| Message ID | 20201020215613.8972-5-sean.j.christopherson@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: VMX: Clean up Hyper-V PV TLB flush | expand |
Sean Christopherson <sean.j.christopherson@intel.com> writes: > Combine the for-loops for Hyper-V TLB EPTP checking and flushing, and in > doing so skip flushes for vCPUs whose EPTP matches the target EPTP. > > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > --- > arch/x86/kvm/vmx/vmx.c | 20 ++++++-------------- > 1 file changed, 6 insertions(+), 14 deletions(-) > > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > index bba6d91f1fe1..52cb9eec1db3 100644 > --- a/arch/x86/kvm/vmx/vmx.c > +++ b/arch/x86/kvm/vmx/vmx.c > @@ -502,31 +502,23 @@ static int hv_remote_flush_tlb_with_range(struct kvm *kvm, > > spin_lock(&kvm_vmx->ept_pointer_lock); > > - if (kvm_vmx->ept_pointers_match == EPT_POINTERS_CHECK) { > + if (kvm_vmx->ept_pointers_match != EPT_POINTERS_MATCH) { > kvm_vmx->ept_pointers_match = EPT_POINTERS_MATCH; > kvm_vmx->hv_tlb_eptp = INVALID_PAGE; > > kvm_for_each_vcpu(i, vcpu, kvm) { > tmp_eptp = to_vmx(vcpu)->ept_pointer; > - if (!VALID_PAGE(tmp_eptp)) > + if (!VALID_PAGE(tmp_eptp) || > + tmp_eptp == kvm_vmx->hv_tlb_eptp) > continue; > > - if (!VALID_PAGE(kvm_vmx->hv_tlb_eptp)) { > + if (!VALID_PAGE(kvm_vmx->hv_tlb_eptp)) > kvm_vmx->hv_tlb_eptp = tmp_eptp; > - } else if (kvm_vmx->hv_tlb_eptp != tmp_eptp) { > + else > kvm_vmx->ept_pointers_match > = EPT_POINTERS_MISMATCH; > - break; > - } > - } > - } > > - if (kvm_vmx->ept_pointers_match != EPT_POINTERS_MATCH) { > - kvm_for_each_vcpu(i, vcpu, kvm) { > - /* If ept_pointer is invalid pointer, bypass flush request. */ > - if (VALID_PAGE(to_vmx(vcpu)->ept_pointer)) > - ret |= hv_remote_flush_eptp(to_vmx(vcpu)->ept_pointer, > - range); > + ret |= hv_remote_flush_eptp(tmp_eptp, range); > } > } else if (VALID_PAGE(kvm_vmx->hv_tlb_eptp)) { > ret = hv_remote_flush_eptp(kvm_vmx->hv_tlb_eptp, range); Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> I have an unrelated question though. Does it make sense to call hv_remote_flush_eptp() in case all EPTPs matches with ept_pointer_lock spinlock held? Like if we had a match by the time of the call, does it make a difference if the situation will change before or right after we do the hypercall?
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index bba6d91f1fe1..52cb9eec1db3 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -502,31 +502,23 @@ static int hv_remote_flush_tlb_with_range(struct kvm *kvm, spin_lock(&kvm_vmx->ept_pointer_lock); - if (kvm_vmx->ept_pointers_match == EPT_POINTERS_CHECK) { + if (kvm_vmx->ept_pointers_match != EPT_POINTERS_MATCH) { kvm_vmx->ept_pointers_match = EPT_POINTERS_MATCH; kvm_vmx->hv_tlb_eptp = INVALID_PAGE; kvm_for_each_vcpu(i, vcpu, kvm) { tmp_eptp = to_vmx(vcpu)->ept_pointer; - if (!VALID_PAGE(tmp_eptp)) + if (!VALID_PAGE(tmp_eptp) || + tmp_eptp == kvm_vmx->hv_tlb_eptp) continue; - if (!VALID_PAGE(kvm_vmx->hv_tlb_eptp)) { + if (!VALID_PAGE(kvm_vmx->hv_tlb_eptp)) kvm_vmx->hv_tlb_eptp = tmp_eptp; - } else if (kvm_vmx->hv_tlb_eptp != tmp_eptp) { + else kvm_vmx->ept_pointers_match = EPT_POINTERS_MISMATCH; - break; - } - } - } - if (kvm_vmx->ept_pointers_match != EPT_POINTERS_MATCH) { - kvm_for_each_vcpu(i, vcpu, kvm) { - /* If ept_pointer is invalid pointer, bypass flush request. */ - if (VALID_PAGE(to_vmx(vcpu)->ept_pointer)) - ret |= hv_remote_flush_eptp(to_vmx(vcpu)->ept_pointer, - range); + ret |= hv_remote_flush_eptp(tmp_eptp, range); } } else if (VALID_PAGE(kvm_vmx->hv_tlb_eptp)) { ret = hv_remote_flush_eptp(kvm_vmx->hv_tlb_eptp, range);
Combine the for-loops for Hyper-V TLB EPTP checking and flushing, and in doing so skip flushes for vCPUs whose EPTP matches the target EPTP. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> --- arch/x86/kvm/vmx/vmx.c | 20 ++++++-------------- 1 file changed, 6 insertions(+), 14 deletions(-)