[PATCH 06/23] KVM: nSVM: do not mark all VMCB01 fields dirty on nested vmexit

[Paolo Bonzini]

Since L1 and L2 now use different VMCBs, most of the fields remain
the same from one L1 run to the next.  svm_set_cr0 and other functions
called by nested_svm_vmexit already take care of clearing the
corresponding clean bits; only the TSC offset is special.

Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
 arch/x86/kvm/svm/nested.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index f88d0614d9b8..4fc742ba1f1f 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -698,8 +698,11 @@ int nested_svm_vmexit(struct vcpu_svm *svm)
 	svm_set_gif(svm, false);
 	svm->vmcb->control.exit_int_info = 0;
 
-	svm->vmcb->control.tsc_offset = svm->vcpu.arch.tsc_offset =
-		svm->vcpu.arch.l1_tsc_offset;
+	svm->vcpu.arch.tsc_offset = svm->vcpu.arch.l1_tsc_offset;
+	if (svm->vmcb->control.tsc_offset != svm->vcpu.arch.tsc_offset) {
+		svm->vmcb->control.tsc_offset = svm->vcpu.arch.tsc_offset;
+		vmcb_mark_dirty(svm->vmcb, VMCB_INTERCEPTS);
+	}
 
 	svm->nested.ctl.nested_cr3 = 0;
 
@@ -717,8 +720,6 @@ int nested_svm_vmexit(struct vcpu_svm *svm)
 	svm->vcpu.arch.dr7 = DR7_FIXED_1;
 	kvm_update_dr7(&svm->vcpu);
 
-	vmcb_mark_all_dirty(svm->vmcb);
-
 	trace_kvm_nested_vmexit_inject(vmcb12->control.exit_code,
 				       vmcb12->control.exit_info_1,
 				       vmcb12->control.exit_info_2,
-- 
2.26.2