Re: [Qemu-devel] [RFC PATCH 1/3] hw/arm/virt-acpi-build: use acpi_get_mcfg() to calculate bus number

[Igor Mammedov]

On Wed, 13 Mar 2019 12:42:51 +0800
Wei Yang <address@hidden> wrote:

> To build MCFG, two information is necessary:
> 
>     * bus number
>     * base address
> 
> Abstract these two information to AcpiMcfgInfo so that build_mcfg and
> build_mcfg_q35 will have the same declaration.
> 
> Signed-off-by: Wei Yang <address@hidden>
> ---
>  hw/arm/virt-acpi-build.c    | 28 ++++++++++++++++++++--------
>  hw/i386/acpi-build.c        |  5 -----
>  include/hw/acpi/aml-build.h |  5 +++++
>  3 files changed, 25 insertions(+), 13 deletions(-)
> 
> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index 57679a89bf..7713c2d809 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -545,23 +545,32 @@ build_srat(GArray *table_data, BIOSLinker *linker, 
> VirtMachineState *vms)
>                   "SRAT", table_data->len - srat_start, 3, NULL, NULL);
>  }
>  
> -static void
> -build_mcfg(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
> +static bool acpi_get_mcfg(AcpiMcfgInfo *mcfg)
>  {
> -    AcpiTableMcfg *mcfg;
> +    VirtMachineState *vms = VIRT_MACHINE(qdev_get_machine());
>      const MemMapEntry *memmap = vms->memmap;
>      int ecam_id = VIRT_ECAM_ID(vms->highmem_ecam);
> +
> +    mcfg->mcfg_base = memmap[ecam_id].base;
> +    mcfg->mcfg_size = memmap[ecam_id].size;
> +
> +    return true;
> +}
> +
> +static void
> +build_mcfg(GArray *table_data, BIOSLinker *linker, AcpiMcfgInfo *info)
> +{
> +    AcpiTableMcfg *mcfg;
>      int len = sizeof(*mcfg) + sizeof(mcfg->allocation[0]);
>      int mcfg_start = table_data->len;
>  
>      mcfg = acpi_data_push(table_data, len);
> -    mcfg->allocation[0].address = cpu_to_le64(memmap[ecam_id].base);
> +    mcfg->allocation[0].address = cpu_to_le64(info->mcfg_base);
>  
>      /* Only a single allocation so no need to play with segments */
>      mcfg->allocation[0].pci_segment = cpu_to_le16(0);
>      mcfg->allocation[0].start_bus_number = 0;
> -    mcfg->allocation[0].end_bus_number =
> -        PCIE_MMCFG_BUS(memmap[ecam_id].size - 1);
> +    mcfg->allocation[0].end_bus_number = PCIE_MMCFG_BUS(info->mcfg_size - 1);
>  
>      build_header(linker, table_data, (void *)(table_data->data + mcfg_start),
>                   "MCFG", table_data->len - mcfg_start, 1, NULL, NULL);
> @@ -779,6 +788,7 @@ void virt_acpi_build(VirtMachineState *vms, 
> AcpiBuildTables *tables)
>      VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(vms);
>      GArray *table_offsets;
>      unsigned dsdt, xsdt;
> +    AcpiMcfgInfo mcfg;
>      GArray *tables_blob = tables->table_data;
>  
>      table_offsets = g_array_new(false, true /* clear */,
> @@ -802,8 +812,10 @@ void virt_acpi_build(VirtMachineState *vms, 
> AcpiBuildTables *tables)
>      acpi_add_table(table_offsets, tables_blob);
>      build_gtdt(tables_blob, tables->linker, vms);
>  
> -    acpi_add_table(table_offsets, tables_blob);
> -    build_mcfg(tables_blob, tables->linker, vms);
> +    if ( acpi_get_mcfg(&mcfg)) {
> +        acpi_add_table(table_offsets, tables_blob);
> +        build_mcfg(tables_blob, tables->linker, &mcfg);
> +    }

acpi_get_mcfg used only once and always true so one doesn't need condition
I'd go for simpler:

diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index d7e2e4885b..a28e04c249 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -803,8 +803,13 @@ void virt_acpi_build(VirtMachineState *vms, 
AcpiBuildTables *tables)
     build_gtdt(tables_blob, tables->linker, vms);
 
     acpi_add_table(table_offsets, tables_blob);
-    build_mcfg(tables_blob, tables->linker, vms);
-
+    {
+        const AcpiTableMcfg mcfg = {
+           .mcfg_base = vms->memmap[VIRT_ECAM_ID(vms->highmem_ecam)].base;
+           .mcfg_size = vms->memmap[VIRT_ECAM_ID(vms->highmem_ecam)].size;
+        };
+        build_mcfg(tables_blob, tables->linker, &mcfg);
+    }
     acpi_add_table(table_offsets, tables_blob);
     build_spcr(tables_blob, tables->linker, vms);

and get rid of acpi_get_mcfg() helper function

>      acpi_add_table(table_offsets, tables_blob);
>      build_spcr(tables_blob, tables->linker, vms);
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index 9ecc96dcc7..c5b1c3be99 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -86,11 +86,6 @@
>  /* Default IOAPIC ID */
>  #define ACPI_BUILD_IOAPIC_ID 0x0
>  
> -typedef struct AcpiMcfgInfo {
> -    uint64_t mcfg_base;
> -    uint32_t mcfg_size;
> -} AcpiMcfgInfo;
> -
>  typedef struct AcpiPmInfo {
>      bool s3_disabled;
>      bool s4_disabled;
> diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
> index 1a563ad756..b63b85d67c 100644
> --- a/include/hw/acpi/aml-build.h
> +++ b/include/hw/acpi/aml-build.h
> @@ -223,6 +223,11 @@ struct AcpiBuildTables {
>      BIOSLinker *linker;
>  } AcpiBuildTables;
>  
> +typedef struct AcpiMcfgInfo {
> +    uint64_t mcfg_base;
> +    uint32_t mcfg_size;
mcfg_ prefix in fields probably isn't necessary.

> +} AcpiMcfgInfo;
> +
>  /**
>   * init_aml_allocator:
>   *