diff options
| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2020-03-20 14:28:17 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-04-21 09:12:51 -0400 |
| commit | 4a41e43cbe2c0f47d7ec80d156ab786d03cdaacd (patch) | |
| tree | 74291a112a04e7ad434b221ca66dcc644546fca0 /arch/x86 | |
| parent | 33d19ec9b14c0e304f5d44a0dd1403539360968b (diff) | |
KVM: SVM: Document the ASID logic in svm_flush_tlb()
Add a comment in svm_flush_tlb() to document why it flushes only the
current ASID, even when it is invoked when flushing remote TLBs.
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200320212833.3507-22-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 2ad6a8d1a77f..fa5bb1b62059 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -3157,6 +3157,13 @@ void svm_flush_tlb(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); + /* + * Flush only the current ASID even if the TLB flush was invoked via + * kvm_flush_remote_tlbs(). Although flushing remote TLBs requires all + * ASIDs to be flushed, KVM uses a single ASID for L1 and L2, and + * unconditionally does a TLB flush on both nested VM-Enter and nested + * VM-Exit (via kvm_mmu_reset_context()). + */ if (static_cpu_has(X86_FEATURE_FLUSHBYASID)) svm->vmcb->control.tlb_ctl = TLB_CONTROL_FLUSH_ASID; else |