdt_entry_size = sizeof(xsdt->table_offset_entry[0]);
+    const size_t xsdt_len = sizeof(*xsdt) + table_data_len;
+
+    xsdt = acpi_data_push(table_data, xsdt_len);
+    xsdt_entries_offset = (char *)xsdt->table_offset_entry - table_data->data;
+    for (i = 0; i < table_offsets->len; ++i) {
+        uint64_t ref_tbl_offset = g_array_index(table_offsets, uint32_t, i);
+        uint64_t xsdt_entry_offset = xsdt_entries_offset + xsdt_entry_size * i;
+
+        /* xsdt->table_offset_entry to be filled by Guest linker */
+        bios_linker_loader_add_pointer(linker,
+            ACPI_BUILD_TABLE_FILE, xsdt_entry_offset, xsdt_entry_size,
+            ACPI_BUILD_TABLE_FILE, ref_tbl_offset);
+    }
+    build_header(linker, table_data,
+                 (void *)xsdt, "XSDT", xsdt_len, 1, oem_id, oem_table_id);
+}
+
+
 static
 void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)
 {
     VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(vms);
     GArray *table_offsets;
-    unsigned dsdt, rsdt;
+    unsigned dsdt, xsdt;
     GArray *tables_blob = tables->table_data;
 
     table_offsets = g_array_new(false, true /* clear */,
@@ -817,12 +846,12 @@  void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)
         build_iort(tables_blob, tables->linker);
     }
 
-    /* RSDT is pointed to by RSDP */
-    rsdt = tables_blob->len;
-    build_rsdt(tables_blob, tables->linker, table_offsets, NULL, NULL);
+    /* XSDT is pointed to by RSDP */
+    xsdt = tables_blob->len;
+    build_xsdt(tables_blob, tables->linker, table_offsets, NULL, NULL);
 
     /* RSDP is in FSEG memory, so allocate it separately */
-    build_rsdp(tables->rsdp, tables->linker, rsdt);
+    build_rsdp(tables->rsdp, tables->linker, xsdt);
 
     /* Cleanup memory that's no longer used. */
     g_array_free(table_offsets, true);
diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h
index 4cc3630e613e..bf37acf4c4c6 100644
--- a/include/hw/acpi/acpi-defs.h
+++ b/include/hw/acpi/acpi-defs.h
@@ -238,6 +238,17 @@  struct AcpiRsdtDescriptorRev1
 typedef struct AcpiRsdtDescriptorRev1 AcpiRsdtDescriptorRev1;
 
 /*
+ * ACPI 2.0 eXtended System Description Table (XSDT)
+ */
+struct AcpiXsdtDescriptorRev2
+{
+    ACPI_TABLE_HEADER_DEF       /* ACPI common table header */
+    uint64_t table_offset_entry[0];  /* Array of pointers to other */
+    /* ACPI tables */
+} QEMU_PACKED;
+typedef struct AcpiXsdtDescriptorRev2 AcpiXsdtDescriptorRev2;
+
+/*
  * ACPI 1.0 Firmware ACPI Control Structure (FACS)
  */
 struct AcpiFacsDescriptorRev1