diff mbox

[v3,08/13] nEPT: Some additional comments

Message ID 1368939152-11406-8-git-send-email-jun.nakajima@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Nakajima, Jun May 19, 2013, 4:52 a.m. UTC
From: Nadav Har'El <nyh@il.ibm.com>

Some additional comments to preexisting code:
Explain who (L0 or L1) handles EPT violation and misconfiguration exits.
Don't mention "shadow on either EPT or shadow" as the only two options.

Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
Signed-off-by: Jun Nakajima <jun.nakajima@intel.com>
Signed-off-by: Xinhao Xu <xinhao.xu@intel.com>
---
 arch/x86/kvm/vmx.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

Comments

Paolo Bonzini May 20, 2013, 1:21 p.m. UTC | #1
Il 19/05/2013 06:52, Jun Nakajima ha scritto:
> From: Nadav Har'El <nyh@il.ibm.com>
> 
> Some additional comments to preexisting code:
> Explain who (L0 or L1) handles EPT violation and misconfiguration exits.
> Don't mention "shadow on either EPT or shadow" as the only two options.
> 
> Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
> Signed-off-by: Jun Nakajima <jun.nakajima@intel.com>
> Signed-off-by: Xinhao Xu <xinhao.xu@intel.com>
> ---
>  arch/x86/kvm/vmx.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index b79efd4..4661a22 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -6540,7 +6540,20 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu)
>  		return nested_cpu_has2(vmcs12,
>  			SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES);
>  	case EXIT_REASON_EPT_VIOLATION:
> +		/*
> +		 * L0 always deals with the EPT violation. If nested EPT is
> +		 * used, and the nested mmu code discovers that the address is
> +		 * missing in the guest EPT table (EPT12), the EPT violation
> +		 * will be injected with nested_ept_inject_page_fault()
> +		 */
> +		return 0;
>  	case EXIT_REASON_EPT_MISCONFIG:
> +		/*
> +		 * L2 never uses directly L1's EPT, but rather L0's own EPT
> +		 * table (shadow on EPT) or a merged EPT table that L0 built
> +		 * (EPT on EPT). So any problems with the structure of the
> +		 * table is L0's fault.
> +		 */
>  		return 0;
>  	case EXIT_REASON_PREEMPTION_TIMER:
>  		return vmcs12->pin_based_vm_exec_control &
> 

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index b79efd4..4661a22 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6540,7 +6540,20 @@  static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu)
 		return nested_cpu_has2(vmcs12,
 			SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES);
 	case EXIT_REASON_EPT_VIOLATION:
+		/*
+		 * L0 always deals with the EPT violation. If nested EPT is
+		 * used, and the nested mmu code discovers that the address is
+		 * missing in the guest EPT table (EPT12), the EPT violation
+		 * will be injected with nested_ept_inject_page_fault()
+		 */
+		return 0;
 	case EXIT_REASON_EPT_MISCONFIG:
+		/*
+		 * L2 never uses directly L1's EPT, but rather L0's own EPT
+		 * table (shadow on EPT) or a merged EPT table that L0 built
+		 * (EPT on EPT). So any problems with the structure of the
+		 * table is L0's fault.
+		 */
 		return 0;
 	case EXIT_REASON_PREEMPTION_TIMER:
 		return vmcs12->pin_based_vm_exec_control &