diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/vmx.c | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index c4845bc..98f05e2 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -12104,12 +12104,20 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu, load_vmcs12_mmu_host_state(vcpu, vmcs12); - if (enable_vpid) { - /* - * Trivially support vpid by letting L2s share their parent - * L1's vpid. TODO: move to a more elaborate solution, giving - * each L2 its own vpid and exposing the vpid feature to L1. - */ + /* + * If vmcs01 don'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. + * + * 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. + */ + if (enable_vpid && + !(nested_cpu_has_vpid(vmcs12) && to_vmx(vcpu)->nested.vpid02)) { vmx_flush_tlb(vcpu, true); } |
