KVM: async_pf: Force a nested vmexit if the injected #PF is async_pf

Add an nested_apf field to vcpu->arch.exception to identify an async page
fault, and constructs the expected vm-exit information fields. Force a
nested VM exit from nested_vmx_check_exception() if the injected #PF is
async page fault.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
This commit is contained in:
Wanpeng Li 2017-07-13 18:30:41 -07:00 committed by Radim Krčmář
parent 1261bfa326
commit adfe20fb48
5 changed files with 35 additions and 10 deletions

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@ -23,6 +23,7 @@ struct x86_exception {
u16 error_code;
bool nested_page_fault;
u64 address; /* cr2 or nested page fault gpa */
u8 async_page_fault;
};
/*

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@ -550,6 +550,7 @@ struct kvm_vcpu_arch {
bool reinject;
u8 nr;
u32 error_code;
u8 nested_apf;
} exception;
struct kvm_queued_interrupt {
@ -651,6 +652,7 @@ struct kvm_vcpu_arch {
u32 id;
bool send_user_only;
u32 host_apf_reason;
unsigned long nested_apf_token;
} apf;
/* OSVW MSRs (AMD only) */

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@ -2423,15 +2423,19 @@ static int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr,
if (!is_guest_mode(&svm->vcpu))
return 0;
vmexit = nested_svm_intercept(svm);
if (vmexit != NESTED_EXIT_DONE)
return 0;
svm->vmcb->control.exit_code = SVM_EXIT_EXCP_BASE + nr;
svm->vmcb->control.exit_code_hi = 0;
svm->vmcb->control.exit_info_1 = error_code;
svm->vmcb->control.exit_info_2 = svm->vcpu.arch.cr2;
vmexit = nested_svm_intercept(svm);
if (vmexit == NESTED_EXIT_DONE)
svm->nested.exit_required = true;
if (svm->vcpu.arch.exception.nested_apf)
svm->vmcb->control.exit_info_2 = svm->vcpu.arch.apf.nested_apf_token;
else
svm->vmcb->control.exit_info_2 = svm->vcpu.arch.cr2;
svm->nested.exit_required = true;
return vmexit;
}
@ -2653,7 +2657,7 @@ static int nested_svm_intercept(struct vcpu_svm *svm)
}
/* async page fault always cause vmexit */
else if ((exit_code == SVM_EXIT_EXCP_BASE + PF_VECTOR) &&
svm->vcpu.arch.apf.host_apf_reason != 0)
svm->vcpu.arch.exception.nested_apf != 0)
vmexit = NESTED_EXIT_DONE;
break;
}

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@ -2422,13 +2422,24 @@ static void skip_emulated_instruction(struct kvm_vcpu *vcpu)
* KVM wants to inject page-faults which it got to the guest. This function
* checks whether in a nested guest, we need to inject them to L1 or L2.
*/
static int nested_vmx_check_exception(struct kvm_vcpu *vcpu, unsigned nr)
static int nested_vmx_check_exception(struct kvm_vcpu *vcpu)
{
struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
unsigned int nr = vcpu->arch.exception.nr;
if (!(vmcs12->exception_bitmap & (1u << nr)))
if (!((vmcs12->exception_bitmap & (1u << nr)) ||
(nr == PF_VECTOR && vcpu->arch.exception.nested_apf)))
return 0;
if (vcpu->arch.exception.nested_apf) {
vmcs_write32(VM_EXIT_INTR_ERROR_CODE, vcpu->arch.exception.error_code);
nested_vmx_vmexit(vcpu, EXIT_REASON_EXCEPTION_NMI,
PF_VECTOR | INTR_TYPE_HARD_EXCEPTION |
INTR_INFO_DELIVER_CODE_MASK | INTR_INFO_VALID_MASK,
vcpu->arch.apf.nested_apf_token);
return 1;
}
nested_vmx_vmexit(vcpu, EXIT_REASON_EXCEPTION_NMI,
vmcs_read32(VM_EXIT_INTR_INFO),
vmcs_readl(EXIT_QUALIFICATION));
@ -2445,7 +2456,7 @@ static void vmx_queue_exception(struct kvm_vcpu *vcpu)
u32 intr_info = nr | INTR_INFO_VALID_MASK;
if (!reinject && is_guest_mode(vcpu) &&
nested_vmx_check_exception(vcpu, nr))
nested_vmx_check_exception(vcpu))
return;
if (has_error_code) {

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@ -450,7 +450,12 @@ EXPORT_SYMBOL_GPL(kvm_complete_insn_gp);
void kvm_inject_page_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault)
{
++vcpu->stat.pf_guest;
vcpu->arch.cr2 = fault->address;
vcpu->arch.exception.nested_apf =
is_guest_mode(vcpu) && fault->async_page_fault;
if (vcpu->arch.exception.nested_apf)
vcpu->arch.apf.nested_apf_token = fault->address;
else
vcpu->arch.cr2 = fault->address;
kvm_queue_exception_e(vcpu, PF_VECTOR, fault->error_code);
}
EXPORT_SYMBOL_GPL(kvm_inject_page_fault);
@ -8582,6 +8587,7 @@ void kvm_arch_async_page_not_present(struct kvm_vcpu *vcpu,
fault.error_code = 0;
fault.nested_page_fault = false;
fault.address = work->arch.token;
fault.async_page_fault = true;
kvm_inject_page_fault(vcpu, &fault);
}
}
@ -8604,6 +8610,7 @@ void kvm_arch_async_page_present(struct kvm_vcpu *vcpu,
fault.error_code = 0;
fault.nested_page_fault = false;
fault.address = work->arch.token;
fault.async_page_fault = true;
kvm_inject_page_fault(vcpu, &fault);
}
vcpu->arch.apf.halted = false;