diff mbox series

[5/7] KVM: nSVM: fix running nested guests when npt=0

Message ID 20210217145718.1217358-6-mlevitsk@redhat.com (mailing list archive)
State New, archived
Headers show
Series KVM: random nested fixes | expand

Commit Message

Maxim Levitsky Feb. 17, 2021, 2:57 p.m. UTC
In case of npt=0 on host,
nSVM needs the same .inject_page_fault tweak as VMX has,
to make sure that shadow mmu faults are injected as vmexits.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
---
 arch/x86/kvm/svm/nested.c | 18 ++++++++++++++++++
 arch/x86/kvm/svm/svm.c    |  5 ++++-
 arch/x86/kvm/svm/svm.h    |  1 +
 3 files changed, 23 insertions(+), 1 deletion(-)

Comments

Maxim Levitsky Feb. 17, 2021, 3:27 p.m. UTC | #1
On Wed, 2021-02-17 at 16:57 +0200, Maxim Levitsky wrote:
> In case of npt=0 on host,
> nSVM needs the same .inject_page_fault tweak as VMX has,
> to make sure that shadow mmu faults are injected as vmexits.
> 
> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
> ---
>  arch/x86/kvm/svm/nested.c | 18 ++++++++++++++++++
>  arch/x86/kvm/svm/svm.c    |  5 ++++-
>  arch/x86/kvm/svm/svm.h    |  1 +
>  3 files changed, 23 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
> index 1bc31e2e8fe0..53b9037259b5 100644
> --- a/arch/x86/kvm/svm/nested.c
> +++ b/arch/x86/kvm/svm/nested.c
> @@ -53,6 +53,23 @@ static void nested_svm_inject_npf_exit(struct kvm_vcpu *vcpu,
>  	nested_svm_vmexit(svm);
>  }
>  
> +void svm_inject_page_fault_nested(struct kvm_vcpu *vcpu, struct x86_exception *fault)
> +{
> +       struct vcpu_svm *svm = to_svm(vcpu);
> +       WARN_ON(!is_guest_mode(vcpu));
> +
> +       if (vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_EXCEPTION_OFFSET + PF_VECTOR) &&
> +	   !svm->nested.nested_run_pending) {
> +               svm->vmcb->control.exit_code = SVM_EXIT_EXCP_BASE + PF_VECTOR;
> +               svm->vmcb->control.exit_code_hi = 0;
> +               svm->vmcb->control.exit_info_1 = fault->error_code;
> +               svm->vmcb->control.exit_info_2 = fault->address;
> +               nested_svm_vmexit(svm);
> +       } else {
> +               kvm_inject_page_fault(vcpu, fault);
> +       }
> +}
> +
>  static u64 nested_svm_get_tdp_pdptr(struct kvm_vcpu *vcpu, int index)
>  {
>  	struct vcpu_svm *svm = to_svm(vcpu);
> @@ -531,6 +548,7 @@ int enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb12_gpa,
>  	if (ret)
>  		return ret;
>  
> +
Sorry for this whitespace change.
Best regards,
	Maxim Levitsky
>  	svm_set_gif(svm, true);
>  
>  	return 0;
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index 74a334c9902a..59e1767df030 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -3915,7 +3915,10 @@ static void svm_load_mmu_pgd(struct kvm_vcpu *vcpu, unsigned long root,
>  
>  static void svm_complete_mmu_init(struct kvm_vcpu *vcpu)
>  {
> -
> +	if (!npt_enabled && is_guest_mode(vcpu)) {
> +		WARN_ON(mmu_is_nested(vcpu));
> +		vcpu->arch.mmu->inject_page_fault = svm_inject_page_fault_nested;
> +	}
>  }
>  
>  static int is_disabled(void)
> diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
> index 7b6ca0e49a14..fda80d56c6e3 100644
> --- a/arch/x86/kvm/svm/svm.h
> +++ b/arch/x86/kvm/svm/svm.h
> @@ -437,6 +437,7 @@ static inline bool nested_exit_on_nmi(struct vcpu_svm *svm)
>  	return vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_NMI);
>  }
>  
> +void svm_inject_page_fault_nested(struct kvm_vcpu *vcpu, struct x86_exception *fault);
>  int enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa, struct vmcb *vmcb12);
>  void svm_leave_nested(struct vcpu_svm *svm);
>  void svm_free_nested(struct vcpu_svm *svm);
diff mbox series

Patch

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 1bc31e2e8fe0..53b9037259b5 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -53,6 +53,23 @@  static void nested_svm_inject_npf_exit(struct kvm_vcpu *vcpu,
 	nested_svm_vmexit(svm);
 }
 
+void svm_inject_page_fault_nested(struct kvm_vcpu *vcpu, struct x86_exception *fault)
+{
+       struct vcpu_svm *svm = to_svm(vcpu);
+       WARN_ON(!is_guest_mode(vcpu));
+
+       if (vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_EXCEPTION_OFFSET + PF_VECTOR) &&
+	   !svm->nested.nested_run_pending) {
+               svm->vmcb->control.exit_code = SVM_EXIT_EXCP_BASE + PF_VECTOR;
+               svm->vmcb->control.exit_code_hi = 0;
+               svm->vmcb->control.exit_info_1 = fault->error_code;
+               svm->vmcb->control.exit_info_2 = fault->address;
+               nested_svm_vmexit(svm);
+       } else {
+               kvm_inject_page_fault(vcpu, fault);
+       }
+}
+
 static u64 nested_svm_get_tdp_pdptr(struct kvm_vcpu *vcpu, int index)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
@@ -531,6 +548,7 @@  int enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb12_gpa,
 	if (ret)
 		return ret;
 
+
 	svm_set_gif(svm, true);
 
 	return 0;
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 74a334c9902a..59e1767df030 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3915,7 +3915,10 @@  static void svm_load_mmu_pgd(struct kvm_vcpu *vcpu, unsigned long root,
 
 static void svm_complete_mmu_init(struct kvm_vcpu *vcpu)
 {
-
+	if (!npt_enabled && is_guest_mode(vcpu)) {
+		WARN_ON(mmu_is_nested(vcpu));
+		vcpu->arch.mmu->inject_page_fault = svm_inject_page_fault_nested;
+	}
 }
 
 static int is_disabled(void)
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 7b6ca0e49a14..fda80d56c6e3 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -437,6 +437,7 @@  static inline bool nested_exit_on_nmi(struct vcpu_svm *svm)
 	return vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_NMI);
 }
 
+void svm_inject_page_fault_nested(struct kvm_vcpu *vcpu, struct x86_exception *fault);
 int enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa, struct vmcb *vmcb12);
 void svm_leave_nested(struct vcpu_svm *svm);
 void svm_free_nested(struct vcpu_svm *svm);