Re: [Qemu-devel] [PATCH] hw/arm/virt: generate 64-bit addressable ACPI objects

[Andrew Jones]

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 <address@hidden>
> ---
>  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 <address@hidden>