[RFC PATCH v2 01/25] KVM: nSVM: Flush the TLB after forcefully leaving nested

[Yosry Ahmed <yosry@kernel.org>]

KVM flushes the TLB on nested VM-Enter and nested VM-Exit, but not when
forcefully leaving nested. In this case, L2 TLB entries can leak into
L1. Flush the TLB after forcefully exiting L2, similar to nested
VM-Exits.

Note that vmx_leave_nested() handles this correctly, as it reuses
nested_vmx_vmexit(), which handles the necessary TLB flushes on an L2 ->
L1 transition.

Cc: stable@vger.kernel.org
Signed-off-by: Yosry Ahmed <yosry@kernel.org>
---
 arch/x86/kvm/svm/nested.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 1ab8b95975a4b..c85aa5cf670f4 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -1550,6 +1550,8 @@ void svm_leave_nested(struct kvm_vcpu *vcpu)
 
 		svm_switch_vmcb(svm, &svm->vmcb01);
 
+		nested_svm_transition_tlb_flush(vcpu);
+
 		nested_svm_uninit_mmu_context(vcpu);
 		vmcb_mark_all_dirty(svm->vmcb);
 
-- 
2.54.0.1136.gdb2ca164c4-goog