KVM: nVMX: Assume TLB entries of L1 and L2 are tagged differently if L0 use EPT

Since commit 1313cc2bd8 ("kvm: mmu: Add guest_mode to kvm_mmu_page_role"),
guest_mode was added to mmu-role and therefore if L0 use EPT, it will
always run L1 and L2 with different EPTP. i.e. EPTP01!=EPTP02.

Because TLB entries are tagged with EP4TA, KVM can assume
TLB entries populated while running L2 are tagged differently
than TLB entries populated while running L1.

Therefore, update nested_has_guest_tlb_tag() to consider if
L0 use EPT instead of if L1 use EPT.

Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Liran Alon 2019-11-20 14:24:52 +02:00 committed by Paolo Bonzini
parent 5637f60b68
commit 992edeaefe

View File

@ -1126,7 +1126,9 @@ static int nested_vmx_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3, bool ne
* populated by L2 differently than TLB entries populated
* by L1.
*
* If L1 uses EPT, then TLB entries are tagged with different EPTP.
* If L0 uses EPT, L1 and L2 run with different EPTP because
* guest_mode is part of kvm_mmu_page_role. Thus, 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
@ -1136,7 +1138,7 @@ static bool nested_has_guest_tlb_tag(struct kvm_vcpu *vcpu)
{
struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
return nested_cpu_has_ept(vmcs12) ||
return enable_ept ||
(nested_cpu_has_vpid(vmcs12) && to_vmx(vcpu)->nested.vpid02);
}