[PATCH 08/11] KVM: SVM: Activate nested state only when guest state is complete

[Joerg Roedel <joerg.roedel@amd.com>]

Certain functions called during the emulated world switch
behave differently when the vcpu is running nested. This is
not the expected behavior during a world switch emulation.
This patch ensures that the nested state is activated only
if the vcpu is completly in nested state.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
---
 arch/x86/kvm/svm.c |   15 +++++++++------
 1 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index d7b75fb..4e8d42b 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1628,6 +1628,9 @@ static int nested_svm_vmexit(struct vcpu_svm *svm)
 	if (!nested_vmcb)
 		return 1;
 
+	/* Exit nested SVM mode */
+	svm->nested.vmcb = 0;
+
 	/* Give the current vmcb to the guest */
 	disable_gif(svm);
 
@@ -1715,9 +1718,6 @@ static int nested_svm_vmexit(struct vcpu_svm *svm)
 	svm->vmcb->save.cpl = 0;
 	svm->vmcb->control.exit_int_info = 0;
 
-	/* Exit nested SVM mode */
-	svm->nested.vmcb = 0;
-
 	nested_svm_unmap(page);
 
 	kvm_mmu_reset_context(&svm->vcpu);
@@ -1752,14 +1752,14 @@ static bool nested_svm_vmrun(struct vcpu_svm *svm)
 	struct vmcb *hsave = svm->nested.hsave;
 	struct vmcb *vmcb = svm->vmcb;
 	struct page *page;
+	u64 vmcb_gpa;
+
+	vmcb_gpa = svm->vmcb->save.rax;
 
 	nested_vmcb = nested_svm_map(svm, svm->vmcb->save.rax, &page);
 	if (!nested_vmcb)
 		return false;
 
-	/* nested_vmcb is our indicator if nested SVM is activated */
-	svm->nested.vmcb = svm->vmcb->save.rax;
-
 	trace_kvm_nested_vmrun(svm->vmcb->save.rip - 3, svm->nested.vmcb,
 			       nested_vmcb->save.rip,
 			       nested_vmcb->control.int_ctl,
@@ -1874,6 +1874,9 @@ static bool nested_svm_vmrun(struct vcpu_svm *svm)
 
 	nested_svm_unmap(page);
 
+	/* nested_vmcb is our indicator if nested SVM is activated */
+	svm->nested.vmcb = vmcb_gpa;
+
 	enable_gif(svm);
 
 	return true;
-- 
1.6.6