On 23/07/2018 21:32, Sean Christopherson wrote:
> Conceptually, this series is fairly simple: the host's FS/GS selector
> and base values rarely change, so only update their corresponding VMCS
> fields when necessary. VMWRITE takes ~27 cycles on modern hardware,
> i.e. eliminating writes to HOST_{FS,GS}_{SEL,BASE} can save upwards of
> ~100 cycles when reloading a vCPU after an exit to userspace.
>
> The actual optimization is implemented in the final two patches. The
> preceding nine patches are a mix of refactoring and cleansing; KVM's
> FS/GS related code in particular has become a bit crusty as KVM has
> evolved over the years.
Very nice, queued.
Paolo
