Re: [PATCH v5 03/12] Add async PF initialization to PV guest.

Avi Kivity
2010-08-23T15:27:55Z

On 07/19/2010 06:30 PM, Gleb Natapov wrote:
> Enable async PF in a guest if async PF capability is discovered.
>
> Signed-off-by: Gleb Natapov<gleb@redhat.com>
> ---
> arch/x86/include/asm/kvm_para.h | 5 +++
> arch/x86/kernel/kvm.c | 68 +++++++++++++++++++++++++++++++++++++++
> 2 files changed, 73 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h
> index 5b05e9f..f1662d7 100644
> --- a/arch/x86/include/asm/kvm_para.h
> +++ b/arch/x86/include/asm/kvm_para.h
> @@ -65,6 +65,11 @@ struct kvm_mmu_op_release_pt {
> __u64 pt_phys;
> };
>
> +struct kvm_vcpu_pv_apf_data {
> + __u32 reason;
> + __u32 enabled;
> +};
> +

The guest will have to align this on a 64 byte boundary, should this be
marked __aligned(64) here?

> @@ -231,12 +235,72 @@ static void __init paravirt_ops_setup(void)
> #endif
> }
>
> +void __cpuinit kvm_guest_cpu_init(void)
> +{
> + if (!kvm_para_available())
> + return;
> +
> + if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF)) {
> + u64 pa = __pa(&__get_cpu_var(apf_reason));
> +
> + if (native_write_msr_safe(MSR_KVM_ASYNC_PF_EN,
> + pa | KVM_ASYNC_PF_ENABLED, pa>> 32))
> + return;
> + __get_cpu_var(apf_reason).enabled = 1;
> + printk(KERN_INFO"KVM setup async PF for cpu %d\n",
> + smp_processor_id());
> + }
> +}

Need a way to disable apf from the guest kernel command line.

> +
> +static int __cpuinit kvm_cpu_notify(struct notifier_block *self,
> + unsigned long action, void *hcpu)
> +{
> + switch (action) {
> + case CPU_ONLINE:
> + case CPU_ONLINE_FROZEN:
> + kvm_guest_cpu_init();
> + break;
> + default:
> + break;

Should we disable apf if the cpu is dying here?

> + }
> + return NOTIFY_OK;
> +}
> +

--
error compiling committee.c: too many arguments to function