From 2b1be677413b63e2464ec18b998524482eb42bcf Mon Sep 17 00:00:00 2001 From: Nadav Har'El Date: Mon, 5 Aug 2013 11:07:19 +0300 Subject: [PATCH] nEPT: Some additional comments 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. Reviewed-by: Xiao Guangrong Signed-off-by: Nadav Har'El Signed-off-by: Jun Nakajima Signed-off-by: Xinhao Xu Signed-off-by: Yang Zhang Signed-off-by: Gleb Natapov Signed-off-by: Paolo Bonzini --- 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 5e084d6..66af929 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -6669,7 +6669,20 @@ 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 & -- 2.7.4