Re: [PATCH v5 02/12] x86/xen: simplify flush_lazy_mmu()

[Anshuman Khandual <anshuman.khandual@xxxxxxx>]

On 24/11/25 6:52 PM, Kevin Brodsky wrote:
> arch_flush_lazy_mmu_mode() is called when outstanding batched
> pgtable operations must be completed immediately. There should
> however be no need to leave and re-enter lazy MMU completely. The
> only part of that sequence that we really need is xen_mc_flush();
> call it directly.
> 
> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
> Reviewed-by: Ryan Roberts <ryan.roberts@xxxxxxx>
> Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
> Signed-off-by: Kevin Brodsky <kevin.brodsky@xxxxxxx>
> ---

Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>

>  arch/x86/xen/mmu_pv.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c
> index 2a4a8deaf612..7a35c3393df4 100644
> --- a/arch/x86/xen/mmu_pv.c
> +++ b/arch/x86/xen/mmu_pv.c
> @@ -2139,10 +2139,8 @@ static void xen_flush_lazy_mmu(void)
>  {
>       preempt_disable();
>  
> -     if (xen_get_lazy_mode() == XEN_LAZY_MMU) {
> -             arch_leave_lazy_mmu_mode();
> -             arch_enter_lazy_mmu_mode();
> -     }
> +     if (xen_get_lazy_mode() == XEN_LAZY_MMU)
> +             xen_mc_flush();
>  
>       preempt_enable();
>  }