2017-06-27 21:30 GMT+08:00 Paolo Bonzini <pbonzini@xxxxxxxxxx>:
>
>
> On 27/06/2017 03:46, Wanpeng Li wrote:
>> From: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
>>
>> This patch adds the L1 guest async page fault #PF vmexit handler, such
>> #PF is converted into vmexit from L2 to L1 on #PF which is then handled
>> by L1 similar to ordinary async page fault.
>>
>> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
>> Cc: Radim Krčmář <rkrcmar@xxxxxxxxxx>
>> Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
>> ---
>> arch/x86/kvm/vmx.c | 34 ++++++++++++++++++++++++++++------
>> 1 file changed, 28 insertions(+), 6 deletions(-)
>>
>> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
>> index df825bb..f533cc1 100644
>> --- a/arch/x86/kvm/vmx.c
>> +++ b/arch/x86/kvm/vmx.c
>> @@ -616,6 +616,7 @@ struct vcpu_vmx {
>> bool emulation_required;
>>
>> u32 exit_reason;
>> + u32 apf_reason;
>
> Can you instead of move vcpu_svm's apf_reason field to kvm_vcpu_arch?
> (e.g. vcpu->arch.apf.host_apf_reason)?
Agreed.
>
>> /* Posted interrupt descriptor */
>> struct pi_desc pi_desc;
>> @@ -5648,14 +5649,31 @@ static int handle_exception(struct kvm_vcpu *vcpu)
>> }
>>
>> if (is_page_fault(intr_info)) {
>> - /* EPT won't cause page fault directly */
>> - BUG_ON(enable_ept);
>> cr2 = vmcs_readl(EXIT_QUALIFICATION);
>> - trace_kvm_page_fault(cr2, error_code);
>> + switch (vmx->apf_reason) {
>> + default:
>> + /* EPT won't cause page fault directly */
>> + BUG_ON(enable_ept);
>> + trace_kvm_page_fault(cr2, error_code);
>>
>> - if (kvm_event_needs_reinjection(vcpu))
>> - kvm_mmu_unprotect_page_virt(vcpu, cr2);
>> - return kvm_mmu_page_fault(vcpu, cr2, error_code, NULL, 0);
>> + if (kvm_event_needs_reinjection(vcpu))
>> + kvm_mmu_unprotect_page_virt(vcpu, cr2);
>> + return kvm_mmu_page_fault(vcpu, cr2, error_code, NULL, 0);
>> + break;
>> + case KVM_PV_REASON_PAGE_NOT_PRESENT:
>> + vmx->apf_reason = 0;
>> + local_irq_disable();
>> + kvm_async_pf_task_wait(cr2);
>> + local_irq_enable();
>> + break;
>> + case KVM_PV_REASON_PAGE_READY:
>> + vmx->apf_reason = 0;
>> + local_irq_disable();
>> + kvm_async_pf_task_wake(cr2);
>> + local_irq_enable();
>> + break;
>> + }
>> + return 0;
>> }
>
>
> This code can be moved to a common function
>
> int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
> u64 fault_address);
>
> in mmu.c. It can be used by vmx.c here and in svm.c's pf_interception.
>
> You can change "enable_ept" to "tdp_enabled" (but please make that a
> WARN_ON_ONCE, too).
Agreed. :)
Regards,
Wanpeng Li
