Re: [Qemu-devel] [PATCH v3 2/2] smbios: Set system manufacturer, product & version by default

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Oct 30, 2013 at 01:56:40PM +0100, armbru@redhat.com wrote:
> From: Markus Armbruster <armbru@redhat.com>
> 
> Currently, we get SeaBIOS defaults: manufacturer Bochs, product Bochs,
> no version.  Best SeaBIOS can do, but we can provide better defaults:
> manufacturer QEMU, product & version taken from QEMUMachine desc and
> name.
> 
> Take care to do this only for new machine types, of course.
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>

I feel applying this one would be a mistake.

Machine desc is for human readers.
For example, it currently says "Standard PC (Q35 + ICH9, 2009)"
but if we add a variant with IDE compatibility mode we will likely want to
tweak it to say "Standard PC (Q35 + ICH9/AHCI mode, 2009)"
and add another one saying ""Standard PC (Q35 + ICH9/compat mode,
2009)".

In other words we want the ability to tweak
description retroactively, and exposing it to guest will
break this ability.

So we really need a new field not tied to the human description.

> ---
>  hw/i386/pc_piix.c        |  9 +++++++++
>  hw/i386/pc_q35.c         |  7 +++++++
>  hw/i386/smbios.c         | 14 ++++++++++++++
>  include/hw/i386/smbios.h |  2 ++
>  4 files changed, 32 insertions(+)
> 
> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> index c6042c7..417ad33 100644
> --- a/hw/i386/pc_piix.c
> +++ b/hw/i386/pc_piix.c
> @@ -28,6 +28,7 @@
>  #include "hw/loader.h"
>  #include "hw/i386/pc.h"
>  #include "hw/i386/apic.h"
> +#include "hw/i386/smbios.h"
>  #include "hw/pci/pci.h"
>  #include "hw/pci/pci_ids.h"
>  #include "hw/usb.h"
> @@ -59,6 +60,7 @@ static const int ide_irq[MAX_IDE_BUS] = { 14, 15 };
>  
>  static bool has_pvpanic;
>  static bool has_pci_info = true;
> +static bool smbios_type1_defaults = true;
>  
>  /* PC hardware initialisation */
>  static void pc_init1(QEMUMachineInitArgs *args,
> @@ -124,6 +126,10 @@ static void pc_init1(QEMUMachineInitArgs *args,
>      guest_info = pc_guest_info_init(below_4g_mem_size, above_4g_mem_size);
>      guest_info->has_pci_info = has_pci_info;
>      guest_info->isapc_ram_fw = !pci_enabled;
> +    if (smbios_type1_defaults) {
> +        smbios_set_type1_defaults("QEMU", args->machine->desc,
> +                                  args->machine->name);
> +    }
>  
>      /* allocate ram and load rom/bios */
>      if (!xen_enabled()) {
> @@ -240,6 +246,7 @@ static void pc_compat_1_6(QEMUMachineInitArgs *args)
>  {
>      has_pci_info = false;
>      rom_file_in_ram = false;
> +    smbios_type1_defaults = false;
>  }
>  
>  static void pc_compat_1_5(QEMUMachineInitArgs *args)
> @@ -304,6 +311,7 @@ static void pc_init_pci_1_2(QEMUMachineInitArgs *args)
>  static void pc_init_pci_no_kvmclock(QEMUMachineInitArgs *args)
>  {
>      has_pci_info = false;
> +    smbios_type1_defaults = false;
>      disable_kvm_pv_eoi();
>      enable_compat_apic_id_mode();
>      pc_init1(args, 1, 0);
> @@ -312,6 +320,7 @@ static void pc_init_pci_no_kvmclock(QEMUMachineInitArgs *args)
>  static void pc_init_isa(QEMUMachineInitArgs *args)
>  {
>      has_pci_info = false;
> +    smbios_type1_defaults = false;
>      if (!args->cpu_model) {
>          args->cpu_model = "486";
>      }
> diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
> index ca84e1c..9e3213f 100644
> --- a/hw/i386/pc_q35.c
> +++ b/hw/i386/pc_q35.c
> @@ -39,6 +39,7 @@
>  #include "hw/pci-host/q35.h"
>  #include "exec/address-spaces.h"
>  #include "hw/i386/ich9.h"
> +#include "hw/i386/smbios.h"
>  #include "hw/ide/pci.h"
>  #include "hw/ide/ahci.h"
>  #include "hw/usb.h"
> @@ -49,6 +50,7 @@
>  
>  static bool has_pvpanic;
>  static bool has_pci_info = true;
> +static bool smbios_type1_defaults = true;
>  
>  /* PC hardware initialisation */
>  static void pc_q35_init(QEMUMachineInitArgs *args)
> @@ -111,6 +113,10 @@ static void pc_q35_init(QEMUMachineInitArgs *args)
>      guest_info = pc_guest_info_init(below_4g_mem_size, above_4g_mem_size);
>      guest_info->has_pci_info = has_pci_info;
>      guest_info->isapc_ram_fw = false;
> +    if (smbios_type1_defaults) {
> +        smbios_set_type1_defaults("QEMU", args->machine->desc,
> +                                  args->machine->name);
> +    }
>  
>      /* allocate ram and load rom/bios */
>      if (!xen_enabled()) {
> @@ -224,6 +230,7 @@ static void pc_compat_1_6(QEMUMachineInitArgs *args)
>  {
>      has_pci_info = false;
>      rom_file_in_ram = false;
> +    smbios_type1_defaults = false;
>  }
>  
>  static void pc_compat_1_5(QEMUMachineInitArgs *args)
> diff --git a/hw/i386/smbios.c b/hw/i386/smbios.c
> index d3f1ee6..e8f41ad 100644
> --- a/hw/i386/smbios.c
> +++ b/hw/i386/smbios.c
> @@ -256,6 +256,20 @@ static void smbios_build_type_1_fields(void)
>      }
>  }
>  
> +void smbios_set_type1_defaults(const char *manufacturer,
> +                               const char *product, const char *version)
> +{
> +    if (!type1.manufacturer) {
> +        type1.manufacturer = manufacturer;
> +    }
> +    if (!type1.product) {
> +        type1.product = product;
> +    }
> +    if (!type1.version) {
> +        type1.version = version;
> +    }
> +}
> +
>  uint8_t *smbios_get_table(size_t *length)
>  {
>      if (!smbios_immutable) {
> diff --git a/include/hw/i386/smbios.h b/include/hw/i386/smbios.h
> index b08ec71..18fb970 100644
> --- a/include/hw/i386/smbios.h
> +++ b/include/hw/i386/smbios.h
> @@ -16,6 +16,8 @@
>  #include "qemu/option.h"
>  
>  void smbios_entry_add(QemuOpts *opts);
> +void smbios_set_type1_defaults(const char *manufacturer,
> +                               const char *product, const char *version);
>  uint8_t *smbios_get_table(size_t *length);
>  
>  /*
> -- 
> 1.8.1.4