Wei Liu <wei.liu@xxxxxxxxxx> writes:
> Microsoft Hypervisor requires the root partition to make a few
> hypercalls to setup application processors before they can be used.
>
> Signed-off-by: Lillian Grassin-Drake <ligrassi@xxxxxxxxxxxxx>
> Signed-off-by: Sunil Muthuswamy <sunilmut@xxxxxxxxxxxxx>
> Co-Developed-by: Lillian Grassin-Drake <ligrassi@xxxxxxxxxxxxx>
> Co-Developed-by: Sunil Muthuswamy <sunilmut@xxxxxxxxxxxxx>
> Signed-off-by: Wei Liu <wei.liu@xxxxxxxxxx>
> ---
> CPU hotplug and unplug is not yet supported in this setup, so those
> paths remain untouched.
> ---
> arch/x86/kernel/cpu/mshyperv.c | 27 +++++++++++++++++++++++++++
> 1 file changed, 27 insertions(+)
>
> diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
> index f7633e1e4c82..4795e54550e6 100644
> --- a/arch/x86/kernel/cpu/mshyperv.c
> +++ b/arch/x86/kernel/cpu/mshyperv.c
> @@ -31,6 +31,7 @@
> #include <asm/reboot.h>
> #include <asm/nmi.h>
> #include <clocksource/hyperv_timer.h>
> +#include <asm/numa.h>
>
> struct ms_hyperv_info ms_hyperv;
> EXPORT_SYMBOL_GPL(ms_hyperv);
> @@ -208,6 +209,30 @@ static void __init hv_smp_prepare_boot_cpu(void)
> hv_init_spinlocks();
> #endif
> }
> +
> +static void __init hv_smp_prepare_cpus(unsigned int max_cpus)
> +{
> +#if defined(CONFIG_X86_64)
'#ifdef CONFIG_X86_64' is equally good as you can't compile x86_64
support as a module :-)
> + int i;
> + int ret;
> +
> + native_smp_prepare_cpus(max_cpus);
> +
So hypotetically, if hv_root_partition is true but 'ifdef CONFIG_X86_64'
is false, we won't even be doing native_smp_prepare_cpus()? This doesn't
sound right. Either move it outside of #ifdef or put the #ifdef around
'smp_ops.smp_prepare_cpus' assignment too.
> + for_each_present_cpu(i) {
> + if (i == 0)
> + continue;
> + ret = hv_call_add_logical_proc(numa_cpu_node(i), i, cpu_physical_id(i));
> + BUG_ON(ret);
> + }
> +
> + for_each_present_cpu(i) {
> + if (i == 0)
> + continue;
> + ret = hv_call_create_vp(numa_cpu_node(i), hv_current_partition_id, i, i);
> + BUG_ON(ret);
> + }
> +#endif
> +}
> #endif
>
> static void __init ms_hyperv_init_platform(void)
> @@ -364,6 +389,8 @@ static void __init ms_hyperv_init_platform(void)
>
> # ifdef CONFIG_SMP
> smp_ops.smp_prepare_boot_cpu = hv_smp_prepare_boot_cpu;
> + if (hv_root_partition)
> + smp_ops.smp_prepare_cpus = hv_smp_prepare_cpus;
> # endif
>
> /*
--
Vitaly
