KVM: nSVM: do not mark all VMCB01 fields dirty on nested vmexit
authorPaolo Bonzini <pbonzini@redhat.com>
Mon, 16 Nov 2020 11:38:19 +0000 (06:38 -0500)
committerPaolo Bonzini <pbonzini@redhat.com>
Mon, 15 Mar 2021 08:42:32 +0000 (04:42 -0400)
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@redhat.com>
arch/x86/kvm/svm/nested.c

index 366147f..d76b77a 100644 (file)
@@ -700,8 +700,11 @@ 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;
 
@@ -719,8 +722,6 @@ 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,