svn commit: r358848 - in head/sys/amd64/vmm: intel io

[John Baldwin]

On 3/10/20 9:53 AM, Michael Reifenberger wrote:
> Author: mr
> Date: Tue Mar 10 16:53:49 2020
> New Revision: 358848
> URL: https://svnweb.freebsd.org/changeset/base/358848
> 
> Log:
>   Untangle TPR shadowing and APIC virtualization.
>   This speeds up Windows guests tremendously.
>   
>   The patch does:
>   Add a new tuneable 'hw.vmm.vmx.use_tpr_shadowing' to disable TLP shadowing.
>   Also add 'hw.vmm.vmx.cap.tpr_shadowing' to be able to query if TPR shadowing is used.
>   
>   Detach the initialization of TPR shadowing from the initialization of APIC virtualization.
>   APIC virtualization still needs TPR shadowing, but not vice versa.
>   Any CPU that supports APIC virtualization should also support TPR shadowing.
>   
>   When TPR shadowing is used, the APIC page of each vCPU is written to the VMCS_VIRTUAL_APIC field of the VMCS
>   so that the CPU can write directly to the page without intercept.
>   
>   On vm exit, vlapic_update_ppr() is called to update the PPR.
>   
>   Submitted by:	Yamagi Burmeister
>   MFC after:	2 weeks
>   Differential Revision:	https://reviews.freebsd.org/D22942

Reviewed by:	grehan

Also, it is still good form to wrap the commit logs to fit in
80 cols.

-- 
John Baldwin