Re: [PATCH v2 11/11] powerpc/kvm: Use the PACA virt/real mode info instead of mfmsr

[Paul Mackerras <paulus@xxxxxxxxxx>]

On Thu, Nov 23, 2017 at 03:36:19PM +1100, Benjamin Herrenschmidt wrote:
> This shaves off a bunch of cycles from the KVM exit path
> and the XIVE related hypercall.

Comment below...

> diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> index 83862fba8cfb..ade13f7a9077 100644
> --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> @@ -81,6 +81,8 @@ _GLOBAL_TOC(kvmppc_hv_entry_trampoline)
>  	RFI
>  
>  kvmppc_call_hv_entry:
> +	li	r0,0
> +	stb	r0,HSTATE_EXIT_VIRT(r13)

Don't we need to clear HSTATE_EXIT_VIRT(r13) similarly in the entry
path for offline secondary CPU threads, i.e. somewhere around the
kvm_secondary_got_guest label?

Paul.