diff options
| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2020-03-20 14:28:22 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-04-21 09:12:54 -0400 |
| commit | c51e1ffee50121a2b2e00208f517a695493ee85d (patch) | |
| tree | b588a61f56ffaed65da01dc3ab0221a1d8c2e616 /arch/x86 | |
| parent | 8c8560b833909cbf2e3a73d4dc8e65a60ba66f07 (diff) | |
KVM: nVMX: Selectively use TLB_FLUSH_CURRENT for nested VM-Enter/VM-Exit
Flush only the current context, as opposed to all contexts, when
requesting a TLB flush to handle the scenario where a L1 does not expect
a TLB flush, but one is required because L1 and L2 shared an ASID. This
occurs if EPT is disabled (no per-EPTP tag), VPID is enabled (hardware
doesn't flush unconditionally) and vmcs02 does not have its own VPID due
to exhaustion of available VPIDs.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200320212833.3507-27-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/vmx/nested.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 567a7a0f30e0..deddf0f0f6e7 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -1152,8 +1152,8 @@ static void nested_vmx_transition_tlb_flush(struct kvm_vcpu *vcpu, * * If VPID is enabled and used by vmc12, but L2 does not have a unique * TLB tag (ASID), i.e. EPT is disabled and KVM was unable to allocate - * a VPID for L2, flush the TLB as the effective ASID is common to both - * L1 and L2. + * a VPID for L2, flush the current context as the effective ASID is + * common to both L1 and L2. * * Defer the flush so that it runs after vmcs02.EPTP has been set by * KVM_REQ_LOAD_MMU_PGD (if nested EPT is enabled) and to avoid @@ -1165,8 +1165,10 @@ static void nested_vmx_transition_tlb_flush(struct kvm_vcpu *vcpu, * mapping between vpid02 and vpid12, vpid02 is per-vCPU and reused for * all nested vCPUs. */ - if (!nested_cpu_has_vpid(vmcs12) || !nested_has_guest_tlb_tag(vcpu)) { + if (!nested_cpu_has_vpid(vmcs12)) { kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu); + } else if (!nested_has_guest_tlb_tag(vcpu)) { + kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu); } else if (is_vmenter && vmcs12->virtual_processor_id != vmx->nested.last_vpid) { vmx->nested.last_vpid = vmcs12->virtual_processor_id; |