iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

KVM: SVM: Document the ASID logic in svm_flush_tlb()

Browse Source 
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>
This commit is contained in:
Sean Christopherson 2020-03-20 14:28:17 -07:00 committed by Paolo Bonzini
parent 33d19ec9b1
commit 4a41e43cbe
1 changed files with 7 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
arch/x86/kvm/svm/svm.c
View File

@ -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