return 0;
}
+/*
+ * Returns if KVM is able to config CPU to tag TLB entries
+ * populated by L2 differently than TLB entries populated
+ * by L1.
+ *
+ * If L1 uses EPT, then TLB entries are tagged with different EPTP.
+ *
+ * If L1 uses VPID and we allocated a vpid02, TLB entries are tagged
+ * with different VPID (L1 entries are tagged with vmx->vpid
+ * while L2 entries are tagged with vmx->nested.vpid02).
+ */
+static bool nested_has_guest_tlb_tag(struct kvm_vcpu *vcpu)
+{
+ struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
+
+ return nested_cpu_has_ept(vmcs12) ||
+ (nested_cpu_has_vpid(vmcs12) && to_vmx(vcpu)->nested.vpid02);
+}
+
static void prepare_vmcs02_full(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
* influence global bitmap(for vpid01 and vpid02 allocation)
* even if spawn a lot of nested vCPUs.
*/
- if (nested_cpu_has_vpid(vmcs12) && vmx->nested.vpid02) {
+ if (nested_cpu_has_vpid(vmcs12) && nested_has_guest_tlb_tag(vcpu)) {
if (vmcs12->virtual_processor_id != vmx->nested.last_vpid) {
vmx->nested.last_vpid = vmcs12->virtual_processor_id;
- __vmx_flush_tlb(vcpu, vmx->nested.vpid02, false);
+ __vmx_flush_tlb(vcpu, nested_get_vpid02(vcpu), false);
}
} else {
/*
load_vmcs12_mmu_host_state(vcpu, vmcs12);
/*
- * If vmcs01 don't use VPID, CPU flushes TLB on every
+ * If vmcs01 doesn't use VPID, CPU flushes TLB on every
* VMEntry/VMExit. Thus, no need to flush TLB.
*
- * If vmcs12 uses VPID, TLB entries populated by L2 are
- * tagged with vmx->nested.vpid02 while L1 entries are tagged
- * with vmx->vpid. Thus, no need to flush TLB.
+ * If vmcs12 doesn't use VPID, L1 expects TLB to be
+ * flushed on every VMEntry/VMExit.
*
- * Therefore, flush TLB only in case vmcs01 uses VPID and
- * vmcs12 don't use VPID as in this case L1 & L2 TLB entries
- * are both tagged with vmx->vpid.
+ * Otherwise, we can preserve TLB entries as long as we are
+ * able to tag L1 TLB entries differently than L2 TLB entries.
*
* If vmcs12 uses EPT, we need to execute this flush on EPTP01
* and therefore we request the TLB flush to happen only after VMCS EPTP
* has been set by KVM_REQ_LOAD_CR3.
*/
if (enable_vpid &&
- !(nested_cpu_has_vpid(vmcs12) && to_vmx(vcpu)->nested.vpid02)) {
+ (!nested_cpu_has_vpid(vmcs12) || !nested_has_guest_tlb_tag(vcpu))) {
kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
}