Re: [PATCH 3/4] KVM: nVMX: Don't flush TLB when vmcs12 uses VPID

[Jim Mattson <jmattson@xxxxxxxxxx>]

On Tue, May 22, 2018 at 7:16 AM, Liran Alon <liran.alon@xxxxxxxxxx> wrote:

> +       /*
> +        * 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.
> +        *

Furthermore, If vmcs12 uses EPT, TLB entries populated by L2 are
tagged with the vmcs02 EP4TA while L1 entries are tagged with the
vmcs01 EP4TA. Thus, no need to flush the TLB.