[PATCH 08/10] KVM: SVM: Activate nested state only when guest state is complete

Joerg Roedel
2010-02-18T11:39:33Z

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 2a3d525..a64b871 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1631,6 +1631,9 @@ 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);

@@ -1718,9 +1721,6 @@ 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(nested_vmcb);

kvm_mmu_reset_context(&svm->vcpu);
@@ -1753,14 +1753,14 @@ static bool nested_svm_vmrun(struct vcpu_svm *svm)
struct vmcb *nested_vmcb;
struct vmcb *hsave = svm->nested.hsave;
struct vmcb *vmcb = svm->vmcb;
+ u64 vmcb_gpa;
+
+ vmcb_gpa = svm->vmcb->save.rax;

nested_vmcb = nested_svm_map(svm, svm->vmcb->save.rax);
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,
@@ -1875,6 +1875,9 @@ static bool nested_svm_vmrun(struct vcpu_svm *svm)

nested_svm_unmap(nested_vmcb);

+ /* nested_vmcb is our indicator if nested SVM is activated */
+ svm->nested.vmcb = vmcb_gpa;
+
enable_gif(svm);

return true;
--
1.6.6