Re: [Qemu-devel] [PATCH v4] i386: Introduce ARAT CPU feature

[Eduardo Habkost]

(Fixing subject line)

On Tue, May 26, 2015 at 06:35:45AM +0200, Jan Kiszka wrote:
> From: Jan Kiszka <address@hidden>
> 
> ARAT signals that the APIC timer does not stop in power saving states.
> As our APICs are emulated, it's fine to expose this feature to guests,
> at least when asking for KVM host features or with CPU types that
> include the flag. The exact model number that introduced the feature is
> not known, but reports can be found that it's at least available since
> Sandy Bridge.
> 
> Signed-off-by: Jan Kiszka <address@hidden>
> ---
> 
> Changes in v4:
>  - followed suggestions by Eduardo, now using PC_COMPAT_2_3 define
> 
>  hw/i386/pc_piix.c    |  4 ++++
>  hw/i386/pc_q35.c     |  4 ++++
>  include/hw/i386/pc.h |  8 ++++++++
>  target-i386/cpu.c    | 33 ++++++++++++++++++++++++++++++++-
>  target-i386/cpu.h    |  3 +++
>  target-i386/kvm.c    |  2 ++
>  6 files changed, 53 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> index 212e263..b675d2c 100644
> --- a/hw/i386/pc_piix.c
> +++ b/hw/i386/pc_piix.c
> @@ -543,6 +543,10 @@ static QEMUMachine pc_i440fx_machine_v2_3 = {
>      PC_I440FX_2_3_MACHINE_OPTIONS,
>      .name = "pc-i440fx-2.3",
>      .init = pc_init_pci_2_3,
> +    .compat_props = (GlobalProperty[]) {
> +        PC_COMPAT_2_3,
> +        { /* end of list */ }
> +    },
>  };
>  
>  #define PC_I440FX_2_2_MACHINE_OPTIONS PC_I440FX_2_3_MACHINE_OPTIONS
> diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
> index e67f2de..38c3cf2 100644
> --- a/hw/i386/pc_q35.c
> +++ b/hw/i386/pc_q35.c
> @@ -439,6 +439,10 @@ static QEMUMachine pc_q35_machine_v2_3 = {
>      PC_Q35_2_3_MACHINE_OPTIONS,
>      .name = "pc-q35-2.3",
>      .init = pc_q35_init_2_3,
> +    .compat_props = (GlobalProperty[]) {
> +        PC_COMPAT_2_3,
> +        { /* end of list */ }
> +    },
>  };

This breaks pc-*-2.2 and pc-*-2.1, because 2.2 nas no .compat_props set,
and 2.1 has .compat_props = HW_COMPAT_2_1.

Those issues are fixed by the series:
  [PATCH v2 00/13] pc, hw, spapr: Cleanup of {HW, PC, SPAPR}_COMPAT_* macros

I suggest we base this patch on top of it.

-- 
Eduardo