Re: [Qemu-devel] [PATCH 2/4] target-i386: add VME to all CPUs

[Eduardo Habkost]

On Fri, Dec 05, 2014 at 06:44:24PM +0100, Paolo Bonzini wrote:
> vm86 mode extensions date back to the 486.  All models should have
> them.
> 
> Signed-off-by: Paolo Bonzini <address@hidden>

TCG doesn't support VME (that's probably why we didn't have it set on
most CPU models), and I would like to eventually make check/enforce mode
work on TCG as well.

I was going to suggest adding it to kvm_default_features instead, but as
we have existing models that have CPUID_VME already, let's be consistent
and add it to all of them (and deal with TCG check/enforce mode later,
if necessary).

> ---
>  hw/i386/pc_piix.c | 15 +++++++++++++++
>  hw/i386/pc_q35.c  | 15 +++++++++++++++
>  target-i386/cpu.c | 30 +++++++++++++++---------------
>  3 files changed, 45 insertions(+), 15 deletions(-)
> 
> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> index 5ad23d0..3f1524e 100644
> --- a/hw/i386/pc_piix.c
> +++ b/hw/i386/pc_piix.c
> @@ -305,6 +305,21 @@ static void pc_init_pci(MachineState *machine)
>  
>  static void pc_compat_2_2(MachineState *machine)
>  {
> +    x86_cpu_compat_set_features("kvm64", FEAT_1_ECX, CPUID_EXT_VME, 0);

qemu/hw/i386/pc_piix.c:313:54: error:
‘CPUID_EXT_VME’ undeclared (first use in this function)
     x86_cpu_compat_set_features("kvm64", FEAT_1_ECX, CPUID_EXT_VME, 0);


> +    x86_cpu_compat_set_features("kvm32", FEAT_1_ECX, CPUID_EXT_VME, 0);
> +    x86_cpu_compat_set_features("coreduo", FEAT_1_ECX, CPUID_EXT_VME, 0);
> +    x86_cpu_compat_set_features("Conroe", FEAT_1_ECX, CPUID_EXT_VME, 0);
> +    x86_cpu_compat_set_features("Penryn", FEAT_1_ECX, CPUID_EXT_VME, 0);
> +    x86_cpu_compat_set_features("Nehalem", FEAT_1_ECX, CPUID_EXT_VME, 0);
> +    x86_cpu_compat_set_features("Westmere", FEAT_1_ECX, CPUID_EXT_VME, 0);
> +    x86_cpu_compat_set_features("SandyBridge", FEAT_1_ECX, CPUID_EXT_VME, 0);
> +    x86_cpu_compat_set_features("Haswell", FEAT_1_ECX, CPUID_EXT_VME, 0);
> +    x86_cpu_compat_set_features("Broadwell", FEAT_1_ECX, CPUID_EXT_VME, 0);
> +    x86_cpu_compat_set_features("Opteron_G1", FEAT_1_ECX, CPUID_EXT_VME, 0);
> +    x86_cpu_compat_set_features("Opteron_G2", FEAT_1_ECX, CPUID_EXT_VME, 0);
> +    x86_cpu_compat_set_features("Opteron_G3", FEAT_1_ECX, CPUID_EXT_VME, 0);
> +    x86_cpu_compat_set_features("Opteron_G4", FEAT_1_ECX, CPUID_EXT_VME, 0);
> +    x86_cpu_compat_set_features("Opteron_G5", FEAT_1_ECX, CPUID_EXT_VME, 0);


The features need to be _removed_ when running an older machine-type,
not added. It should be:
    x86_cpu_compat_set_features(MODEL, FEAT_1_EDX, 0, CPUID_VME);

But the list of CPU models is correct, and matches what is being changed
on builtin_x86_defs[].

-- 
Eduardo