Re: [Qemu-devel] [PATCH v12 2/5] apic: use per CPU AS to map APIC MMIO for TCG

[Igor Mammedov]

On Wed, 16 Sep 2015 17:19:12 +0800
Zhu Guihua <address@hidden> wrote:

> TCG supports per CPU address space, and the emulation quality is
> a bit better with it.
> So use per CPU address space to map APIC MMIO area. This allows the
> APIC base address of each cpu to be moved independent of others.
> 
> Signed-off-by: Zhu Guihua <address@hidden>

Reviewed-by: Igor Mammedov <address@hidden>

> ---
>  target-i386/cpu.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> index 050ce11..692a284 100644
> --- a/target-i386/cpu.c
> +++ b/target-i386/cpu.c
> @@ -2759,9 +2759,18 @@ static void x86_cpu_apic_realize(X86CPU *cpu, Error 
> **errp)
>      object_property_set_bool(OBJECT(cpu->apic_state), true, "realized",
>                               errp);
>  
> -    /* Map APIC MMIO area */
> +    /* Map APIC MMIO area, use per-CPU address space if available (TCG
> +     * supports it, KVM doesn't). This allows the APIC base address of
> +     * each CPU to be moved independently.
> +     */
>      apic = APIC_COMMON(cpu->apic_state);
> -    if (!apic_mmio_map_once) {
> +    if (tcg_enabled()) {
> +        memory_region_add_subregion_overlap(cpu->cpu_as_root,
> +                                            apic->apicbase &
> +                                            MSR_IA32_APICBASE_BASE,
> +                                            &apic->io_memory,
> +                                            0x1000);
> +    } else if (!apic_mmio_map_once) {
>          memory_region_add_subregion_overlap(get_system_memory(),
>                                              apic->apicbase &
>                                              MSR_IA32_APICBASE_BASE,